Performance margin-based reliability analysis for aircraft lock mechanism considering multi-source uncertainties and wear

Abstract

The failures of the lock mechanism of the aircraft landing gear door can impede the retraction and extension processes of the landing gear and cause severe accidents; thus, the aircraft lock mechanism is always required with extremely high reliability. During manufacturing and usage stages, uncertainties are ubiquitous and performance degradation is inevitable, and they influence the reliability of the aircraft lock mechanism. In this paper, based on the reliability science principles, a performance margin-based reliability analysis considering performance degradation caused by wear and multi-source uncertainties is developed for an aircraft lock mechanism. Firstly, the performance margin model with the degradation of the aircraft lock mechanism is constructed based on the functional principles and the influence mechanism of wear. Then, we analyze the essence of each uncertainty source including the uncertainties in manufacturing imperfections, material properties, operational and environmental stresses, and performance thresholds, and quantify each uncertainty with a probability distribution. Finally, the reliability model is established. A numerical study of an aircraft lock mechanism is conducted and the reliability sensitivity analysis is implemented. The results show that the proposed method can provide guidance to the design and manufacturing processes of the aircraft lock mechanism to meet reliability requirements.