非恒定温度场合弹上性能退化型部件贮存可靠性评估

Storage Reliability Assessment for Missile Component with Degradation Failure Mode in a Temperature Varying Environment

导弹在贮存期内要反复经历运输、存放、检测、维修和战备值班等过程,其环境温度并不恒定,而是在一定范围内发生动态变化。对性能参数有变化趋势的弹上部件而言,有必要考虑环境温度变化对其可靠性的影响,因此提出一种非恒定温度剖面下的贮存可靠性评估方法。首先,分析产品实际性能退化的特点,选择带有非线性漂移项的Wiener过程描述产品的退化性能,推导出试验环境下产品的寿命分布。然后,采用Gamma分布拟合贮存期间的弹内温度分布。进而利用比例风险模型描述温度变化对产品可靠性的影响,推导弹上性能退化型部件在非恒定温度剖面下的无条件寿命分布,并给出模型参数的极大似然估计。算例表明本方法实际可行。

A missile will experience transportation, storage, detection, maintenance and readiness repeatedly in its storage period, during which the environmental temperature is not constant, but dynamically changing within a certain range. For some missile components with performance change, it is necessary to consider the influence of varying environment on its storage reliability. Therefore, this paper presents a storage reliability assessment method for a storage environment where temperature is varying. Firstly, by analyzing the characteristics of missile components, the degradation process is modeled as a Wiener process with nonlinear drift. Based on the model, the life distribution under test environment is proposed. Then, Gamma distribution is chosen to fit the temperature distribution. On this basis, a proportional hazards model is used to de- scribe the impact of varying temperatures on the product storage reliability, thus deriving the unconditional probability densi- ty function of its storage life. Finally, model parameters are assessed using the maximum likelihood method. An example is given to illustrate the effectiveness of the method.