某弹用电子部件贮存寿命评估

Storage Life Assessment of Electronic Component in a Missile

目的研究使用定时截尾步进应力加速寿命试验方法评估某弹用电子部件在一定可靠度下的贮存寿命。方法首先将其在应力S_i(i>1)下的作用时间全部转化为在应力S1下的等效作用时间,然后建立威布尔分布加速寿命模型,采用Newton-Raphson方法求解似然方程,得到模型未知参数的极大似然估计结果,最后外推得到正常温度下的贮存寿命。结果在25℃下可靠度为0.9999时,使用定时截尾步进应力加速寿命试验方法评估电子部件的寿命约为11.89年,使用恒定应力加速寿命试验评估寿命为13.32年,两种试验方法的评估结果相差不大。结论步进应力加速寿命试验时间短、样本量少、成本低,相对于恒定应力加速寿命试验方法,具有一定的优越性。

The paper aims to estimate the storage life of electronic components in a missile under a certain degree of reliability based on censoring data from step-up-stress accelerated life test. First, the testing time under the stress of S_i（i1） was converted to the equivalent time under the stress S1. Then, a Weibull step-up-stress accelerated life test model was established and the Newton-Raphson method was applied to solve the likelihood equation. At last, the storage life at normal temperature was estimated according to the MLE result of unknown parameters in the model. When the reliability was 0.9999 at 25 degrees Celsius, the storage life of electronic components based on censoring data from step-up-stress accelerated test was about 11.89 years, and the life based on constant-stress accelerated test was about 13.32 years. The evaluation results of the two test methods were not quite different. Step-up-stress accelerated life test time is short, the sample is small and the cost is low. It has certain superiority compared with constant-stress accelerated test.