摘要
针对工程上加速寿命试验仍然存在时间长、试样多的问题,提出一种小样本加速寿命试验设计与评估方法。该方法只需在两个加速应力水平下进行加速寿命试验,即可对产品在正常使用应力水平下高置信度、高可靠度的可靠寿命进行评估。文中首先利用工程上常用的线性加速模型(如阿伦尼斯模型、逆幂律模型和指数模型等)建立了正常使用应力水平下可靠寿命的单侧置信下限与两个加速应力水平下的可靠寿命置信限之间的数学关系式,给出了正常使用应力水平下高置信度、高可靠度的可靠寿命单侧置信下限评估方法。然后分别对指数分布、两参数Weibull分布和对数正态分布的定数截尾加速寿命试验情况进行了详细讨论,给出了相应的正常使用应力水平下高置信度、高可靠度的可靠寿命单侧置信下限计算公式。该方法计算简单,而且对完全数据、不完全数据以及各种分布均适用。大量工程算例和Monte Carlo模拟验证表明,与需要在多个加速应力水平下进行寿命试验的传统方法相比,本文方法不但可以节省大量试样和试验时间,而且理论上更加严谨,精度更高。
A small-sample accelerated life test design and evaluation method is proposed to overcome the limitations of conventional accelerated life tests,such as being time-consuming and requiring large samples.By conducting life tests at only two accelerated stress levels,this method can evaluate the product’s reliable life at normal stress level with high confidence and high reliability.Firstly,the relationship between the lower confidence limit of the reliable life at normal stress level and the confidence limits of the reliable life at two accelerated stress levels is modeled by using the linear acceleration models(e.g.,Arrhenius model,inverse power law model and exponential model,etc.),and the method of evaluating the lower confidence limit of the reliable life at normal stress level with high confidence and high reliability is presented.Then,the accelerated life tests with exponential,Weibull and lognormal distributions and Type-II censoring are discussed in detail,and the reliability assessment formulas are derived respectively.The method is easy to implement and suitable for complete and incomplete data as well as various distributions.The Monte Carlo simulations demonstrate that the method can significantly save the specimens and time,and is more rigorous and precise than the conventional methods which need to conduct life tests at multiple stress levels.
作者
傅惠民
郭建超
付越帅
李子昂
FU Hui-Min;GUO Jian-Chao;FU Yue-Shuai;LI Zi-Ang(Research Center of Small Sample Technology,Beihang University,Beijing100191,China)
出处
《机电产品开发与创新》
2024年第1期1-5,共5页
Development & Innovation of Machinery & Electrical Products
基金
国家自然科学基金(U2037602)《月基装备自主操控与多机协同基础理论与关键技术研究》
工信部2018年智能制造综合标准化项目《基于数字仿真的机械产品可靠性测试方法标准研究与试验验证》。
关键词
加速寿命试验
小样本
试验设计
可靠性评估
寿命预测
置信下限
Accelerated life test
Small sample
Test design
Reliability assessment
Life prediction
Lower confidence limit
