Dynamic modelling and simulation of metro train collision and derailment

Abstract To investigate the dynamic response and instability mechanisms of urban rail vehicles under extreme collision and derailment scenarios, a high-fidelity dynamic simulation model of a metro train system was developed based on the ADAMS/Rail platform. The model integrates three-dimensional nonlinear contact mechanics and structural topological evolution, enabling the simulation of the complete process from normal operation to post-collision derailment. Two representative collision scenarios were designed and analyzed: frontal collision and oblique collision. The study systematically evaluated the influence of operating speed (20–40 km.h−1) and collision angle (90°–70°) on the dynamic behavior of the train. Simulation results show that train derailment is governed by both speed and collision angle. Frontal collisions at speeds exceeding 40 km.h−1 cause excessive lateral and vertical displacement of the leading wheelsets, triggering derailment, as the energy-absorbing components fail to fully mitigate the impact. Under oblique collision conditions at 30 km.h−1, derailment probability increases significantly when the collision angle is below 85°, and continuous derailments of multiple wheelsets are observed at an angle of 80°. The wheelset response exhibits marked temporal and spatial sensitivity, with the front wheelsets of the leading car identified as the primary source of instability. The findings offer theoretical insights and engineering guidance for derailment protection structure design, energy absorption system optimization, and safety assessment of metro trains under extreme operating conditions.