Stress Constraint in Altair OptiStruct Posted May 13, 2019 · Report reply Okay, thanks a lot! One last question I got: I run a topology optimization using a stress constraint of 40,000 MPa. I got the message, that all constraints are satisfied but doing a FE-reanalysis the maximum stress is above 40,000 MPa. How can this be explained? Did I put the density threshhold too high?