基于状态转移法的冷却水系统动态可靠性分析

  目的  对于共因失效（CCF）的可靠性分析，现有研究基本上都假设发生共因失效事件必将导致相关单元失效。该假设对于电子元器件是准确的，但是对于可靠度高、结构复杂的机械设备会出现状态缺失的问题。为此，通过理论推导，提出一种考虑概率共因失效（PCCF）的多状态可靠度计算方法。  方法  该方法将共因分为致命型和非致命型，且将每种共因的作用分解在各单元上，采用显式法建立各单元的通用生成函数（UGF）模型，分别采用现有方法和所提方法对单元独立失效与致命型概率及非致命型概率共因失效的计算结果进行对比。  结果  结果表明对概率共因失效假设具有正确性，提出的可靠度计算方法有效。  结论  相比传统的CCF分析法，采用PCCF分析法的可靠度计算结果准确度更高，能较好地解决单元和系统状态丢失的问题。

An implicit method for incorporating common-cause failures in system analysis

  Objectives  The previous researches into the reliability analysis on common cause failure mostly assume that the common cause failure event will necessarily cause the relevant unit to fail. This assumption is accurate for electronic components, but it can lead to state loss problems for mechanical equipment with high reliability and complex structure. Therefore, a multi-state reliability calculation method that considers the Probabilistic Common Cause Failure(PCCF) is proposed through theoretical derivation.  Methods  The common causes include fatal common cause and non-fatal common cause, and the effect of each common cause is applied to each unit, and the Universal Generating Function(UGF) model of each unit using explicit method is established. The existing method and the method of this paper are compared in terms of the calculation results of unit independent failure, fatal PCCF, and non-fatal PCCF.  Results  The results verify the validity of the hypothesis of probabilistic common cause failure and the validity of the proposed reliability calculation method.  Conclusions  Compared with the traditional common cause failure analysis method, if the analysis method of probabilistic common cause failure is used, the reliability calculation result is more accurate, which can solve the problem of unit and system state loss.