Multidisciplinary robust design optimization based on time-varying sensitivity analysis

The performance of complex mechanical systems often degrades over time primarily due to time-varying uncertainties. Improving the design of such systems entails addressing time-varying uncertainties through Multidisciplinary design optimization (MDO). In this study, a multidisciplinary robust design optimization method that is based on time-varying sensitivity analysis is proposed. First, the indices for the time-varying reliability sensitivity of limit state functions are calculated by combining sensitivity analysis and an empirical correction formula. The propagation effects of these time-varying uncertainties are qualified by combining the simplified implicit uncertainty propagation and sequential quadratic programming methods. Finally, the robust design method is integrated with MDO to reduce the effects of time-varying uncertainties. The feasibility and effectiveness of the proposed method are illustrated with a mathematical problem and an engineering example.