Reliability and sensitivity of bogie frame of high-speed train with strength degradation

Lü Hao(吕昊)¹, ZHANG Yi-min(张义民)¹, ZHANG Xu-fang(张旭方)¹, LU Hao(卢昊)²

(1. School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China;
2. College of Mechanical and Electrical Engineering, China University of Mining and Technology,
Xuzhou 221116, China)

Abstract:High-speed bogie frame is a key mechanical component in a train system. The reliability analysis of the bogie is necessary to the safety of high-speed train. Reliability analysis of a bogie frame was considered. The equivalent load method was employed to account for random repeated loads in structural reliability analysis. Degradation of material strength was regarded as a Gamma process. The probabilistic perturbation method was, then, employed for response moment computation. Example of a high-speed train bogie structure under time-variant load was employed for reliability and sensitivity analyses. Monte-Carlo simulation verifies the accuracy and efficiency of the proposed method in time-variant reliability analysis. The analysis results show that the reliability calculation considering the strength degradation and repeated load is closer to the practicality than the method of considering reliability calculation only. Its decreasing velocity is faster than the traditional reliability. The reliability sensitivity value changes over time. The analysis results provide a variation trend of reliability and sensitivity to design and usage of bogie frame.

Key words:reliability; sensitivity; repeated load; strength degradation; time-dependent reliability