累积冲击作用下可恢复退化过程的可靠度评估

以对激光器进行可靠度评估为背景,在考虑累积冲击与自然退化同时引起产品失效的基础上,重点研究了冲击时间间隔对产品退化量的影响,建立了累积冲击作用下可恢复的退化模型。根据自然退化过程及泊松冲击更新理论,研究了累积冲击模型和累积冲击下的退化失效模型。引入条件分布,分析冲击时间间隔对退化量的影响,得出了累积泊松冲击下的可恢复退化失效模型。结合性能退化分析,给出了可恢复的退化过程的失效分布函数和可靠度函数。进行了激光器退化试验,结果表明:当激光器工作2 000h时,利用累积冲击下可恢复的退化失效模型评估得到的可靠度为0.53,与仿真结果相符,为利用累积冲击下退化失效模型评估得到的可靠度的2.79倍。结果验证了本文提出的利用可恢复的退化模型进行可靠度评估的合理性。

Reliability evaluation of recoverable degradation process under cumulative shock

For evaluating the reliability of lasers,this paper focuses on the effects of shock time intervals on the product degradation based on the product failure from both nature degradation process and cumulative shock process.Then it establishes a recoverable degradation model in cumulative shock process.Based on natural degradation process and Poisson shock renewal theory,a cumulative shock model and a degradation failure model under cumulative shock are presented.According to the model above mentioned,the effect of shock time interval on degradation is analyzed by introducing the condition distribution and the recoverable degradation failure model under the cumulative Poisson Shock is obtained.After analyzing the performance degradation,the failture distribution function and the reliability function of the recoverable degradation process are given.A laser performance degradation experiment is performed and the results indicate that when the lasers run for 2 000 h,the reliability is 0.53 by the recoverable degradation failure model under the cumulative shock,which is more consistent with simulation result,and is 2.79 times as much as the result by the degradation failure model under cumulative shock.It verifies the rationality of evaluation by the proposed recoverable degradation failure model.