基于竞争失效的单部件系统可靠性建模与维修

摘要

针对同时受自然退化和随机冲击影响的单部件系统可靠性评估问题,首先,建立了退化型与突发型竞争失效过程的可靠性模型,该模型考虑了冲击对退化的影响,即冲击会增加系统的退化量;其次,提出了基于状态的维修策略,构建了一个成本率函数;最后,以一个由4个零件串联而成的单部件系统为研究对象,确定了该系统的可靠度函数和最优的预防更换阈值.该结果不仅验证了可靠性模型的合理性和有效性,而且体现了基于状态的维修策略的可行性与经济性.%Aiming to resolve the problem of reliability assessment of a single-unit system which is affected by natural degradation and random shocks,a reliability model based on two competing failure processes is developed.The model takes into account the impact of shocks to degradation,which is the increase of degradation resulted from random shocks.Then a condition-based maintenance strategy is proposed and a cost rate function is constructed.Finally a single-unit system consisting of four components in series is applied to estimate the reliability and the condition-based maintenance strategy is used to analyze it.The system's reliability function and optimal prevention threshold are determined.The results not only validate the rationality and effectiveness of the model,but also reflect the feasibility and economy of the condition-based maintenance strategy.