【作者】 李超；

【导师】 陆中；

【作者基本信息】 南京航空航天大学 ， 载运工具运用工程， 2022， 硕士

【摘要】 非包容转子失效是指高能碎片从转子脱落并飞出机匣,对飞机造成危害的失效。开展非包容转子失效的概率风险评估是民机进行安全性分析的重要组成部分,具有重要的理论意义和工程价值。本文对非包容转子失效的概率风险评估方法进行研究,主要内容和创新性成果如下:1)提出了基于贝叶斯网络的非包容转子失效概率风险评估的解析方法。构建了适用于多种失效模型的最小割集触发概率计算模型;提出了面向非包容转子失效概率风险评估的贝叶斯网络建模方法,在该模型的基础上提出了风险概率计算方法。该方法能够实现灾难性危险发生概率的高效计算。2)针对当前非包容转子失效分析飞散风险角和平动风险角无法准确表示部件危险窗的缺陷,利用空间投影法提出了非包容转子失效概率风险评估的蒙特卡洛仿真方法。提出了碎片撞击部件时的柱面投影与投影边界提取方法,通过提取部件投影边界可获得部件危险窗;提出了基于蒙特卡洛随机模拟的飞机灾难性危险概率仿真方法。该方法可以获得关键部件精确的危险窗,实现飞机灾难性危险概率的精确计算。3)提出了面向非包容转子失效的飞机关键部件重要度分析方法。给出了关键部件重要度分析的原则,提出了基于解析方法和蒙特卡洛方法的关键部件重要度计算方法;利用关键部件重要度,提出了关键部件改进顺序的确定方法。所提方法可确定对关键部件采取防护措施的顺序,提高飞机非包容设计的效率。更多还原

【Abstract】 Uncontained Rotor Failure refers to the condition that causes harm to the aircraft when high-energy debris breaks away from the rotor and penetrates the aircraft engine.The probabilistic risk assessment of uncontained rotor failure is an important part of safety analysis for civil aircraft and it provides theoretical significance and engineering value.The probabilistic risk assessment methods for the uncontained rotor failure are investigated.The main contribution and innovative achievements are as follows:1)The analytic method of probabilistic risk assessment based on the Bayesian network for uncontained rotor failure is proposed.The calculation model of minimal cut set trigger probability suitable for various failure models is established;A Bayesian network modeling method for probabilistic risk assessment of uncontained rotor failure is proposed,then a calculation method of risk probability is proposed based on the model.This method can calculate the probability of catastrophic hazards efficiently.2)A Monte Carlo simulation method for the probabilistic risk assessment of uncontained rotor failure is proposed using the spatial projection method to address the defects of the current uncontained rotor failure analysis where the spread risk angle and the translational risk angle can not accurately represent the component threat window.The cylindrical projection method and projection boundary extraction method are proposed when fragment impact component and the threat windows of components are obtained by extracting the projection boundaries;A simulation method of aircraft catastrophic hazard probability based on Monte Carlo stochastic simulation is proposed.This method can obtain accurate threat windows of critical components,and the accurate result of aircraft catastrophic hazard probability is calculated.3)The importance analysis method of aircraft critical components for uncontained failure is presented.The principles of critical components importance are given,and the calculation methods of components importance based on the analytic method and the Monte Carlo method are proposed;Based on the importance of critical components,a method to determine the improvement sequence of critical components is proposed.The proposed method can determine the sequence of protective measures for critical components and improve the efficiency of the uncontained design.更多还原