I'm trying to perform a topology optimisation where the constraint is a certain value of stress and the objective is minimise the volume. The optimization just ends up setting the density of all elements to zero (which is a very good way to eliminate stress by the way). Is there any way I can get around this problem so that a sensible value is given for the element densities?
Please read the OptiStrruct FAQs where it is said that 'It is not recommended to use the global stress constraint along with a mass/volume constraint. The constrained mass/volume may not allow the stress constraint to be satisfied.'
Try the following:
1) Run only analysis and check if you see any stress/displacement at all. If there is no load going to the structure you will see a similar error.
If the structure is taking load and still you get the error:
2) Try with a different constraint like displacement instead of stress and check whether you have an expected result.
Altair Employee
Hi Hypernoob,
Please read the OptiStrruct FAQs where it is said that 'It is not recommended to use the global stress constraint along with a mass/volume constraint. The constrained mass/volume may not allow the stress constraint to be satisfied.'
Try the following:
1) Run only analysis and check if you see any stress/displacement at all. If there is no load going to the structure you will see a similar error.
If the structure is taking load and still you get the error:
2) Try with a different constraint like displacement instead of stress and check whether you have an expected result.