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Crashworthiness Simulation of Urban Rail Vehicles Based on ASME Standard

Based on ASME standard and technical conditions of vehicle bidding document, the crashworthiness of an urban rail vehicle is simulated by software HyperMesh and LS-DYNA. The collision simulation model applies braking force through beam elements to simulate the emergency braking status of the vehicle during the collision. The longitudinal stiffness gradient design evaluation of the carbody structure is realized by simulation analysis of the overall longitudinal impact. The crashworthiness of the train is evaluated from the aspects of energy absorption, longitudinal acceleration of the vehicle, climbing and derailment, longitudinal stiffness of the carbody structure, etc. The simulation results show that the crashworthiness of the urban rail vehicle meets the corresponding technical requirements. At the same time, a simulation method of vehicle braking behavior and the verification procedure of longitudinal stiffness gradient design of carbody structure are proposed. Introduction Operation safety of rail transportation, especially the safety of vehicle collision accidents, is receiving more and more attention. A. Erskine [1] summarized research data on the crashworthiness of rail vehicles around the world, conducted comparative analysis to current British operation, the latest viewpoints and development worldwide. S. Bounds [2] described principal findings in the project of Whole Train Dynamics (WTD), investigated the factors affecting the dynamic stability and general crashworthiness in event of an end on collision. W. Wang et al. [3] proposed a joint simulation analysis method for train crashworthiness analysis based on nonlinear finite element method and one-dimensional multi-rigid dynamics technology. H. Zhou et al. [4] studied the climbing phenomenon during the collision of rail trains based on the nonlinear finite element method and three-dimensional multi-rigid dynamics joint simulation method. S. Xiao et al. [5] proposed a simulation method for analyzing the characteristics of couplers and buffers based on the discrete beam in LS-DYNA. Yang et al. [6] simulated train colliding with a static train at a speed of 25km/h on curved and linear tracks based on LS-DYNA. At present, Chinese institutes and vehicle design manufacturers carry out the design and evaluation of the crashworthiness of rail vehicles [7-10] based on the EN 15227 standard [11]. Research on vehicle crashworthiness against the corresponding US standards is rare. H. Liu [12] and F. Luo [13] analyzed the elastic-plastic deformation law of the collision post and the crashworthiness of the end structure for a North American urban rail vehicle based on the American subway carbody design standard ASME RT-2-2014 [14], but the vehicle collision calculation model construction, vehicle braking simulation, and longitudinal stiffness gradient design of the carbody structure were not involved. Based on ASME RT-2:2014 standard and technical conditions in the employer's bidding document, this paper takes urban rail vehicle as the object, establishes a detailed train collision simulation model according to the design variable such as cars-formation, structural characteristics of the carbody,