可修产品的步进应力加速寿命试验统计分析

为了通过可修产品在步进应力加速寿命试验中产生的故障数据,评估可修产品的寿命和可靠性指标,基于产品在两个不同应力水平下的累积故障强度函数相等的原则,提出了可修系统步进应力加速寿命试验的时间折合公式.通过反复迭代,可修系统在步进应力加速寿命试验过程中产生的故障数据可以折合到相同试验条件下.在产品进行最小修复的假设下,采用引入位置参数的三参数Weibull过程结合Peck加速模型对试验过程进行拟合.通过使用该模型对折合后的数据进行处理,外推得到了可修产品在正常应力条件下的寿命和可靠性指标.使用剩余分布抽样方法进行计算机仿真,验证本文方法的正确性.结果证明该模型和方法不仅在参数估计方面比传统的模型有更高的精度,而且还可以应用到可靠性增长试验的数据评估中.

Statistical analysis of step-stress accelerated life testing for repairable product

During step-stress accelerated life testing(SSALT),in order to evaluate life and reliability characteristics of repairable product,the equation principle of accumulative hazard functions under two different stress levels was put forward.On the base of the rule,time conversion function was presented.After failure data were converted to the same stress condition by the way of iterative algorithm,the three-parameter Weibull process that includes the position element with Peck accelerated model was utilized to fit them.This model assumed "minimal repairing" such that any repair had no impact on the failure rate.By the use of maximum likelihood estimation,life and reliability of repairable system under normal stress conditions could be extrapolated.Residual distribution sampling was used to generate the two simulation examples.Results show that the model and method proposed is not only good at parameter evaluation with high accuracy in comparison with the traditional,but also can be applied to reliability growth testing.