Dynamic precision reliability of the aircraft landing gear retraction mechanism under coupled extreme working conditions

Extreme working conditions pose a serious challenge to the functionality, longevity, and reliability of mechanical systems; however, current research on the reliability of mechanical systems under these conditions is very limited. Consequently, this study proposes a methodology for modeling and analyzing the dynamic precision reliability of the aircraft landing gear retraction mechanism (ALGRM) under coupled extreme conditions such as high temperature, high humidity, and salt spray corrosion. First, an improved Kriging (I-K) model is proposed by optimizing the hyperparameters of the traditional Kriging (T-K) model via the artificial fish swarm algorithm (AFSA), and two cases are used to demonstrate that the I-K model has higher prediction precision. Second, a mathematical model of clearance joint is built, and the corrosion characteristics of motion joint under extreme working conditions are simulated using COMSOL software. The Lagrange method is applied to establish the dynamic model of the ALGRM considering multiple random variables. Finally, the limit state function is derived between the random variables and the extreme output response of the ALGRM via the I-K model. The dynamic precision reliability model for the ALGRM under coupled extreme working conditions is solved using the first order second moment (FOSM) method and the parameter sensitivity is evaluated. This study contributes some insights into the modeling and evaluation of the reliability of mechanical systems under coupled extreme working conditions, thereby enhancing the broader understanding of mechanical reliability theory.