基于多态故障树的伺服刀架可靠性分析

Reliability analysis of servo turret based on multi-state fault tree

为了描述工程实际中某些故障现象的退化过程,定义了两状态事件、多状态事件和多态表决门单元,并提出多态故障树的建造方法.首先从系统故障顶事件逐级细分出可能出现的各种故障模式,根据实际工况将故障模式分为功能失效模式和状态恶化模式两大类,分别视为两状态事件和多状态事件;然后判断出各故障模式对应的所有故障部位,视为多状态事件.不同状态事件间的逻辑关系通过多态表决门来表征.采用最小路集法建立基于多态故障树的可靠性定量分析模型,求解系统可靠度及事件概率重要度.将该方法应用在伺服刀架可靠性分析中,结果表明,所建立的多态故障树能描述实际工况,据此来判别影响系统可靠性的薄弱环节具有指导意义.

To describe the degradation processes of some fault phenomena in practical engineering,a method for the construction of multi-state fault tree is proposed based on the definitions of two-state event,multi-state event,and multi-state voting gate.First,according to the actual working condi-tions,the top event is subdivided into functional failure modes and deteriorated modes,which can be recognized as two-state events and multi-state events,respectively.Then all corresponding failure parts are distinguished as multi-state events.Multi-state voting gate is defined to characterize the log-ical relationship among different events.The minimum path set method is adopted to establish a quantitative reliability analysis model,and then the system reliability and probability importance of an individual event are calculated.This method is applied to the reliability analysis of a servo turret. The results show that the established multi-state fault tree can describe the actual working conditions. Therefore,the distinguishing of the system＆#39;s weak parts is credible.