Optimization of fatigue maintenance strategies based on prognosis results

Abstract

A general approach to determine the optimal set of maintenance alternatives for fatigue safety is introduced in this paper. The optimal maintenance alternatives are the solutions to maximize the fatigue reliability of aircrafts fleet subject to maintenance budget. A novel equivalent stress transformation model and the first-order-reliability method (FORM) are adopted to determine the failure probability or reliability associated with future fatigue loading. The equivalent stress transformation model is capable to transform future random loading to an equivalent constant loading, and does not require cycle-by-cycle simulation. First-order-reliability-method can resolve the computational complexity. Optimal maintenance solution can be efficiently found considering the future fatigue loading. Numerical examples are performed to demonstrate the application of the proposed approach.