民用航空发动机顶层故障事件的概率计算研究

为满足民用航空发动机的安全性目标,发动机顶层故障事件(顶事件)的风险应被控制至可接受状态。针对顶事件的风险控制要求,细化为顶事件的预期发生概率应被控制至可接受值以下。基于顶事件的预期发生概率要求,提出了从上到下分析导致顶事件发生的潜在原因并逐级建造故障树的方法,阐述了故障树分析的开展时机及作用。然后,对顶事件发生概率的计算进行了研究,通过考虑顶事件的飞行阶段影响因素、故障树最小割集及其概率、底事件失效率及其风险时间,提出了顶事件发生概率的计算模型。同时,结合示例对顶事件发生概率的计算模型进行了应用,以验证顶事件概率计算方法的可行性。提出顶事件概率计算模型,为发动机顶层故障事件风险控制要求提供有力的技术支撑。

Research on probability calculation of top level failure event for civil aviation engine

To satisfy the safety requirement of civil aircraft engine,it is required that the risk of top level engine failure event shall be controlled to an acceptable level.According to the risk control requirements of top event,the expected probability of top level event shall be controlled below the acceptable value.Based on the predicted probability requirement of top level event,this paper provides a“top-down”fault tree analysis method to analyze the potential causes of top level event and build fault tree step by step,and explains the role of fault tree analysis Then the calculation of top level event probability is studied.By considering the influence factors of flight phase of top level event,the minimal cut set of fault tree and its probability,the failure rate of basic event and its risk time,the calculation model of top level event occurrence probability is provided.Meanwhile,the calculation model of top event probability is applied with an example to verify the feasibility of the calculation method of top event probability.The top event probability calculation model proposed in this paper can provide strong technical support for the risk control requirements of engine top-level fault events.