中文摘要：

以运行工况时变的单机设备为研究对象,假设不同工况下失效时间分布满足加速寿命模型（ALM）,建立工况转换时的设备失效率函数演化模型;同时将设备在不同工况下的役龄转换为在基准工况下的运行等效役龄,引入故障率递增和役龄残余因子,建立设备运行工况时变下的非完美维护模型.考虑未来工况不可预知情况下,以当前预防维护周期的可用度为目标函数和一个给定的可靠度阈值作为限制条件,随着实际运行工况的不断更新,动态地决策出每一个预防维护周期.通过案例分析表明,本文提出的预防维护策略可以有效地动态决策出单设备运行工况时变下的预防维护时间序列.

英文摘要：

This paper dealt with a single machine system operating at time-varying environmental state.Assuming that the failure time distribution of the system can be represented by the accelerated life model（ALM）at different environmental states,the evolution model of the hazard rate was built when environmental state changes.The time interval operated at different environmental states was converted to the equivalent working time at the baseline state,the imperfect maintenance model was proposed at the dynamic environmental state with the recursion decline factor and failure rate ascending factor.Considering the fact that the future environmental state was unknown,and taking the availability of current PM interval as an objective and a given reliability threshold as a constraint,the optimal PM intervals were calculated dynamically along with variable environmental state.The results of a numerical example indicate that the PM strategy is valid for a single machine at time-varying environmental state at a finite interval.