串并联系统可靠度置信下限计算方法  

Calculation Method on Lower Confidence Limit of Reliability of Series and Parallel System

作　　者：傅惠民[1] 文歆磊 杨海峰 FU Hui-Min;WEN Xin-Lei;YANG Hai-Feng(Research Center of Small Sample Technology,Beihang University,Beijing100191,China)

机构地区：[1]北京航空航天大学小样本技术研究中心

出　　处：《机电产品开发与创新》2020年第1期1-4,共4页Development & Innovation of Machinery & Electrical Products

基　　金：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》;国家重点基础研究发展计划(2012CB720000)

摘　　要：建立了串(并)联系统可靠度(不可靠度)置信下(上)限干涉模型,给出其置信度计算方法。在此基础上,严格证明了串联系统可靠度单侧置信下限等于各子系统可靠度单侧置信下限的乘积,并联系统不可靠度单侧置信上限等于各子系统不可靠度单侧置信上限的乘积,从而解决了这一长期悬而未决的难题。文中对目前工程上常用的串并联系统可靠度置信下限的计算方法进行了分析讨论,指出LM法、MML法、SR法等计算得到的串联系统可靠度置信下限和LR法、AO法等计算得到的并联系统可靠度置信下限误差较大,有时偏于危险,特别是当子系统无失效时,有些方法还无法计算。从对比算例可以看到,文中方法优于传统方法,且计算简单,便于工程应用。Interference model of lower(upper)confidence limit of reliability(unreliability)of series(parallel)system is constructed,then calculation method on confidence level is given.On this basis,we further demonstrate the long-standing problem that one-side lower confidence limit of reliability of series system equals to the product of one-side lower confidence limit of reliability of all subsystems,and one-side upper confidence limit of unreliability of parallel system equals to the product of one-side upper confidence limit of unreliability of all subsystems.Some frequently-used calculating methods are also discussed in the study.It is illustrated that the obtained lower confidence limit of reliability of series system by LM,MML and SR method,and that of parallel system by LR and AO method,tend to be dangerous.Especially when the test result of subsystem is zero-failure data,some of the methods cannot even provide a complete calculation.According to the comparative example,the proposed method in this paper is superior to the conventional ones,and the easy calculation also makes it convenient for engineering application.

关 键 词：系统可靠性 串联系统 并联系统 可靠度置信限 干涉模型 

分 类 号：TB114[理学—概率论与数理统计] N945[理学—数学]