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algo de shell
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From shape to shell: a design tool to materialize freeform shapes using
gridshell structures.
Lionel du PelouxUR Navier, Ecole des Ponts ParisTech, Champs-sur-Marne, FranceT/E/S/S, Paris, FranceDr. Olivier BaverelUR Navier, Ecole des Ponts ParisTech, Champs-sur-Marne, FranceENSAG, Grenoble, FrancePr. Jean-François CaronUR Navier, Ecole des Ponts ParisTech, Champs-sur-Marne, FranceAl. Frederic TayebUR Navier, Ecole des Ponts ParisTech, Champs-sur-Marne, France
• Frei Otto et al., 1974, IL10 Gitterschalen
• Pinned connection between continuous bars
=> No shear rigididy during the erection;
• Bracing with a third direction of bar in order to get a shell behaviour
What is a gridshell?
3
Textile membrane
Grid Shell in GFRP in 2011
Design Process
3D Modeling
Wireframe geometry NURBS patch.
Shape Optimization
𝜎=𝜎𝑐𝑜𝑚𝑝+𝜎 𝑏𝑒𝑛𝑑≅ 𝜎𝑏𝑒𝑛𝑑=𝑀𝐼 /𝑣
=𝐸 .𝑣
𝑅𝑐𝑢𝑟𝑣𝑎𝑡𝑢𝑟𝑒Geometric curvature minimization in three steps. Rmin [blue = 3,00m ; red = ∈10,00m].
Shape Meshing
Shape Meshing
the gridshell surface
Shape Meshing
Shape Meshing
Shape Meshing
Shape Meshing
• Different sets of guide-curves are chosen and the resulting meshes are compared according to this criterion:
Mesh testing
Developed surface
Structural Analysis
Construction
CONCLUSION
This paper has presented the different steps for the design of a gridshell in GFRP built for the Solidays festival in 2011 in Paris.
The steps were:• the optimization of the shape in order to avoid
concentrations of curvature locally. • Automatically mesh a surface using the compass method.• Optimum orientation of the mesh.• Mesh relaxation.• structural analysis of the gridshell.
ACKNOWLEDGEMENTS
The authors would like to thank:• the students of the école des ponts (E. Roux, E. Blache, J.-R.
Nguyen, A. Grandi, G. Frambourt, T. Perarnaun), • their university supervisor (R. Mège) • The association Solidarité Sida, • The consultant T/E/S/S • The constructor Viry • Partners such as: Serge Ferrari, Top Glass & Solutions
Composites, Owens Corning Reinforcement, DSM Resins, ENSG, Esmery Caron, Axmann, Chastagner and ¨Paris Voile.
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