基于紧缩阈值加速退化试验的长寿命产品可靠性评估

Reliability Assessment for Long-Life Products Based on ADT with Tightened Critical Values

对于退化失效型产品,当产品的特性参数超过给定阈值时即发生失效,失效阈值定义越严格则对产品功能要求越高,则产品越容易发生因不满足该功能要求而失效,可见产品的寿命数据与失效阈值的定义密切相关.对于长寿命产品,通过紧缩失效阈值的方法,可以在低应力水平下得到更多的失效数据.论文建立了寿命分布与试验应力和失效阈值的关系模型,并提出了通过紧缩阈值加速退化试验数据对长寿命产品进行可靠性评估的方法,最后通过实例验证了方法的有效性.

For products whose failures are defined in terms of performance characteristics exceeding their critical values,reliability assessment can be based on degradation measurements by using degradation models.Since the time-to-failure depends on the level of critical value,more life data can be obtained by tightening the critical value.This paper presents a method for the estimation of life distribution for long life products by using life data from degradation measurements.The relationship between life and critical value and stress is modeled and used to estimate the life distribution at a usual critical value design stress.The model parameters are estimated by using maximum likelihood and least square method.At last,an example is used to illustrate the validity of the method.