针对定时测试综合应力加速寿命试验设计问题,就恒定应力加速寿命试验方法,根据所提出的加速寿命试验方案优化设计的准则和方法,以产品在正常工作应力水平时寿命估计值的方差最小为目标,在确定了每个应力水平组合下定时测试时间获取方式后,以各加速因子的试验应力水平、各次试验的试样分配比例及各次试验的截尾时间为设计变量,应用极大似然估计理论,建立了定时测试综合应力加速寿命试验方案优化设计的数学模型。对航天电连接器的定时测试综合应力加速寿命试验方案优化设计的结果表明,经过优化以后的定时测试试验方案不仅可以提高试验数据的估计精度、减少试验次数,而且还可以在相同置信度下减少试验所需的样本数量,并能够缩短试验时间。
Aiming at the design problems of multiple stress accelerated life test under periodic inspection and based on the proposed criteria and method of accelerated life test plan optimum design, minimum variance of product life estimated value at normal working stresses is taken as the design object for constant stress accelerated life test method. After determining the manner of getting the periodic inspection time, test stress levels of each accelerated factor, allocation proportion of test samples and censored times of each test are adopted as design variables; the optimum design mathematic model of multiple stress accelerated life test under periodic inspection is built by using maximum likelihood estimation theory. The optimum design result of multiple stress accelerated life test under periodic inspection for electrical connectors used in astronautic projects shows that the optimized test plan can not only greatly improve the estimation precision of test data, reduce the number of tests, but also cut down the number of test samples and shorten the test time under the same degree of confidence.