Ansys Solved Tutorials

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Wel come to the ANSYS Tutor i als

Tutorials | We lcome to the ANSYS ANSYS Tutorial Tutorials s

www.kxcad.net Hom Ho me > CAE Index > ANSYS Index > Release 11.0 Documentation for ANSYS

The ANSYS Tutorials provide an introduction to the extensive capabilities of the ANSYS family of products. Each tutorial is a complete step-by-step ANSYS analysis procedure. You can choose from several analysis disciplines. The tutorials are designed designed to be run interactively, on the same screen as the ANSYS program. Included are full color ANSYS graphics and animations that are exact replicas of what appear at several points within the steps of the tutorials. A glossary of terms is also included that you can view as a stand-alone document with an alphabetical listing of the terms, or you can view the definition of terms on demand by simply clicking on linked terms within the context of the tutorials. Before you begin a tutorial, read the Start Here section for recommendations on preparing your screen for displaying the tutorial window on the same screen as ANSYS, as well as descriptions of the formats and conventions used in the tutorials.

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C hapter 1. Star t Her e

Tutorials |

Chapter 1. Start Here


About These Tutorials Preparing Your Screen Formats and a nd Conv C onventi entions ons Used Jobnames and Preferences Choosing a Tutorial

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1.1. About These Tutor ial s

Tutorials | Chapter 1. Start Here |

1.1. About These Tutorials


The purpose of these tutorials is to introduce you to the extensive capabilities of the ANSYS family of products - recognized worldwide as the most powerful engineering design and analysis software. This introduction is done through tutorials that are designed to be run interactively, online at your computer terminal. 1.1.1. Preparing Your Screen

Running the tutorials online while running ANSYS requires that you make the best use of your screen's real estate. By making minor adjustments to the dimensions of the browser and the ANSYS GUI, you will be able to read a tutorial's instructions on one side of your screen, and perform the instructions in ANSYS on the other side. Presented below is a sample screen layout captured on a 21 inch monitor. It is a typical representation of how a screen looks while running a tutorial using the PC version of ANSYS.

For this layout, the tutorial window containing the tabs was removed by clicking the Undock button (large button located furthest to the right), then minimizing the tabbed window. The tutorial window was then moved to the right side of the screen and the ANSYS window was reduced horizontally to accommodate the tutorial window. You should use this layout as a model to adjust your screen accordingly, based on the size of your monitor. It is assumed that you are proficient in moving ANSYS moving ANSYS dialog boxes because there are times when they "pop up" on www.kxcad.net/ansys/ANSYS/ansyshel p/star t_her e2.html

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top of either the tutorial or the ANSYS window. If this occurs, you can simply move them anywhere on the screen by dragging the window header. 1.1.2. Forma Formats ts and and Conventions Conventions Use d

Each tutorial begins with a problem description that includes approaches and assumptions. A summary of steps in the form of tasks is then presented with each step being a hyperlink to a detailed series of procedural action substeps for each major task step. The analysis action substeps are shown explicitly in terms of menu choices, graphical picks, and text input. 1.1.2.1. Task Steps

Task steps are numbered sequentially and contain a series of related menu paths and action substeps. Step titles are formatted according to the task you will be performing in the step. Example step titles are "Add areas," "Define material properties," "Mesh the area," and "Plot the deformed shape." There are approximately 20 steps in a tutorial with the number varying depending on the complexity of the tutorial. 1.1.2.2. 1.1.2. 2. Action Subste Substeps ps

For each overall task step, there are any number of substeps that guide you through the actions that you need to perform perform in order to to accompl accompliish the the task task step. A menu enu path is typi typical callly one of the the fi first substeps substeps with withiin a task task step. An example of a menu path substep is: 1. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Ope Ope rate rate > Add> Add> Are Are as A menu path represents the complete location of a particular function in the Graphical User Interface (GUI) . The first part of the path (Main Menu) determines where the function is found. It is usually either the Main Menu or the Utility Menu. Go to that region to perform the function. The remaining part of the path lists the menu topics that you click with the left mouse button. The action substeps that are presented after a menu path either guide you through completing a dialog box, or instruct you graphically on picking locations. The graphical picking convention is described in the next section. For completing a dialog box, the substeps are either spelled out in detail or use a condensed procedure format. Detailed Detailed substeps substep s are followed followed by b y a red arrow arr ow ( ) indicati indicating ng that a small small picture picture of the dialog dialog box is avail available able if if you scroll to the right. The picture includes large red numbers that cross-reference the numbers of the action. The numbers are positioned in the dialog box at the locations where you are to perform the actions (button, box, drop-down list, etc.). Substeps in several of the tutorials use a condensed procedure format that uses the following conventions: Items that you need to fill in reproduce the wording in the dialog boxes and are in quotes, followed by an equal sign, then the value you should enter. Example: 3. “Load VOLT Value” = 5 Button labels are in brackets. Example: 4. [Pick All] www.kxcad.net/ansys/ANSYS/ansyshel p/star t_her e2.html

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Actions, locations, or any other items that may not be obvious are enclosed in parentheses before or after GUI wording in quotes. Examples: 2. (double-cl (double-c lick) “Structural” “Structural” 5. (drop down) “Action” 7. “Scaler Tet 98” (right column) 1.1.2. 1.1 .2.3. 3. Picking Grap Graphics hics

Some substeps instruct you to pick specific entities on a graphic. An example of the convention is shown below: 6. Pick lines 17 and 8

Here, red numbers are displayed on the picture at the locations where you are to pick. The red number is a cross reference to the procedural substep. 1.1.2.4. Interim Result Graphics

Following the substeps, a task step typically concludes with a small interim result graphic that shows how the ANSYS graphic should appear in the Graphics window at a particular point in a tutorial. An example is shown below: below:

1.1.3. Jobnam Jobnamee s and and Pre Pre fe re nces

Though not required, it is good practice for you to specify a particular jobnam jobnamee for each tutorial analysis. This will help you identify files generated by ANSYS that are related to a particular analysis. When starting ANSYS, you can specify the jobname in the launcher. While in ANSYS, you can change the jobname by choosing: Utility Menu > File > Change Jobname

then typing the jobname, and choosing OK. It is also good practice to specify pref specify preferen erences ces for each tutorial analysis. When you specify a preference for a particu particullar engi engine neeri ering ng disci discipl pliine, ANSYS fi filters menu enu choi choices ces such such that that th the onl only choi choices ces tha thatt appear apply apply to the the discipline you specified. If you do not specify preferences, menu choices for all disciplines are shown, but nonwww.kxcad.net/ansys/ANSYS/ansyshel p/star t_her e2.html

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applicable choices are dimmed based on the set of element types in the model. It is a good idea to specify preferen preferences ces at or near near the the begi beginning of an anal analys ysiis. Most of the the tutori tutorial alss hav havee thi this step step bui built in in before before the the model model is meshed. You can specify a preference by choosing: Main Menu > Preferences

then checking the box associated with the particular discipline, and choosing OK. 1.1.4. Choosing a Tutorial

We recommend that you run "Structural Tutorial" first, even if you typically run analyses in other engineering disciplines. The Structural tutorial is documented extensively, includes graphics of all dialog boxes used, and introduces you to ANSYS terms that you'll see in other tutorials. Once you have successfully performed this tutorial, you can run any of the others in any order. You may want to choose a problem that demonstrates the ANSYS features in your discipline. However, all of the tutorials in some way demonstrate ANSYS techniques that are universal for ANSYS users. You can learn something from every problem, even if it is not in your particu particullar fi field eld of interest terest or experi experien ence! ce! You can access a tutorial through the main Table Of Contents or by clicking on the name of the tutorial in the following list: "Structural Tutorial" "Thermal Tutor Tutorial ial"" "Electromagnetics Tutorial" "CF CFD D Tutorial Tutorial"" "Micro-Electromechanical System (MEMS) Tutorial" "Expli Explicit cit Dynami Dynamics cs Tutor Tutorial" ial" "Contact Tutorial" "Modal Tutorial" "Probabilistic Design System (PDS) Tutorial" "ANIMATE Program"

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1.2. Gl ossar y

Tutorials | Chapter 1. Start Here |

1.2. Gloss ary ary


1.2.1. ANSYS ED Program

An educational program that can be used as a personal training tool in industry, at universities and other academic institutions, and at home. The ANSYS ED program is similar to ANSYS Multiphysics in that it contains virtually all of the features of ANSYS Multiphysics and uses the same GUI, but it contain limits for the size of the model that can be created and solved. 1.2.2. ANSY ANSYS Feature Feature s Demonstrated Demonstrated

Lists the noteworthy features demonstrated in the problem. 1.2.3. Analysis Options

Typical analysis options are the method of solution, stress stiffening on or off, and Newton-Raphson options for nonlinearities. 1.2.4. Analysis Type

Any of seven analysis types offered in ANSYS: static, modal, harmonic, transient, spectrum, eigenvalue buckling, and substructuring. Whether the problem is linear or nonlinear will be identified here. 1.2.5. Applicable ANSYS Products

Indicates which ANSYS programs can be used to run the example problem. Applicable products are determined by the discipline and complexity of the problem. Possibilities include: ANSYS Multiphysics, ANSYS Mechanical, ANSYS Professional, ANSYS Structural, ANSYS LS-DYNA, ANSYS Emag, ANSYS FLOTRAN, ANSYS PrepPost, ANSYS ED. ED. 1.2.6. 1.2.6. Appli Applicab cable le He Help lp Available Available

Information in the ANSYS help system that is relevant to the overall topics covered in a particular tutorial. 1.2.7. Boolean Boo lean Operation Operationss

Boolean Operations (based on Boolean algebra) provide a means of combining sets of data using such logical operators as add, subtract, intersect, etc. There are Boolean operations available for volume, area, and line solid model entities. 1.2.8. Dire Dire ct Element Gener Gene ration ation www.kxcad.net/ansys/ANSYS/ansyshel p/g l ossar y.html

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Defining an element by defining nodes directly. 1.2.9. Disciplin Disciplinee

Any of five physical (engineering) disciplines may be solved by the ANSYS program: structural, thermal, electric, magnetic, and fluid. Note that you can use the ANSYS Multi-field solver, which considers the effects of the physi physical cal phenom phenomen enaa coupl coupled ed togeth together, er, such such as temperatu temperature re and and displ displacem acemen entt in in a therm thermal al-stress -stress an analys alysiis. 1.2.10 . Element Eleme nt Option Optionss

element options to specify such things as element behavior and Many element types also have additional element assumptions, element results printout options, etc. 1.2.11. Element Ty Types Use d

Indicates the element types used in the problem; over 100 element types are available in ANSYS. You choose an element type which characterizes, among other things, the degree-of-freedom set (displacements and/or rotations, temperatures, etc.) e tc.) the characteristic characteristic shape of the element element (line, (line, quadri quadr ilateral, bri br ick, etc.), whether whether the element lies in 2-D space or 3-D space, the response of your system, and the accuracy level you're interested in. 1.2.12. Gaussian Distribution

The Gaussian or normal distribution is a very fundamental and commonly used distribution for statistical matters. It is typically used to describe the scatter of the measurement data of many physical phenomena. Strictly speaking, every random variable follows a normal distribution if it is generated by a linear combination of a very large number of other random effects, regardless which distribution these random effects originally follow. The Gaussian distribution is also valid if the random variable is a linear combination of two or more other effects if those effects also follow a Gaussian distribution. You provide values for the mean value μ and the standard deviation σ of the random variable x .

1.2.13 . Higher-Or Higher-Order der Elements

Higher-order, or midside-node elements, have a quadratic shape function (instead of linear) to map degree-offreedom values within the element. 1.2.14 . Interactive Interactive Time Time Require Require d

This is an approximate range, in minutes, for you to complete the interactive step-by-step solution. Of course the amount of time it takes you to perform the problem depends on the computer system you use, the amount of www.kxcad.net/ansys/ANSYS/ansyshel p/g l ossar y.html

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1.2. Gl ossar y

network "traffic" on it, the working pace that is comfortable for you, and so on. 1.2.15. Jobname Jobname.ex t , where The file name prefix used for all files generated in an ANSYS analysis. All files are named Jobname.ext ext is a unique ANSYS extension that identifies the contents of the file. The jobname specified in the launcher when you start ANSYS is called the initial jobnam jobname. e. You can alway alwayss chan change ge the the jobnam jobnamee with withiin an ANSYS session.

1.2.16. Latin Hypercube Sampling

The Latin Hypercube Sampling (LHS) technique is a Monte Carlo Simulation method that is more advanced and efficient than the Direct Monte Carlo Sampling technique. LHS has a sample "memory," meaning it avoids repeating samples that have been evaluated before (it avoids clustering samples). It also forces the tails of a distribution to participate in the sampling process. 1.2.17. Level of Difficulty

Three levels are offered: easy, moderate, and advanced. Although the "advanced" problems are still easy to follow using the interactive step-by-step solution, they include features that are typically thought of as advanced ANSYS ANS YS capabil capa biliities, ties, such as nonli nonlineariti nearities, es, macros, or advanced postprocess postp rocessiing. ng. 1.2.18. Lognormal Distribution

The lognormal distribution is a basic and commonly used distribution. It is typically used to describe the scatter of the measurement data of physical phenomena, where the logarithm of the data would follow a normal distribution. The lognormal distribution is very suitable for phenomena that arise from the multiplication of a large number of error effects. It is also correct to use the lognormal distribution for a random variable that is the result of multiplying two or more random effects (if the effects that get multiplied are also lognormally distributed). 1.2.19. Material Properties

Physical properties of a material such as modulus of elasticity or density that are independent of geometry. Although they are not necessarily tied to the element type, the material properties required to solve the element matrices are listed for each element type for your convenience. Depending on the application, material properties may be linear, nonlinear, and/or anisotropic. As with element types and real constants, you may have multiple material property sets (to correspond with multiple materials) within one analysis. Each set is given a reference number. 1.2.20. Monte Carlo

The Monte Carlo Simulation method is the most common and traditional method for a probabilistic analysis. This method lets you simulate how virtual components behave the way they are built. One simulation loop represents one manufactured component that is subjected to a particular set of loads and boundary conditions. 1.2.21. Plane Stress

A state of stress in which the normal stress and the shear stresses directed perpendicular to the plane are assumed to be zero. www.kxcad.net/ansys/ANSYS/ansyshel p/g l ossar y.html

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1.2.22. Postpr Postproces sing

ANSYS analysis phase where you review the results of the analysis through graphics displays and tabular listings. The general postprocessor (POST1) is used to review results at one substep (time step) over the entire model. The time-history postprocessor (POST26) is used to review results at specific points in the model over all time steps. 1.2.23. Preferences

The "Preferences" dialog box allows you to choose the desired engineering discipline for context filtering of menu choices. By default, menu choices for all disciplines are shown, with non-applicable choices "dimmed" based on a set of element types in your model. If you prefer not to see the dimmed choices at all, you should turn on filtering. For example, turning on structural filtering completely suppresses all thermal, electromagnetic, and fluid menu topics. 1.2.24. Preprocessing

ANSYS analysis phase where you provide data such as the geometry, materials, and element types to the program program.. 1.2.25 . Prim Primiti itive ve s

Simple predefined geometric shapes that ANSYS provides. A rectangle primitive, for example defines the following solid model entities in one step: one area, four lines, and four keypoints. 1.2.26. Probabilistic Analysis File

A probabilistic analysis file is an ANSYS input file that contains a complete analysis sequence (preprocessing, solution, postprocessing). It must contain a parametrically defined model using parameters to represent all inputs and outputs which will be used as random input variables (RVs) and random output parameters (RPs). From this file, a probabilistic design loop file (Jobname.LOOP) is automatically created and used by the probabilistic design system to perform analysis loops. 1.2.27 . Probab Probabili ilistic stic Design De sign

Probabilistic Design is a technique you can use to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can find out how much the results of a finite element analysis are affected by uncertainties in the model. 1.2.28 1.2 .28.. Probab Probabilistic ilistic Simula Simulation tion

A simulation is the collection of all samples that are required or that you request for a certain probabilistic analysis. A simulation contains the information used to determine how the component would behave under reallife conditions (with all the existing uncertainties and scatter), and all samples therefore represent the simulation of this behavior. 1.2.29. Random Input Variables

Random Input Variables (RVs) are quantities that influence the result of an analysis. In probabilistic literature, www.kxcad.net/ansys/ANSYS/ansyshel p/g l ossar y.html

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these random input variables are also called the "drivers" because they drive the result of an analysis. 1.2.30. Random Output Parameters

Random Output Parameters (RPs) are the results of a finite element analysis. The RPs are typically a function of the random input variables (RVs); that is, changing the values of the random input variables should change the value of the random output parameters. 1.2.31 . Re al Constan Constants ts

Provide additional geometry information for element types whose geometry is not fully defined by its node locations. Typical real constants include shell thicknesses for shell elements and cross-sectional properties for beam elem elemen ents. ts. Al All properti properties requi required as inpu inputt for for a parti particul cular elem elemen entt type type are entered entered as one one set of real constants. 1.2.32 . Solution Solution

ANSYS analysis phase where you define analysis type and options, apply loads and load options, and initiate the finite element solution. A new, static analysis is the default. 1.2.33 1.2 .33.. Standa Standard rd Deviation

The standard deviation is a measure of variability (dispersion or spread) about the arithmetic mean value; this is often used to describe the width of the scatter of a random output parameter or of a statistical distribution function. The larger the standard deviation the wider the scatter and the more likely it is that there are data values further apart from the mean value. 1.2.34 1.2 .34.. Uniform Uniform Distribution Distribution

The uniform distribution is a very fundamental distribution for cases where no other information apart from a lower and an upper limit exists. If is very useful to describe geometric tolerances. It can also be used in cases where there is no evidence that any value of the random variable is more likely than any other within a certain interval. You provide the lower and the upper limit x min and and x max of the random variable x .

1.2.35. Working Plane (WP)

An imaginary plane with an origin, a 2-D coordinate system (either Cartesian or Polar), a snap increment, and a display grid. It is used to locate solid model entities. By default, the working plane is a Cartesian plane located at www.kxcad.net/ansys/ANSYS/ansyshel p/g l ossar y.html

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1.2. Gl ossar y

the global origin.

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Chapter 2. Str uctur al Tutor i al

Tutorials |

Chapter 2. 2 . Stru Structura cturall Tutoria Tuto riall


Static Static Analys Analys is of a Corne Corne r Bracket Bracke t

Pro bl blem em Spec Specification ification Pro bl blem em Desc Descri ri ption ption Build Geometry Define Materials Generate Ge nerate Mesh Apply Loads Obtain Solution Review Results

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2.1. Static Anal ysi s of a Cor ner Br acket

Tutorials | Chapter 2. Structural Tutorial |

2.1. Static Analysis of a Corner Bracket


2.1.1. Problem Specification Applicable ANSYS Products:

ANSYS ANSYS Mu ltiphys ics, A NSYS NSYS Mech anical, ANSYS ANSYS Structural, ANSYS ED

Leve evell of Di Diffi fficulty culty :

easy

Interactive Time Required:

60 to 90 minute minute s

Discipline:

structural

Analysis Type:

linear static

Elemen t Ty p es Us ed :

PLA NE82

ANSYS Features Demonstrated:

so lid lid modeling including prim primitives itives , Boolean o perations , and fill fillets; tapered tapered pressure load; deformed deformed shape and stress displays; listing listing of reaction reaction forces; examination of st ructural energy error error

Applicable Help Available:

Structural Static Static An alysis in the Structural Analysis Guide,, PLANE82 in the Elemen Guide the Elements ts Referenc e.

2.1.2. 2.1.2. Problem Description

This is a simple, single load lo ad step, structural structural static static anal a nalysi ysiss of o f the the corner c orner ang a nglle bracke b rackett shown below. The upper left-hand left-hand pin hole is is constrained (welded) around its entire circumference, and a tapered pressure load is applied to the bottom of the lower right-hand pin hole. The objective of the problem is to demonstrate the typical ANSYS analysis procedure. The US Customary system of units is used.

2.1.2.1. Given

The dimensions of the corner bracket are shown in the accompanying figure. The bracket is made of A36 steel with a Young’s modulus of 30E6 psi and Poisson’s ratio of .27. www.kxcad.net/ansys/ANSYS/ansyshel p/str uctur al _cb.html

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2.1.2. 2.1 .2.2. 2. Approach Approach and and Ass As s umption umptionss

Assume pl Assume plan anee stress stress for this analysis. Since the bracket is thin in the z the z direction direction (1/2 inch thickness) compared to its x ts x and and y dimensions, and since the pressure load acts only in the x-y the x-y pl plan ane, e, thi this is is a val valiid assum assumption. ption. Your approach is to use solid modeling to generate the 2-D model and automatically mesh it with nodes and elements. (Another alternative in ANSYS is to create the nodes and elements directly.) 2.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Note

If your system includes a Flash player (from Macromedia, Inc.), you can view demonstration videos of each step by pointing your web browser to the following URL address: http://www.ansys.com/techmedia/structural_tutorial_videos.html . Build Geometry

1. Defi Define ne rec rectangl tangles. es. 2. Chang Changee pl p lot control c ontrolss and a nd repl rep lot. 3. Change working plane to polar and create first circle. 4. Move working plane and create second circle. 5. Add areas. 6. Create line fillet. 7. Create fillet area. 8. Add areas together. 9. Create first pin hole. 10. Move workin wor king g plane plane and a nd create crea te second se cond pi p in hole. hole. 11. Subtract pin holes from bracket. 12. Save the database as model.db. Back To Top Define Materials

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13. Set Preferences. 14. Define Material Properties. 15. Define element types and options. 16. Define real constants. Back To Top Generate Mesh

17. Mesh the area. 18. Save the database as mesh.db. Back To Top Apply Loads

19. Apply displacement constraints. 20. Apply pressure load. Back To Top Obtain Solution

21. Solve. Back To Top Revie w Results Results

22. Enter the general postprocessor and read in the results. 23. Plot the deformed shape. 24. Plot the von Mises equivalent stress. 25. List the reaction solution. 26. Ex Exiit the ANSYS AN SYS program. 2.1.3. Build Ge Ge ometry www.kxcad.net/ansys/ANSYS/ansyshel p/str uctur al _cb.html

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This is the beginning of Preprocessing of Preprocessing.. 2.1.3.1. Step 1: Define rectangles.

There are several ways to create the model geometry within ANSYS, some more convenient than others. The first step is to recognize that you can construct the bracket easily with combinations of rectangles and circle Primitives.. Primitives Decide where the origin will be located and then define the rectangle and circle primitives relative to that origin. The location of the origin is arbitrary. Here, use the center of the upper left-hand hole. ANSYS does not need to know where the origin is. Simply begin by defining a rectangle relative to that location. In ANSYS, this origin is called the global origi n. 1. Main Menu> Preprocessor> Model odeling ing> > Create> Areas> Rectangle Rectangle > By Dimensions 2. Enter the th e following following:: X1 = 0 (Note: Press the Tab k ey between entries) X2 = 6 Y1 = -1 Y2 = 1

3. App ly to create the fir first st rectangle. 4. Enter the th e following following:: X1 = 4 X2 = 6 Y1 = -1 Y2 = -3

5. OK to create the second rectangle rectangle and close th e dialog dialog b ox. ox.


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2.1.3.2. Step 2: Change plot controls and replot.

The area plot shows both rectangles, which are areas, areas, in the same color. To more clearly distinguish between areas, turn on area numbers and colors. The "Plot Numbering Controls" dialog box on the Utility Menu controls how items are displayed in the Graphics Window. By default, a "replot" is automatically performed upon execution of the dialog box. The replot operation will repeat the last plotting operation that occurred (in this case, an area plot).

1. Utility Menu> Plot Ctrls> Numbering 2. Turn on area area numbers. numbers. 3. OK to chang e controls, close the dialog dialog box, and replot.

Before going to the next step, save the work you have do ne s o far. far. ANSYS ANSYS stores any inpu t data in ANSYS data base . To memory to the ANSYS save th at databas e to a file file,, use the SAVE SAVE operation, available available as a to ol on the Toolbar. ANSY ANSYS names names the datab ase file file using t he format format jobn ame.db. ame.db . If you st arted A NSY NSYS using the p roduct launcher, launcher, you can specify a jobn a jobn am amee at that po int (the default jobname is file is file). ). You You can check the current jobname at any time time Menu> Lis t> by cho os ing Utili ty Menu> Status> Status > Global Global S tatus tatus . You You can also save th e database at specific specific mileston ileston e po ints in the an alysis alysis (such as after the model is is complete, complete, or after the model is meshed) by choosing Utility Menu> File> Save As and sp ecifying ecifying different different jobnames (model.db, model.db , or mesh.db or mesh.db,, etc.). www.kxcad.net/ansys/ANSYS/ansyshel p/str uctur al _cb.html

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It is important to do an occasional sav e s o th at if you make make a mist mist ake, you can rest ore the model from from the last last saved state. You You restore the model using the RESUME operation, also av ailable ailable on the Toolbar. (You (You can also find find SAVE SAVE and RESUME RESUME on the Utili Utility ty Menu , und er File. File.)) 4. Toolbar: SAVE_DB .

2.1.3.3. Step 3: Change working plane to polar and create first circle.

The next step in the model construction is to create the half circle at each end of the bracket. You will actually create a full circle on each end and then combine the circles and rectangles with a Boolean "add" operation o peration (discussed in step 5.). To create the circles, you will use and display the working plane. plane. You could have shown the working plane as you created the rectangles but it was not necessary. Before you begin however, first "zoom out" within the Graphics Window so you can see more of the circles as you create them. You do this using the "Pan-Zoom-Rotate" dialog box, a convenient graphics control box you’ll use often in any ANSYS session. 1. Utility Menu> PlotCtrls> Pan, Zoom, Rotate 2. Click Click on s mall dot do t onc e to zoo zoo m ou t. 3. Clos Clos e dialog box. 4. Utility Menu> WorkPlane> Display Working Plane (toggle on)

Notice th e working working p lane origin is imm immediately ediat ely plotted plot ted in the Graph Graph ics Windo W indow. w. It It is indicat ed b y the W X and WY sy mbols; right right now coincident with the global origin X and Y symbols. Next you will will change t he WP ty pe to polar, polar, change th e s nap increment, increment, and display t he g rid. rid. 5. Utility Menu> WorkPlane> WP Settings 6. Click Click on Polar. 7. Click Click on Grid Grid and Triad. 8. Enter .1 for s nap increment.


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9. OK to define settings an d close the dialog box. box.

10. Main Menu> Preprocess Preproces s or> Mod Model eling ing> > Create> Areas> Circle> Solid Circle Be sure to read prompt prompt before picking. picking. 11. 11. Pick Pick center point at: WP X = 0 (in Graphics Window sho wn below) below) WP Y = 0 12. 12. Mov e mous mous e to radius of 1 and click click left left butto n to create circle.

13. OK to clos e picking picking menu. 14. Toolbar: SAVE_DB . Note

While you are positioning the cursor for picking, the "dynamic" WP X and Y values are displayed in the Solid Circular Area dialog box. Also, as an alternative to picking, you can type these values along with the radius into the dialog box. 2.1.3.4. 2.1.3. 4. Step 4: Move Mov e working orking plane plane and cre cre ate ate se cond circle. circle.

To create the circle at the other end of the bracket in the same manner, you need to first move the working plane to the origin of the circle. The simplest way to do this without entering number offsets is to move the WP to an average keypoint location by picking the keypoints at the bottom corners of the lower, right rectangle. 1. Utility Menu> WorkPlane> Offset WP to> Keypoints 2. Pick keypoint at lower lower left left corner corner of rectangle. 3. Pick keypoint at lower lower right right of of rectangle.

4. OK to close picking picking menu. menu. www.kxcad.net/ansys/ANSYS/ansyshel p/str uctur al _cb.html

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5. Main Menu> Preprocessor> Modeling> Create> Areas> Circle> Solid Circle 6. Pick center point at: WP X = 0 WP Y = 0 7. Move mouse to radius of 1 and cli click left button to create cre ate circle.

8. OK to close picking picking menu. menu.

9. Toolbar: SAVE_DB . 2.1.3.5. 2.1.3. 5. Step 5: Add are are as.

Now that that th the appropriate appropriate pieces pieces of the the model model are defi defined (rectan (rectang gles and and circl circles), es), you you need need to add th them together so the model becomes one continuous piece. You do this with the Boolean add operation for areas. Preproces s or> Mod Model eling ing> > 1. Main Menu> Preprocess Operate> Booleans> Add> Areas

2. Pick All for all all areas to t o be added ad ded .

3. Toolbar: SAVE_DB .

2.1.3.6. 2.1.3. 6. Step 6: Create line fillet. fillet. til ity Menu> PlotCtrls > Numb Numberi ng 1. Utility

2. Turn on line line numbering. numbering. 3. OK to chan ge cont rols, close the dialog bo x, and aut a utomaticall omatically y replot .

4. Utility Menu> WorkPlane> Display ff) Working Plane (toggle o ff)

Preproces s or> Mod Model eling ing> > 5. Main Menu> Preprocess Create> Create> Lines> Line Fillet Fill et www.kxcad.net/ansys/ANSYS/ansyshel p/str uctur al _cb.html

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6. Pick lines lines 17 and 8.

7. OK to finish picki p icking ng lines (in picking picking menu). 8. Enter .4 as the radius. 9. OK to create line fil fillet let and close t he dialog box. til ity Menu> Plot> Lines 10. Utility

2.1.3.7. 2.1.3. 7. Step Ste p 7: Create fille ille t are are a. 1. Utility Menu> PlotCtrls> Pan, Zoom, Rotate 2. Click Click on Zoo m but ton . 3. Mov e mous mous e to fillet fillet region, region, click click left left butt on, move mous e out and c lick lick again.

Preproces s or> Mod Model eling ing> > Create> 4. Main Menu> Preprocess Areas> Arbitrary> By Lines

5. Pick lines lines 4, 5, and 1.

6. OK to create area and close th e picking picking menu. menu. 7. Click Click on Fit bu tto n. 8. Clos Clos e the Pan, Zoom, Rotat Rotat e dialog dialog b ox. ox. til ity Menu> Plot> Areas 9. Utility


2.1.3.8. 2.1.3. 8. Step 8: Add ar are as toge the the r. 1. Main Menu> Preproces s or> Mod Model eling ing> > Operate> Operate> Booleans> Add> Areas 2. Pick All for all all areas to t o be added ad ded .


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2.1.3.9. 2.1.3. 9. Step 9: Cre Cre ate ate firs irs t pin hole.

1. Utility Menu> WorkPlane> Display Working Plane (toggle on)

2. Main Menu> Preprocessor> Modeling> Create> Areas> Circle> Solid Circle 3. Pick center point at: WP X = 0 (in Graphics Window) WP Y = 0 4. Move mouse to radius ra dius of .4 (shown ( shown in in the the picking menu) menu) and click click left button to create cre ate ci c ircle. 5. OK to close picking picking menu. menu.


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Chapter 3. Ther mal Tutor i al

Tutorials |

Chapter 3. Thermal Tutorial


Solidification of a Casting

Pro bl blem em Spec Specification ification Problem Description Prepare for a Thermal Analysis Inp In put Geometry Define De fine Materials Generate Mesh Apply Loads Obtain Solution Review Results

www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_tut.html

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3.1. Sol idifi cation of a Casti ng

Tutorials | Chapter 3. Thermal Tutorial |

3.1. Solidification of a Casting



ANSYS ANSYS Mu ltiphys ics, A NSYS NSYS Mechan Mec han ical, ANSYS ANSYS ED


moderate



Discipline:

thermal

Analysis Type:

nonlinear transient


PLA NE55


conduction, convection, phas e change, s electing, electing, solution solution control, control, time-hi time-history story pos tprocessing, us e of a "get function"


Transient Thermal Transient Thermal Analysis in the Thermal Analysis Guide,, PLANE55 in the Elemen Guide the Elements ts Reference Reference..

3.1.2. Problem Problem De scr sc ription iption

This is a transient heat heat transfer analysis of a casting casting process. process. The The objectiv o bjectivee is to track the temperature distributi distribution on in the steel casting and the mold during the solidification process, which occurs over a duration of 4 hours. The casting is made in an L-shaped sand mold with 4 inch thick walls. Convection occurs between the sand mold and the ambient ambient air.

3.1.2.1. Given Mat eria l Prop erties erti es for San d Co n d u ctiv it y (KXX)

0.025 Bt u / (h r-in -o F)

Den s it y (DENS)

0.054 lb /in3

Sp ecific h eat (C)

0.28 Btu / (lb -o F)

Conducti vity (KXX) for Steel www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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at 0oF

1.44 Btu / (h r-in -oF)

at 2643o F

1.54

at 2750o F

1.22

at 2875o F

1.22

Entha Ent ha lpy lp y (ENTH) (EN TH) for for St eel at 0oF

0.0 Bt u / in3

at 2643o F

128.1

at 2750o F

163.8

at 2875o F

174.2

Initia Init iall Co ndit nd itio ions ns Temp erat u re o f s t eel

2875 oF

Temp erat u re o f s an d

80 o F

Convection Properties Film co efficien t

0.014 Bt u / (h r-in2-oF)

A mb ien t t emp erat u re

80 o F


You will perform a 2-D analysis of a one unit thick slice. Half symmetry is used to reduce the size of the model. The lower half is the portion you will model.

The mold material (sand) has constant material properties. The casting (steel) has temperature-dependent thermal conductivity and enthalpy; both are input in a table of values versus temperature. The enthalpy property table captures the latent heat capacity of the metal as it solidifies. Radiation effects are ignored. Solution control is used to establish several nonlinear options, including automatic time stepping. Automatic time stepping determines the proper time step increments needed to converge the phase change nonlinearity. This means that smaller time step sizes will be used during the transition from molten metal to solid state. 3.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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Prepare for a Thermal Analysis

1. Set preferences. Back To Top Input Input Geometry Geome try

2. Read in the geometry of the casting. Back To Top Define Materials

3. Define material properties. 4. Plot material material properties prop erties vs. tem te mperature. 5. Define element type. Back To Top Generate Mesh

6. Mesh the model. Back To Top Apply Loads

7. Apply convection loads on the exposed boundary lines. Back To Top Obtain Solution

8. Define analysis type. 9. Examine solution control. 10. Specify initial conditions for the transient. 11. Set time, time step size, and related parameters. www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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12. Set output controls. 13. Solve. Back To Top Revie w Results Results

14. Enter the time-history postprocessor and define variables. 15. Plot temperature vs. time. 16. Set up to animate the results. 17. Animate the results. 18. Ex Exiit the ANSYS AN SYS program. 3.1.3. Prepare for a Thermal Analysis 3.1.3.1. Step 1: Set preferences.

To Set Preferences Preferences:: 1. Main Menu> Preferences 2. (check) (check ) “Indivi “Individual dual discipli discipline(s) ne(s) to show s how in in the the GUI” = Thermal Thermal 3. [OK] 3.1.4. Input Geometry 3.1.4.1. 3.1.4. 1. Step 2: Read Re ad in the the ge ometry of the the casting. casting.

You will begin by reading in a file that includes the model of the casting. 1. Utility Menu> File> Read Input from ... 2. File File name: casting.inp UNIX version:

/ansys_inc/v110/ansys/data/models/casting.inp PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\casting.inp 3. [OK]

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3.1.5. Define Define Materials Materials 3.1.5.1. 3.1.5. 1. Step 3: Def De fine ine materia materiall properti propertiee s .

Define the sand mold material properties as material number 1. These are not functions not functions of temperature. 1. Main Menu> Preprocessor> Material Props> Material Models 2. (double-c (do uble-cllick) “Thermal “Thermal”, ”, then then “Co “Conductiv nductiviity”, then “Isotropic” “Isotro pic” 3. “KXX” = 0.025 4. [OK] 5. (double-cl (double-c lick) “Sp “Specif ecifiic Heat” 6. “C” = 0.28 7. [OK] 8. (double-c (do uble-cllick) “Density” “Density” 9. “DENS” “DENS” = 0.54 0.5 4 10. [OK] Note PC Users:

You can view a demo on defining one material model by pointing your Internet Explorer browser to the following URL address: http://www.ansys.com/techmedia/one_material.html

The metal casting is defined as material number 2. These properties change significantly as the metal cools down from the liquid phase to the solid phase. Therefore, they are entered in a table of properties versus temperature. First define the temperature dependent thermal conductivity. 11. Mater Mate rial> New Model 12. 12 . “Defi “Define Material ID” = 2 13. [OK] 14. (double-cl (double-c lick) “Isotropic” www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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15. [Add Temperature] three tim times to create c reate fields fields for for the four temperatures. temperatures. 16. “T1” “T1” = 0 17. “T2” “T2” = 2643 264 3 18. “T3” “T3” = 2750 275 0 19. “T4” “T4” = 2875 287 5 20. “KXX” at “T1” “T1” = 1.44 21. “KXX” at “T2” “T2” = 1.54 22. “KXX” at “T3” “T3” = 1.22 23. “KXX” at “T4” “T4” = 1.22 You will now copy the four temperatures so you will be able to paste them into the Enthalpy dialog box. 24. 24 . Select Se lect the the temperatures tempera tures by holdin holding g the left left mouse mouse button butto n and dragg dra ggin ing g across across the temperature tempera ture row so that the row is highlighted. 25. [Ctrl] then then [c] to copy the the temperatures. temperatures. 26. [OK] Next, Next, defi define the the temperatu temperature re dependen dependentt enth enthal alpy. py. 27. 27 . (double-c (do uble-cllick) “Enthal “Enthalpy” py” 28. [Add Temperature] three tim times to create c reate fields fields for for the four temperatures. temperatures. 29. 29 . Paste Paste the temperatures temper atures into the dialog dialog box bo x by hig highl hlig ighti hting ng the T1 temperature tempera ture field, field, and press p ressin ing g [Ctrl] then [v]. 30. 30 . “EN “EN TH” at “T1” “T1” = 0 31. “ENTH” “ENTH” at “T2” “T2” = 128.1 128. 1 32. “ENTH” “ENTH” at “T3” “T3” = 163.8 163. 8 33. “ENTH” “ENTH” at “T4” “T4” = 174.2 174. 2 34. [OK] Note PC Users:

You can view a demo on adding a temperature dependent material model by poin pointin ting your Intern Internet et Ex Explorer plorer browser browser to to the the fol folllowing owing URL URL address: http://www.ansys.com/techmedia/add_temp_material.html


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3.1.5.2. Step 4: Plot material properties vs. temperature.

1. (double-c (do uble-cllick) “Thermal “Thermal conduct. co nduct. (iso) (iso)”” under Material Model Number 2. 2. [Graph] 3. [OK]

Note PC Users:

You can view a demo on graphing a temperature dependent material model by poin pointin ting your Intern Internet et Ex Explorer plorer browser browser to to the the fol folllowing owing URL URL address: http://www.ansys.com/techmedia/graph_temp_material.html

4. (double-c (do uble-cllick) “Enthal “Enthalpy” py” under the right right or left window. window. 5. [Graph] 6. [OK]

7. Material> Exit 8. Toolbar: SAVE_DB 3.1.5.3. Step 5: Define element type.

You will now define the elem element ent type t ype as PLANE55 PLANE55.. Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 1. Main

2. [Add ...] 3. “Ther “Thermal mal Soli So lid” d” (left (left colu co lumn mn)) 4. “Quad 4node 55” 55 ” (right (right col co lumn) umn) 5. [OK] 6. [Close] 7. Toolbar: SAVE_DB 3.1.6. Generate Mesh 3.1.6.1. Step 6: Me sh the model. model. www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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1. Utility Menu> Plot> Areas

Specify a SmartSize of 4. This will allow a slightly finer mesh than the default and yet the resulting number of elements will be within the ANSYS ED program limits for the maximum number of elements. Prepr eproces oces sor> Mes M es hing> hing> MeshTool Me shTool 2. Main Me nu> Pr

3. (check) “Smart “Smart Size” Size” 4. (slide) (slide) “Fine “Fine Course” Course ” = 4 5. [Mesh] Mesh the mold area first. Note that the material attribute reference number defaults to 1 and there is no need to set attributes before meshing the area. 6. Pick the mold mold area A5 (Hint: (Hint: Place the mouse cursor on o n top of the the A5 label when when you pick -- - thi t hiss is is the picki pickin ng "hot spot," based on the the centroi centroid d of the the area.). area.).

7. [OK]

Before meshing the casting area, set the material attribute to that of steel (material 2). 8. (drop (dr op down d own in in MeshTool) MeshToo l) “Elem “Element ent Attributes” Attributes” = Glob Global, al, then then [Set] 9. (drop (dr op down) “Mate “Material rial number” number” = 2 10. [OK] 11. Utility Menu> Plot> Areas 12. [Mesh] in MeshTool 13. Pick Pick area A4

14. [OK] 15. [Close] in MeshTool 16. Utility Menu> Plot> Elements

Note: The The mesh mesh you obtain obtain may vary vary sli slightl ghtly y from the the mesh mesh shown shown here. As As a resu result of thi this, you you may see slightly different results during postprocessing. For a discussion of results accuracy, see Planning Your Approach in the Modeli the Modeling ng and Meshing Meshing Guide. Guide.


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To verify that the elements have the right materials, plot them with different colors for different materials. M e nu nu> > PlotCtrls> Numberin Numbering g 17. Utility Me

18. 18 . (drop (dr op down) d own) “Elem “Elem / Attrib num number beriing” = Material Mate rial numbe numbers rs 19. [OK]

Note: the the elem elemen ents ts of materi aterial 1 form form the the sand sand mol mold. d. The The elem elemen ents ts of material aterial 2 form form the the steel steel casting casting.. You can also plot the elements showing materials in different colors without displaying the associated material numbers. 20. Utility Me M e nu nu> > PlotCtrls> Numberin Numbering g 21. 21 . (drop (dr op down) do wn) “Numbe “Numberin ring g shown with” with” = Colors Co lors only only 22. [OK]

23. Toolbar: SAVE_DB 3.1.7. 3.1 .7. Apply Apply Loads Loads 3.1.7.1. 3.1.7. 1. Step Ste p 7: Apply Apply convection loads loads on the e xpose d bound boundar ary y lines lines .

Apply the convection to the lines of the solid model. Loads applied to solid modeling entities are automatically transferred to the finite element model during solution. 1. Utility Menu> Plot> Lines Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De D e fine fine Loads> Apply> Apply> Thermal> Thermal> Convection> On Lines Lines 2. Main

3. Pick the three three lines lines that that are exposed expos ed to am a mbient bient air. air.

4. [OK] 5. “Film “Film coeff co effici icient” ent” = 0.014 0.0 14 6. “Bulk “Bulk temperature” tempera ture” = 80 7. [OK]

8. Toolbar: SAVE_DB 3.1.8. Obtain Solution 3.1.8.1. 3.1.8. 1. Step 8: Def De fine ine anal analysis ysis type. type.

1. Main Menu> Solution> Analysis Type> New Analysis www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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2. (check) (check ) “Type “Type of analysis” analysis” = Transient Transient 3. [OK] 4. (check) (check ) “So “Solu lution tion method” = Full Full 5. [OK] 3.1.8.2. Step 9: Examine solution control.

The Approach and Assumptions section of this tutorial mentioned that solution control is used to establish several nonlinear options. In this step, you will be directed to the online help for solution control so you can examine the details of this feature. You will access this help topic by clicking on the Help button from within the Nonlinear Solution Control dialog box. 1. Main Menu> Solution> Load Step Opts> Solution Ctrl Note that that solu solution tion control control is on by defau defaullt. Before clicking on the Help button in the next step, you should be aware that the help information may appear in the same window as this tutorial, replacing the replacing the contents of the tutorial. If this is the case, after reading the help information, you will need to click on the Back button to return to this tutorial. If the help information appears in a separate a separatewindow window from the tutorial, you can minimize or close the help window after you read the help information. 2. [Help] then read rea d the detail de tailss on Sol So lution ution Control. Contro l. 3. If the the help inf information ormation replaced the tutorial, tutorial, click click on o n the the Back button to return re turn to the tutorial. tutorial. If the help help information appears in a separate window, you can close or minimize that window. 4. [Cancel] to remove remove the the dialog dialog box. 3.1.8.3. Step 10: Specify initial conditions for the transient.

The mold is initially at an ambient temperature of 80o F and the molten metal is at 2875 o F. Use select entities to obtain the correct set of nodes on which to apply the initial temperatures. First select the casting area, then select the nodes within that area and apply the initial molten temperature to those nodes. Next, invert the selected set of nodes and apply ap ply the the am a mbient bient temperature to the mold mold nodes. Start by plotting areas. 1. Utility Menu> Plot> Areas 2. Utility Menu> Select> Entities 3. (first (first drop down) do wn) “Areas” “Areas”


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4. [OK] 5. Pick area A4, which which is the casting. casting.

6. [OK] 7. Utility Menu> Select> Everything Below> Selected Areas 8. Utility Utility Me nu nu> > Plot> Nodes Node s

9. Main Menu> Solution> Define Loads> Apply> Initial Condit'n> Define 10. [Pick Al All] to use sele use selected cted nodes. nodes. 11. (drop down) d own) “DOF “DOF to be specif spe cifiied” = TEMP TEMP 12. 12 . “Initial “Initial value value of DOF” DO F” = 2875 28 75 13. [OK] 14. Utility Menu> Select> Entities 15. (first (first drop down) “Nodes” “Node s” 16. (second drop down) “Attached Attached to” 17. (check) “Areas, “Areas, all all” 18. 18 . [Invert] This This is an action command; command; the selected selecte d set se t of nod nodes es is imm immediately ediately inv inverte erted. d. 19. [Cancel] to close the the dialog dialog box. Utility Me nu nu> > Plot> Nodes Node s 20. Utility

21. Main Menu> Solution> Define Loads> Apply> Initial Condit'n> Define 22. [Pick All All] to use all all selected nodes. 23. 23 . “Initial “Initial value value of DOF” DO F” = 80 24. [OK] Remember Remember to t o always select select Everything Ev erything again when you are finished finished selecting selecting the nodes! Utility Me M e nu nu> > Se lect> Everythin Everything g 25. Utility

26. Toolbar: SAVE_DB www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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3.1.8.4. 3.1.8. 4. Step 11 : Set time, time s tep s ize ize , and related related param paramee ters.

Stepped boundary conditions simulate the sudden contact of molten metal at 2875 o F with the mold at ambient temperature. The program will choose automatic time stepping that will enable the time step size to be modified depending on the severity of nonlinearities in the system (for example, it will take smaller time steps while going through the phase change). The maximum and minimum time step sizes represent the limits for this automated procedure. procedure. 1. Main Menu> Solution> Load Step Opts> Time/Frequenc> Time-Time Step 2. “Tim “Timee at end of load step” step ” = 4 Note

This represents 4 hours. hours. 3. “Tim “Timee step size” size” = 0.01 4. (check) “Stepped or ramped ramped b. c.” = Stepped 5. “Minim “Minimum um time time step size” = 0.00 0.001 1 6. “Maximum “Maximum time time step size” = 0.25 0.2 5 7. [OK] 3.1.8.5. 3.1.8. 5. Step 12 : Set output output controls. controls.

1. Main Menu> Solution> Load Step Opts> Output Ctrls> DB/Results File 2. (check) (check ) “Fil “Filee write write freq frequency” uency” = Every Every subste substep p 3. [OK] 4. Toolbar: SAVE_DB 3.1.8.6. Step 13: Solve.

1. Main Menu> Solution> Solve> Current LS 2. Review Review the inf information ormation in in the the status stat us window, window, then choose. choo se. File> Close (Windows), or Close (X11/Moti (X11/Mo tif), f), to close the window. window.

3. [OK [O K ] to initi initiate ate the solution. solution. 4. [Close] [Close] when the soluti solution on is is done. While ANSYS is solving the analysis, the Graphical Solution Tracking (GST) monitor plots the "Absolute Convergence Norm" as a function of the "Cumulative Iteration Number." Notice that the solution is assumed to www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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have converged for values less than or equal to the convergence criteria.

3.1.9. Re view Results Results 3.1.9.1. Step 14: Enter the time-history postprocessor and define variables.

Use the time-history postprocessor to look at the variation of temperature with respect to time at one point on the casting (on the symmetry plane). M e nu nu> > PlotCtrls> Numberin Numbering g 1. Utility Me

2. (check) “No “Node de num numbers” bers” = On 3. (drop down) “Numbers “Numbers shown with” with” = Colors C olors & num numbers 4. [OK] 5. Utility Menu> Plot> Elements

The node at the center of the casting on the symmetry plane is the node of interest. Use a "get function" to define a variable equal to the value of the node number at the location of interest (16,6,0). By using a variable to identify the node at the center point, the analysis will be more flexible in that the center node will always be used even if the mesh, and therefore node numbers, change. 6. Utility Menu> Parameters> Scalar Parameters 7. “Selection” “Selection”=cntr_pt =cntr_pt = node (16,6,0 (16, 6,0)) 8. [Accept} Note the the center center poin point node node nu number. Thi Thiss nu number can vary due to dif differences erences in in the the mesh mesh.. 9. [Close] Ma in Menu Me nu> > Time Time Hist Postp Pos tproc roc 10. Main

11. [+] to add data. 12. 12 . (double-c (do uble-cllick) “N “N odal od al Solu So lution” tion”,, then “DOF Solu So lution” tion”,, then “Tempera “Temperature” ture” 13. “Variabl “Variablee Name” = center 14. [OK] 15. Type Type cntr_pt in the picker, picker, then press Enter. Enter. 16. [OK] [OK ] in the picker. 17. File> Close www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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3.1.9.2. 3.1.9. 2. Step 15: Plot temperatur temperaturee vs . time time .

1. Main Menu> TimeHist Postpro> Graph Variables 2. “1st variable variable to graph” = 2 3. [OK [O K] to plot the resul res ults ts at cntr_point cntr_p oint as a function function of time. time. Notice Notice from from thi this graph graph that that th the soli solidif dification cation regi region is approxi approximately ately between between 2643oF and 2750o F. Your graph may vary slightly. 3.1.9.3. 3.1.9. 3. Step 16: Se t up to anim animat atee the res ults. ults.

Next, Next, ani animate the the soli solidif dification cation of the the mol molten ten metal. etal. To To better better vi visual sualiize the the soli solidif dification cation process, specif specify three three contours. One will represent the molten metal (T greater than 2750 o F), one will represent the solidified metal (T less than 2643 o F), and the third will represent everything in between. But first, to perform an animation, you must enter the General Postprocessor and read the first set of results. 1. Main Menu> General Postproc> Read Results> First Set 2. Utility Me M e nu nu> > PlotCtrls> Numberin Numbering g 3. (check) “No “Node de num numbers” = Off 4. (drop (dr op down) d own) “Elem “Elem / Attrib num number beriing” = No N o number numberin ing g 5. (drop down) d own) “Replot “Replot upon OK/Apply OK /Apply?” ?” = Do not not replot 6. [OK] 7. Utility Menu> Plot> Elements

8. Utility Menu> PlotCtrls> Style> Contours> Non_uniform Contours Note that that as indicated dicated in in the the brackets brackets at the the upper lef leftt corner corner of the the dial dialog og box, box, the the comm command and to speci specify non_uniform contours is /CVAL. You will later use this command to set the contours to their default setting. 9. “V1” “V1” = 2643 264 3 10. “V2” “V2” = 2750 275 0 11. “V3” “V3” = 3000 300 0 Note

These three values represent the upper bounds of the first, second, and third contours, www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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respectively. 12. [OK] 3.1.9.4. Step 17: Animate the results.

[Note [Not e for UNIX UN IX systems systems only: only: To capture the animation sequence in terminal segment memory, it is necessary to reduce the size of the Graphics Window or you will run out of terminal memory. Although this depends on your particular system, and the size of the animation file to be created, for this exercise it is suggested that the ratio of the original window size to the reduced window size should be about 2:1.] Procedure on all systems: 1. Utility Menu> PlotCtrls> Animate> Over Time 2. “Numbe “Numberr of animati animation on frames” frames” = 30 3. (check) (check ) “Auto “Auto contour scali sca ling” ng” = Off 4. [OK] During the animation, notice the three separate colors - red for temperatures greater than 2750 oF (molten steel), green for temperatures between 2643 oF and 2750 o F (the "mushy" phase change region), and blue blue for temperatu temperatures res below below 2643 o F (the solidified steel and the sand mold). As you would expect, the last region to solidify is the material at the center of the casting. (Remember that a symmetry model was used.) 5. Make Mak e choices in in the Animati Animation on Control Contro ller (not (not shown), if necessary, necess ary, then [Cl [C lose]. ose ]. To visualize the temperature distribution throughout the model over the 4 hour span, animate the temperature distribution with the default contour settings. To change the contour settings back to their default value, simply type /CVAL in the ANSYS Input Window. Note that /CVAL is the command you used earlier to set non_uniform contours. The same outcome can be achieved by going back to the Non_Un Non_Uniform Contou Contours rs wi window and and setti setting all all the the val valu ues to zero. zero. 6. Type Type /CVAL, then then press Enter. Enter. 7. Utility Menu> PlotCtrls> Animate> Over Time 8. [OK]

9. Make Mak e choices in in the Animati Animation on Control Contro ller (not (not shown), if necessary, necess ary, then [Cl [C lose]. ose ]. 3.1.9.5. Step 18: Exit the ANSYS program.

1. Toolbar: QUIT www.kxcad.net/ansys/ANSYS/ansyshel p/ther mal_cast.html

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2. (check) “Quit Quit - No Save!” 3. [OK] Congratula Congratulations! tions! You have complete d this tutorial tutorial..

Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for: Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. Sending animations over the web.


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Chapter 4. El ectr omag netics Tutor ial

Tutorials |

Chapter Chapter 4. Electrom Elec tromagnetics agnetics Tutorial Tutorial


Magnetic Analysis of a Solenoid Actuator

Pro bl blem em Speci Specif f ication Problem Description Inp In put Geometry Defi De fine ne Mater M ateriial Generate Ge nerate Mesh Apply Loads Obtain Solution Review Results

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4.1. Mag neti c Anal ysi s of a Solenoi d Actuator

Tutorials | Chapter 4. Electromagnetics Tutorial |

4.1. Magnetic Analysis of a Solenoid Actuator



ANSYS Multiphysics, ANSYS Emag, ANSYS ED


easy



Discipline:

electromagnetics

Analysis Type:

linear static


PLA NE13


axisym axisymm metry, vect or plots , element element table o perations , path operations

A p p licab le Help A v ailab le:

Two -d imen s io n al Static M ag n et ic A n aly s is in the Lowthe Low Frequ enc y Elect romag net ic Anal An alysis ysis Guid e, PLANE13 in the th e Elemen Elements ts Reference Referenc e.

4.1.2. Problem Problem De scr sc ription iption

A solenoid solenoid actuator is actuator is to be analyzed as a 2-D axisymmetric axisymmetric model. For the given current, determine the force on the armature. 4.1.2.1. Given

The dimensions of the solenoid actuator are in centimeters. The armature is the moving component of the www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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actuator. The back-iron is the stationary iron component of the actuator that completes the magnetic circuit around the coil. The stranded, wound coil of coil of 650 windings with 1 amp/turn supplies the predefined current. The current per winding is 1 amp. The air-gap is the thin rectangular region of air between the armature and the pole faces of the back-iron. 4.1.2. 4.1 .2.2. 2. Approach Approach and and Ass As s umption umptionss

The magnetic flux produced by the coil current is assumed to be so small that no saturation of the iron occurs. This allows a single iteration linear analysis. The flux leakage out of the iron at the perimeter of the model is assumed to be negligible. This assumption is made simple to keep the model small. The model would normally be created with a layer of air surrounding the iron equal to or greater than the maximum radius of the iron. The air gap is modeled so that a quadrilateral mesh is possible. A quadrilateral mesh allows for a uniform thickness of the air elements adjacent to the armature where the virtual work force calculation is performed. This is desirable for an accurate force calculation. The program requires the current to be input in the form of current density (current over the area of the coil). The assumption of no leakage at the perimeter of the model means that the flux will be acting parallel to this surface. This assumption is enforced by the "flux parallel" boundary condition placed around the model. This boundary boundary condi conditi tion on is used used for for model modelss in in whi which the the fl flux is contai contain ned in in an iron circu circuiit. Forces for the virtual work calculation are stored in an element table and then summed. The force is also calculated by the Maxwell Stress Tensor method and the two values are found to be relatively close. 4.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Input Input Geometry Geome try

1. Read in geometry input file. Back To Top Define Materials

2. Set preferences. 3. Specify material properties. Back To Top Generate Mesh

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4. Define element type and options. 5. Assign material property attributes. 6. Specify meshing-size controls on air gap. 7. Mesh the model using the MeshTool. 8. Scale model to meters for solution. Back To Top Apply Loads

9. Define the armature as a component. 10. Apply force boundary conditions to armature. 11. Apply the current density. 12. Obtain a flux parallel field solution. Back To Top Obtain Solution


14. Plot the flux lines in the model. 15. Summarize magnetic forces. 16. Plot the flux density as vectors. 17. Plot the magnitude of the flux density. 18. Ex Exiit the ANSYS AN SYS program. 4.1.3. Input Geometry 4.1.3.1. Step 1: Read in geometry input file.

You will begin by reading in a file that includes the model. www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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1. Utility Menu> File> Read Input from ... 2. File File name: solenoid.inp UNIX version:

/ansys_inc/v110/ansys/data/models/solenoid.inp PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\solenoid.inp 3. [OK]

4.1.4. Define Define Materials Materials 4.1.4.1. Step 2: Set preferences.

You will now set pref set preferen erences ces in order to filter quantities that pertain to this discipline only. 1. Main Menu> Preferences 2. (check) “Magneti “Magneticc-No Nodal” dal” 3. [OK] 4.1.4.2. Step 3: Specify material properties.

Now specif specify the the material properties for the magnetic permeability of air, back-iron, coil, and armature. For simplicity, all material properties are assumed to be linear. (Typically, iron is input as a nonlinear B-H curve.) Material 1 will be used for the air elements. Material 2 will be used for the back-iron elements. Material 3 will be used for the coil elements. Material 4 will be used for the armature elements. 1. Main Menu> Preprocessor> Material Props> Material Models 2. (double-c (do uble-cllick) “Electr “Electromagneti omagnetics”, cs”, then "Relati "Relative ve Permeabil Per meabiliity”, then then “Co “Constant” nstant” 3. “MURX” = 1 4. [OK] 5. Edit> Copy 6. [OK] [OK ] to copy Material Material Model Mode l Number 1 to become Material Material Model Mode l Number 2. www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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7. (double-c (do uble-cllick) “Mate “Material rial Model Mod el Number 2”, then “Permeabil “Permeab ility ity (Constant)” (C onstant)” 8. “MURX” “MURX” = 1000 100 0 9. [OK] 10. Edit> Copy 11. 11 . “from “from Material Mate rial Number” = 1 12. “to Material Number” = 3 13. [OK] 14. Edit> Copy 15. 15 . “from “from Material Mate rial Number” = 2 16. “to Material Number” = 4 17. [OK] 18. 18 . (double-c (do uble-cllick) “Mate “Material rial Model Mod el Number 4”, then “Permeabil “Permeab ility ity (Constant)” (C onstant)” 19. “MURX” “MURX” = 2000 200 0 20. [OK] 21. Material> Exit 22. Utility Utility Me nu nu> > List> Prope Prope rties rties > All Materials Ma terials 23. 23 . Review Review the list list of mater materiials, then: File> Close (Windows),

or Close (X11/Motif) to close the window. 4.1.5. Generate Mesh 4.1.5.1. 4.1.5. 1. Step 4: De fine ine e lement type type s and and options. options.

In this step you will define element types and specify options associated with these element types. The The higher-order element PLANE53 is normally preferred, but to keep the model size small, use the lower-order element PLANE13 PLANE13.. Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 1. Main www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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2. [Add...] 3. “Magnetic “Magnetic Vector” Vecto r” (left (left column column)) 4. “Vect Quad 4nod13 4nod13 (PLANE13 (PLANE13”” (right column) 5. [OK] 6. [Options...] 7. (drop (dr op down) d own) “Elem “Element ent behavior” behavior” = Axisym Axisymmetri metricc 8. [OK] 9. [Close] 4.1.5.2. 4.1.5. 2. Step Ste p 5: As sign materia materiall properti propertiee s.

Now assig assign material properties to air gaps, iron, coil, and armature areas. 1. Main Me nu> Pr Prepr eproces oces sor> Mes M es hing> hing> MeshTool Me shTool 2. (drop down) “El “Element ement Attributes” Attributes” = Areas; then then [Set] 3. Pick four four areas of air air gaps, A13, A13 , A14, A17, and A18 (the picking picking "hot "hot spot" is is at the area number number label).

4. [OK] 5. (drop (dr op down) “Mate “Material rial number” number” = 1 6. [Apply] 7. Pick the the fi five backback - iron areas, A7, A8, A8, A9, A11, A12.

8. [OK] 9. (drop (dr op down) “Mate “Material rial number” number” = 2 www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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10. [Apply] 11. Pick coil area, A4.

12. [OK] 13. (drop down) d own) “Material “Material num number” = 3 14. [Apply} 15. Pick Pick armatu armature re area, A10, A10, A15, A16.

16. [OK] 17. (drop down) d own) “Material “Material num number” = 4 18. [OK] 19. Toolbar: SAVE_DB 4.1.5.3. Step 6: Specify meshing-size controls on air gap.

Adjust meshing size controls to get two element divisions through the air gap. 1. Main Menu> Preproc Prep rocesso essor> r> Meshing> Meshing> Size Size Cntrls> ManualSize> ManualSize> Lin Lines> es> Picked P icked Lines Lines 2. Pick four vertical vertical lin lines es through air gap. gap.

3. [OK] 4. “No. of o f element element divisi divisions” ons” = 2 www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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5. [OK] 4.1.5.4. Step 7: Me sh the model model using using the M es hT hTool. ool.

1. “Size “Size Control Contro l Global” = [Set] 2. “Elem “Element ent edge length” length” = 0.25 0.2 5 3. [OK] 4. (drop down) “Mesh” “Mesh” = Areas Areas 5. [Mesh] 6. [Pick All] All] 7. [Close] Note: Due Due to ANSYS ED FEA limitations, choose a coarse mesh. However, for production use, a finer mesh can be used, especially in the air-gap region. 8. Utility Me M e nu nu> > PlotCtrls> Numberin Numbering g 9. (drop (dr op down) d own) “Elem “Elem / attrib numberin numbering” g” = Material Mat erial numbers numbers 10. [OK]

Note: Your Your mesh mesh may vary sli slightl htly from the the mesh mesh shown shown here. As As a resu result, you you may see sli slightly tly dif different erent resul results ts during postproce during postprocessi ssin ng. For a discussion of results accuracy, see Planning Your Approach in the Modeli the Modeling ng and Meshing Meshi ng Guide. Guide. 4.1.5.5. 4.1.5. 5. Step 8: Scale Scale mode mode l to mete rs for solution. solution.

For a magnetic analysis, a consistent set of units must be used. In this tutorial, MKS units are used, so you must scale the model from centimeters to meters. 1. Main Menu> Preprocessor> Modeling> Operate> Scale> Areas 2. [Pick All] All] 3. “RX,RY,RZ “RX,RY,RZ Scal Sca le Factors” = 0.01, 0.01, 0.01 , 1 4. (drop (dr op down) d own) “Exi “Existin sting g areas are as will will be” be ” = Moved www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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5. [OK] 6. Toolbar: SAVE_DB 4.1.6. 4.1 .6. Apply Apply Loads Loads 4.1.6.1. Step 9: Define the armature as a component.

The armature can conveniently be defined as a component by selecting its elements. 1. Utility Menu> Select> Entities 2. (first (first drop down) “El “Elements” ements” 3. (second drop down) “By “By Attributes” Attributes” 4. “Min, “Min, Max, Inc” = 4 5. [OK] 6. Utility Menu> Plot> Elements

7. Utility Utility Me M e nu nu> > Se S e lect> Comp/ Comp/Ass Assee mbly> bly> Cre Cre ate Compon Componee nt 8. “Component name” name” = ARM ARM 9. (drop (dr op down) do wn) “Component is is mad madee of” = Elements Elements 10. [OK] 4.1.6.2. Step 10: Apply force boundary conditions to armature.

1. Main Menu> Preprocessor> Loads> Define Loads> Apply> Magnetic> Flag> Comp. Force/Torq 2. (highl (highlig ight) ht) “C “Component ompo nent name” name” = ARM 3. [OK] 4. Utility Utility Me M e nu nu> > Se lect> Everythin Everything g 5. Utility Menu> Plot> Elements


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4.1.6.3. Step 11: Apply the current density.

The current density is defined as the number of coil windings times the current, divided by the coil area. This equals (650)(1)/2, or 325. To account for scaling from centimeters to meters, the calculated value needs to be divided by .01**2. 1. Utility Menu> Plot> Areas

2. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De fine fine Loads> Apply> Apply> Magnetic> M agnetic> Excitation> Cur Curr Density> On Areas 3. Pick the coil area, are a, which which is is the area in the center. 4. [OK] 5. “Curr density density value” value” = 325/.01* 325/. 01**2 *2 6. [OK] Close any warning messages that appear. 4.1.6. 4.1 .6.4. 4. Step 12: 1 2: Obtain a flux flux parall parallee l fie fie ld soluti so lution. on.

Apply a perimeter boundary condition to obtain a “flux parallel” field solution. This boundary condition assumes that the flux does not leak out of the iron at the perimeter of the model. Of course at the centerline this is true due to axisymmetry. 1. Utility Menu> Plot> Lines 2. Main Menu> Preprocessor> Loads> Define Loads> Apply> Magnetic> Boundary> Vector Poten> Flux Par'l> On Lines 3. Pick all lines lines around aro und perimeter perimeter of o f model (14 lines). lines).


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4. [OK] 5. Toolbar: SAVE_DB 4.1.7. Obtain Solution 4.1.7.1. Step 13: Solve.

1. Main Menu> Solution> Solve> Electromagnet> Static Analysis> Opt & Solve 2. [OK [O K ] to initi initiate ate the solution. solution. 3. [Close] [Close] the inf information ormation window window when solution solution is done. do ne. 4.1.8. Re view Results Results 4.1.8.1. 4.1.8. 1. Step 14 : Plot the the flux lux lines in the the mode mode l.

Note that that a certai certain n amoun amountt of undesirabl desirablee fl flux leakage eakage occurs occurs out out of the the back-iron back-iron.. 1. Main Menu> General Postproc> Plot Results> Contour Plot> 2D Flux Lines 2. [OK] Close any Notes or Warnings.

Your results may vary slightly from what is shown here due to variations in the mesh. 4.1.8.2. Step 15: Summarize magnetic forces.

1. Main Menu> General Postproc> Elec & Mag Calc> Component Based> Force 2. (highl (highlig ight) ht) “Compone “Co mponent nt name(s)” name(s) ” = ARM 3. [OK] 4. Review Review the information, nformation, then then choose: File> Close (Windows), www.kxcad.net/ansys/ANSYS/ansyshel p/emag _sa.html

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or Close (X11/Moti (X11/Mo tif), f), to close the window. window. 4.1.8.3. 4.1.8. 3. Step 16: Plot the flux flux density as as ve ctors.

1. Main Menu> General Postproc> Plot Results> Vector Plot> Predefined 2. “Flux & gra gradient” dient” (left colu co lumn mn)) 3. “Mag flu flux x dens de ns B” (right column) column) 4. [OK]

4.1.8.4. Step 17: Plot the magnitude of the flux density.

Plot the magnitude of the flux density without averaging the results across material discontinuities. 1. Main Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Plot Re sults> Contour Contour Plot> Plot> Nodal N odal Solu 2. Choose Choo se "Magnetic "Magnetic Flu F lux x Density," Density," then then "Magnetic "Magnetic flux flux density density vector sum." sum." 3. [OK]

Next, Next, you you wil will see how how the the flux densi density ty is distri distribut buted ed throu throug ghout the the enti entire re actua actuator. tor. Up Up to thi thiss poin point, the the analysis and all associated plots have used the 2-D axisymmetric model, with the axis of symmetry aligned with the left vertical portion of the device. ANSYS will continue the analysis on the 2-D finite element model, but will allow you to produce a three-quarter expanded plot representation of the flux density throughout the device, based on the defined axisymmetry. This function is purely graphical. No changes to the database will be made when you produce this expanded plot. 4. Utility Menu> PlotCtrls> Style> Symmetry Expansion> 2D Axi-Symmetric 5. (check) “3/4 “3/4 expansi expansion” on” 6. [OK]


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Obtain an isometric view for a more meaningful representation. 7. Utility Menu> PlotCtrls> Pan,Zoom,Rotate 8. [Iso] 9. [Close]

4.1.8.5. Step 18: Exit the ANSYS program.

1. Toolbar: QUIT 2. (check) “Quit Quit - No Save!” 3. [OK] Congratulations! You have completed this tutorial.


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Chapter 5. CFD Tutor i al

Tutorials |

Chapter 5. CFD Tutorial


Laminar and Turbulent Flow Analyses A nalyses in a 2-D Duct

Pro bl blem em Speci Specifficati cation on Problem Description Preprocessing (Laminar Analysis) Solution So lution (Laminar Analysis) Postproc Po stprocessin essing g (Laminar (Laminar Analysis) Solution (Laminar Analysis with Change in Inlet Velocity) Postprocessing (Laminar Analysis Using New Inlet Velocity) Preprocessing (Laminar Analysis with Increase in Duct Length) Solution (Laminar Analysis Using New Duct Length) Postprocessing (Laminar Analysis Using New Duct Length) Solution (Turbulent Analysis) Postprocessing (Turbulent Analysis)

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5.1. Laminar and Tur bul ent Fl ow Anal yses i n a 2- D Duct

Tutorials | Chapter 5. CFD Tutorial |

5.1. Laminar and Turbulent Flow Analyses in a 2-D Duct



ANSYS Multiphysics, ANSYS FLOTRAN, ANSYS ED


advanced


1-1/2 to 2 hours

Discipline:

Compu Compu tat ional Fluid Dyn amics amics (CFD)

Analysis Type:

steady-state


FLUID141


so lid lid modeling, modeling, mapped mesh ing, defining defining an abbreviation on the Toolbar, restart of FLOTRAN solution, multiple solutions, vector displays, line line g raphs, path operations operations , trace particle particle animat animation ion


Ov erv iew o f FLOTRA N CFD A n aly s es in the Flu the Fluid idss Ana lysi lysiss Guide, Guide , FLUID141 in the Elemen the Elements ts Referenc e.

5.1.2. 5.1.2. Problem Description Descriptio n

This probl This problem em models air flow in a two-dimensional duct. First, you define an arbitrary inlet velocity to simulate laminar flow with a Reynolds number of 90. After you obtain the solution and examine the results, you will increase the inlet velocity to investigate its effects on the flow profile and obtain a new solution. Then, in the third part, you will increase the duct length to allow the flow to achieve a fully developed profile in the solution. Finally, after calculating that the Reynold's number is greater than 4000, you will restart the solution using the turbulent model.

5.1.2.1. Given Dimensio ns & Pro pert ies

In let len g t h

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4 in

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In let h eig h t

1 in

Tran s itio n len g t h

2 in

Ou t let h eig h t

2.5 in

In itial o u t let len g t h

4 in

A d d ed o u tlet len g t h

30 in

Air density

1.21x10-7 lbf -s 2 /in4

Air viscosity

2.642x10-9 lbf -s/in2

In let v elo cit y

1 in /s ec*

Ou t let p res s u re

0 ps i

*Initial *Initial value of 1 will will be ch anged to 50 upo n res tart.


You will perform two-dimensional analyses using the FLOTRAN element FLUID141. This problem is divided into four parts: A laminar analysis of the flow of air with a Reynolds number of 90 An investigation of how a higher inlet velocity affects the flow profile using the laminar model A laminar analysis of air with a longer duct length to observe a more fully developed flow profile A turbulent analysis of the flow of air with a Reynolds number of ~4600 For all solutions, you will apply a uniform velocity profile at the inlet. This includes specification of a zero velocity condition at the inlet in the direction normal to the inlet flow. You will apply no-slip (zero velocity) conditions all along the walls (including where the walls intersect the inlets and outlets). The fluid is considered incompressible and you can assume that the properties will be constant. In such cases, only the relative value of pressure is important, and a zero relative pressure is applied at the outlet. For the initial analysis, the flow is in the laminar regime (Reynold's number < 3000). To compute the Reynolds number of the flow for internal duct flows, the equation is as follows: www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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(Note that in a two-dimensional geometry, the hydraulic diameter is twice the inlet height.) You will increase the inlet velocity to 50 in/s for the second analysis (which will increase the Reynolds number accordingly) and you will rerun the solution. The flow profile for the second analysis shows that the flow is not fully developed, therefore the logical next step would be to increase the duct length in order to allow for a more complete profile. You will increase the length of the duct by 30 inches and rerun the solution. For internal flows, the transition to turbulence occurs within the Reynolds number range of 2000-3000. Therefore for the last solution of air in the duct (Reynolds number ~4,500), the flow will be turbulent. For the last analysis, you will initiate the solution using the turbulent model. You will restart the analysis here (instead of rerunning it) because the problem domain has not changed. 5.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Before you begin, delete any results files (.rfl (.rfl ) from previous CFD analyses that still reside in your working directory. If you begin an ANSYS session to start a new CFD analysis, and use the same jobn jobnam amee from a file stored from a previous CFD analysis, the program will not start from scratch, but will restart and append to files with the same name ( Jobname.rfl an Jobname.rfl and d Jobname.pfl ). ). To avoid this situation, delete these results files when starting a new CFD analysis. Another way of avoiding this situation is to change the jobname to one that was not used in a previous CFD analysis. You can change the jobname in the product launcher before starting ANSYS, or during an ANSYS session by choosing Utility Menu> File> Change Jobname . Pre Pre proce proce s s ing (Lamina (Laminarr Analysis Analysis))

1. Set preferences. 2. Define element type. 3. Create rectangle for the inlet region. 4. Cre Create ate the outl outlet et rectang re ctanglle. 5. Create the transition region between the rectangles. 6. Establish mesh patterns. 7. Create the finite element mesh. 8. Create command on the Toolbar.


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9. Apply boundary conditions. Back To Top Solution (Laminar Analysis)

10. Establish fluid properties. 11. Set execution controls. 12. Change reference conditions. 13. Execute FLOTRAN solution. Back To Top Postprocessing (Laminar Analysis)

14. Read in the results for postprocessing. 15. Plot velocity vectors. 16. Plot total pressure contours. 17. Animate velocity of trace particles. particles. 18. Make a path plot of the velocity through the outlet. outlet . Back To Top Solution (Laminar Analysis with Change in Inlet Velocity)

19. Increase the inlet velocity. 20. Run the analysis. Back To Top Postprocessing (Laminar Analysis Using New Inlet Velocity)

21. Plot total pressure contours. 22. Animate velocity of trace particles. particles. 23. Make a path plot of the velocity through the outlet. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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Back To Top Preprocessing (Laminar Analysis with Increase in Duct Length)

24. Delete pressure boundary condition. 25. Construct additional outlet region. 26. Establish mesh divisions for the new rectangle and mesh. 27. Apply boundary conditions on new region. Back To Top Solution (Laminar Analysis Using New Duct Length)

28. Change the jobname and execute solution. Back To Top Postprocessing (Laminar Analysis Using New Duct Length)

29. Read in the new results and plot velocity vectors. 30. Plot total pressure contours. 31. Animate velocity of trace particles. 32. Make a path plot of the velocity through the outlet. 33. Calculate Reynolds number. Back To Top Solution (Turbulent Analysis)

34. Specify FLOTRAN solution options and execution controls. 35. Restart the analysis. Back To Top Postprocessing (Turbulent Analysis) www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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36. Plot total pressure contours. 37. Animate velocity of trace particles. 38. Make a path plot of the velocity through the outlet. 39. Ex Exiit the ANSYS AN SYS program. 5.1.3. Preprocessing (Laminar Analysis) 5.1.3.1. Step1: Set preferences.

You will now set pref set preferen erences ces in order to filter quantities that pertain to this discipline only.

1. Main Menu > Preferences 2. Turn on FLOTR FLOTRAN AN CFD filtering. 3. OK.

5.1.3.2. Step 2: Define element type. 1. Main Menu > Preprocessor > Element le ment Type Type > Add/Edit/Delete 2. Add an elem element ent type.

3. Choos Choo s e FLOTR FLOTRAN AN CFD. 4. Choos e 2D FLOTRAN FLOTRAN elem e lemen entt (FLUID141 FLUID141). ). 5. OK. 6. Close.


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5.1.3.3. 5.1.3. 3. Step 3: Cre Cre ate ate re ctangle ctangle for the the inlet region. 1. Main Menu> Preprocessor> Model odeling ing> > Create> Areas> Rectangle Rectangle > By Dimensions 2. Enter the th e following following:: X1 = 0 X2 = 4 3. Enter the th e following following:: Y1 = 0 Y2 = 1 4. App ly to create the fir first st rectangle and preserve the d ialog ialog box for for the second rectangle. rectangle.

5.1.3.4. Step 4: Create the outlet rectangle. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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1. Enter the th e following following:: X1 = 6 X2 = 10 2. Enter the th e following following:: Y1 = 0 Y2 = 2.5 3. OK.


5.1.3.5. 5.1.3. 5. Step 5: Create the tran transition sition re re gion be be twe twe e n the the re ctangles ctangles..

The transition region, where the flow expands, is bordered on the top by a smooth line tangent to the upper line of both rectangles. This line is created with the "Tangent to 2 lines" option. Note that the prompt in the Input Window will indicate what is to be picked (lines, ends of lines). The area is then created as an arbitrary area through the four keypoints. Note that the area will be bounded by existing lines through those keypoints. 1. Main Menu> Preprocessor> Modeling> Create> Lines> Lines> Tan to 2 Lines 2. Pick first first line (upp er line line of left left rectan gle).

3. OK (in picking menu). menu ). 4. Pick Pick the tange ncy en d of the first first line line (uppe r right right corner).

5. OK (in picking menu). menu ). 6. Pick Pick the se cond line line (upp er line line of the larger larger rectangle.

7. OK (in picking menu). menu ). www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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8. Pick Pick the tang ency end of the secon d line. line.

9. OK to create th e line line The result is a smooth line between the two areas.

Now create th e thir th ird d area as an arbitrary arb itrary area thro ugh ug h keyp oints. oint s. 10. Main Menu> Preprocessor> Modeling> Create> Areas> Arbitrary> Through KPs 11. Pick 4 corners corn ers in cou nterclockwi nt erclockwiss e order.

12. OK in the picking picking menu.

13. Toolbar: SAVE_DB

5.1.3.6. 5.1.3. 6. Step 6: Establish Establish me me s h pattern patterns. s.

To create a mapped mesh, set the specific size controls along the lines ( LESIZE command). The establishment of a good finite element mesh is quite important in CFD analyses. The general finite element philosophy of putting more elements in regions with higher solution gradients applies here. The mesh density should be sufficient to enable the program to capture the nature of the phenomena. For example, a small recirculation region is likely to develop in the expansion region. The greater the number of applied elements implies a higher level of flow details that will be captured. Apply 10 elements in the transverse direction (Y) and bias them slightly towards the top and bottom boundaries. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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This will help capture boundary layer effects. For high Reynolds number problems, finer meshes should be used. Along the inlet flow direction (X) in the inlet, use the number of divisions tabulated below. Mesh Division Divisi on Strategy Strate gy

Transverse (Y) direction

walls 10 divis ivis ions - bias towards walls

Inlet region, flow direction (X)

15 divis ivis ions - bias bias t owards inlet and trans ition ition

Transition region

12 divis ivis ions - uniform spacing

Outlet region (initial)

15 divis ivis ions - larger larger elements elements near o utlet

Before attempting this step, plot the lines for clarity. til ity Menu> Plot> Lines 1. Utility

2. Main Menu> Preprocessor> Meshing> Mesh Tool 3. Choos e Lines Set. Set. 4. Pick lines lines in flow flow direction alon g the inlet.

5. Ap ply (in (in the th e picking picking menu menu ). 6. Enter 15 as t he No. of elem element ent d ivisions ivisions . 7. Enter -2 as th e Spacing ratio ratio (this produ ces s maller aller elements near both ends of the line). 8. Apply.

The mesh ratio ch os en res ults in s maller aller elements elements near the inlet, inlet, where the flow is dev eloping, and near the expansion, in which more elements will be placed becaus bec aus e of the high s olution olut ion gradient g radientss in www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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that region. There should be a relatively smooth transition in element size from region to region throug hou t the en tire tire problem domain. domain. You will will repeat th is proces s of picking picking the lines lines and en tering tering t he nu mber of divisions divisions and th e ratios, ratios, us ing the mesh division division s trategy above. Note that t hat the th e mes mes h divis ion ratio is ap plied to t he direction direction o f the lines lines , the larger elem elements ents being at the end of the line. line. This This is t he reason for the us e of a number less less than 1 for for the up per line line of the o utlet region and a nu mber greater than 1 for for the lower line. (The line directions follow a counterclockwise direction, according to how they were generated.) Transition region: 9. Pick Pick the top and b otto m lines lines in the cen ter area. area.

10. Ap ply (in (in the th e picking picking menu menu ). 11. 11. Enter 12 as t he No. of elem element ent d ivisions ivisions . 12. Enter 1 as th e Spac Spacing ing ratio (un (un iform iform sp acing). acing ). 13. Apply. Outlet region: 14. 14. Pick Pick the top and b otto m lines lines in the ou tlet region. region.

15. Ap ply (in (in the th e picking picking menu menu ). 16. 16. Enter 15 as t he No. of elem element ent d ivisions ivisions . 17. 17. Enter 3.0 3.0 as the Spacing ratio (bias towards o utlet).

18. OK.


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Notice th at the t he u pper pp er line line is n ot b iased towards to wards the t he transition. The line bias needs to be "flipped." 19. 19. Choos e Fli Flip p in in the Mes h Tool. (toggle to Mesh Tool as necess ary.) ary.) 20. Pick th e upper line only.

21. OK (in (in the th e picking picking menu).

Transverse direction: 22. 22. Choos e Lines Lines Set. 23. 23. Pick Pick the 4 transv erse direction direction lines.

24. OK to clos e picking picking menu. 25. 25. Enter 10 as t he No. of elem element ent d ivisions ivisions . 26. 26. Enter -2 as th e Spacing ratio ratio (bias towards to p and bo tto m walls walls ). 27. OK.


5.1.3.7. Step 7: Create the finite element mesh. 1. Choos e Mapp ed mesh er. 2. Choos e Mesh. 3. Pick All. 4. Close the Mesh Too l. (Toggle (Toggle to the Mesh Tool as necess ary.) ary.)

5.1.3.8. Step 8: Create command on the ANSYS Toolbar. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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The ANSYS Toolbar contains a set of buttons that execute commonly used ANSYS functions. It is convenient to establish a command on the ANSYS Toolbar that turns off the display of the triad at the origin. You will accomplish this by accessing the menu controls on the Utility Menu and then choosing to edit the Toolbar. Enter the command name and command itself as an abbreviation. 1. Utility Menu> MenuCtrls> Edit Toolbar 2. Typ e TRI,/triad,off TRI,/triad,off after *ABBR. *ABBR. 3. Accept. 4. Close. 5. Turn off triad triad display us ing the new butto n TRI. TRI. This will unclutter subsequent result displays. til ity Menu> Plot> Lines 6. Utility

5.1.3. 5.1 .3.9. 9. Step 9: 9 : Apply bounda boundary ry conditions conditions .

A velocity of 1 inch/second is applied in the X direction (VX) at the inlet, and a zero velocity is applied in the transverse direction at the inlet (VY in the Y direction). Zero velocities in both directions are applied all along the walls, and a zero pressure is applied at the outlet. These boundary conditions are being applied to the lines now so that they do not have to be applied again if remeshing is required. Apply the inlet boundary condition.

1. Main Menu> Preprocessor> Loads > Define Loads> Apply> Fluid/CFD> Fluid/CFD> Velocity> Veloci ty> On Lines 2. Pick the th e inlet line line (the vertical ve rtical line line at th e far left).

3. OK in the picking picking menu. 4. Enter Ent er 1.0 for VX. VX. 5. Enter Ent er 0.0 for VY VY. 6. OK.

Apply the wall boundary conditions. Choose the lines which make up th e walls walls and then apply zero velocities velocities in the X and Y directions. 7. Main Menu> Preprocessor> Loads> Define Loads> Apply> Fluid/CFD> Fluid/CFD> Velocity> Veloci ty> On Lines 8. Pick Pick the six lines lines o n the to p and bo tto m. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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9. OK in picking picking menu. 10. Enter Ent er 0.0 for VX VX and VY. VY. 11. 11. OK to apply the cond ition. ition.

You will will su bs eque ntly s ee tha t th e wall wall condition of zero zero velocity will will automatically automatically prevail at the corners where the inlets inlets intersect th e walls. walls. Apply the o utlet condition. condition. 12. Main Menu> Preprocessor> Loads> Define Loads> Apply> Fluid/CFD> Pressure DOF> On Lines 13. Pick the th e out let line line (vertical line line on t he far right).

14. OK (in picking menu). menu ). 15. Enter 0 for the Press ure value. 16. 16. Set endp oints to Yes. Yes. 17. OK.

18. Toolbar: SAVE_DB . At t his p oint, the finite elem element ent model is is c omplete omplete and the FLOTR FLOTRAN AN menus menus are access ed t o s pecify the fluid properties along with any oth er FLOTR FLOTRAN AN cont rols rols that may b e required.

5.1.4. Solution (Laminar Analysis) 5.1.4.1. Step 10: Establish fluid properties.

Fluid properties will be established for air in the “inches” set of units, where the unit of mass is (lb f -sec2)/in. 1. Main Menu> Solution> FLOTRAN Set Up> Fluid Properties 2. Choos e AIR-I AIR-IN N for bot h dens ity and visco visco sity. 3. OK. 4. OK.

5.1.4.2. Step 11: Set execution controls.

Choose the execution control from the FLOTRAN Set Up Menu.


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1. Main Menu> Solution> FLOTRAN Set Up> Execution Ctrl 2. Enter 40 Global iterations (Note: 40 40 global iterat iterations ions is arbitrary with with no guarantee of convergence.) 3. OK to apply and close.

5.1.4.3. 5.1.4. 3. Step 12: Change Change ref refee re nce cond co nditi itions. ons.

The reference pressure is changed from the default value of 101 KPa to 14.7 psi to maintain a consistent set of units. Likewise, the nominal stagnation and reference temperatures are changed from 293 oK to 530oR by setting them to 70o R and adding an offset temperature of 460 o R. 1. Main Menu> Solution> FLOTRAN Set Up> Flow Envir nvironment> onment> Ref Conditi Conditions ons 2. Change the reference reference press ure to 14.7 14.7 ps i (equivalent to 1 atmos atmos phere). 3. Change the no minal, inal, st agna tion, and refer reference ence temperatures (in oR) to 70. 4. Change the temperature offset offset (in (in o R) from absolute 0 to 460. 5. OK. 6. Toolbar: SAVE_DB .

5.1.4.4. 5.1.4. 4. Step 13: Exe cute FLOTRAN FLOTRAN solut s olution. ion. 1. Main Menu> Solution> Run FLOTRAN While running the FLOTRAN solution, ANSYS will plot the "Normali "Normalizzed Rate o f Chang Chang e" as a funct ion of th e " Cumulative Cumulative Iteration Number." This is the Graphical Solution Tracker which which allows allows v isual monitoring monitoring of the so lution for convergence. 2. Clos Clos e the inform information windo windo w when the s olution is done.

5.1.5. Postprocessing (Laminar Analysis) 5.1.5.1. 5.1.5. 1. Step 14: Re ad in the the res ults ults for pos pos tproces tproces sing.

Enter the general postprocessor and read in the latest set of solution results, and then create a vector plot. General al Pos tproc> tproc> Read Res Res ults > 1. Main Menu> Gener Last set


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5.1.5.2. Step 15: Plot velocity vectors. 1. Main Menu> General Postproc> Plot Results> Vector Plot> Predefined 2. Choos e DOF DOF so lution. 3. Choos Choo s e Velocity Velocity V. V. 4. OK. The resulting vector plot shows the recirculation region that occurs in the up per region region of the duct.

5.1.5.3. 5.1.5. 3. Step 16 : Plot total total pre pre s sure contou co ntours. rs. General al Pos tproc> tproc> Plot Pl ot Results> Resul ts> Contour 1. Main Menu> Gener Plot> Nodal Nodal S olu

2. Choos Choo s e Other FL FLOTRAN OTRAN Quant ities. 3. Choos e Total Stagnat ion Press Press ure. 4. OK. The resulting resulting co ntour plot s hows the total static and d ynamic ynamic pres su res th at occu o ccurr in in th e du ct.

5.1.5.4. Step 17: Animate velocity of trace particles. 1. Main Menu> General Postproc> Plot Results>Defi Trace Pt 2. Pick Pick two two or three points aroun d the inlet region region and o ne or two po ints in th e recirculati recirculation on region (along (along the u ppe r wall wall of the transition region).

3. OK (in picking menu). menu ). 4. Utility Menu> PlotCtrls> Animate> Particle Flow 5. Choos Choo s e DOF DOF Solution . 6. Choos Choo s e Velocity Velocity VX. VX. 7. OK. Ignore an y warning messa ges abou t maxim maximum um number number of loops (Choo (Choo se Clos Clos e). ANSY ANSYS creates a pa rticle rticle flow flow pat h bas ed u po n approxi ap proxim mation s t hat do not no t form clos ed loops loo ps . The resu lting lting t race plot sh ows th e path of flow flow particles particles through the duct. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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8. Make choices in th e Animation Animation Controller Controller (not (not sh own), if if necess ary, then choo se Close. Close.

5.1.5.5. Step 18: Make a path plot of velocity through the outlet. General al Postproc> P ostproc> Path Operations Operations> > 1. Main Menu> Gener Define Path> By Nodes Nodes

2. Pick Pick the lowest lowest and then the highest p oint of the outlet.

3. OK (in picking menu). menu ). 4. Enter Ente r OUTLET OUTLET for the Path Pat h Name. Name. 5. OK. 6. File> Close (Windows) or Close (X11/Motif)

Now spe cify the v elocity in th e X direct direction ion (VX) (VX) to map onto the path. 7. Main Menu> General Postproc> Path Operations> Map onto Path 8. Enter Ent er VEL VELOCITY OCITY as labe la bel. l. 9. Choos Choo s e DOF DOF Solution . 10. Choos Choo s e Velocity Velocity VX. VX. 11. OK. 12. Main Menu> Gener General al Postproc> P ostproc> Path Operations Operations> > Plot Pl ot Path Item> On Graph 13. Choos Choo s e the label VEL VELOC OCITY ITY that th at you yo u previou s ly defined.

14. 14. OK to create path plot. 15. 15. Clos Clos e any warning warning mess ages . The resulting path plot shows the flow has an almost fully developed laminar profile. The curve looks relatively uniform and has a parabolic parabolic shape.

Now for for the th e next stu dy, dy , inv inv es tigate tigat e the th e effects of increas ing th e inlet velocity to 50 inches/second. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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5.1.6. Solution (Laminar Analysis with Change in Inlet Velocity) 5.1.6.1. Step 19: Increase the inlet velocity.

The inlet velocity affects the flow profile. Increasing the inlet velocity by a factor of 50 will increase the Reynolds number accordingly. Return to the apply loads function and change the inlet velocity, then execute the solution from a different jobname.

til ity Menu> Plot> Lines 1. Utility

2. Main Menu> Solution> Define Loads> Apply> Fluid/CFD> Velocity> On Lines 3. Pick the th e inlet line line (the vertical ve rtical line line at th e far left).

4. OK (in (in picking menu menu ) 5. Enter Ent er 50 for VX. VX. 6. Enter Ent er 0 for VY VY. 7. OK.

5.1.6.2. 5.1.6. 2. Step Ste p 20: Run the the anal analysis. ysis.

You will now restart the analysis from the initial result. 1. Main Menu> Solution> Run FLOTRAN An error message appears stating that the coefficient matrix has a ne gative d iagonal. ANSYS ANSYS produ ced t his message because it uses the Streamline Upwind/PetrovGalerkin (SUPG) advection scheme by default. Although it is more more accurate tha n ot her advect ion sch emes, emes, th e SUPG SUPG scheme can lead lead to spu rious rious oscill oscillations in the solution, and may may cause n onphy sical solutions or convergence difficulti difficulties. es. To remedy remedy t his s ituation witho witho ut ch anging t o anot her advec tion s cheme, you will will first first ad d s ome modified inertial relaxation, and then will execute the solution again. 2. OK to remov remov e the error error mes mes sa ge. 3. Close. 4. Main Menu> Solution> FLOTRAN Setup> Relax/Stab/Cap> MIR Stabilizatio 5. Enter 0.1 0.1 for the Momentu m Equation . 6. OK.


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7. Main Menu> Solution> Run FLOTRAN Once again, the Graphical Solution Tracker is displayed. 8. Close. You will now repeat the preceding postprocessing steps exactly exactly to s how the effects o f the higher inlet inlet velocity. These s teps are as follow follows: s: 9. Main Menu> General Postproc> Read Results> Last Set 10. Main Menu> General Postproc> Plot Results> Vector Plot> Predefined 11. Choos Choo s e DOF DOF Solution . 12. Choos Choo s e Velocity Velocity V. V. 13. OK.

5.1.7. Postprocessing (Laminar Analysis Using New Inlet Velocity) 5.1.7.1. 5.1.7. 1. Step 21 : Plot total total pre pre s sure contou co ntours. rs. 1. Main Menu> General Postproc> Postproc> Plot Results> Resul ts> Contour Plot> Nodal Solu 2. Choos Choo s e Other FL FLOTRAN OTRAN Quantities. 3. Choos e Total Total stagn ation pres su re. 4. OK. The resulting resulting contour plot shows th e total static and dynamic dynamic press ures that occur in the duct.

5.1.7.2. Step 22: Animate velocity of trace particles. 1. Main Menu> General Postproc> Plot Results> Defi Trace Pt 2. Pick Pick two two or three points around t he inlet region region and o ne or two po ints in the recirculation region (along (alon g th e up per wall of the trans ition ition region).

3. OK (in picking menu). menu ). 4. Utility Menu> PlotCtrls> Animate> Particle Flow 5. Choos Choo s e DOF DOF Solution . www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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6. Choos Choo s e Velocity Velocity VX. VX. 7. OK. Ignore th e warning mess mess ages abou t maxim maximum um number number of loop s (Choo (Choo se Clos Clos e). ANSY ANSYS creates a p article article flow flow path bas ed upon approximations that do not form closed loops. The resu lting lting t race plot sh ows th e path of flow flow particles particles through the duct.

8. Make choices in th e Animation Animation Controller Controller (not (not sh own), if if necess ary, then choo se Close. Close.

5.1.7.3. Step 23: Make a path plot of velocity through the outlet. 1. Main Menu> General Postproc> Path Operations Op erations> > Define Path> By Nodes Nodes 2. Pick Pick the lowest lowest and th en the highes t point of the outlet.

3. OK (in picking menu). menu ). 4. Enter Ente r OUTLET OUTLET for the Path Pat h Name. Name. 5. OK. 6. File> Close (Windows)

or Close (X11/Motif).

Now spe cify the v elocity in th e X direct direction ion (VX) (VX) to map map onto th e path. 7. Main Menu> General Postproc> Path Operations > Map onto Path 8. Enter Ent er VEL VELOCITY OCITY as labe la bel. l. 9. Choos Choo s e DOF DOF Solution . 10. Choos Choo s e Velocity Velocity VX. VX. 11. OK. 12. Main Menu> General Postproc> Path Operations> Plot Path Item> On Graph 13. Choos Choo s e the label VEL VELOC OCITY ITY that th at you yo u previou s ly defined. 14. 14. OK to create path plot. 15. 15. Clos Clos e any warning warning mess ages .


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The resulting path plot shows the curve has a bias towards one edge of the outlet. This indicates that the flow has not yet fully developed. (Note that if your plot appears as a mirror image of this one, it is because you reversed the order of picking, that is, you picked from highest to lowest instead of from lowest to highest points at the outlet.)

Now in in the the nex nextt stu study, if the the len leng gth of the the duct's duct's outl outlet et regi region on is in increased, creased, the the fl flow may may reach a fu fully devel developed oped profi profile. Increase Increase the the duct duct len leng gth by 30 in inches. ches. 5.1.8. Preprocessing (Laminar Analysis with Increase in Duct Length) 5.1.8.1. 5.1.8. 1. Step Ste p 24: De lete pre pre ss ure ure bound boundar ary y conditi condition. on.

The results for the lower viscosity case indicate that the recirculation region has extended well beyond the outlet. To allow the flow to fully develop by the time it reaches the exit, it must be given more room to do so.

1. Main Menu> Preproces s or> Load Loads > Define Load Loads > Delete> Fluid/CFD> Pressure DOF> On Lines 2. Pick All (in (in picking menu menu ) to delete de lete all pres s ure bou nd ary conditions.

5.1.8.2. Step 25: Construct additional outlet region. 1. Main Menu> Preprocess Preproces s or> Mod Model eling ing> > Create> Create> Areas> Rectangle> B y Dimensions 2. Enter the th e following following:: X1 =10 X2 = 40 3. Enter the th e following following:: Y1 = 0 Y2 = 2.5 4. OK.

The new rectangle rectangle has unique keypoints and lines lines . These must be merged merged with with their counterparts on the existing areas. 5. Main Menu> Preprocessor> Numbering Ctrls> Merge Items 6. Choos e All for the Typ e of item itemss to b e merged. 7. OK. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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A warning warning mess mess age appears s tating that an un mesh ed line line is to merged into a previous prev ious ly mes mes hed line. line. This Th is is as it sho uld be. Close Close the message box. box. 8. Close. til ity Menu> Plot> Lines 9. Utility

5.1.8.3. Step 26: Establish mesh divisions for the new rectangle and mesh. 1. Main Menu> Preprocessor> Meshing> MeshTool 2. Choos e Lines Set. Set. 3. Pick line line at new outlet.

4. OK (in picking menu). menu ). 5. Enter 10 10 for No. No. of element element d ivisions ivision s (as before). b efore).

6. Enter -2 -2 for Spacing ratio. 7. Apply. Repeat the procedure for the upper and lower lines lines of the rectang le. 8. Pick Pick lines lines at the to p and bo tto m of new out let.

9. OK (in picking menu). menu ). 10. Enter 20 20 for No. No. of element element d ivisions. ivision s. 11. Enter 3 for Spac Spacing ing ratio. 12. OK. Flip Flip the line bias on the u pper line. line. 13. Choos Choo s e Lines Flip. Flip. 14. Pick the th e upper uppe r line. line.

15. OK (in picking menu). menu ). 16. Toolbar: SAVE_DB. 17. 17. Choos e Mesh. 18. Pick the th e outlet ou tlet area. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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19. OK (in (in picking menu menu ) to begin b egin mes mes h.

20. 20. Clos Clos e the Mesh Tool.

5.1.8.4. Step 27: Apply boundary conditions on new region.

You must apply boundary conditions to the new region. You will apply zero velocities in both directions along the walls, and a zero pressure at the outlet. til ity Menu> Plot> Lines 1. Utility

2. Main Menu> Preprocessor> Loads> Define Loads> Apply> Fluid/CFD> Fluid/CFD> Velocity> Veloci ty> On Lines 3. Pick Pick the new upp er and lower lower walls walls that do n't have bo und ary conditions.

4. OK (in picking menu). menu ). 5. Enter Ent er 0 for VX VX and VY. VY. 6. OK. Now apply t he p ress ure bo un dary con c ondition dition at a t th e ou tlet. 7. Main Menu> Preprocessor> Loads> Define Loads> Apply> Fluid/CFD> Pressure DOF> On Lines 8. Pick Pick the new outlet.

9. OK (in picking menu). menu ). 10. Enter 0 for the Press ure value. 11. 11. Set endp oints to Yes. Yes. 12. 12. OK to apply the bound ary cond ition. ition. til ity Menu> Plot> Lines 13. Utility

5.1.9. Solution (Laminar Analysis Using New Duct Length) 5.1.9.1. 5.1.9. 1. Step 28 : Change Change the jobna jobname me and exe cute s olution. olution.

Because the addition of an outlet has changed the problem domain, a new analysis is required. You can start a new analysis by changing the jobname from the Utility Menu. Note that that a warn warniing message essage wil will appear stati statin ng that that you you must exi exit the the Solut Solutiion processor processor in in order to to chan change ge the the name. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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1. Utility Menu> File> Change Jobname 2. Clos Clos e to exit exit Solution . 3. Enter "newLengt "newLengt h" for the new jobn jobn ame. ame. 4. OK. Anoth er way way to start a new analysis analysis is b y deleting th e resu lts file, file, named file.rfl named file.rfl (by (by d efault). efault). You can d elete a file file in in on e of two ways: Utility Menu> File> File Operations> Delete

Pick Pick the file file name, then ch oos e OK OR

Execute a /SYS command and remove the file with the appropriate operating system command. ANSYS ANSYS will will auto au tom matically renam ren amee an incorrect results file. file. Now execu execu te th e new solut s olution. ion. 5. Main Menu> Solution> Run FLOTRAN 6. Clos Clos e the information information windo windo w when when s olution is done.

5.1.10. Postprocessing (Laminar Analysis Using New Duct Length) 5.1.10 .1. Step 29: Re ad in the the ne w resul res ults ts and plot plot velocity ve locity ve ctors ctors . 1. Main Menu> General Postproc> Read Results> Last Set 2. Main Menu> General Postproc> Plot Results> Vector Plot> Predefined 3. Choos Choo s e DOF DOF Solution . 4. Choos Choo s e Velocity Velocity V. V. 5. OK.

5.1.10 .2. Step 30: Plot total total pre pre ss ure ure contours. contours. 1. Main Menu> General Postproc> Plot Results> Contour Plot> Nodal Nodal S olu 2. Choo se Other FLOTR FLOTRAN AN Quan tities. tities . www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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3. Choo se Total Stagnation Stagnation Press Press ure. 4. OK.

The resulting contour plot shows the total static and dynamic pressures that occur in the duct.

5.1.10.3. Step 31: Animate velocity of trace particles. 1. Main Menu> General Postproc> Plot Results>Defi Trace Trace Pt 2. Pick Pick two two or three points aroun d the inlet region region and one o r two two po ints in the recirculation recirculation region (along (along the u pper wall wall of the trans ition ition region).

3. OK (in picking menu). menu ). 4. Utility Menu> PlotCtrls> Animate> Particle Flow 5. Choos Choo s e DOF DOF Solution . 6. Choos Choo s e Velocity Velocity VX. VX. 7. OK. Ignore th e warning mess mess ages abou t maxim maximum um number number of loops (choos e Clos Clos e). ANSY ANSYS S creates a particle particle flow flow path bas ed up on approxim approximations ations that do n ot form closed loop s. The resulting trace plot shows the path of flow particles throug thro ug h th e du ct.

8. Make choices in the An imation imation Controller Controller (not (not sho wn), wn), if if necessary, then choos e Close. Close.

5.1.10.4. Step 32: Make a path plot of the velocity through the outlet.

The outlet velocity profile can be examined with a path plot. First, establish a path for the path plot. 1. Main Menu> General Postproc> Path Operations Op erations> > Define Path> By Nodes Nodes 2. Pick Pick the lowest lowest po int, and then th e highes highes t po int of th e outlet. ou tlet.

3. OK (in (in the th e picking picking menu). www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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4. Enter "out let" for for the path name. 5. OK. 6. File> Close (Windows) or Close (X11/Motif)

Now spe cify the v elocity in th e X direct direction ion (VX) (VX) to map ont o th e path . 7. Main Menu> General Postproc> Path Operations > Map onto Path 8. Enter "velocity" as th e User User label. label. 9. Choos e DOF DOF so lution. 10. Choos Choo s e Velocity Velocity VX. VX. 11. OK. 12. Main Menu> General Postproc> Path Operations> Plot Path Item> On Graph 13. Choos Choo s e the labe l VELOC ELOCITY ITY that th at yo u previous prev ious ly defined. 14. 14. OK to create path plot. 15. 15. Clos Clos e any warning warning mess ages .

The resulting path plot shows that the flow is almost fully developed. Since the velocity has been increased so much, the flow may be in the turbulent regime. The next step is to check the Reynold's number and activate turbulence if necessary. A consequence of the increased diffusion associated with turbulence is a decrease in the size of the recirculation region. 5.1.10.5. Step 33: Calculate Reynolds number.

Calculate Reynolds number in order to determine if the analysis is indeed in the turbulent region (Re > 3000). Recall that the Reynolds number is determined by the following formula:

Our flow material is AIR, which has the following properties: p = density = 1.21e-7 V = Velocity = 50 www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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Dh = hydraulic diameter = 2*inlet height = 2

Viscosity ty= = 2.642e2 .642e- 9 µ = Viscosi Therefore, Re = 4600, which is turbulent. So the next step is to restart the analysis using the turbulent model. 5.1.11. Solution (Turbulent Analysis) 5.1.11.1. Step 34: Specify FLOTRAN solution options and execution controls. 1. Main Menu> Solution> FLOTRAN Set Up> Solution Sol ution Options Options 2. Choos e Turbulent opt ion. 3. OK. With the increased turbulence resulting from the low viscos ity, the non linear linear effects effects in the problem are more more pron oun ced and more global iterations will will be required req uired to achieve ach ieve a go od s olution. olut ion. You You will increase th is nu mber in th e Execution Execution Control dialog dialog bo x. 4. Main Menu> Solution> FLOTRAN Set Up> Execution Ctrl 5. Enter 80 80 Global iteration iteration s. 6. OK.

5.1.11 .2. Step 35: Re start start the the anal analysis. ysis.

Note that that th this is is a restart restart of the the anal analy ysis. sis. Resta Restarti rtin ng an ANSYS FLOTR FLOTRAN AN solu solution tion requi requires tha thatt the the problem problem domain (specifically, the nodal geometry) is not changed. Since the only changes that were specified were a change the model (from laminar to turbulent) and a change in the number of equilibrium iterations, restarting the analysis is acceptable. Therefore, the solution will pick up where it left off, and 80 global iterations will be executed. 1. Main Menu> Solution> Run FLOTRAN Once again, th e Graphical Graphical Solution Solution Tracker is is displayed. 2. Close. You will now repeat the preceding postprocessing steps exactly to show the effects of the higher inlet velocity. These steps are as follows: General al Pos tproc> tproc> Read Res Res ults > Las Las t 3. Main Menu> Gener Set Se t www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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4. Main Menu> General Postproc> Plot Results> Vector Plot> Predefined 5. Choos Choo s e DOF DOF Solution . 6. Choos Choo s e Velocity Velocity V. V. 7. OK.

5.1.12 . Postproce Postproce s sing (Tu (Turb rbul ulee nt Analy Analysis sis ) 5.1.12 .1. Step 36: Plot total total pre pre ss ure ure contours. contours. 1. Main Menu> General Postproc> Plot Results> Contour Plot> Nodal Solu 2. Choos e Other quan tities. 3. Choos e Total Press Press ure PTOT. PTOT. 4. OK.

The resulting contour plot shows the total static and dynamic pressures that occur in the duct.

5.1.12.2. Step 37: Animate velocity of trace particles. 1. Main Menu> General Postproc> Plot Results> Results > Defi Defi Trace Pt 2. Pick Pick two or three points aroun d the inlet region and one or two points in the recirculation recirculation region (along t he upp er wall wall of the t ransition region).

3. OK (in picking menu). menu ). til ity Menu> PlotCtrls > Animate> Animate> 4. Utility Particle Flow

5. Choos Choo s e DOF DOF Solution . 6. Choos Choo s e Velocity Velocity VX. VX. 7. OK. Ignore any warning warning mess mess ages about maximum number of loops (choose Clos Clos e). ANSYS ANSYS creates a pa rticle flow flow path based upon approxim approximations that do n ot form closed loops. www.kxcad.net/ansys/ANSYS/ansyshel p/cfd_l t.html

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The resulting resulting t race race plot s hows th e pat h of flow particles particles throug th roug h th e duct.

8. Make choices in in the Animation Animation Controller Controller (not (not sh own), if if neces sary, then choos e Cl Close.

5.1.12.3. Step 38: Make a path plot of velocity through the outlet. 1. Main Menu> General Postproc> Path Operations Op erations> > Define Path> By Nodes Nodes 2. Pick Pick the lowest lowest and th en the highes t point of the outlet.

3. OK (in (in the th e picking picking menu). 4. Enter OUTL OUTLE ET as th e Path Name. Name. 5. OK. 6. File> Close (Windows). or Close (X11/Motif)

Now spe cify the v elocity in th e X direct direction ion (VX) (VX) to map map onto th e path. 7. Main Menu> General Postproc> Path Operations > Map onto Path 8. Enter Ent er VEL VELOCITY OCITY as labe la bel. l. 9. Choos Choo s e DOF DOF Solution . 10. Choos Choo s e Velocity Velocity VX. VX. 11. OK. 12. Main Menu> General Postproc> Path Operations> Plot Path Item> On Graph 13. Choos Choo s e the label VEL VELOC OCITY ITY that th at you yo u previou s ly defined. 14. 14. OK to create path plot. 15. 15. Clos Clos e any warning warning mess ages .


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Note that that wi with the the turbu turbullent ent model model is turn turned ed on for the the anal analy ysis, sis, the the fl flow looks looks fu fully devel developed oped and and the the path plot plot appears to be flatter on the top (instead of parabolic, as in the laminar analyses). Thus the flow is turbulent and the observed results are as expected. 5.1.12.4. Step 39: Exit the ANSYS program. 1. Toolbar: QUIT. 2. Choos e Quit Quit - No Save! Save! 3. OK.

Congratulations! You have completed this tutorial. Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for: Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. Sending animations over the web.


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C hapter 6. M icr o- El ectr omechani cal System ( MEM S) Tutor i al

Tutorials |

Chapter Chapter 6. Micro-Electrom Micro-Ele ctromee chanical chanical Sys Sys tem te m (MEMS) (MEM S) Tutorial Tutorial


Multiphysics Analysis of a Thermal Actuator

Problem Specification Pro bl blem em Desc Description ription Im port Geom Geomet etry ry Defi De fine ne Mater M ateriial Generate Mesh Ap pl ply y Loa Loads ds Obtain Solution Review Results

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6.1. M ul ti physi cs Anal ysis of a Ther mal Actuator

Tutorials | Chapter 6. Micro-Electromechanical System (MEMS) Tutorial |

6.1. 6.1 . M ultiphy ultiphyss ics Analy Analyss is of a The The rmal rmal Actuator Actuator



ANSYS Multiphysics


easy


app roxim roximately ately 30 minut minutes es

Discipline:

structural, thermal, electric

Analysis Type:

static, nonlinear

Elem lement ent Types Used:

Coupled-Field SOLID98


impo importing rting a n IGE IGES mod mod el, SmartSiz SmartSizing, ing, s electing ent ities, applying voltage, temperature, and displacement boundary conditions conditions , plotting plotting vol voltage, temperature, temperature, and displacement displacemen t resu resu lts, animating animating disp lacement lacement results, list list ing heat flow flow and current


Coupled-Field Coupled-Fiel d Analys is and Direct Coupled-Field Analysis in th e Coupled -F -Field ield Analysis Guide, Guide, SOLID98 in th e Elements Elemen ts Reference Referenc e.


This tutorial demonstrates demonstrates how to analyze an electrical-thermal actuator used in a micro-electromechanical system system (MEMS). The thermal actuator is fabricated from polysilicon and is shown below.

The thermal actuator works on the basis of a differential thermal expansion between the thin arm and blade. The required analysis is a coupled-field multiphysics analysis that accounts for the interaction (coupling) between thermal, electric, and structural fields. A potential difference applied across the electrical connection pads induces a current to flow through the arm and www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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blade. blade. Th The curren currentt fl flow and and the the resisti resistivi vity ty of the the polys polysiilicon produce produce Joul Joule heati heatin ng (I2R) in the arm blade. The Joule heating causes the arm and the blade to heat up. Temperatures in the range of 700 -1300 o K are generated. These temperatures produce thermal strain and thermally induced deflections. The resistance in the thin arm is greater than the resistance in the blade. Therefore, the thin arm heats up more than the blade, which causes the actuator to bend towards the blade. The maximum deformation occurs at the actuator tip. The amount of tip deflection (or force applied if the tip is restrained) is a direct function of the applied potential difference. Therefore, the amount of tip deflection (or applied force) can be accurately calibrated as a function of applied voltage. These thermal actuators are used to move micro devices, such as ratchets and gear trains. Arrays of thermal actuators can be connected together at their blade tips to multiply the effective force. The main objective of the analysis is to compute the blade tip deflection for an applied potential difference across the electrical connection pads. Additional objectives are to: Obtain temperature, voltage, and displacement plots Animate Animate displacement results r esults Determine total current and heat flow. 6.1.2.1. Given

You are supplied with a solid model in an IGES file. Dimensions are in micrometers. The thermal actuator has an overall length of approximately 250 micrometers, and a thickness of 2 micrometers. The given potential difference across the electrical connection pads is 5 volts. Mat erial eria l Prope rties rtie s for Polysil ico n

Yo u n g 's mo d u lu s

169 GPa

Po is s o n 's ratio

0.22

Res is t iv it y

2.3e-5 o h m-m

Coefficient of thermal expansion

2.9e-6/ o K

Thermal Thermal con duc tivity

150 W/m W/ mo K


Coupled-field problems can be solved using the direct method or the sequential method. The direct method perform performss the the coupl coupled-fi ed-fiel eld d anal analy ysis sis in in one step usi using ng coupl coupled-fi ed-fiel eld d elem elemen ents. ts. Th The sequen sequenti tial al method ethod perform performss the the coupled-field analysis in multiple steps, where the results from one step are used as input to the next step. www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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Coupled field elements are not required for the sequential method. This tutorial uses the direct method to evaluate the actuator. The direct approach is the most efficient method for this problem. However, if it were necessary to include the effects of temperature-dependent material properties and/or thermal radiation, it would probably be more efficient to use the sequential method. The nonlinear thermal-electric problem could be solved using SOLID98 elements with only the TEMP and VOLT degrees of freedom active, and the mechanical problem could be solved using SOLID92 elements. The temperatures calculated in the thermal analysis could be applied as loading to the mechanical model using the LDREAD command. For this problem, you first import the file actuator.iges into ANSYS. Next, you define the element type as SOLID98 using the default degrees of freedom [KEYOPT(1)]: UX, UY, UZ, TEMP, VOLT, MAG. The element simulates the coupled thermal-electric-structural response. The MAG degree of freedom is not required for this analysis so you will not assign a magnetic material property. To define material properties for this analysis, you must convert the given units for Young's modulus, resistivity, and thermal conductivity to μMKSV units. The units have been converted to μMKSV for you, and are shown in the following table. Mat erial eria l Prope rties rtie s for Polysil ico n (μMKSV (μMKSV units)

Yo u n g 's mo d u lu s

169e3 M Pa

Po is s o n 's ratio

0.22

Res is t iv it y

2.3e-11 o h m-μm

Coefficient of thermal expansion

2.9e-6/ o K

Thermal Thermal con duc tivity

150e6 pW/μmoK

Next, Next, you you mesh the the model model with with the the coupl coupled ed fi field eld elem elemen ents. ts. You You then then apply apply voltag voltages es to the the electri electrical cal conn connection ection pads and and set the theiir temperat temperatur uree to an assum assumed 30 o C. You then mechanically fix the electrical connection pads in the X, Y, and Z directions. Finally, you obtain the solution and post process the results to achieve the analysis objectives, as stated above. 6.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Import Geometry www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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1. Import IGES file. Back To Top Define Materials

2. Define element type. 3. Define material properties. Back To Top Generate Mesh

4. Mesh the model. Back To Top Apply Loads

5. Plot areas. 6. Apply boundary conditions to electrical connection pad 1. 7. Apply boundary conditions to electrical connection pad 2. Back To Top Obtain Solution


9. Plot temperature resul results. ts. 10. Plot voltage results. 11. Plot displacement results and animate. 12. List total heat flow and current. www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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13. Ex Exiit the ANSYS AN SYS program. 6.1.3. Import Geometry 6.1.3.1. Step 1: Import IGES file.

You will begin by importing the model of the actuator. It is provided for you in the form of an IGES file. 1. Utility Menu> File> Import> IGES 2. “No defeaturi defeat uring” ng” 3. [OK] 4. File File name: actuator.iges UNIX version:

/ansys_inc/v110/ansys/data/models/actuator.iges PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\actuator.iges 5. [OK]

Note

If the model does not import, and a “Fatal error” message appears stating that more scratch space is needed, you will need to restart ANSYS, and, on the Interactive tab (UNIX version), or in the Interactive dialog box (PC version), change the memory settings to Total Workspace = 120 MB and Database = 32 MB. 6.1.4. Define Define Materials Materials 6.1.4.1. Step 2: Define element type.

You will now specify the elem element ent type typ e as coupled-field element SOLID98 SOLID98,, and the default degrees of freedom [KEYOPT(1) = 0]: UX, UY, UZ, TEMP, VOLT, MAG. This problem makes use of all but the MAG degree of freedom. Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 1. Main

2. [Add ...] 3. “Coupled Field” (left (left column column)) www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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4. “Scalar Tet 98” (right (right column column)) 5. [OK] 6. [Close] 6.1.4.2. 6.1.4. 2. Step 3: Def De fine ine materia materiall properti propertiee s .

You will now enter the material property prope rty values for polysilicon. These values are for Young's modulus, Poisson's ratio, thermal expansion coefficient, thermal conductivity, and resistivity. The units for these values are μMKSV. 1. Main Menu> Preprocessor> Material Props> Material Models 2. (double-c (do uble-cllick) “Structural,” then then “Li “Linear, near,”” then “El “Elastic,” astic,” then “Isotropic” “Isotro pic” 3. “EX” “EX” = 169e3 169 e3 4. “PRXY” “PRXY” = 0.22 0.2 2 5. [OK] 6. (double-c (do uble-cllick) “Thermal “Thermal Expansion,” Expansion,” then “Secant “Seca nt Coefficient,” Coefficient,” then “Isotropic” “Isotro pic” 7. “ALPX” ALPX” = 2.9e-6 2.9e- 6 8. [OK] 9. (double-c (do uble-cllick) “Thermal “Thermal,” ,” then then “Co “Conductiv nductiviity,” then “Isotropic” “Isotro pic” 10. “KXX” = 150e6 11. [OK] 12. 12 . (double-c (do uble-cllick) “Electromagneti “Electromagnetics, cs,”” then “Resistiv “Resistivity ity,” ,” then then “Co “Constant” nstant” 13. “RSVX” = 2.3e-11 2.3e- 11 14. [OK] 15. Material> Exit 6.1.5. Generate Mesh 6.1.5.1. Step 4: Me sh the model. model.

You will now obtain a course volume mesh using tetrahedral shapes. Setting the SmartSizing control to 10 (maximum) achieves the course mesh. Prepr eproces oces sor> Mes M es hing> hing> MeshTool Me shTool 1. Main Me nu> Pr

2. (check) “SmartSiz “SmartSize” e” www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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3. (sli (slide) “Co “Course” urse” = “10” “10” 4. [Mesh] 5. [Pick All] All]

6. [Close] MeshTool 6.1.6. 6.1 .6. Apply Apply Loads Loads 6.1.6.1. 6.1.6. 1. Step 5: Plot are are as.

You will now plot individual areas in preparation for when you apply the boundary conditions to the electrical connection pads, which you will do in the next two steps. You will first set ANSYS to display each of the areas in a distinguishing color and number. 1. Utility Me M e nu nu> > PlotCtrls> Numberin Numbering g 2. (check) “Area “Area num numbers” to “On” “On” 3. [OK] 4. Utility Menu> Plot> Areas

6.1.6.2. Step 6: Apply boundary conditions to electrical connection pad 1.

You will now apply the voltage, temperature, and displacement boundary conditions to electrical connection pad 1. You will first select this pad area so you only have to perform the picking function once there, even though you are applying three different types of boundary conditions. 1. Utility Menu> Select> Entities 2. (first (first drop down) do wn) “Areas” “Areas” 3. (second drop down) “By “By Num/Pick” Num/Pick” 4. [OK]

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5. Pick electrical electrical connection connection pad 1 (the upper pad). pad ). Ensure Ensure that you have have picked the correct corr ect area are a by holdin holding g the mouse button down and dragging the mouse until ONLY the pad area highlights, then release the button button..

6. [OK] Now apply apply the the vol voltag tagee bounda boundary ry condi conditi tion on to pad 1. 7. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De fine fine Loads> Apply> Apply> Electric> Boundar Boundary> y> Voltage> Voltage > On Areas 8. [Pick All] All] By choosing Pick All, you pick only the area representing pad 1 because that is the only entity you currently have selected. 9. “Loa “Load d VOLT Value” Value” = 5 10. [OK]

Notice Notice the the vol voltag tagee boun boundary condi conditi tion on sy symbols bols added to pad pad 1. Now apply apply the the temperatu temperature re boun boundary condi conditi tion on to pad 1. 11. Main Ma in Me nu nu> > Preproce Preprocess ss or> Loads> De D e fine fine Loads> Apply> Apply> Thermal> Thermal> Tem Te mperature> perature> On Are Are as 12. 12 . [Pick All] All] 13. “DOF “DOF to be constrained” constrained” = TEMP TEMP 14. “Load “Load TEMP valu value” e” = 30 15. [OK]


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Notice Notice the the temperatu temperature re bounda boundary ry condi conditi tion on sym symbols bols added to to pad 1. Now apply apply the the displ displacem acemen entt boun boundary condi conditi tions ons to pad 1. Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De D e fine fine Loads> Apply> Apply> Structu Structural> ral> Displacem Displace me nt> nt> On 16. Main Areas

17. 17 . [Pick All] All] 18. “DOF “DOFss to to be constrained” constrained” = UX 19. 19 . “Displace “Displacemen mentt valu value” e” = 0 20. [Apply] 21. 21 . [Pick All] All] 22. “DOF “DOFss to to be constrained” constrained” = UY 23. [Apply] 24. 24 . [Pick All] All] 25. “DOF “DOFss to to be constrained” constrained” = UZ 26. [OK]

Notice Notice that that ANSYS ANSYS cumu cumulative ativelly added the the displ displacem acemen entt boun boundary condi conditi tion on sym symbols bols to the the pad after after you applied them (i.e., X constraint, then Y constraint, then Z constraint). 6.1.6.3. Step 7: Apply boundary conditions to electrical connection pad 2.

You will now apply the voltage, temperature, and displacement boundary conditions to electrical connection pad 2. The procedure you follow is identical to the one you just performed to add boundary conditions to pad 1. 1. Utility Menu> Select> Entities 2. (first (first drop down) do wn) “Areas” “Areas” www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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3. (second drop down) “By “By Num/Pick” Num/Pick” 4. [OK] 5. Pick electrical electrical connection connection pad 2 (the lower pad). pad ). Ensure Ensure that you have have picked the correct corr ect area are a by holdin holding g the mouse button down and dragging the mouse until ONLY the pad area highlights, then release the button button..

6. [OK] Now apply apply the the vol voltag tagee bounda boundary ry condi conditi tion on to pad 2. 7. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De fine fine Loads> Apply> Apply> Electric> Boundar Boundary> y> Voltage> Voltage > On Areas 8. [Pick All] All] By choosing Pick All, you pick only the area representing pad 2 because that is the only entity you currently have selected. 9. “Loa “Load d VOLT Value” Value” = 0 10. [OK]

Notice Notice the the vol voltag tagee boun boundary condi conditi tion on sy symbols bols added to pad pad 2. Now apply apply the the temperatu temperature re boun boundary condi conditi tion on to pad 2. 11. Main Ma in Me nu nu> > Preproce Preprocess ss or> Loads> De D e fine fine Loads> Apply> Apply> Thermal> Thermal> Tem Te mperature> perature> On Are Are as 12. 12 . [Pick All] All] 13. “DOF “DOF to be constrained” constrained” = TEMP TEMP 14. “Load “Load TEMP Valu Value” e” = 30 15. [OK]


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Notice Notice the the temperatu temperature re bounda boundary ry condi conditi tion on sym symbols bols added to to pad 2. Now apply apply the the displ displacem acemen entt boun boundary condi conditi tions ons to pad 2. 16. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De D e fine fine Loads> Apply> Apply> Structu Structural> ral> Displacem Displace me nt> nt> On Areas 17. 17 . [Pick All] All] 18. “DOF “DOFss to to be constrained” constrained” = UX 19. 19 . “Displace “Displacemen mentt valu value” e” = 0 20. [Apply] 21. 21 . [Pick All] All] 22. “DOF “DOFss to to be constrained” constrained” = UY 23. [Apply] 24. 24 . [Pick All] All] 25. “DOF “DOFss to to be constrained” constrained” = UZ 26. [OK]

Notice Notice that that ANSYS ANSYS cumu cumulative ativelly added the the displ displacem acemen entt boun boundary condi conditi tion on sym symbols bols to the the pad after after you applied them (i.e., X constraint, then Y constraint, then Z constraint). Before solving the problem, you must select the entire finite element model. Utility Me M e nu nu> > Se lect> Everythin Everything g 27. Utility 6.1.7. Obtain Solution 6.1.7.1. Step 8: Solve.

You will now initiate the ANSYS solution. 1. Main Menu> Solution> Solve> Current LS 2. Review Review the inf information ormation in in the the status stat us window, window, then choose: choo se: File> Close (Windows platforms),

or Close (UNIX platforms), after reviewing the information in the status window. www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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3. [OK] 4. [Yes] to warning warning message. This message is not relevant to this problem since you are not using the MAG DOF. 5. [Close] [Close] the informati information on window window when the solution solution is is done. do ne. 6.1.8. Re view Results Results 6.1.8.1. 6.1.8. 1. Step 9: Plot tempe tempe ratur raturee resul res ults. ts.

You will now plot the temperature results. This is one of the objectives of this analysis. 1. Main Menu> General Postproc> Read Results> Last Set 2. Main Ma in Menu Me nu> > General Ge neral Postproc> Postproc> PlotRes PlotRe s ults> ults> Contour Contour Plot> Nodal Solu 3. “DOF solution” solution” 4. “Temperature” 5. [OK]

Refer to the legend beneath your plot for a numerical interpretation of the colors in the plot. Note that the electrical connection pads are the same color, reflecting the constant temperature boundary condition. Note also that there is a change in color in the blade, as viewed from the pads end to the blade tip end, indicating that the voltage difference across the pads causes a temperature difference across the blade. Note that the thin arm is at higher temperatures than the blade. 6.1.8.2. Step 10: Plot voltage results.

You will now plot the voltage results. This is one of the objectives of this analysis. 1. Main Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Plot Re sults> Contour Contour Plot> Plot> Nodal N odal Solu 2. “DOF solution” solution” 3. “Electric “Electric potential po tential”” 4. [OK]

Refer to the legend beneath your plot for a numerical interpretation of the colors in the plot. Note that the electrical connection pads are distinctly two different colors, reflecting the voltage difference across the pads. Note also also that that the there re is is a chan change ge in color color in in the the blade, blade, as vi viewed from from the the pads end end to the the blade blade tip tip end, end, indi indicati catin ng that the voltage drop from pad 1 to pad 2 is distributed along the electrical conduction path of the actuator. 6.1.8.3. Step 11: Plot displacement results and animate. www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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You will now plot and animate the displacement results. These are two of the objectives of this analysis. Ma in Menu Me nu> > General Ge neral Postproc> Postproc> PlotRes PlotRe s ults> ults> Contour Contour Plot> Nodal Solu 1. Main

2. “DOF solution” solution” 3. “Y“Y- Com Co mponent of displacement” displacement” 4. [OK]

Refer to the legend beneath your plot for a numerical interpretation of the colors in the plot. Note that the electrical connection pads are the same color, reflecting that the pads are constrained in all directions. Note especial especiallly the the gradu gradual al chan change ge in color color in in the the blade blade and and thi thin arm, arm, as vi viewed from from the the pads end end to the the blade blade tip tip end. end. Thi Thiss displ display ay,, along along with with the the ani animation ation you wil will produce produce nex next, t, clearl clearly y show show the the bendi bending ng of the the thermal actuator. Note also also from from the the leg legen end d that that th the color color of the the tip tip of the the blade blade indi indicates cates a defl deflection ection of approxi approximately ately 3.07 micrometers. This deflection results from the 5 volts applied across the pads. You have just achieved the main objective of this analysis. You will now produce the corresponding animation. 5. Utility Menu> PlotCtrls> Animate> Deformed Results 6. (left (left column column)) “DO “DOF F solution” solution” 7. (right colu co lumn mn)) “Translation UY” 8. [OK]

9. [Close] [Close] after making making desired desired choices in in the Anim Animation ation Controller. 6.1.8.4. Step 12: List total heat flow and current.

You will now obtain a listing of results including the total heat flow and current. These are two of the objectives for this analysis. 1. Utility Menu> Plot> Areas 2. Utility Menu> Select> Entities 3. (first (first drop down) do wn) “Areas” “Areas” 4. (second drop down) “By “By Num/Pick” Num/Pick” 5. [OK] 6. Pick the electrical electrical connection connection pad on o n the the thin thin side side of o f the the actuator ac tuator (lower pad as shown below). www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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7. [OK] 8. Utility Menu> Select> Entities 9. (first (first drop down) “Nodes” “Node s” 10. (second drop down) “Attached Attached to” 11. 11 . “Areas, all” all” 12. [OK] 13. Utility Menu> List> Results> Reaction Solution 14. “1s t 10 items” 15. [OK] Scroll to the bottom of the list and note that the total heat flow is approximately 8.07e9 pW and the total current is is approxim ap proximately ately 3.23e9 3.23e 9 pA. p A. 16. 16 . When you you are done do ne viewing viewing the listi listing ng,, choose: choo se: File> Close (Windows platforms),

or Close (UNIX platforms)

17. Utility Utility Me M e nu nu> > Se lect> Everythin Everything g 6.1.8.5. Step 13: Exit the ANSYS program.

1. Toolbar: Quit 2. “Quit “Quit - No Save!” 3. [OK] Congratula Congratulations! tions! You have complete d this tutorial tutorial..

Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for: Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. www.kxcad.net/ansys/ANSYS/ansyshel p/mems_ta.html

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Sending animations over the web.


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Chapter 7. Expl ici t Dynamics Tutor ial

Tutorials |

Chapter 7. Explicit Dynamics Tutorial


Drop Test of a Container

Pro bl blem em Spec Specification ification Problem Description Define Analysis Type Inp In put Geometry Define De fine Element Type, Type, Real Constants, Material Model Properties Generate Mesh Apply Loads Obtain Solution Review Results

www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_tut.html

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7.1. Dr op Test of a Contai ner ( Expli cit Dynami cs)

Tutorials | Cha Chapter pter 7. Ex plicit Dynamics Tutorial Tutorial |

7.1. 7.1 . Drop Te s t of a Container Container (Explicit Dynam Dynamics ics))



ANSYS LS-DYNA, ANSYS ED


moderate



Discipline:

structural

Analysis Type:

transient dyn amics amics (expli (explicit cit method)


SHELL163


direct direct gen eration eration o f nodes and elements elements , array array parameters, parameters, automatic meshing, animation


The ANS The ANSYS YS LS-DYNA User's User's Guid e, SHELL163 in the Elemen ts Reference Elements Referenc e.

7.1.2. 7.1.2. Problem Description Description

This is a dynamic analysis of dropping an aluminum container on a steel table top. As shown below, the container is a five-sided five-sided square square box, 20 inches on all sides and 0.1 inches thick. It has been rotated 45 o about each of the X, Y, Y, and Z axes. The table top is a square steel plate 100 inches on each side and 0.1 inches thick. The only force acting on the box is its own weight. It is dropped from a distance of 72 inches. The problem is typical of a drop test. The objective objective of the problem is to demonstrate the explicit dynamics capabilities of ANSYS LSDYN DYNA -- ideal for large deformation d eformation and complex contact dynamic problems.

7.1.2.1. Given

The dimensions of the container and table top are shown above. The container is made of aluminum alloy with Young's modulus of 10.3E6 psi, density of 2.5E-4 lb f -sec2/in /in4, Poisson's ratio of 0.334, Yield Stress of 5,000 www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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psi, psi, and and a tang tangent ent modu modullus of 20,000 psi. psi. Th The table table top is is made made of carbon steel steel with with Youn Young's modulu odulus of 30.0E6 psi, psi, densi density ty of 7.3E-4 lb lbf -sec2/in /in4, and Poisson's ratio of 0.292. 7.1.2. 7.1 .2.2. 2. Approach Approach and and Ass As s umption umptionss

During the free fall stage, the container is simply accelerating due to gravity. To save CPU time, start the analysis at 20 inches above the table top and apply an initial velocity of 200 inches per second to simulate the first 52 inches of free fall. 200 inches per second is an approximation derived using Vf = SQRT (2*a*s) where Vf is the final velocity, a is the acceleration due to gravity, and s is the displacement. Friction from the air is neglected. Assume a rigid behavior for the table top and bilinear kinematic hardening von Mises plasticity for the container. Solid modeling is used to generate the 3-D model of the container, which then will be meshed. Direct generation of nodes and elements will be used to model the table top. The table top will be modeled as a rigid element and only one element will be used to represent it. 7.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Define Analysis Type

1. Set preferences. Back To Top Input Input Geometry Geome try

2. Read in geometry of the container. Back To Top Define Element Type, Real Constants, Material Model Properties

3. Define element type. 4. Define real constants. 5. Specify material models. Back To Top Generate Mesh www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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6. Mesh the container. 7. Generate tabl tab le top to p elem elements. ents. 8. Create container component. 9. Create table top component. 10. Specify contact parameters. Back To Top Apply Loads

11. Apply initial velocity to the container. 12. Apply acceleration to the container. Back To Top Obtain Solution

13. Spe Specif cify y Output O utput Controls. 14. Solve. Back To Top Revie w Results Results

15. Animate stress contours. 16. Animate deformed shape. 17. Ex Exiit the ANSYS AN SYS program. 7.1.3. Define Analysis Type 7.1.3.1. Step 1: Set Preferences.

You will first set pref set preferen erences ces in order to filter quantities that pertain to this discipline only. 1. Main Menu> Preferences 2. (check) (check ) “Indivi “Individual dual discipli discipline(s) ne(s) to show in the GUI” = Structural St ructural 3. (check) (check ) “Disci “Discipli pline ne options” = LS-DYN LS- DYNA A Expli Explicit cit www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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4. [OK] 7.1.4. Input Geometry 7.1.4.1. Step 2: Read in geometry of the container.

You will begin by reading in a file that includes the model of the container. 1. Utility Menu> File> Read Input from ... 2. File File name: container.inp UNIX version:

/ansys_inc/v110/ansys/data/models/container.inp PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\container.inp 3. [OK]

7.1.5. Define Define Element Type, Type, Real Constants, Constants, Material Material Model Mo del Prope Prope rties rties 7.1.5.1. Step 3: Define element type.

Since the model is a container made of thin walls hitting the surface of a table, shell elements will be used to simulate the physical model. More precisely, SHELL163 SHELL163,, an explicit thin structural shell, is the element of choice. This 4-node element can take both in-plane and normal loads. Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 1. Main

2. [Add...] 3. “LS-DYN “LS- DYNA A Explicit” Explicit” (left colu co lumn) mn) 4. “Thin “Thin Shell She ll 163” 16 3” (right (right column) column) 5. [OK] Now, specif specify the the S/R corotati corotational onal Hugh Hughes-Li es-Liu u elem elemen entt form formu ulation ation to eli eliminate certai certain n hourg ourgllass modes. modes. 6. [Options...] 7. (drop (dr op down) do wn) “Elem “Element ent Formu Fo rmulati lation” on” = S/R corota cor otation tion www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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8. [OK] 9. [Close] 7.1.5.2. 7.1.5. 2. Step 4: De fine ine re al constant constants. s.

Next, Next, defi define the the thi thickness ckness of the the shel shelll elem elemen ents ts by defi defining the the appropriate appropriate real real constan constant. t. 1. Main Menu> Preprocessor> Real Constants 2. [Add...] 3. [OK] [OK ] to choose element element Type Type 1 for for SHELL163 SHELL163.. 4. [OK] [OK ] to define define real constant set No. 1. 5. “SHRF” = 1 6. “NIP” “NIP ” = 2 (For (Fo r demonstration demonstra tion purposes purpo ses in this this tutorial, the the defaul de faultt value value of 2 is is suffi sufficient. cient. However, for most nonlinear analyses, the NIP should be set higher than 2.) 7. “T1” “T1” = 0.1 8. “T2” “T2” = 0.1 9. “T3” “T3” = 0.1 10. “T4” “T4” = 0.1 11. “NLOC” “NLOC ” = Mid surface surface 12. [OK] 13. [Close] 7.1.5.3. Step 5: Specify material models.

Now specif specify material aterial models odels for for the the contact contact and and target target surf surfaces. aces. 1. Main Menu> Preprocessor> Material Props> Material Models 2. (double-c (do uble-cllick) “LS“LS- DYNA”, DYN A”, then then “Ri “Rigi gid d Material” Mat erial” to specify sp ecify the table top, top , which which is is “Material Model Mod el Number Number 1”. 1”. 3. “DENS DENS”” = 7.3e-4 7.3e- 4 4. “EX” “EX” = 30e6 5. “NUXY” = 0.292 0.2 92

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6. (drop (dr op down) do wn) “Translational “Translational Constraint Co nstraint Parameter Pa rameter”” = All All disps. 7. (drop (dr op down) do wn) “Rotational Constraint Co nstraint Parameter” Pa rameter” = All All rotations rota tions 8. [OK] Mate rial> New Model to specify the material for the container, which is “Material Model Number 2”. 9. Mater

10. 10 . “Defi “Define Material ID” = 2 11. [OK] 12. 12 . (double-c (do uble-cllick) “Nonl “No nlin inear ear”, ”, then “Inelastic”, “Inelastic”, then “K “K inematic inematic Hardeni Harde ning” ng”,, then “Bil “Bilinear inear K inematic” inematic” 13. “DENS DENS”” = 2.5e-4 2.5e- 4 14. “EX” “EX” = 10.3e6 10. 3e6 15. “NUXY” = 0.334 16. “Yi “Yield Stress” Stress ” = 5000 17. 17 . “Tangent “Tangent Modul Mod ulus” us” = 2000 20 000 0 18. [OK] 19. Material> Exit 20. Toolbar: SAVE_DB 7.1.6. Generate Mesh 7.1.6.1. Step 6: Mesh the container.

In an explicit solver, such as ANSYS LS-DYNA, the analysis time is highly dependent on the smallest element in the model. Therefore, for efficient results, a uniform element size should be used. For this example, use the default element size. This should give a 3x3 mesh on each face of the container. 1. Main Me nu> Pr Prepr eproces oces sor> Mes M es hing> hing> MeshTool Me shTool 2. (drop (dr op down) do wn) “Elem “Element ent Attributes” Attributes” = Global; then [Set] [S et] 3. (drop (dr op down) “Mate “Material rial number” number” = 2 4. [OK] 5. (drop down) “Mesh” “Mesh” = Areas Areas 6. (check) “Mapped” www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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7. [Mesh] 8. [Pick All] All]

9. Toolbar: SAVE_DB 7.1.6.2. Step 7: Generate table top elements.

Now mesh mesh the the table table top by direct element generation. generation. The table top will be defined as a rigid surface and therefore only one element is needed to model this surface. Create this model by defining its four corner nodes and then building the elements from those nodes. 1. Utility Menu> PlotCtrls> Pan, Zoom, Rotate 2. [Obliq] 3. [Close] 4. Utility Me M e nu nu> > PlotCtrls> Numberin Numbering g 5. (check) “No “Node de num numbers” bers” = On 6. [OK]

7. (drop (dr op down d own in in MeshTool) MeshToo l) “Elem “Element ent Attributes” Attributes” = Glob Global; al; then [Set] [S et] 8. (drop (dr op down) “Mate “Material rial number” number” = 1 9. [OK] 10. [Close] MeshTool 11. Main Menu> Preprocessor> Modeling> Create> Nodes> In Active CS 12. 12 . “Node “Nod e number number”” = Leave blank so it defaul de faults ts to the next avail available able node numbe number. r. 13. “X Y Z Location in active active CS” = -50, -50 , -20, -2 0, -50 - 50 www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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14. 14 . [Apply [App ly]] to genera generate te the node in the far far left left corner. co rner. 15. “X Y Z Location in active active CS” CS ” = -50, - 50, -20, - 20, 50 50 16. 16 . [Apply [App ly]] to genera generate te the node in the near near left left corner. 17. “X Y Z Location in active active CS” CS ” = 50, - 20, 50 50 18. 18 . [Apply [App ly]] to genera generate te the node in the near near right right corner. 19. “X Y Z Location in active active CS” CS ” = 50, - 20, -50 - 50 20. [OK] [OK ] to generate generate the node in in the the far far right right corner. Now create create the the elem elemen ent. t. 21. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Modelin Mo deling> g> Create> Create > Elem Ele me nts> nts> Auto Auto Num N umbered> bered> Thru Thru Nodes 22. In a counterclockwise counterclockwise direction, direction, pick pick the four four node nodess just just created. created .

23. [OK] 24. Utility Menu> Plot> Elements

7.1.6.3. 7.1.6. 3. Step 8: Cre Cre ate ate contain containee r component. component.

Most of the contact algorithms require contact parameters, which can be components, part IDs, or part assembly IDs. For this tutorial, create a component made of nodes from the container. 1. Utility Menu> Select> Entities 2. (first (first drop down) “El “Elements” ements” 3. (second drop down) “By “By Attributes” Attributes” 4. (check) (check ) “Material num” num” 5. “Min,Max,I “Min,Max,Inc.” nc.” = 2 www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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6. [Apply] 7. (first (first drop down) “Nodes” “Node s” 8. (second drop down) “Attached “Attached to” 9. (check) (check ) “Elem “Elements” ents” 10. [OK] Utility Me M e nu nu> > Se S e lect> Comp/ Comp/Ass Assee mbly> bly> Cre Cre ate Compon Componee nt 11. Utility

12. “Component “Component name” name” = BOX 13. (drop down) do wn) “Component “Component is is made made of” = Nodes Nod es 14. [OK] 15. Utility Utility Me nu nu> > Plot> Nodes Node s

16. Utility Utility Me M e nu nu> > Se lect> Everythin Everything g 7.1.6.4. 7.1.6. 4. Step 9: Cre Cre ate ate tabl tablee top component. component.

Now, create create a compone componen nt made made of nodes nodes from from the the table table top. 1. Utility Menu> Select> Entities 2. (first (first drop down) “El “Elements” ements” 3. (second drop down) “By “By Attributes” Attributes” 4. (check) (check ) “Material num” num” 5. “Min,Max,I “Min,Max,Inc” nc” = 1 6. [Apply] 7. (first (first drop down) “Nodes” “Node s” 8. (second drop down) “Attached “Attached to” 9. (check) (check ) “Elem “Elements” ents” www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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10. [OK] Utility Me M e nu nu> > Se S e lect> Comp/ Comp/Ass Assee mbly> bly> Cre Cre ate Compon Componee nt 11. Utility

12. 12 . “Component name” name” = TABLE TABLE 13. (drop down) do wn) “Component “Component is is made made of” = Nodes Nod es 14. [OK] Utility Me nu nu> > Plot> Nodes Node s 15. Utility

Utility Me M e nu nu> > Se lect> Everythin Everything g 16. Utility

17. Toolbar: SAVE_DB 7.1.6.5. Step 10: Specify contact parameters.

In an analysis in which the contact behavior is known, the appropriate contact algorithm can be chosen for the best resu resullts. Howev However, er, due due to the the nature ature of thi this problem problem,, contact contact condi conditi tions ons wil will be un unpredictabl predictable. e. Th Thus, us, by choosing automatic surface to surface contact, the program will automatically adjust for the changes which occur during this simulation. Ma in Menu Me nu> > Pre Pre proce process ss or> LS-DYNA LS-DYNA Options> Options> Contact> De fine fine Contact Contact 1. Main

2. “Contact “Contac t Type” = “Surface to Surf S urf”” (left (left column); column); “Automatic “Automatic (ASTS)” (ASTS )” (right (right column) column) 3. [OK] 4. (drop down) do wn) “Contact Component Component or Part no.” = BOX 5. (drop down) d own) “Target “Target Com Co mponent or Part no.” no.” = TABL TABLE E 6. [OK] 7. Toolbar: SAVE_DB 7.1.7. 7.1 .7. Apply Apply Loads Loads 7.1.7.1. Step 11: Apply initial velocity to the container.

1. Main Ma in Menu Me nu> > Solution> Solution> Initial Initial Velocity> Ve locity> On Nodes> Nodes > w/Nodal w/Nodal Rotate 2. (drop (dr op down) do wn) “Input velocity velocity on component” compo nent” = BOX www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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3. “Glob “Global al (Translational) (Translational) Y-co Y- component” mponent” = - 200 20 0 4. [OK] In a transient dynamic analysis, loads must be defined for the duration of the analysis. To do so, create an array containing this data. 5. Utility Menu> Parameters> Array Parameters> Define/Edit 6. [Add...] 7. “Parameter name” name” = TIME 8. [OK] 9. [Edit...] 10. “1” = 0 11. “2” = 1 12. File> Apply/Quit 13. [Add...] 14. “Parameter name” name” = ACC ACCG G 15. [OK] 16. 16 . (highl (highlig ight) ht) “ACCG” “ACC G” 17. [Edit...] 18. “1” = 386.4 19. “2” = 386.4 20. File> Apply/Quit 21. [Close] 7.1.7.2. Step 12: Apply acceleration to the container.

1. Main Menu> Solution> Loading Options> Specify Loads 2. “Load “Load Labels” = ACLY 3. (drop down) “Component “Component name name or PART P ART num number:” = BOX 4. (drop (dr op down) do wn) “Pa “Parameter rameter name for time time values:” values:” = TIME www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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5. (drop down) d own) “Para “Param meter name name for for data values: values:”” = ACCG ACC G 6. [OK]

7.1.8. Obtain Solution 7.1.8.1. Step 13: Specify output controls.

1. Main Menu> Solution> Time Controls> Solution Time 2. “Terminate “Terminate at Time:” Time:” = 1.0 3. [OK] 4. Main Menu> Solution> Output Controls> File Output Freq> Number of Steps 5. “Specif “Spe cify y Results File File Output Outp ut Interval” = 50 6. “Specif “Spe cify y Time Time Histo History ry Output Interval” Interval” = 50 7. [OK] 8. Main Menu> Solution> Analysis Options> Energy Options 9. [OK [O K ] to turn on all all energy options op tions 10. Toolbar: SAVE_DB 7.1.8.2. Step 14: Solve.

1. Main Ma in Menu Me nu> > Solution> Solution> Solve 2. Review Review the inf information ormation in in the the status stat us window, window, then choose: choo se: File> Close (Windows) or Close (X11/Moti (X11/Mo tif), f), to close the window. window.


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3. [OK [O K ] to ini initiate tiate solution. solution. Note: A veri veriffication cation wi window wil will appear to to noti notiffy you of a warn warning message. essage. Th This warn warniing was generate enerated d due to constraining the table top by defining it as a rigid element rather than using degrees of freedom constraints. Therefore the warning can be ignored. 4. [Yes] 5. [Close] 7.1.9. Re view Results Results 7.1.9.1. Step 15: Animate stress contours.

1. Utility Menu> Plot> Elements 2. Utility Menu> PlotCtrls> Pan, Zoom, Rotate 3. [Front] 4. [Close] M e nu nu> > PlotCtrls> Numberin Numbering g 5. Utility Me

6. (check) “No “Node de num numbers” = Off 7. [OK]

8. Main Menu> General Postproc> Read Results> First set [ Note Not e for UNIX systems system s only: only: To capture the animation sequence in terminal segment memory, it is necessary to reduce the size of the Graphics Window or you will run out of terminal memory. Although this depends on your particular system, and the size of the animation file to be created, for this exercise it www.kxcad.net/ansys/ANSYS/ansyshel p/expdyn_dt.html

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is suggested that the ratio of the original window size to the reduced window size should be about 3:1.] 9. Utility Menu> PlotCtrls> Animate> Over Results 10. (check) “Auto “Auto contour scaling scaling”” = On (Make sure that the the box is is checked.) checked .) 11. 11 . “Contour data d ata for animation” animation” = Stres S tresss (left (left column); column); von Mises SEQV SEQ V (right (right column column)) 12. [OK]

13. 13 . Make Mak e choices in in the Animati Animation on Control Contro ller (not (not shown), if necessary, necess ary, then [Cl [C lose]. ose ]. 7.1.9.2. Step 16: Animate deformed shape.

1. Utility Menu> PlotCtrls> Animate> Over Results 2. (check) (check ) “Auto “Auto contour scali sca ling” ng” = On 3. “Contour data d ata for animation” animation” = DOF DO F Soluti S olution on (left (left column); column); Deformed Shape Shap e (right (right column) column) 4. [OK]

5. Make Mak e choices in in the Animati Animation on Control Contro ller (not (not shown), if necessary, necess ary, then [Cl [C lose]. ose ]. 7.1.9.3. Step 17: Exit the ANSYS program.

1. Toolbar: Quit 2. (check) “Quit Quit - No Save!” 3. [OK] Congratulations! You have completed this tutorial. Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for:


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Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. Sending animations over the web.


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C hapter 8. Contact Tutor i al

Tutorials |

Chapter 8. Contact Tutorial


Interference Fit and Pin Pull-Out Contact Analysis

Problem Specification Problem Description Inp In put Geometry Defi De fine ne Mater M ateriial Property and Element Type Generate Mesh Specify Solution Criteria Load Step 1 Load Step 2 Postprocessing

www.kxcad.net/ansys/ANSYS/ansyshel p/ffcontact_tut.html

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8.1. Inter fer ence Fi t and Pi n Pull - Out C ontact Anal ysis

Tutorials | Chapter 8. Contact Tutorial |

8.1. 8.1 . Interfe Interfe rence Fit and and Pin Pull-Out Pull-Out Contact Contact Analys Analys is





moderate


45 to 60 minutes minutes (includes (includes 15 to 20 minutes minutes for solution)

Discipline:

structural

Analysis Type:

nonlinear quasi-static


SOLID185, TARGE170 TARGE170,, CONTA174


symmetry boundary conditions, flexible-to-flexible surface contact, contact, contact contact wizard, automatic automatic time stepping, multiple load steps, symmetry symmetry expans expans ion, animation, animation, time time h istory pos po s tproces tp roces sing , Solution Con trols d ialog bo x


The Contact Technology Guide, Guide, SOLID185 SOLID185,, TARGE170 TARGE170,, and CONTA174 in the Elemen the Elements ts Reference Referenc e.


This is a 3-D analysis of a of a steel pin contacting a smooth pinhole in a block. Because of the inherent symmetry of the model, model, you will will perform the analysis on a quarter symmetry model. You will define two different load steps. The objective of the first load step is to observe the interference fit stresses of the pin which is geometrically thicker than its pinhole. The objective of the second load step is to observe the stresses, contact pressures and reaction forces due to the motion of the pin being pulled out from the block. 8.1.2.1. Given

The dimensions of the model are as follows: PIN radius = 0.5 units, length = 2.5 units. BLOCK width = 4 units, length = 4 units, depth = 1 unit. PINHOLE radius = 0.49 units, depth = 1 unit. Both solids are made of structural steel (stiffness = 36e6, Poisson's ratio = 0.3) and are assumed to be flexible. 8.1.2. 8.1 .2.2. 2. Approach Approach and and Ass As s umption umptionss

A quarter symmetry model is appropriate to simulate the contact phenomena. You will use two load steps to set up the analysis: Load Step 1: Interference Fit -- solve the problem with no additional displacement constraints. www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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The pin is constrained within the pinhole due to its geometry. Stresses are generated due to the general misfit between between the the targe targett (pin (pinhole) ole) and and the the contact contact (pin (pin) surf surfaces. aces. Load Load Step 2: Pull Pull-out -- move move the the pin pin by 1.7 un units out of the block using DOF displacement conditions on coupled nodes. Explicitly invoke Automatic Time Stepping to guarantee solution convergence. Read results for every 10th substep during solution. 8.1.2.3. Summary of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Note

To run this tutorial, you will need a total workspace memory of at least 64MB, preferably higher (100-200 MB). Before starting the tutorial, check your workspace memory as follows: 1. Utility Menu> List> Status> Configuration 2. Scrol Scro ll down to the MEMORY STATISTICS heading heading and and read rea d the num number of o f MB for for Requested Initial Work Space. 3. If this this number number is accepta acce ptable, ble, procee pro ceed d with the tutorial. tutorial. If the the number number is is too low, quit ANSYS ANS YS without without saving saving chang changes, es, restart ANSYS ANS YS and, in the the ANSYS AN SYS Interactive Interactive dialog dialog box, enter enter th the appropriate appropriate num number ber in in the the Memory Memory requeste requested d for for Total Total Workspace field eld before before choosi choosin ng Run. Run. Input Input Geometry Geome try

1. Read in the model of the pin and the block. Back To Top Define Material Property and Element Type

2. Define material. 3. Define element type for solid volume. Back To Top Generate Mesh

4. Mesh solid volume. 5. Smooth element edges for graphics display. 6. Create contact pair using Contact Wizard. www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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Back To Top Specify Solution Criteria

7. Apply symmetry constraints on (quartered) volume. 8. Define boundary constraints on block. 9. Specify a large displacement static analysis. Back To Top Load Step 1

10. Define interference fit analysis options. 11. Solve load step 1. Back To Top Load Step 2

12. Set DOF displ displacement acement for for pin pin.. 13. Define pull-out analysis options. 14. Write results to file. 15. Solve load step 2. Back To Top Postprocessing

16. Expand model from quarter symmetry to full volume. 17. Ob Observe serve interference interference fit fit stress state. 18. Observe intermediate contact pressure on pin. 19. Observe pulled-out stress state. 20. Animate pin pull-out. 21. Plot reaction forces for pin pull-out. www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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22. Ex Exiit the ANSYS AN SYS program. 8.1.3. Input Geometry 8.1.3.1. Step 1: Read in the model of the pin and block.

You will begin by reading in a file that includes a quarter symmetry representation of the pin and block. 1. Utility Menu> File> Read Input from ... 2. File File name: block.inp UNIX version:

/ansys_inc/v110/ansys/data/models/block.inp PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\block.inp 3. OK

8.1.4. Define Material Property and Element Type 8.1.4.1. Step 2: Define material.

You will now define the material property prope rty.. 1. Main Menu> Preprocessor> Material Props> Material Models 2. Double-click Structural, then Linear, Elastic, and Isotropic. 3. EX = 36e6 4. PRXY = 0.3 . 5. Click OK . 6. Select Material> Exit from the menu bar. 8.1.4.2. Step 3: Define element types.

You will now define the elem element ent type t ype.. Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 1. Main www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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2. Click Add Add. Struct uctur ural al Mas M asss - Solid. 3. Select Str

4. Select Brick 8node 185 (right column). 5. Click OK . 6. Click Close. 8.1.5. Generate Mesh 8.1.5.1. Step 4: Mesh solid volume.

Prepr eproces oces sor> Mes M es hing> hing> MeshTool Me shTool 1. Main Me nu> Pr

2. Select Lines - Set. 3. Pick the horizontal horizontal and vertical lines lines on the front front edge ed ge of the the pin.

4. Click OK . 5. Enter 3 for No. of element divisions . 6. Uncheck SIZE,NDIV can be changed to indicate No. 7. Click OK . 8. Select Lines - Set. 9. Pick the curved li line on the front front of the the block.

10. Click OK . 11. Enter 4 for No. of element divisions . 12. Click OK . 13. Select Volumes from the Mesh drop-down menu. www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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14. Select Hex. 15. Select Sweep. 16. Click Click the Sweep button. 17. 17 . Pick the pin and block volum volumes. es.

18. Click OK and and Close any warning messages that appear.

19. Close the MeshTool. 8.1.5.2. 8.1.5. 2. Step Ste p 5: Smooth Smooth e lement e dges for graph graphics ics dis dis play play..

1. Utility Menu> PlotCtrls> Style> Size and Shape 2. From the Face Face ts/elem ts/ele ment ed e dge drop-down menu, select 2 facets/edge . 3. Click OK .

8.1.5. 8.1 .5.3. 3. Step 6: 6 : Create contact pair pair us us ing Contact Wiz Wizar ard. d.

1. Main Menu> Preprocessor> Modeling> Create> Contact Pair 2. Select the Contact Wizard button (located in the upper left corner of the Contact Manager). 3. Select Areas from the Target Surface field. 4. Select Flexible from the Target Type field. 5. Click Pick Targe Targett.

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6. Pick surface surface of o f pin hole hole on block as the target.

7. Click OK . 8. Click Next. 9. Select Areas from Contact Sur S urface face field. 10. Click Pick Contact. 11. Pick surface surface area of pin as the contact.

12. Click OK . 13. Click Next. 14. Select Include Initial penetration. 15. Select 1 from Material ID drop-down menu. 16. Enter 0.2 for the Coefficient of friction. 17. Click Optional settings . 18. Enter 0.1 for Normal Normal penalty stiffn s tiffnee ss . 19. Select the Friction tab. 20. Select Unsymmetric from the Stiffne Stiffne ss matrix atrix drop-down menu. 21. Click OK . 22. Click Create . 23. Click Finish and close the Contact Manager.

24. Utility Menu> Plot> Areas


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25. Toolbar>SAVE_DB. 8.1.6. 8.1 .6. Sp Spee cify cify Solution Solution Criteria 8.1.6.1. Step 7: Apply symmetry constraints on (quartered) volume.

1. Main Menu> Solution> Define Loads> Apply> Structural> Displacement> Symmetry B. C.> On Areas 2. Pick the four four interior interior areas area s that that were exposed expo sed when origi original nal model was quartered quarte red..

3. Click OK .

8.1.6.2. Step 8: Define boundary constraints on block.

1. Main Menu> Solution> Define Loads> Apply> Structural> Displacement> On Areas 2. Pick left left side of block. block .

3. Click OK . 4. Select All DOF for DOFs to be constrained. Dis place acem me nt value value . 5. Enter 0 for the Displ

6. Click OK to apply the constraints. www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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8.1.6.3. Step 9: Specify a large displacement static analysis.

In this step, you will specify the analysis option as a static analysis in which large deformation effects are to be included. To do this, you will use the Solution Controls dialog box, a central control panel where you can adjust the most commonly used settings for a structural static or full transient analysis. It consists of five tabbed "pages," each of which contains a set of related solution controls. You will use the Solution Controls dialog box again in this tutorial, to specify options for each of the load steps. 1. Main Menu> Solution> Analysis Type> Sol'n Controls 2. Select Large Displacement Static from the Analysis Options pull-down menu. Continue with the next step. 8.1.7. Load Load Ste Ste p 1 8.1.7.1. Step 10: Define interference fit analysis options.

Note that that for for both load steps, steps, ramped ramped loadi loadin ng wil will autom automati atical callly be appli applied in instead of stepped loadi loadin ng. Thi This is is the the default condition for a static analysis when the SOLCONTROL command is ON (which it is, also by default). 1. Enter 100 as the Time at end of load step. Off f from the Automatic Automatic time s tepp te pping ing drop-down menu. 2. Select Of

3. Enter 1 as the Number of substeps . 4. Click OK to apply the settings. 5. Toolbar>SAVE_DB. 8.1.7.2. Step 11: Solve load step 1.

1. Main Menu> Solution> Solve> Current LS 2. Review Review the inf information ormation in in the the status stat us window, window, then File> Close to close the window.


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3. Click OK to begin the solution. Choose Yes if a Verify window appears, and ignore any warning messages, but do not close the warning message window yet. 4. Close the note window when solution is done. 5. Utility Utility Me M e nu nu> > Plot> Re plot plot. Continue with the next step.

8.1.8. Load Load Ste Ste p 2 8.1.8.1. Step 12: Set DOF displacement for pin.

You will now apply a displacement value of 1.7 to all nodes on the front of the pin in order to observe the effects of pulling the pin out of the block. 1. Utility Menu> Select> Entities 2. First drop down do wn menu = Nodes . 3. Second Seco nd dropdrop - down menu = By Location. 4. Select Z coordinates . 5. Enter 4.5 for Min, Max. 6. Click OK . 7. Main Menu> Solution> Define Loads> Apply> Structural> Displacement> On Nodes 8. Click Pick all. 9. Select UZ for the DOFs to be constrained. 10. Enter Enter a Displ Dis place acem me nt value value of 1.7 . www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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11. Click OK . 8.1.8.2. Step 13: Define pull-out analysis options.

1. Main Menu> Solution> Analysis Type> Sol'n Controls 2. Enter 200 as the Time at end of load step. 3. Select On from the Automatic Automatic time s tepp te pping ing drop-down list. 4. Enter 100 for the Number of substeps . 5. Enter 10000 for the Max no. of substeps . 6. Enter 10 for the Min no. of substeps . Continue with the next step. 8.1.8.3. 8.1.8. 3. Step 14: Write Write res ults ults to file. file.

1. Select Write every Nth substep from the Frequency drop-down list. 2. Enter -10 in the where N equals (=) field. 3. Click OK . 4. Utility Utility Me M e nu nu> > Se lect> Everythin Everything g 5. Toolbar>SAVE_DB. 8.1.8.4. Step 15: Solve load step 2.

ANSYS may produce several warning messages while solving this second load step. They will appear in a popup wi window and and in in the the Outpu Outputt Win Window, but but they they wil will not preven preventt the the solut solutiion from occurri occurrin ng. Howev However, er, you you should be aware that by default, ANSYS only displays the first 5 warning messages in the window. If more warning messages occur, which may be the case in the solution of this load step, they are not displayed, nor is the “Solution is Done!” message displayed . To ensure that the “Solution is Done!” message appears, you are highly advised to change the setting that controls the number of messages that are displayed from 5 to 100. To do this, type the following in the Input Window, Window, then press the Enter key:

/NERR,100,100,OFF This also ensures that ANSYS will not abort if it encounters an error during solution. You can then proceed with the following steps to obtain the solution. 1. Main Menu> Solution> Solve> Current LS 2. Review Review the inf information ormation in in the the status stat us window, window, then choose: choo se:


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File> Close (Windows),

or (X11/Mo tif), f), to close the window. window. Close (X11/Moti

3. Click OK to begin the solution. Ignore any warning messages, but do not close the warning message window yet. 4. Close the note window when solution is done. 8.1.9. Postpr Postproces sing 8.1.9. 8.1 .9.1. 1. Step 16: 1 6: Expand Expand mode modell from from quarter quarter sym s ymmetry metry to full full volume.

1. Utility Menu> PlotCtrls> Style> Symmetry Expansion> Periodic/Cyclic Symmetry D ihee dral dral Sym. 2. Check 1/4 Dih

3. Click OK . 4. Utility Menu> Plot> Elements

5. Toolbar>SAVE_DB. 8.1.9.2. Step 17: Observe interference fit stress state.

1. Main Menu> General Postproc> Read Results> By Load Step 2. Load step num number = 1. 3. Click OK . Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Plot Re sults> Contour Contour Plot> Plot> Nodal N odal Solu 4. Main www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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5. Select Stress and then von Mises stress . 6. Click OK .

8.1.9.3. 8.1.9. 3. Step 18 : Obse rve interme interme diat diatee contact contact pre pre ss ure ure on pin. pin.

1. Main Menu> General Postproc> Read Results> By Time/Freq 2. Enter 120 as the Value of time or freq. 3. Click OK . 4. Utility Menu> Select> Entities 5. In the fi first drop- down lilist, select select Elements . 6. In the second dropdrop - down lilist, select select By Elem Name . 7. Enter 174 as the Element name . 8. Click OK . 9. Utility Menu> Plot> Elements

Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Plot Re sults> Contour Contour Plot> Plot> Nodal N odal Solu 10. Main

11. Select Contact. 12. Select Contact Pressure . 13. Click OK .

8.1.9.4. Step 19: Observe pulled-out stress state.

Utility Me M e nu nu> > Se lect> Everythin Everything g 1. Utility

2. Main Menu> General Postproc> Read Results> By Load Step 3. Enter 2as the Load step number. 4. Click OK . Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Plot Re sults> Contour Contour Plot> Plot> Nodal N odal Solu 5. Main www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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6. Select Stress and then von Mises stress . 7. Click OK .

8.1.9.5. Step 20: Animate pin pull-out.

1. Utility Menu> Plot Ctrls> Animate> Over Results 2. Select Load Step Range for the Model result data. 3. Check Include last SBST for each LDST. 4. Check Auto contour scaling (On). 5. (In the left left colu co lumn mn)) Contour data for animation = Stress . 6. (In the right right colu co lumn mn)) Contour data for animation = von Mises SEQV. 7. Click OK .

8. Make Mak e choices in the Animati Animation on Controll Co ntroller er (not shown), if necessary, necess ary, then Close . 8.1.9.6. Step 21: Plot reaction forces for pin pull-out.

1. Utility Menu> List> Nodes 2. Click OK . 3. Make note of all all the node node numbers numbers whose Z coordi coord inates are 4.5. 4.5 . Your node numbers may be different from those shown here. 4. File> Close (Windows), or (X11/Mo tif), f), to close the window. window. Close (X11/Moti

5. Utility Menu> Plot> Volumes 6. Main Ma in Menu Me nu> > Time Time Hist Postp Pos tproc roc 7. Select Add Data (left most button). 8. Select Reaction Forces , Structural Forces , and then Z-Component of Force . 9. Click OK . www.kxcad.net/ansys/ANSYS/ansyshel p/contact_ff.html

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10. Pick a node on o n the the front surface surface of the the pin whose num number corresp c orresponds onds to one o ne of the the nodes listed listed above a bove for z = 4.5. (Hold down the left mouse button and drag the mouse cursor across the front of the pin. The highlighted node numbers appear in the picking menu. Upclick on the one you want to select.) 11. Click OK . 12. 12 . Verify Verify that that the node numbe numberr you picked picke d above ab ove is displayed in the Node No de number number field. field. Your node number may be different from the one shown here. 13. Click Graph data (third button from left) . 14. Close all EXTREM Command windows. 15. File> Close the the Time History Variables window.


1. Toolbar: Quit. 2. Select Quit - No Save! 3. Click OK . Congratulations! You have completed this tutorial.

Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for: Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. Sending animations over the web.


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Chapter 9. Modal Tutor ial

Tutorials |

Chapter 9. Modal Tutorial


Modal Analysis of a Model Airplane Wing

Pro bl blem em Speci Specif f ication Pro bl blem em Desc Description ription Input Geometry Defi De fine ne Mater M ateriial Generate Ge nerate Mesh Ap pl ply y Loa Loads ds Obtain Solution Review Results

www.kxcad.net/ansys/ANSYS/ansyshel p/modal _tut.html

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9.1. Modal Anal ysi s of a Model Ai r pl ane Wing

Tutorials | Chapter 9. Modal Tutorial |

9.1. Modal Analysis of a Model Airplane Wing





easy



Discipline:

structural

Analysis Type:

modal


PLA NE42 and SOLID45


extrusion extrusion with with a mesh mesh , selecting, eigenv alue modal modal analysis, animation animation


Mo dal Analysis Mod Analysis in the Structural Structural Analysis Analysis Guide, Guide, PLANE4 PLAN E42 2 and SOLID45 in the El the El ements ements Reference. Reference.

9.1.2. 9.1.2. Problem Description Descriptio n

This is a simple modal analysis of a wing of a model airplane. The wing is of uniform configuration along its length and its its cross-sectional cross-sectional area is defined to be a straight line and a spline as shown. It is held fixed to the body of the airplane airplane on one end and hangs freely at the other. The objective of the problem is to find the wing's natural frequencies frequencies and mode shapes.

9.1.2.1. Given

The dimensions of the wing are as shown above. The wing is made of low density polyethylene with a Young's modulus of 38x103 psi, Poisson's ration of 0.3, and a density of 8.3E-5 lb f -sec2/in /in4. 9.1.2. 9.1 .2.2. 2. Approach Approach and and Ass As s umption umptionss www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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Assume the side of the wing connected to the plane is completely fixed in all degrees of freedom. The wing is solid solid and material material properties prop erties are constant and isotropic. Solid modeling is used to generate a 2-D model of the cross-section of the wing. You then create a reasonable mesh and extrude the cross-section into a 3-D solid model which will automatically be meshed. Additionally, the mesh used in this example will be fairly coarse for the element types used. This coarse mesh is used here so that this tutorial can be used with the ANSYS ED product. 9.1.2.3. Summary of Steps

Use the information in this description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Input Input Geometry Geome try

1. Read in geometry input file. Back To Top Define Materials

2. Set preferences. 3. Define constant material properties. Back To Top Generate Mesh

4. Define element type. 5. Mesh the area. 6. Extrude the meshed area into a meshed volume. Back To Top Apply Loads

7. Unselect 2-D elements. 8. Apply constraints to the model.

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Back To Top Obtain Solution

9. Specify analysis types and options. 10. Solve. Back To Top Revie w Results Results

11. List the natural frequencies. 12. Animate the five mode shapes. 13. Ex Exiit the ANSYS AN SYS program. 9.1.3. Input Geometry 9.1.3.1. Step 1: Read in geometry input file.

You will begin by reading in a file that includes the model. 1. Utility Menu> File> Read Input from ... 2. File File name: wing.inp UNIX version:

/ansys_inc/v110/ansys/data/models/wing.inp PC version:

\Program Files\Ansys Inc\V110\ANSYS\data\models\wing.inp 3. [OK]

9.1.4. Define Define Materials Materials 9.1.4.1. Step 2: Set preferences.

You will now set pref set preferen erences ces in order to filter quantities that pertain to this discipline only. www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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1. Main Menu> Preferences 2. (check) “Structural” “Structural” 3. [OK] 9.1.4.2. Step 3: Define constant material properties.

1. Main Menu> Preprocessor> Material Props> Material Models 2. (double-c (do uble-cllick) “Structural”, then then “Li “Linear”, near”, then “El “Elastic”, astic”, then “Isotropic” “Isotro pic” 3. “EX” “EX” = 38000 380 00 4. “PRXY” “PRXY” = 0.3 5. [OK] 6. (double-c (do uble-cllick) “Density” “Density” 7. “DENS DENS”” = 8.3e-5 8.3e- 5 8. [OK] 9. Material> Exit 9.1.5. Generate Mesh 9.1.5.1. Step 4: Define element types.

Define two element types: a 2-D element and a 3-D element. Mesh the wing cross-sectional area with 2-D elements, and then extrude the area to create a 3-D volume. The mesh will be "extruded" along with the geometry so 3-D elements will automatically be created in the volume. 1. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Eleme Eleme nt Type Type > Add/Ed Add/Edit/Dele it/Dele te 2. [Add...] 3. “Structura “Structurall Soli So lid” d” (left colu co lumn mn)) 4. “Quad 4node 42” 42 ” (right (right col co lumn) umn) 5. [Apply] [Apply] to choose the Quad 4 node (PLANE42 (PLANE42)) 6. “Structura “Structurall Soli So lid” d” (left colu co lumn mn)) 7. “Brick “Brick 8node 8nod e 45” (right (right col co lumn) umn) 8. [OK] [OK ] to choose the the Brick Brick 8 node node (SOLID45 (SOLID45)) 9. [Close] www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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10. Toolbar: SAVE_DB 9.1.5.2. Step 5: Mesh the area.

The next step is to specify mesh controls in order to obtain a particular mesh density. Prepr eproces oces sor> Me shing> shing> Mes M es h Tool Tool 1. Main Me nu> Pr

2. “Size “Size Controls Co ntrols Glob Global” al” = [Set] [S et] 3. “Elem “Element ent edge length” length” = 0.25 0.2 5 4. [OK] 5. [Mesh] 6. [Pick All] All] 7. [Close] [C lose] Warni War ning. ng.

8. [Close] Meshtool 9. Toolbar: SAVE_DB In designing this problem, the maximum node limit of ANSYS of ANSYS ED was taken into consideration. That is why the 4-node PLANE42 element, element, rather than the the 88 - node PLANE82 element was used. Note that the mesh contains a PLANE42 triangle, which results in a warning. If you are not using ANSYS ED, you may use PLANE82 during the element definitions to avoid this message. Note however that PLANE82 does not work unless you get rid of the Global Element edge length (which was set to 0.25). Note

The mesh you see on your screen may vary slightly from the mesh shown above. As a result of this, you may see slightly different results during postprocessing. For a discussion of results accuracy, see Planning Your Approach in the Modeli the Modeling ng and Meshing Meshing Guide. Guide. 9.1.5.3. 9.1.5. 3. Step 6: Extrude Extrude the mes hed are are a into into a me me she d volume. volume.

In this step, the 3-D volume is generated by first changing the element type to SOLID45 SOLID45,, which is defined as element type 2, and then extruding the area into a volume. 1. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Modelin Mo deling> g> Operate> Extrud Extrudee > Elem Ele m Ext Ext Opts 2. (drop (dr op down) do wn) “Elem “Element ent type type number number”” = 2 SOLID45 www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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3. “No. Elem Elem divs” = 10 4. [OK] 5. Main Menu> Preprocessor> Modeling> Operate> Extrude> Areas> By XYZ Offset 6. [Pick All] All] 7. “Offsets “Offsets for for extrusion” extrusion” = 0, 0, 10 8. [OK] 9. [Close] [C lose] Warni War ning. ng. Using SOLID45 to run this problem in ANSYS ED will produce this warning message. If ANSYS ED is not being used, then SOLID95 (20-node brick) can be used as element type 2. Using PLANE82 and and SOLID95 produces a warning message about shape warning limits for 10 out of 127 elements in the volume. 10. Utility Menu> PlotCtrls> Pan, Zoom, Rotate 11. [Iso] 12. [Close]

13. Toolbar: SAVE_DB 9.1.6. 9.1 .6. Apply Apply Loads Loads 9.1.6.1. Step 7: Unse Unse lect 2-D ele me nts. nts.

Before applying constraints to the fixed end of the wing, unselect all PLANE42 elements used in the 2-D area mesh since they will not be used for the analysis. 1. Utility Menu> Select> Entities 2. (first (first drop down) “El “Elements” ements” 3. (second drop down) “By “By Attributes” Attributes” 4. (check) (check ) “El “Elem em type num” num” 5. “Min,Max,I “Min,Max,Inc” nc” = 1


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6. (check) “Unsel “Unselect” ect” 7. [Apply] 9.1.6.2. Step 8: Apply constraints to the model.

Constraints will be applied to all nodes located where the wing is fixed to the body. Select all nodes at z = 0, then apply the displacement constraints. 1. (first (first drop down) “Nodes” “Node s” 2. (second drop down) “By “By Location” Location” 3. (check) “Z coordin coo rdinates” ates” 4. “Min,Max” “Min,Max” = 0 5. (check) (check ) “From Full” Full” 6. [Apply] 7. Main Ma in Menu Me nu> > Pre Pre proce process ss or> Loads Loads > De D e fine fine Loads> Apply> Apply> Structu Structural> ral> Displacem Displace me nt> nt> On Nodes 8. [Pick All All] to pick all all selected selected nodes. nodes. 9. “DOF “DOFss to be constrained” constrained” = All All DOF 10. 10 . [OK [O K ] Note No te that by leavin leaving g “Displ “Displace acemen ment” t” blank, blank, a defaul d efaultt value value of zero is used.

Now, resel reselect all all nodes. 11. (second drop down) “By “By Num/Pick” Num/Pick” 12. 12 . [Sele [Se le All] All] to imm immediately ediately select all nodes node s from from entire entire datab da tabase ase.. 13. [Cancel] to close close dialog dialog box. 14. Toolbar: SAVE_DB 9.1.7. Obtain Solution 9.1.7.1. Step 9: Specify analysis type and options.

Specify a modal analysis type. www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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1. Main Menu> Solution> Analysis Type> New Analysis 2. (check) “Modal” 3. [OK] Ma in Menu Me nu> > Solu So lution tion> > Analysis Type Type > Analysis Op Option tionss 4. Main

5. (check) (check ) “Block “Block Lanczos” (Bloc (Block k Lanczos is is the default default for for a modal moda l analysis.) analysis.) 6. “No. of modes to extract” = 5 7. “No. of modes to expand” = 5 8. [OK] 9. [OK [O K ] All All default values values are accep ac ceptab tablle for this this analysis. analysis. 10. Toolbar: SAVE_DB 9.1.7.2. Step 10: Solve.

1. Main Menu> Solution> Solve> Current LS 2. Review Review the inf information ormation in in the the status stat us window, window, then choose: choo se: File> Close (Windows),

or Close (X11 / Motif), to close the window.

3. [OK [O K ] to initi initiate ate the solution. solution. 4. [Yes] 5. [Yes] Based on previous discussions, the warnings are accepted. The messages presented in the verification window are due to the fact that PLANE42 elements have been defined but not used in the analysis. They were used to mesh a 2-D cross-sectional area. 6. [Close] to acknowl ac knowledge edge that the the soluti solution on is is done. 9.1.8. Re view Results Results 9.1.8.1. Step 11: List the natural frequencies.

Ma in Menu Me nu> > General Ge neral Postproc> Postproc> Re R e sults Summ Summary 1. Main

2. [Close] [Close] after observi obse rving ng the listi listing ng.. www.kxcad.net/ansys/ANSYS/ansyshel p/modal _aw.html

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9.1.8.2. 9.1.8. 2. Step 12: Animat Animatee the five five mode mode shape shape s.

Set the results for the first mode to be animated. 1. Main Menu> General Postproc> Read Results> First Set 2. Utility Menu> PlotCtrls> Animate> Mode Shape 3. [OK] Observe the first mode shape:

4. Make Mak e choices in in the Animati Animation on Control Contro ller (not (not shown), if necessary, necess ary, then choose choo se Cl C lose. ose . Animate the next mode shape. Me nu> General General Postpr Postproc> oc> Read Re ad Resu Res ults> Ne xt Set 5. Main Men

6. Utility Menu> PlotCtrls> Animate> Mode Shape 7. [OK] Observe the second mode shape:

Repeat red steps 4 through 7 above, and view the remaining three modes. Observe the third mode shape:

Observe the fourth mode shape:


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Observe the fifth mode shape:


1. Toolbar: QUIT 2. (check) “Quit Quit - No Save!” 3. [OK] Congratulations! You have completed this tutorial. Even though you have exited the ANSYS program, you can still view animations using the ANSYS ANIMATE program prog ram.. The ANIMATE program runs only on the PC and is extremely useful for: Viewing ANSYS animations on a PC regardless of whether the files were created on a PC (AVI files) or on a UNIX workstation (ANIM files). Converting ANIM files to AVI files. Sending animations over the web.


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Chapter 10. Pr obabi l isti c D esig n System ( PDS) Tutor i al

Tutorials |

Chapter Chapter 10. 10 . Probab Probabilistic ilistic De s ign Syste m (PDS) (PDS) Tutorial Tutorial


Probabilistic Design of a Simple Plate with a Single Force Load

Pro bl blem em Speci Specif f ication Pro bl blem em Desc Descri ripti ption on Specify Analysis File Define Input and Output Obtain Solution Perform Postprocessing Generate Report

www.kxcad.net/ansys/ANSYS/ansyshel p/pds_tut.html

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10.1. Pr obabi li sti c Desi g n of a Si mple Pl ate wi th a Si ng l e For ce Load

Tutorials | Chapter 10. Probabilistic Design System (PDS) Tutorial |

10.1. Probabilistic Design of a Simple Plate with a Single Force Load



ANSYS ANSYS Multiph ys ics, ANSY A NSYS S Mech anical, ANSYS ANSYS Structu ral, ANSYS ED


moderate


app roxim roximately ately 30 minut minutes es

Discipline:

structural

Analysis Type:

st atic, linear linear


SHELL63


Probabilistic Design System (PDS) Analysis


Pro b ab ilis t ic Des ig n in th e Adva nce nced d Ana lysi lysiss Techniq Techn iques ues Guide, SHELL63 in the Elemen Guide, the Elements ts Referenc e.

10.1.2. 10.1.2. Problem Description Description

This is a structural probabilistic p robabilistic analysis of a square plate fixed on two sides and loaded in the center, as shown belo below.

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The input parameters are subject to uncertainty. Measurements show that the plate dimensions can vary significantly. Specimen tests show that the material properties can also vary. The applied force is also subject to uncertainty. You will determine the variation of the output parameters given the uncertainty of the plate dimensions, material properties, properties, and and appli applied force. force. Th The outpu outputt param parameters that that you you wil will study study are the the maxi aximum defl deflection ection of the the plate plate and the maximum equivalent stress at the clamped edges. The following are your main objectives: Review statistical results to determine if enough simulation loops have been performed. Determine the probability that the maximum deflection remains below a specified value. Determine the maximum deflection that will give a specified probability that the deflection is below that value. Quantify how sensitive the results are with respect to the variability of the input parameters. Produce scatter plots for the output parameters as a function of the most important random input variables. Determine the correlation coefficients between the output parameters and input variables. 10.1.2.1. Give Give n

You are given an input file for a deterministic analysis of the plate, where uncertainties have been ignored. The www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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square plate is 100 mm long and 1.0 mm thick. Young's modulus and density are equal to the values shown in the table below. The force is 100.0 N. The manufacturing process produces plates with an accuracy of ±0.1 mm. The following are the material properties. Mat erial eria l Prope rty

Nominal Va lue

Distributio Distrib ution n

Youn g's modu lus

210.0 N/mm2

Gaussian Standard deviation 3 - 5%

Density

8.0e-6 kg/m kg/ mm3

Uniform Standard deviation 5%

The force can only be positive and has a standard deviation of 10% of its mean value. 10.1.2.2. Approach and Assumptions

For this problem, you first enter the Probabilistic Design System (PDS), execute the file for the deterministic model and then specify it as the analysis file for the probabilistic analysis. Next, Next, you you defi define the the random input variables and and random output parameters for your probabilistic analysis. For this problem, you define the length and thickness of the plate, Young's modulus and density, and force as random input variables with various distribution functions. You will define length and width as a uniform distribution with lower and upper bounds based on the manufacturing accuracy of ±0.1 mm. To be conservative, you will use a 5% standard deviation for the Young's modulus. To demonstrate that density has no significant impact on the results, you will use a uniform distribution from 50% to 150% of its nominal value. For force, you will use a lognormal distribution with a mean value equal to the nominal value and a standard devi deviation ation of 10% of its mean value. You define the maximum deflection and maximum equivalent stress at the fixed edges as the output parameter parameters. s. Next, Next, you you defi define Monte Carlo as the probabilistic analysis method and execute the Monte Carlo probabi Carlo probabillisti sticc simulations.. simulations Finally, you visualize and evaluate the Monte Carlo results to achieve the analysis objectives, as stated above. 10.1.2 10. 1.2.3. .3. Su Summ mmar ary y of Steps

Use the information in the problem description and the steps below as a guideline in solving the problem on your own. Or, use the detailed interactive step-by-step solution by choosing the link for step 1. Specify Analysis File

1. Enter PDS and specify analysis file. www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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Back To Top Define Input and Output

2. Define input variables. 3. Define output parameters. Back To Top Obtain Solution

4. Execute Monte Carlo simulations. Back To Top Perform Postprocessing

5. Perform statistical postprocessing. 6. Perform trend postprocessing. Back To Top Ge nerate nerate Report

7. Generate HTML report and exit. 10.1.3. Specify Analysis File 10.1.3.1. Step 1: Enter PDS and specify analysis file.

You begin by entering the Probabilistic Design System (PDS) and executing the file plate.mac for the deterministic model. The plate.mac file contains a complete analysis sequence for a simple plate with a single force load. It uses parameters to define all inputs and outputs. If you are using the UNIX version of ANSYS, the file resides at /ansys_inc/v110/ansys/data/models . If you are using the PC version of ANSYS, the file resides at \Program Files\Ansys Inc\V110\ANSYS\data\models . Before performing substep 1 below, it is highly recommended that you copy the file plate.mac to your working directory. 1. Main Menu> Prob Design 2. Utility Menu> File> Read Input from 3. File File name:plate.mac www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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4. [OK] 5. [Close]

Now defi define plate.mac as the analysis file for the probabilistic analysis. PDS uses plate.mac to create a file for performing analysis loops. PDS uses the plate.mac input and output param para meters as random input input variables variables (RVs) and a nd random output parameters pa rameters (RPs). 6. Main Menu> Prob Design> Analysis File> Assign 7. File File name: plate.mac 8. [OK] 10.1.4 10. 1.4.. De fine Input Input and Outpu Outputt 10.1.4.1. Step 2: Define input variables.

You will now define the input parameters and their distribution functions. 1. Main Menu> Prob Design> Prob Definitns> Random Input 2. [Add...] Define length as an input variable. 3. “Select “Select a Parameter” = LENGTH LENGTH 4. “Distr “Distribution ibution Type” = Unifor Uniform m 5. [OK] 6. “Lower “Lower Boundary” Boundary” = LENGTH-0. LENGTH-0.1 1 7. “Uppe “Upperr Boundary” Boundary” = LENGTH+0.1 LENGTH+0.1 8. [OK] 9. [Add...] Define thickness as an input variable. 10. “Select “Select a Param Para meter” = THICKN ESS 11. 11 . “Distributi “Distribution on Type” Type” = Uniform Uniform www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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12. [OK] 13. “Lower “Lower Boundary” Boundary” = THICKN ESS-0.1 ESS- 0.1 14. “Uppe “Upperr Boundary” Boundary” = THICKN ESS+0.1 ESS+0 .1 15. [OK] 16. [Add...] Define Young's modulus as an input variable. 17. “Select “Select a Param Para meter” = YOUN YOUNG G 18. 18 . “Distributi “Distribution on Type” = Gauss 19. [OK] 20. “Mean value” value” = YOUNG 21. “Standard deviati deviation” on” = 0.05*YO 0.0 5*YOUNG UNG 22. [OK] 23. [Add...] Define density as an input variable. 24. “Select “Select a Param Para meter” = DENSI DENSITY TY 25. 25 . “Distributi “Distribution on Type” Type” = Uniform Uniform 26. [OK] 27. “Lower “Lower Boun Boundary” dary” = 0.5*DENSITY 0.5*DENS ITY 28. “Uppe “Upperr Boundary” Boundary” = 1.5*DENS 1.5 *DENSITY ITY 29. [OK] 30. [Add...] Define force as an input variable. 31. “Select “Select a Param Para meter” = FORCE FO RCE 32. 32 . “Distributi “Distribution on Type” = LOG1 33. [OK]


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34. “Mean value” value” = FORCE FORC E 35. “Standard deviati deviation” on” = 0.1*FO 0.1 *FORCE RCE 36. [OK] 37. [Close] 10.1.4.2. Step 3: Define output parameters.

You will now define the maximum deflection of the plate and the maximum equivalent stress at the clamped edges as output parameters. 1. Main Menu> Prob Design> Prob Definitns> Random Output 2. [Add...] 3. “Select “Select Parameter” = MAXDEFLE MAXDEFLECTIO CTION N 4. [OK] 5. [Add...] 6. “Select “Select Parameter” = MAXSTRESS MAXSTRESS 7. [OK] 8. [Close] 10.1.5. Obtain Solution 10.1.5 .1. Step 4: Exe cute M onte Carlo Carlo sim s imul ulat ations. ions.

You will now specify the Monte Carlo Simulation method and various options. You will specify the Latin Hypercube sampling technique. For the same accuracy, it generally requires fewer simulation loops than the Direct Monte Carlo Sampling technique. You will set the number of simulations to 40 and the number of repetitions to 1 to give 40 analysis loops. Forty loops will be a sufficient number for demonstration purposes. You will also set a few special options. For more information on the Monte Carlo Simulation method and these options, refer to the PDMETH and and PDLHS commands in the Commands Reference and and Probabilistic Design in the Adv the Advanced anced Analysis Analysis Techniques Guide Guide.. 1. Main Ma in Menu Me nu> > Prob Prob Design> De sign> Prob Prob Me thod> thod> Mont Mo ntee Carlo Carlo Sims 2. “Latin “Latin Hypercube” Hyperc ube” 3. [OK] 4. “Numbe “Numberr of Simul Simulations” ations” = 40 5. “Numbe “Numberr of Repetiti Repe titions” ons” = 1 www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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6. “Random “Rando m Sampli Sa mpling” ng” 7. “Execute “Execute ALL ALL Sims” Sims” 8. “Use 123457 12345 7 INIT” 9. [OK] 10. Main Menu> Prob Design> Run> Exec Serial> Run Serial 11. 11 . “Solution “Solution Set Se t Label” Labe l” = LHSRUN LHSRUN 12. [OK] 13. 13 . Review Review the informati information on in the dialog box, then [OK] [O K] to initiate initiate the solution. solution. The solution is complete when the statement “LOOP 40 OUT OF 40 - CYCLE 1 OUT OF 1 IS FINISHED” appears in the ANSYS Output Window. 10.1.6 . Pe rform Postproce Postproce ss ing ing 10.1.6 .1. Ste Ste p 5: Per Pe rform statistical statistical postproce postproce s sing.

You will now review simulation results and mean value plots for maximum deflection. If the number of simulations is sufficient, the mean value plots for random output variables converge (the curve flattens out). You will also review a histogram plot for the maximum deflection in order to visualize the scatter of this random output parameter To double check that the number of simulation loops is sufficient, you will plot a histogram of the Young's modulus random input variable. The ANSYS PDS not only plots the histogram bars, but also plots a curve for values derived from the distribution function that you specified. If the number of simulations is sufficient, the histogram for Young's modulus will have bars close to the curve derived for the distribution function, which are smooth and without any major gaps. You will also determine the following: The probability that the maximum deflection is below 0.525 mm. The maximum deflection that will give a 90% probability that the deflection is below that value. 1. Main Menu> Prob Design> Prob Results> Statistics> Sampl History 2. “Prob Design Design Variable” = MAXDEFLECTION MAXDEFLECTIO N 3. “Samples” 4. [OK]


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5. Main Menu> Prob Design> Prob Results> Statistics> Sampl History 6. “Prob Design Design Variable” = MAXDEFLECTION MAXDEFLECTIO N 7. “Mean values” values” 8. [OK]

The curve is relatively flat, indicating that the number of simulations is sufficient. 9. Main Menu> Prob Design> Prob Results> Statistics> Histogram 10. “Prob Design Design Variable” Variable” = MAXDEFLECTION MAXDEFLECTION 11. [OK]


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12. Main Menu> Prob Design> Prob Results> Statistics> Histogram 13. “Prob Design Design Variable” Variable” = YOUNG 14. [OK]

The histogram bars resemble the probability density function, indicating that the number of simulations is sufficient. 15. Main Menu> Prob Design> Prob Results> Statistics> CumulativeDF 16. “Prob Design Design Variable” Variable” = MAXDEFLECTION MAXDEFLECTION 17. [OK]


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The curve shows that there is a about a 93% probability that the deflection remains below 0.525. Ma in Menu Me nu> > Prob Prob Design> De sign> Prob Prob Results> Re sults> Statistics> S tatistics> Probab Probabilit ilities ies 18. Main

19. “Prob Design Design Variable” Variable” = MAXDEFLECTION MAXDEFLECTION 20. 20 . “Less “Less than” 21. 21 . “Lim “Limiit Value” Value” = 0.525 0.5 25 22. [OK] Note that that th the probabil probability is 93.026% th that the the max maxiimum defl deflection ection is below below th the val valu ue of 0.525 mm mm. 23. 23 . After revi reviewing ewing the information, information, File> Close (Windows platforms) or Close (UNIX platforms) platforms) 24. Main Menu> Prob Design> Prob Results> Statistics> Inverse Prob 25. “Prob Design Design Variable” Variable” = MAXDEFLECTION MAXDEFLECTION 26. “Target “Target Probabi Probab ility” = 0.90 27. [OK] Note that that th there is is a 90% probabi probabillity that that th the max maxiimum defl deflection ection is below below 0.5209 mm mm. 28. 28 . After reviewing reviewing the results, choose File> Close (Windows platforms) or Close (UNIX platforms). platforms). You have achieved three of your six main objectives for running this tutorial as stated above in Problem Description.. In Step 5, you: Description Reviewed statistical results and determined that 40 simulation loops were sufficient (substeps 8 and 14). Determined that the probability of the maximum deflection being below 0.525 mm, is 93% (substeps 17 and 23). Determined that a deflection limit of 0.5209 mm should be specified to achieve a 90% probability that the deflection is below that value (substep 28). 10.1.6 .2. Ste Ste p 6: Per Pe rform tre tre nd p pos os tpr tproce oce ss ing. ing.

You will now request sensitivity plots for MAXDEFLECTION and MAXSTRESS to determine which random input variables are most significant. You will then request scatter plots of MAXDEFLECTION and MAXSTRESS versus the most significant random input variables. Finally, you will determine the correlation coefficients between the random output parameters and the random input variables. 1. Main Menu> Prob Design> Prob Results> Trends> Sensitivities 2. Choose for the the “Select “Select Response Param” = MAXDEFLECTION MAXDEFLECTION www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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3. [OK]

Note that that th the leg legen end d in indicates dicates that that onl only the the random random input variabl ariablee THICKNESS THICKNESS is is im important portant for for the the random output parameter MAXDEFLECTION.

4. Main Menu> Prob Design> Prob Results> Trends> Sensitivities 5. “Select “Select Response Param” = MAXSTRESS MAXSTRESS 6. [OK]

Note that that th the leg legen end d in indicates dicates that that onl only the the random random input variabl ariables es THICKNESS THICKNESS and and FORCE are are important porta nt for for the random output param para meter MAXSTRESS MAXSTRESS..


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7. Main Menu> Prob Design> Prob Results> Trends> Scatter Plot 8. “Name 1 Select Select Parameter” = THICK THICKNESS NESS 9. “Name 2 Select Param Para meter” = MAXDEFLECTION MAXDEFLECTION 10. [OK]

11. Main Ma in Menu Me nu> > Prob Prob Design> De sign> Prob Prob Results> Re sults> Trends Trends > Corre Corre l Matr M atrix ix 12. 12 . “Type “Type of Matrix Matr ix”” = InputInput-O O utput 13. [OK] 14. [OK] Note the the correlati correlation on coeff coefficien cients. ts. 15. 15 . After reviewing reviewing the results, choose File> Close (Windows platforms) or Close (UNIX platforms). platforms). You have achieved the remaining three of your six total main objectives for running this tutorial as stated above in Problem Description. Description. In Step 6, you: Determined that only the random input variable THICKNESS is important for the random output parameter parameter MAXDE MAXDEFLE FLECTION CTION (substep (substep 3), 3), and and that that onl only the the random random input variabl ariables es THICKNESS THICKNESS and and FORCE are important for the random output parameter MAXSTRESS (substep 6). Produced a scatter plot of the MAXDEFLECTION output parameter as a function of the THICKNESS www.kxcad.net/ansys/ANSYS/ansyshel p/pds_pds.html

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input variable (substep 10). Determined correlation coefficients between output parameters MAXDEFLECTION and MAXSTRESS, and input variables LENGTH, THICKNESS, YOUNG, DENSITY, and FORCE (substep (substep 15). 15 ). 10.1.7. Generate Report 10.1.7 .1. Step Ste p 7: Generate Generate HTML report and and exit.

You will now generate an HTML report for your probabilistic analysis. It includes deterministic model informati information, on, proba pro babil bilisti isticc model od el informati information, on, and probab pro babil iliistic analy a nalysis sis resul re sults. ts. 1. Main Ma in Menu Me nu> > Prob Prob Design> De sign> Prob Prob Results> Re sults> Re R e port> port> Re port port Options Options 2. [OK] [OK ] to use the default default options. options. 3. Main Menu> Prob Design> Prob Results> Report> Generate Report 4. “Report file file name” = Sim S imple ple Plate Analysis Analysis 5. “Your first first name” name” = John 6. “Your last name” name” = Doe 7. [OK] You will find the report and all related files in your current directory in a subdirectory with the report file name. 8. Toolbar: Quit 9. “Quit “Quit - No Save!” 10. [OK] Congratulations! You have completed this tutorial.


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Chapter 11. ANIMATE Pr og r am

Tutorials |

Chapter Chapter 11. 11 . ANIM ATE Program Program


View Animations on a PC Using the ANIMATE program.

The ANIMATE program allows you to view ANSYS animation files on a PC regardless of whether the files were created on a PC (AVI files), or on a UNIX workstation (ANIM files). The program is truly standalone. You can run it without ANSYS even being installed. Also, its small 250kB file size makes it easy to transport as an e-mail attachment, if required. If you create and view AVI animation files on a PC, the ANIMATE program will provide you with better frame speed and window size control than if you use the Windows Media Player. For ANIM files created on UNIX workstations, you not only can view the files directly on a PC using the ANIMATE program, but you can also convert an ANIM file to an AVI file. This provides a substantial reduction in file size -- ideal for producing downloadable animation files for the web. Also, when using the ANIMATE program to view 3-D model animations saved as ANIM files, you can pan, zoom, or rotate the model (using the mouse buttons) while the the animation is in progress. The following procedure will allow you to exercise some of the features of the ANIMATE program. To perform the procedure, you must be using a PC and have an AVI or ANIM animation file stored locally on your Win Windows f ile ile system. Note

If you created an animation in ANSYS, you can save the animation to a file and assign it any name from the Utility Menu, PlotCtrls, Animate, Save Animation, then assign a file name. Any animation file saved this way can be used in the ANIMATE program. For ANIM files in a UNIX file system, you must transfer the ANIM files to the Windows file system using the FTP protocol, SAMBA, or some other file system transfer utility. Another requirement for using the ANIMATE program program is that that th the ANIM fi file mus mustt hav havee been created created usi usin ng pix pixmap ani animation ation as opposed to to displ display ay list www.kxcad.net/ansys/ANSYS/ansyshel p/ani mate_pg m.html

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animation. On a UNIX workstation, you can set this in ANSYS from the Utility Menu by choosing PlotCtrls, Device Options, then checking Pixmaps for Animation mode in the dialog box. After you have fulfilled the requirements stated above, exercise some of the features of the ANIMATE program as follows: 1. With the t he ANSYS ANSYS CD CD in you r CD drive, open ope n a Windo ws file manager (e.g., Windows Explorer) and obtain a listing of file file names names in the root d irectory irectory of the CD. CD. 2. Start the file file named Animate.exe.

3. Click Click on th e Open file butto bu tto n. 4. From the th e file file s election list, cho os e any AVI animation animation file, or an ANIM animation file created using the pixmap animation.

5. Disp Disp lay the An imation imation Controller Controller by clicki clicking ng o n th e Controller bu tto n.

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6. Experiment periment with the v arious arious cont rols on th e Animation Animation Controller. 7. With th e animation animation s till runn ing, experim experiment ent with different different window sizes by clicki clicking ng on the various window window butto ns located on the toolbar. toolbar. 8. If yo u are viewing viewing an A VI fil file, e, you have h ave co mpleted t his procedu proc edu re. Cho Choos os e File > Exit to t erminate erminate the ANIMATE program. If you are viewing an ANIM file, cont inue with with th e remaini remaining ng s teps below. 9. Convert the A NIM NIM file file to an AVI AVI fil filee by ch oos ing File > Save as Save .

then sp ecifying ecifying a file file name, name, and clicki clicking ng on

10. 10. Terminate Terminate the A NIMATE NIMATE program by ch oos ing File > Exit.

11. From yo ur Windo ws file file mana mana ger, compare the size of the original ANIM file with the size of the AVI file you just jus t conv co nverted erted . Not Notee the th e sub s ubss tan tial redu redu ction in file file size size resulting from the co nvers ion.

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