2D geometry function meshing

[Jee-Bee]

I have a some basic questions about the 2D geometry function in the fem module...
First how does the function for a 2D mesh work? As far a tried now i didn't get a result... Not
Is it possible to create a 2D mesh from a 3D shape?

as example see file.

[fandaL]

When you mesh by GMSH you can select “(Mesh) element dimension 2D” – it will create a hollow shell mesh from the solid geometry – I guess it is not what you need.
Usually for 2D mesh you need 2D geometry -> you can split the solid to faces by Draft/Downgrade, select faces from one side and make one shell by Draft/Upgrade, which you can mesh by GMSH. Or create mid-surface somehow else.
If you use faces from one side of the solid you can use offset in CalculiX, e.g. to offset by half of the thickness in direction of element normals:

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*SHELL SECTION,MATERIAL=EL,ELSET=Eall,OFFSET=-0.5

Then check orientation by displaying expanded elements in frd (you need to have

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*NODE FILE, OUTPUT=3d

as example see file.

For rough 2D model I would omit small radii from your geometry

[Jee-Bee]

Thanks

[bernd]

btw, there is a 2D FEM example in StartWB.