随机δ冲击下多相关退化的竞争失效可靠性评估

Reliability Assessment of Competitive Failure for Multi-correlated Degradation under δ Random Shock

针对退化过程为线性退化时,系统受外界δ冲击,出现自然退化和外界冲击导致的失效现象,提出了系统的可靠性评估问题;从两方面考虑相关性,一方面冲击造成的损伤使得内部退化增加,而内部退化量的大小决定了冲击所带来的失效阈值的改变,两者相互影响;另一方面,退化之间具有相关性;将系统退化分为8部分不相容之和进行研究,利用Copula相关理论刻画相关性,得到了系统的可靠度函数;最后,通过案例分析,表明模型的有效性和可操作性。

According to that when degradation process is linear degradation,the system is attacked by externalδshock,by considering that system failure results from external impact and natural degradation and that the natural degradation of the two is correlated,the reliability assessment of the system is proposed.The correlation is considered in two perspectives,on the one hand,the damage caused by the shock makes internal degradation increase while the magnitude of internal degradation determines the change of failure threshold value from the shock,the two affect each other.On the other hand,there is correlation between degradations.The system degradation is divided into eight parts and their incompatibility is studied,the correlation is described by Copula related theories,and the reliability function of the system is obtained.Finally,through case analysis,the validity and operability of the model are shown.