Mechanism reliability and sensitivity analysis of landing gear under multiple failure modes

多失效模式下起落架机构可靠性及灵敏度研究

¹ Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
² AECC Commercial Aircraft Engine Co., Ltd., R&D Center, Shanghai 201108, China

Received: 6 July 2020

Abstract

For a certain type of aircraft landing gear retraction-extension mechanism, a multi-body dynamic simulation model is established, and the time-dependent curves of force and angle are obtained. Considering the random uncertainty of friction coefficient, assembly error, and the change of hinge wear under different retraction times, the reliability model is built including three failure modes of landing gear, i.e. blocking failure, positioning failure and accuracy failure. Based on the adaptive Kriging model, the reliability and sensitivity of retraction-extension system under the condition of single failure mode and multiple failure modes in series are analyzed, and the rule of reliability and sensitivity changing with the number of operations is given. The results show that the system failure probability of landing gear mechanism tends to decrease first and then increase when considering the given information of random factors, and the influences of random factors on the failure probability vary with the number of operations. This work provides a viable tool for the reliability analysis and design of landing gear mechanisms.

摘要

以某型飞机起落架收放机构为研究对象，建立了其多体动力学仿真模型，得到了其运动时所需驱动力与角度随时间的变化规律。考虑摩擦因数、装配误差等因素的随机不确定性，以及在不同收放次数下铰接处磨损量的变化，针对起落架卡滞失效、定位失效、精度失效3种失效模式建立了可靠性模型。基于自适应Kriging代理模型，对单失效模式和多失效模式串联情况下的起落架收放机构可靠性和灵敏度进行了分析，并给出了可靠性和灵敏度随着起落架收放次数的变化规律。考虑文中给出的随机因素信息时，起落架机构整体的失效概率呈现了先下降后上升的趋势，且不同收放次数下各随机因素对失效概率的影响也不同。所提出的分析方法为起落架机构可靠性评估和设计提供了相应方法。