战时基于竞争失效的装备系统可靠性建模与预防性维修策略

Reliability modeling and preventive maintenance strategy for equipment system based on competing failure processes in war

针对战时装备受到使用退化与随机冲击的共同作用发生竞争失效的问题,提出了基于状态的预防性维修策略。首先建立了单系统的可靠性评估模型,该模型考虑了装备系统冲击阈值随总退化量的累计而减少的实际,并提出了阈值连续变化条件下的装备系统可靠性建模方法;其次针对装备的隐蔽功能故障,提出了定期检测下基于状态的预防性维修策略,构建了装备系统的成本率函数;最后结合实例分析,确定了装备系统的可靠度函数和最优预防性更换阈值,并对比分析了不同冲击阈值参数对可靠度的影响。研究结果表明:该模型可以有效解决竞争失效条件下装备系统的可靠性评估问题,同时也可为装备系统预防性维修策略提供模型参考。

Aiming to solve the problem of competing failure process of wartime equipment which is affected by natural degradation and random shocks, a condition-based preventive maintenance strategy is proposed. First, a reliability assessment model of a single-unit system is established, which considers the decrease of shock-threshold resulted from the accumulation of the system degradation. A reliability modeling method for equipment system under continuous shift-threshold is proposed. Then a condition-based preventive maintenance strategy is proposed for the equipment hidden function failure under the condition of the periodic detection and a cost rate function is constructed. Finally, a real example is used to analyze. The system’s reliability function and the optimal preventive replacement threshold are determined. The influence of different shock-threshold parameters on reliability is compared and analyzed. The results show that the proposed method can be adopted to achieve the reliability assessment for the equipment system under the condition of the competing failure, and provides an alternative approach to the optimal preventive maintenance threshold.