车装焊复合加工装备的服役可靠性评估

摘要

目的 评估某型航天用车装焊复合加工装备在服役过程中的服役可靠性.方法 首先分析装备常见的故障模式,统计装备在使用过程中的故障数据,由于装备故障数据样本量较少,所以提出基于贝叶斯理论的小样本车装焊复合加工装备可靠性评估方法,其中通过马尔科夫链蒙特卡罗(MCMC)法抽样解决贝叶斯理论中后验积分复杂的问题.结果 确定了车装焊复合加工装备的寿命威布尔分布模型,并运用贝叶斯方法,计算出该车装焊复合加工装备的平均无故障工作时间(MTBF).结论 评估结果略低于设计要求,原因是目前该装备处于服役初期,服役初期故障数据较多.待进入稳定服役期时,故障率会有一定程度的降低后趋于稳定,MTBF会有一定幅度的增加,所以该车装焊复合加工装备MTBF基本满足设计要求.%Objective To evaluate the operational reliability of a certain type of aerospace turning-assembly-welding composite machining equipment in the operational process.Methods At first, common failure modes of the equipment were studied and its failure data was obtained during operational process. Then, the reliability evaluation model of the turning-assembly-welding composite machining equipment using the Bayesian method was proposed with small-sized sample failure data. The complex problem on Posterior integration in Bayesian theory was solved by the Markov Chain Monte Carlo (MCMC) theory.Results The lifetime Weibull distribution of turning-assembly-welding composite machin-ing equipment was determined. Furthermore, the mean time between failures (MTBF) of turning-assembly-welding com-posite machining equipment was calculated based on the Bayesian method.Conclusion The evaluation result is slightly lower than that of the design. The main reason is that more failure data appeared in the early operational process. The failure rate will decrease and the MTBF will increase in the stable operational process. So the MTBF of the machining equipment basically meets the design requirement.