Contrib:KeesWouters/shell/plotcoq3d

Post processing of COQUE-3D calcalation

[under construction]

In this contribution the main (and only) focus is on the postprocessing of the displacements and stresses of shell COQUE-3D elements. The centre nodes of tria7 and quad9 elements used for the discription of the displacements field of COQUE_3D poses some nasty problems in the postprocessing with Salome. To overcome this problem the results are projected on the original quadratic mesh without the centre node.

• preproccesing:
• definition of geometry in Salome
• partitioning of the geometry and groups
• meshing of the geometry
• definition of the groups
• (maybe: python script which makes editing much easier ...)

• static analysis with pressure or force applied on a group or nodes

• postprocessing:
• viewing displacement in Salome
• determination of stresses, see also tables

• interface ASTK

Definition of the geometry

This time the geometry has been drawn in FreeCAD. It is good enough at this moment (april 2013) to draw some more or less complex geometry, although, in this case, it wouldnot have been much more effort to construct it in Salome. Anyway, I import the brep geometry from FreeCAD into Salome and mesh it there. It is a planar shell with four holes. Main dimensions are Length x Width = 100 x 50. The holes with diameter of 6 are centred along the short centre line of have offset along the long centre line, see picture below. The thickness is defined in the Code Aster *.comm file and can be changed any time: thickness th = 0.02.
As usual no explicit dimensions are used here. But units have to be consistent and will be if you imagine:

• length and displacments [m]
• forces [N] and moments [Nm] and
• Youngs' modulus and stresses [Pa]

Boundary conditions and loads:

• all dof fixed on short side Lxm:
  • (DX=0.0, DY=0.0, DZ=0.0, DRX=0.0, DRY=0.0, DRZ=0.0)
    
• 2 'loads': prescribed in-plane x displacement or out-out-of-plane vertical displacement fixed on short side Lxp:
  • (DZ=Zdisp) or
    
  • (DX=Xdisp)
    

Material:
Material steel

• E = 210e9 Pa
• Nu = 0.28
• rho = 7850 kg/m3 (not needed)

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Results of Ux displacement

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Results of Uz displacement

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