考虑两种失效竞争的多状态冷贮备系统可靠性模型

针对装备系统中多状态工作部件存在退化失效与突发失效竞争的情况，以冷贮备系统为研究对象，假设系统内3个维修台可分别提供预防性维修与两种不同类型的修复性维修，采用随机检测策略，系统性能水平在一定范围内退化时进行预防性维修，部件完全退化失效时进行退化失效修复性维修，而突发失效时进行突发失效修复性维修；利用PH （Phase-type）分布描述模型中各类随机时间变量，外部冲击的到达则采用PH更新过程描述，建立了考虑退化失效与突发失效的多状态冷贮备系统可靠性模型。最后通过算例验证了模型的适用性，演示了预防性维修阈值以及三类维修速率对系统可靠性的影响。

Reliability analysis of multi-state cold standby system with two competing failures

This research investigates a multi-state cold standby system that exists competition between degradation failure and catastrophic failure. Three maintenance stations in the hypothetical system can provide preventive maintenance and two different types of corrective maintenance. Preventive maintenance is performed when the online unit degrades within certain levels, The degradation type maintenance is performed when the online unit is completely degraded, and the catastrophic failure type maintenance is performed when catastrophic failure occurs. The Phase-type (PH) distribution method is used to describe the distribution of various time variables in the model. The external shocks is described by a PH-renewal process. A multi-state cold storage system reliability model considering degradation failure and catastrophic failure is established. Finally, the applicability of the model is verified by numerical applications, and the influence of the different preventive maintenance thresholds and the maintenance rates of the three types of maintenance on the system reliability measure are demonstrated.