Reliability-based design optimization applied to structures submitted to random fatigue loads

Abstract

The reliability-based design optimization (RBDO) aims to find the most balanced design through a compromise between cost and safety when uncertainties affecting the system are considered. This strategy involves the evaluation of probabilistic constraints performed by the reliability analysis, leading to an expensive computational effort in order to solve the problem. For this reason, it is not trivial to take into account the high cycle fatigue in a RBDO method. This work deals with this problem, considering stationary Gaussian random load processes and the Sines multiaxial fatigue criterion. The efficiency is achieved through spectral tools related to the fatigue analysis. Therefore, the probabilistic constraints of the fatigue life in the RBDO problem are transformed in the frequency domain. The limit state function of the reliability analysis is defined by the mechanical component endurance submitted to random loads. The numerical application demonstrates the interest and the effectiveness of our proposal.