威布尔产品加速寿命试验的可靠性分析

利用似然理论对加速寿命试验的多个样本失效数据进行综合分析。在定数截尾场合下，建立威布尔寿命型产品的步进应力加速寿命试验模型，利用Newton Raphson方法求解似然方程，得到寿命参数的极大似然估计。针对迭代公式初始值敏感问题，结合部件寿命信息给出一种精度更高的初始值确定方法，并利用Bootstrap方法构造加速寿命试验参数的置信区间。最后，以固体钽电解电容器为例，利用随机模拟方法验证提出理论的正确性和有效性。

Reliability analysis for accelerated life test based on Weibull distribution

In order to make inference about problems of accelerated life test plan under different experiments, a step stress accelerated life test model of units based on Weibull lifetimes is given. For this model, the maximum likelihood estimates of the parameters in normal stress level are derived under Type II censoring. The Newton Raphson method is using to solve the likelihood equations, and a simplified estimator is presented, which is used as an initial estimate in the iterative process. Bootstrap confidence intervals for the parameters are provided. Some numerical results for solid tantalum electrolytic capacitor are discussed to illustrate validity of this model.