Frontal collision of trains onto offset obstacles at level crossings: Derailment mechanisms and simulation

With the increasing number of heavy road vehicles and railway level crossings, the risk of level crossing collisions is on the rise and EN 15227 introduces this crash scenario for train crashworthiness assessment. In this paper, the dynamic response and derailment process of the train in this scenario are investigated by using finite element simulation method, and the frontal impact of a train on a deformable obstacle at a level crossing is modelled. The derailment safety of obstacles with different offset rates, including impact interface force, body deformation, wheel derailment coefficient, wheel weight reduction rate, vertical displacement, and lateral displacement, was investigated, and the effects of train speed, obstacle mass, and obstacle stiffness on the dynamic response of the train were compared. The results show that the frontal offset collision causes the obstacle to rotate around the point of impact, and the secondary collision of the distal end of the obstacle on the head car during the rotation is an important cause of train derailment.