随机冲击下退化率变化的系统竞争失效可靠性建模

Systematic Reliability Modeling of Competitive Failure Under Changing Degradation Rate Based on Random Shock

考虑非平稳Poisson冲击下,退化率变化的退化失效和突发失效两类失效过程之间相互竞争的可靠性建模问题。以线性过程为基础描述退化过程,幅值和强度逐渐增大的非平稳随机冲击过程描述突发失效过程,研究冲击超过临界阈值导致系统退化过程退化率增大的情况下系统的可靠度问题。通过建立系统退化过程和突发失效过程的分布函数,导出了系统竞争失效的可靠度函数。结合Sandia微引擎系统进行实例分析,并对冲击强度与突发失效的临界阈值做了灵敏度分析,结果验证了模型的正确性,表明该模型可以有效提高可靠性评估的精度。

Considering the reliability problem between two competitive failure processes of degradation failure and traumatic failure under unstationary Poisson random shock. The traumatic failure process described by unstationary random process with increasing amplitude and strength which is based on the linear degradation process,the reliability of the system researched when the degradation rate of the systematic degradation process increases because of shocks exceeding critical threshold. The competitive failure reliability model of the system derived though distribution function of degradation progress and traumatic failure progress. The sensitivity of the critical threshold and shock strength being analyzed based on the system of Sandia micro-engine,the results show the correctness of model which can validly improve the accuracy of reliability.