Evaluation of Railway Vehicle Car Body Fatigue Life and Durability using Multi-disciplinary Analysis Method

Bingrong Miaoa, Weihua Zhangb, Jihui Zhangb, and Dingchang Jin (Southwest Jiaotong University)

CHALLENGE - In this paper, a multi-disciplinary analysis method is proposed for evaluating the fatigue life and durability of railway vehicle car body structure under random dynamic loads. With the increase of commercial speeds of railway vehicles on conventional tracks in China, the car body structures of these vehicles are subject to serious fatigue problems. 

SOLUTION - The procedure is run with Multibody dynamics Simulation (MBS) and Finite Element Analysis (FEA), which derives the load time histories for durability analysis. The full vehicle is modeled and simulated based on the rigid or flexible dynamic property of the car body. To generate standard input data (SIC) of flexible bodies in MBS simulation, the interface program FEMBS is used between the FEA codes - ANSYS and SIMPACK. A detailed car body structure is realized using FEA software ANSYS. The fatigue life of the car body structure is calculated using Wave Analysis for Fatigue and Oceanography toolbox in MATLAB. Objectives for optimization are minimization of weight and better fatigue performance.














BENEFITS -  The fatigue life predictions from FEMBS simulation and modeFRONTIER optimization closely match experimental results. The mean fatigue life prediction error is approximately 30.7%. The majority of fatigue damage to the car body takes place at or below 15Hz and the dynamic behavior of the locomotive plays a significant role in occurrence of car body structure fatigue failure.