Failure Threshold Analysis Based On Multiple Performance Degradation Reliability Assessment Methods

The landing gear cabin door locking mechanism is a key component of the aircraft, and its reliability has a direct impact on the aircraft landing gear retraction function and stealth function. Most of the thresholds for the failure characteristics of the locking mechanism are set, and for multiple failure characteristics in the multivariate degradation model, the time when different thresholds take effect may exist before and after in the regression sense, and the failure thresholds based on the correlation of multiple performance characteristics should be synchronized in the regression sense to ensure the time when they take effect. The problem of inter-threshold synchronization has not been noticed by researchers and needs attention. In the article, based on the analysis of the influencing factors of the life of the locking mechanism, the locking angle of the lock hook and the offset of the locking displacement of the lock hook are selected as the performance degradation characteristic quantities; based on the case that the failure thresholds corresponding to the two failure characteristic quantities have been determined, the degradation model is established by Wiener process, so as to obtain the failure probability density function of both; the correlation of the two failure characteristic quantities and the synchronization of their threshold combinations are discussed, and the use of Copula function is used to establish a multi-performance degradation reliability assessment model, and the synchronization of failure thresholds is verified. It is proposed that there is a need to develop a method for determining the threshold combination reflecting the correlation of the characteristic quantities.