融合外场使用和加速寿命数据的可靠性评估方法

Method on reliability assessment with integrated field using and accelerated life data

针对寿命服从双参数Weibull分布且已在外场使用一段时间后的机电产品,进行单应力、定时转换的步进加速寿命试验,研究外场使用数据和加速寿命试验数据之间的融合评估问题。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;开展融合外场使用历程和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;构建融合过程的极大似然函数,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,采用蒙特卡罗仿真方法产生样本数据,通过对比分析说明本文所提出的模型评估精度更高。

Aiming at the mechanical ＆ electrical product that its lifetime obeys to Weibull distribution and has used in field, a single-stress ＆ time-switching,step-stress accelerated life test is done to study the integrated assessment problem between field using data ：and accelerated life test （ALT） data. Considering the difference between field multi-stress environment and laboratory single-stress environment, a distribution parameter model with the correction factors is constructed. Statistical analysis for the integrated process of field using and the ALT is done. Its cumulative distribution function relationship under each stress is built. The maximum likelihood function of integrated filed using and ALT data is built. The data iteration method is used to determine the estimation value of unknown parameters. A certain mechanical ＆ electrical product is used to design a simulation project. The sample data is obtained by Monte Carlo simulation. A contrastive analysis shows that the proposed model is more accurate.