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

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. The proposed analysis involves the following steps: (1) Multibody dynamics Simulation (MBS) and Finite Element Analysis (FEA), which derives the load time histories for durability analysis, are performed to model the full vehicle complex system and simulate the rigid or flexible dynamic properties of the car body. (2) Car body durability analysis is involving a definition of the useful life and damage distribution of car body structure, including the stress or strain rainflow cycle counting, damage prediction, and remaining life estimation. (3) Multi-Disciplinary Optimization (MDO) method, an iterative procedure incorporated with several kinds of analysis results, is performed in a batch manner using some standard softwares, such as SIMPACK, ANSYS, FE-FATIGUE and modeFRONTIER. The methodology is also illustrated for handling conflicting problems of railway car body design for lightweight and fatigue requirements. Finally, the proposed methodology and its detailed steps are discussed using a locomotive car body structure. A comparison of analysis results with experimental test results and the necessary car body structure fatigue design considering full vehicle dynamic property are also detailed.