Member Weight Method

METHOD 2 SEISMIC ANALYSIS USING MEMBER WEIGHT METHOD

STEPS INVOLVED:

1.Creation of Geometry 2.Giving Member Property 3. Support Condition 4.Giving Loads : 5.Specifying Analysis Type 6.Post Analysis Print 7.Design 8.Analysis. Data: Building size : 15m x 15m Height :33m Concrete Mix M30 Steel Fe415 Loads: LL =1.50 KN/m2 (For Roof slab) 2.0KN/m2 (For floor slab) Member sizes : Beam 300 x 450mm; Column 300x 450mm Slab thickness: 120mm. Soil type: medium. Zone :III Importance factor=1.50

0 0 . 5 1

BEAMS ARE OF SIZE 0.3 X 0.45

3.00

3.00

3.00

3.00

3.00

15.00

COLUMN ARE OF SIZE 0.45 X 0.30

PLAN

     0       0   .      3       3 

     0       0   .      3 

BEAMS SIZE 0.3 X 0.45

COLUMN SIZE 0.45 X 0.30 3.00

3.00

3.00

3.00

3.00

15.00

ELEVATION

The Member Weight method is explained as follows: 1 . Geometry Creation :

New Project

 

Select

 

Space

Length =meters; Force=KN;



File Name=Seismic Coefficient by Member weight method (MW) Select



Open Structure Wizard

 



Select Bay Frame and double click

on it. Each Bay =3.0m

Height Y=3.0m

No. of Bay=1 Each Bay =3.0m

Width Z=15.0m

No. of Bays=5

 Apply Transfer

Model  YesOk.

Go to front view.

Next

Finish.

Change to Frame models from Truss models Length X=15.0m No. of Bays =5

 

Each Bay =3.0m

2.Member Property :

Click General 

 

Property

Define 

Rectangle

YD=0.45

ZD=0.30

 Add 

YD=0.45 ZD=0.30  AddClose . Highlight 0.45 x 0.30 Main menu Select

Beam parallel to  Assign Yes  Assign

 X

, Select

 Highlight

 Beam

parallel to

 Z   Assign

0.45 x 0.30  Select Beam parallel to

to selected beam

to selected beam



 Y 

 Assign Yes Close.

Deselect the nodes. Select beam cursor. Select the entire structure Click Translational repeat  Y No. of steps=10 Default spacing=3m

 Link OK.

3. Supports :

Go to front view. Click Support  Create

 Fixed  Add.

Highlight support 2 and select bottom most

support nodes by windowing using node cursor  Assign Yes

 Close  De

 Assign

to selected nodes



select the nodes and change to beam cursor.

4. Loads :

Main menu Commands  Loading  Definitions

Seismic

load

IS

Seismic Parameters appear. Select IS1893-2002. Click Generate . IS1893 seismic parameters screen will appear. Select Zone =III. Z=0.16 Response Reduction Facto (RF) : (For Special RC MRF) = 5 Importance factor (I) =1.5 Rock/soil type (SS) : (For Medium soil)=2 Structure Type (ST) : (For RC Frame Building)=1 Damping Ratio (DM) = 0.05% Period in X = 0.09 h =0.09 x33

√dx

√12

Period in Z = 0.09 h =0.09 x33

√dz Generate

=0.86 sec. =0.86sec.

√12

 Add  Close.

Click Zone 0.16 RF 5 I 1.5 SS 2 ST 1 DM 0.05 0.86 0.86  Add  Seismic Definition screen will appear.

1893-2002.

Click Self weight

Selfweight

Click Member weight

1

Loading

 

Add.

type: UNI

Weight=12 KN/m   Add.

Weight w1=6 KN/m Add. Weight w1=4 KN/m Add. Click Floor Weight Pressure: 4KN/m2 (Dead load)  Y range: Mini=3.0m Max=30.0m Add. Pressure: 0.5KN/m2 (25% of Live Load)  Y range: Mini=30.2m Max=33.0m Add Close. Highlight selfweight  Select to view  Assign. Click Cut section iconGo to Front view Highlight Member load w1= 12 KN/m  Go to Front view toX and Z. Front elevation view. Right click

  New

Select only typical floor beams except roof beam Plan view 

 Highlight

 Select Beam

view

  create

parallel

 Ok.

new view

Ok.

w1=-12Select the outer portion of beams (9” wall portion ) 

Assign to selected beams  Assign  Yes.

Highlight Member weight w=6KN/m. view Assign to selected beam Go to front view

Select

Select

inner portion of the beam in plan

 Assign YesClose.

top portion by windowing

Right

click  New view

OK.

Plan view Select outer portion of beam and highlight 4KN/m  Assign to selected beam  Assign YesClose. Note: In Seismic analysis always first load case shall be seismic load only. Click load case details on data area  Add. Number 1 Loading type: Seismic Title: EQ in X +ve Add

Close.

Click Load case details  Add. Number 2 Loading type: Seismic Title: EQ in X -ve Add Close. Click Load case details  Add. Number 3 Loading type: Seismic Title: EQ in Z+ve Add Close.

Click Load case details  Add. Number 4 Loading type: Seismic Title: EQ in Z-ve Add. Click Load case details  Add. Number 5: Loading type: Dead Title: DL

 Add

.

Click Load case details  Add. Number 6: Loading type: Live Title: LL

 Add Close.

Highlight Load case1  Add. Seismic load

X

direction Factor: 1 Add.

Highlight Load case 2 Add. Seismic load

X

direction Factor :-1 Add.

Highlight Load case 3  Add. Seismic load

Z

direction Factor :1 Add.

Highlight Load case 4  Add. Seismic load

Z

direction Factor :-1 AddClose.

Click Load case 5 (Dead Load)  Add. Selfweight

Selfweight  Y

Factor:-1  Add.

Member weightLoading type Uni

□ Weight =-12KN/m  Add. (9” wall load)

Weight =-6KN/m  Add. (4.5” wall load) Weight =-4KN/m  Add. (parapet wall load) Floor Load Pressure: -4 KN/m2 Global

Y  Define Y range Mini.=3.0m

Max.=30.0m

 Add

Floor Load Pressure: -5.25 KN/m2 Global

Y  Define Y range Mini.=30.2m

Highlight Selfweight Y -1 

 Assign

Max.=33.0m  Add

to view

 Assign  Yes.

Highlight Member load - 12 KN/m

 Go

to Front view

and Z. Front elevation view. Right click 

 New

Select only typical floor beams except roof beam Plan view 

 Highlight

 Select Beam

view

parallel to X

 Ok.

  create

new view

Ok.

w1=-12Select the outer portion of beams (9” wall portion ) 

Assign to selected beams  Assign  Yes.

Highlight Member weight W=-6KN/m portion of the beam

 Assign

Right click

view

  New

portion of the beam

 

 Cut

section . Go to Plan view

to selected beams

 create

a new view

 OK.

Assign to selected beam

Select

inner

 Assign Yes

Plan view

 Select

outer

 Assign Yes  Close.

Click Load case 6 (Live load) Add. Floor Load pressure :-2 KN/m2 Define Y range Mini.= 3.0m

Max.=30.0m  Add 

Floor load Pressure =-1.50KN/m2. Y range Mini=30.2 Max=33.0  Add. To give Perform Analysis  – Change command: High Light Load case 2: EQ in X-Ve. Click Analysis/Print Perform Analysis Click Change  Add  Check

 Load

Data

 Add  Check

□  After current

□  After current.

High Light Load case 3: EQ in Z+Ve. Click Analysis/Print Perform Analysis Click Change  Add  Check

Load

Data

 Add  Check

□  After current

Data

 Add  Check

□  After current

□  After current.

High Light Load case 4: EQ in Z-Ve. Click Analysis/Print Perform Analysis Click Change  Add  Check

Load

□  After current.

Defining Load Combination Using Auto Load Combination: Commands  LoadingEdit Auto loads Select Indian code. Click New category  Category name: say EQ No. of Rule

: 4 OK.

Rule No. 1 2 3 4

Dead 1.5 1.5 1.2 0.9

Click Update Table

Live 1.5 -1.2 ---

Seismic -1.5 1.2 1.5

Close.

Click Load case details  Add. Click Auto load combination Category: EQ

Click

select

code: Indian.

Generate loads  Check

□ create Repeat Load  Add Close.

Load list: Main menu

 Commands

Loadingload

list



( Select the required load cases

from 7 to 19 on other side by highlighting and clicking > to take the load comb on other side.)

OK.

5.Design :

Click DesignConcreteCurrent code :IS456 Define ParametersFc=30000KN/m2 Add Fymain=415000KN/m2 Add Fysec=415000KN/m2 Add Ratio=3% Add. Click Command Design Beam Add Design Column Add. Take off  AddClose. Highlight Fck =30000 and Select entire structure  Assign Yes

 Assign

.

Highlight Fymain =415000 and Select entire structure  Assign Yes

to selected beam

 Assign

to selected beam

.

Highlight Ratio=3% and Select entire structure  Assign Yes

 Assign

.

Highlight Fysec =415000 and Select entire structure   Assign Yes

to selected beam

 Assign

to selected beam

Highlight Design Beam  SelectBeam parallel to Z

 Assign

to selected beam

X  SelectBeam

parallel to

 Assign Yes.

Highlight Design Column  Select bottom most column in Ground Floor  Assign to selected beam  Assign Yes . Highlight Takeoff  Assign to view Assign  YesClose. 6.Analysis Type  :

Click Analysis/print No print  Add. Click Post printDefine Commands Analysis results AddClose. 7.Perform Analysis  :

From Main Menu  View

 `

output file

 

Analysis

 Run

Analysis



Done.

8. Results : 

Go to post processing mode. Results.

Deflection : Click Deflection icon Results View ValueBeam Results Deflection  Annotate. Bending moment Mz: Click Bending Moment Mz icon  Results View ValueBeam Results Bending Moment

□ Ends □ Mid Span Annotate.

Shear force Fy: Click Shear Force Fy icon Results View ValueBeam Results Shear Force

□ Ends

 Annotate.

 Axial Force Fx: Click Axial Force Fx icon Results View Value Beam Results Axial Force

□ Ends

 Annotate.

Note: Before going to another result remove the tick mark in Beam results. Design Check: Main menu Select

By

specification All failed beams.

Go to modeling mode. Select Column (at bottom portion)

Double

click the columnConcrete design. Check

the bottom most storey column. If some columns in GF inner are failed, change the size of the column for inner portion and again run the analysis, verify the result. Similarly check the beam by double click the particular beam for find the reinforcement. If all are passed ok. Otherwise revise the beam section if failed. Report : Click report set up icon.  Available :

Selected :

Input

1. Sections 2. Supports 3. Loadings

Output

Beam End Forces Reactions Beam Max Axial Forces Beam Max moments Beam Force Details Summary

Click Report setup icon

Click

Ok.

input from available from left side.

Select sections , Loadings and sent to Right side by clicking > Select output. From output select Beam end forces, reactions, Reactions, Shear forces, axial forces, Beam force detail summary. To Take picture: Click Take picture icon

Enter

the title of the sketch. Then Go to report set up. Select

picture Album. If you want to change the sketch title enter the title in caption.  Adjust the picture size by adjusting height & width. Select To export Results in word file: File

 Export

Report

 MS

word file. Click save.

□ Full page.