Learning Forum

[Martin Stejskal]

Hello,

I am unable to perform a topography optimization on my FE model, which consists of both shell and solid bodies (total over 1000 bodies, can't provide further details). The shell bodies are joined via topology share in SpaceClaim, whereas the connection to solid bodies is made using glued contact. The static structural FEA runs perfectly fine, there are no major errors. However, when I try to do the topography optimization on some shell bodies, the solver doesn't even start.

The error I am currently encountering is most likely related to the pivot checking. It says that there are some mesh nodes (on the optimization region) that have unwanted free DOF and that additional boundary conditions might need to be applied. Can I turn the pivot checking off for the optimization, e.g. via command? I've also tried to incorporate springs for stabilization, which didn't help at all. Major changes to the definiton of load cases are also unwanted, because it runs perfectly fine for static analysis.

Another error I've encountered was related to the excessive element distortion, which I've solved by mesh refinement.

Also, I've found that the optimization region needs to be continuous in terms of geometry, meaning the bodies must share atleast one edge. Separating them into different optimization regions doesn't help.

Any suggestions will be greatly appreciated. Thanks in advance!

[Ashish Khemka]

Hi Martin,

I am not sure how the model is but what if you define a bonded contact with larger pinball radius of MPC constraint so that there are no free nodes and you can try running the final design with original constraint (instead of MPC)?

Regards,

Ashish Khemka