基于性能指标融合的随机退化系统竞争失效分析

Competitive failure analysis of a stochastic degradation system based on performance characteristics fusion

针对多元随机退化系统可靠性建模与计算的难点,考虑性能指标融合,构建了2个基于二元Wiener过程的随机退化模型;考虑退化失效和持续时间失效2类竞争失效形式,推导了性能指标不进行融合以及性能指标按照退化量的线性组合进行融合情形下,持续时间失效阈值为常数和随机变量时的系统可靠度解析表达式;提出了基于蒙特卡洛模拟的数值模拟算法,验证了解析结果的正确性,并可用于模拟性能指标按照任意形式进行融合情形下二元以及多元随机退化系统的可靠度。最后,通过数值算例验证了所提出模型与计算方法的有效性。

With the aim of solving the reliability modeling and calculation of multivariate stochastic degradation systems,two stochastic degradation models based on the bivariate Wiener process are proposed,in which two performance characteristics are composited to one variable.Two different failure modes including the defect-based failure and the duration-based failure are considered.The explicit expressions of the system reliability are derived in the cases that the performance characteristics are not composited or the performance characteristics are composited according to the linear combination of the degradation measurements.An algorithm based on the Monte Carlo simulation is proposed to simulate the degradation process,in which the performance characteristics are composited in arbitrary forms,and the correctness of the analytical results is also verified.Finally,some numerical examples are presented to illustrate the present reliability assessment method。