Ensuring support of non-design regions in topology optimization

Sezek_O
Sezek_O Altair Community Member

Hello,

I want to run a topology optimization (TO) which is setted up in SIMLab 2024. For TO i use following seetings:

Design Space constraint:

  • minimum thickness 6mm
  • Overhanging Constraint 45deg
  • angle tolerance 90deg
  • distance tolerance 1mm

Response constraint:

  • massFraction —> Upper Limit 0.6
  • Response —> minimize Static comliance weighted across all subcases

Here the problem now: When I run the simulation the result is not printable, because the non-design-space will have overhangs, because the overhangig constraint is only connected to the design space.

I tried following approach which I did find in an Altair Whitepaper:

the non-design space is included in the design-space and an
additional volume fraction constraint is added for the region which is intended as non-design
space. This volume fraction is set to 1.0 which ensures that the region is filled with material
(making it a de-facto non-design region)

I tried now following boundary conditions with the inlcuded non-design-space:

Design Space constraint:

  • minimum thickness 6mm
  • Overhanging Constraint 45deg
  • angle tolerance 90deg
  • distance tolerance 1mm

Response constraint:

  • massFraction —> Upper Limit 0.3(Only on the design-space body)
  • VolumeFraction —> Lower Limit 1 (only on the non-design-space body)
  • Response —> minimize Static comliance weighted across all subcases

Still it is not working. Do you have maybe some more experience?

Answers