非恒定温度场合弹上性能退化型部件贮存可靠性评估

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。

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

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 describe the impact of varying temperatures on the product storage reliability,thus deriving the unconditional probability density 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.