Stress singularities with pshell elements

Rahul_P1

I just realized, that I have stress singularities in my model which is set up with PSHELL elements. The model consists of I-Bars and there are large differences in stress between the web and the flange plates of the bars. It looks almost as if there is no connection between the shell elements. Please see the attached pictures.

Is there a way how to handle these stress singularities?

Rahul_P1

If you are using Shell elements, it is important to know if you are looking at the stress on the upper or on the lower side of the element. The top and bottom face of the shell can be chosen in the HyperView Contour menu --> layer option. If you used OptiStruct as a solver, Z1 will be the lower side and Z2 the upper face of the shell.
To check whether all shells of the plate are oriented in the same direction, use the HyperMesh --> Mesh --> Check --> Normals function to check and adjust your direction. All Elements within the same plate should be oriented in one direction.

Another reason for the stress difference might be the different shell thicknesses between the flange and the web plates. HyperView does not average stresses over thickness jumps to prevent errors in the result interpretation (it is more conservative to see the maximum stress in the thin plate than seeing the averaged lower stress between both Components). If you however want to have an averaged stress, you need to organize the flange and web elements into one common component.