考虑外场差异的步进加速寿命数据可靠性评估方法

Method on Reliability Assessment of Step-stress Accelerated Data with Field Difference

针对寿命服从双参数Weibull分布的机电产品,进行单应力、定时转换的步进加速寿命试验,研究加速寿命试验数据下的可靠性评估问题。考虑到外场多应力环境与实验室单一应力环境之间的差异性,构建基于修正系数的分布参数计算模型;开展步进加速寿命试验过程的统计分析,建立各应力下的累计分布函数关系;构建极大似然函数,运用数值迭代法,求解未知参数估计;结合某型机电产品进行仿真方案设计,采用Monte Carlo仿真方法产生样本数据,通过对比分析说明所提出的模型评估精度更高。

Aim at mechanical and electrical product that its lifetime obeys to Weibull distribution, a single-stress and time-switching Step-Stress Accelerated Life Test （SSALT） is done to study reliability assessment problem of Accelerated Life Test （ALT） data. Given to the othemess between field multi-stress environment and laboratory single-stress environment, distribution parameter model with the correction factors is constructed. Statistical analysis for SSALT process is done. Its cumulative distribution function relationship under each stress is built. Maximum likelihood function of ALT data is built. Data iteration method is used to determine the estimation value of unknown parameters. A certain mechanical and electrical product is used to design a simulation project. The sample data is obtained by Monte Carlo simulation. A contrastive analysis shows that the present model is more accuracy.