On stress-constrained fail-safe structural optimization considering partial damage

This brief note presents some observations about the modelling of stress constraints in fail-safe structural optimization considering local degradation member properties. An analytical study a three-bar example demonstrates impact constraint choices on optimal design. One notable finding is that one arbitrary may cause worse objective function than complete removal member. The observation similar to singular optimum issue topology with constraints, but applies also sizing problems. deserves special attention and should be considered when constraints.