ForTen 4000 (c) Technology preview
by Gerry D'Anza
Tensile Structures Form Finding Techniques
The Concept of Form Finding in Architecture is a old topic:
Used in conjunction with several construction technologies , today we consider The form finding problem a solved issue
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con cept d esig n & ana lyt ical models
Many systems available for who wants totools investigate the large only topictoofbig Tensile Structure desig I remember justare fifteen yearstoday ago that form-finding where available engineering firms, mainly in house developed, and it was quite impossible for a young architect or engineer get a basic knowledge of this technology. Today's scenario has changed and its quite easy to get a software tool able to find a relaxed shape that satisfies the main rule for tensile structures : negative Gaussian geometry at each point of the surface to guarantee equilibrium under any applied load.
The main theory on which these tools rely on are : FDM - Force Density Method DR - Dynamic Relaxation FEM Linear FEA methods URS -- Non Update reference strategy
These systems have proven to be reliable by a huge number of structures realized in the past years
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Form-finding modules
Linear FDM Module Linear FDM Module
Non Linear FDM Module Non Linear FDM Module
Pres-stressed membrane Pres Pres-stressed membrane or cable net or cable net
URS Module URS Module
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Integration with
Linear FDM Module Linear FDM Module
Technology preview FEA analysi s
Non Linear FDM Module Non Linear FDM Module
Pres-stressed membrane Pres Pres-stressed membrane or cable net or cable net Supporting Structures Supporting Structures Steel,concrete,wood Steel,concrete,wood
Final shape with membrane,cables,steel Final shape with membrane,cables,steel In equilibrium with desired prestress In equilibrium with desired prestress
FEM Analysis FEM Analysis
URS Module URS Module
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Available Modules and WIP modules ( work in progress ) Not available yet to end user
Linear FDM Module Linear FDM Module
Non Linear FDM Module Non Linear FDM Module
Pres-stressed membrane Pres Pres-stressed membrane or cable net or cable net Supporting Structures Supporting Structures Steel,concrete,wood Steel,concrete,wood
Final shape with membrane,cables,steel Final shape with membrane,cables,steel In equilibrium with desired prestress In equilibrium with desired prestress
FEM Analysis FEM Analysis
Structural Analysis Structural Analysis for wi nd, snow etc for win d,snow etc
URS Module URS Module
Patterning Patterning
Connection Connection Connection Details Connection Details Details
Design codes Design codes EC3 EC3
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FDM Form-Finder introduction
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Force Density module
Force Density or FDM is a the most simple method and comes in two flavours : Linear and Non Linear
General net equations of equilibrium k
X = 0;
∑[ k
Y = 0;
∑[ k
F ij L
k ij k ij
F
x j− x i
Px i ]= 0 ;
y j − yi
Py i ]= 0 ;
z j − zi
Pz i ]= 0 ;
Lkij k
Z= 0;
∑[ k
F ij L
k ij
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(c)
Force Density module
With the non-linear FDM method we are able to set different properties :
k ij
C =
F ijk
Force Density Linearisation
k
Lij
With the non-linear method we can specify : k
F ij = Force of Element k
Lij = Length of Element Lu = Unstrained Length of Element k ij
The method is well suited to find cable systems where specific requirements are needed
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Force Density module
Example of FDM Non-Linear model
GMG Motors Baku Group DT Design & Engineering
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Force Density module
Example of FDM Non-Linear model
GMG Motors Baku Group DT Design & Engineering
Forten 4000
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Force Density module
Example of FDM Non-Linear model
GMG Motors Baku Group DT Design & Engineering
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Force Density module
Example of FDM Non-Linear model
GMG Motors Baku Group DT Design & Engineering
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Force Density module
URS Form-Finder introduction
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URS module
URS – Update reference strategy
The Updated Reference Strategy (URS) for form finding of membrane structures has been developed by Prof. Kai-Uwe Bletzinger of the TU Münch en (Germany) For a given topology of a membrane structure and given stress state in the structural elements (pre-tension in the membrane and cables), the corresponding equilibrium shape has to be determined. The URS represents a generalization of the well-known force density method. Due to its continuum-mechanical basis, the method is applicable to both cable and membrane elements without any restrictions: E.g. an arbitrary stress state can be specified for the membrane, which can be isotropic in order to generate real minimal surfaces or orthogonally anisotropic, which is very helpf ul for form finding of textile str uctur with warp and weft direction. It is even possible to consistently include pressure forces, which are acting always normal to the surface at every state of the procedure,in the form finding process of pneumatic structures such as air-in cushions.
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URS module
URS Module Key Features :
Surface Quad-Mesh & Tri-Mesh elements taken in account Warp & Weft direction set by user via U-V mapping control Cables controlled by pretension or Force Density value Truss elements controlled by stiffness Constant ,Linear & quadratic stress law specified over the surface Internal pressure for pneumatics Fast direct sparse matrix solver Visualization of final stress over the surface & reaction forces at fixed nodes
Forte 4000
(c)
URS module
URS Module Key Features :
Surface Quad-Mesh & Tri-Mesh elements taken in account Warp & Weft direction set by user via U-V mapping control Cables controlled by pretension or Force Density value Truss elements controlled by stiffness Constant ,Linear & quadratic stress law specified over the surface Internal pressure for pneumatics Fast direct sparse matrix solver Visualization of final stress over the surface & reaction forces at fixed nodes
Forten 4000
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URS module
Hypar
U-V Coordinates Blue=Warp Red= Weft
Fibre orientation Is simply controlled by u-v mapping
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URS module
Hypar
U-V Coordinates Blue=Warp Red= Weft
Stress distribution based on fibre direction
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URS module
Conical shape = setting up u-v coordinates for warp-weft fiber direction
U-V mapping = warp-weft fibre Shape after 1 step
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URS module
Norwegian expo Pavilion, Shanghai 2010 Architecture: HHA Norway Engineering: Sweco, Khing, studioLD Form finding detailing: studioLD
Modeled with URS from Rhino-Membra
Size: 35 x 56m Height: 13m Size individual 4 point sail: 12 x12m Membrane surface area: 2600m²
Membrane Material: Edge-belt: Structure:
Gore Tenara Architectural fabric 4T20 Polyester Gluelam timber
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Form-finding challenge
(c)
URS Module
Modeled with URS from Rhino-Membran
4 poin t sails mus t wor k as pa rt of the e ntir e roof as well as indivi dually for late r use: -The design idea of the pavilion is to use individual umbrellas made of individual 4-Point sails and timber trees set up as a group of for the expo and individually after the expo.
-Therefore the form has to work both in the continuous surface as well as the individual sails, here the eyelet pre-stress is chosen lower than main membrane and all edge cables have the same geometry with different pre-stress.
The form must offer a mesh sui table for export into Finite- Eleme nt soft ware : -Mesh must be harmonious to get good convergence and realistic stress plots -Shallow angles in corners must be avoided otherwise you get unrealistically high stresses, therefore mesh is made more dense in the eyelet corners before export.
Forten 4000
Form-finding challenge
(c)
URS Module
Modeled with URS from Rhino-Membran
4 poin t sails mus t wor k as pa rt of the e ntir e roof as well as indivi dually for late r use: -The design idea of the pavilion is to use individual umbrellas made of individual 4-Point sails and timber trees set up as a group of for the expo and individually after the expo.
-Therefore the form has to work both in the continuous surface as well as the individual sails, here the eyelet pre-stress is chosen lower than main membrane and all edge cables have the same geometry with different pre-stress.
The form must offer a mesh sui table for export into Finite- Eleme nt soft ware : -Mesh must be harmonious to get good convergence and realistic stress plots -Shallow angles in corners must be avoided otherwise you get unrealistically high stresses, therefore mesh is made more dense in the eyelet corners before export.
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Plan design of sambil barquisimeto
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Plan design of sambil barquisimeto
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Plan design of sambil barquisimeto
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Port of Bari : Cover for waiting area. Design by Baku Group Dt Architects
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Port of Bari : Cover for waiting are. Design by Baku Group Dt Architects
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Port of Bari : Cover for waiting are. Design by Baku Group Dt Architects
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Bridigine college Shade to order
Kakkuri finland Membrane & steel g.danza,l.dibenedetto
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Modeling, Analysis & Patterning overview
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Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
(c)
Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
(c)
Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
(c)
Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
(c)
Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
(c)
Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
Forten 4000
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Technology preview
Modeling, Analysis & Patterning overview
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Patterning Module & special features
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Patterning a flower
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Patterning a flower
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Patterning a boat cover
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Patterning Module
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Patterning a boat cover
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Patterning Module
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IsCube steel detailing
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Thank You Gerry D'Anza
