A general decoupling approach for time- and space-variant system reliability-based design optimization

Performance of complicated products usually changes over time and space at the same time and meanwhile multiple failure modes exist, which enables designers to encounter time- and space-variant system reliability (TS-VSR) measures during the product design and development stages. This paper proposes a general decoupling approach to solving the time- and space-variant system reliability-based design optimization (TS-VSRBDO) problem, which aims at providing an effective tool for reliability-based design of complicated products. For solving the TS-VSR constraints of the TS-VSRBDO problem, an enhanced simulation-based method is firstly proposed, and then the mapping between design variables and TS-VSR constraints is established by combining exponential function approximation with moving least squares method in each cycle. Besides, based on the equivalent deterministic optimization, an iteration mechanism is constructed to ensure the convergence of the whole optimization procedure. The TS-VSRBDO problem is finally decoupled into a series of TS-VSR analysis and deterministic optimization. Several examples are investigated to demonstrate the effectiveness of the proposed method. (C) 2019 Elsevier B.V. All rights reserved.