基于伪寿命的加速退化机理一致性边界检验

Pseudo-life-based test method of mechanism consistency boundary for accelerated degradation testing

根据寿命型随机变量的加速机理一致性条件,提出一种基于伪寿命的加速退化机理一致性边界检验方法,通过由低到高逐一对各个加速应力水平下的退化机理一致性进行检验,来确定加速退化机理一致性的边界应力水平.针对工程常用的两类寿命型分布———对数正态分布和Weibull分布,分别以对数标准差和形状参数为退化机理表征量,在产品伪寿命估计的基础上建立了退化机理表征量齐性检验的F统计量,导出了退化机理一致性检验拒绝域的解析式,给出了退化机理一致性边界检验的具体步骤.该方法能够充分利用多个应力水平下表征产品退化机理一致的横向信息,有效提高了检验的精度.以某镀膜平板玻璃热退化机理一致性边界温度的确定为例,分析说明了该方法的合理性与有效性.

A pseudo-life-based test method of mechanism consistency boundary for accelerated degrada- tion testing was proposed, according to mechanism consistency condition for lifetime random variables. Based on the pseudo life estimates, an F statistie was established to test the homogeneity of degradation mechanism characteristic parameters, where the characteristic parameter is logarithm standard deviation for log-normal dis- tribution and shape parameter for Weibull distribution. And the exact rejection region was given. Using the F statistic, mechanism consistency test was done level by level from lower to higher, until the consistency condi- tion was unsatisfied or the pseudo life estimates at all levels had been analyzed. Then, the stress level of mechanism consistency boundary was determined. This method can make good use of the transverse informa- tion from the degradation mechanism consistency between different accelerated stress levels, and effectively in- erease test precision. It has been used to determine the thermal degradation meehanism consistency boundary temperature for a coating fiat glass, and the results show the rationality and validity of the presented method.