Fatigue and static failure considerations using a topology optimization method

We developed a new layout optimization method that incorporates dynamic fatigue and static failure criteria under constant and proportional mechanical loads. Although fatigue failure is one of the most important design considerations to ensure the safety of a mechanical structure, it has rarely been considered in terms of topology optimization due to several major theoretical and numerical difficulties. In addition to the numerical and theoretical issues associated with static failure criteria, we found that the local mode issue and the non-differentiability of the fatigue failure criteria needed to be addressed prior to performing fatigue constraint topology optimization. By resolving the inherent and newly-found issues associated with fatigue criteria, we were able to perform successful topology optimization with dynamic fatigue criteria under constant and proportional mechanical loads.