贝叶斯网络在机械系统可靠性评估中的应用

Application of Bayesian Network to Reliability Assessment of Mechanical Systems

针对故障树分析方法在可靠性评估方法中的局限性,提出了基于贝叶斯网络的机械系统可靠性评估新方法.首先根据系统可靠性框图建立故障树,然后将故障树直接映射成为贝叶斯网络,构建条件概率表,运用贝叶斯网络的推理能力进行系统的可靠性评估.该方法不但能计算出机械系统的可靠性指标,而且能方便地给出某一个部件或几个部件对系统可靠性的影响大小,识别系统的薄弱环节.最后通过实例验证了用贝叶斯网络进行机械系统可靠性评估的有效性.

A new method based on Bayesian network was proposed to assess the mechanical system reliability because of the limitation of fault tree used in reliability assessment. A fault tree was built first according to the block diagram of system reliability, then it was mapped onto a Bayesian network to generate a conditional probability distribution table so as to assess the system reliability by inference of Bayesian network. The method is able not only to compute the reliability indices of mechanical system but also to analyze easily the effects of a certain components on the system reliability to recognize the vulnerable positions of the system. The validity of the method proposed is verified by exemplification.