An investigation into post-derailment self-protection mechanisms for railway vehicles

•Introducing the polygonal contact model (PCM) for calculating the interactive forces between various components.•Studied the impact of motor installation positions on derailment safety, considering the motor's actual geometric profile.•A comparative analysis of the dynamic behavior of vehicles on CRTS I and CRTS II following derailment. With the rapid expansion of railway networks and increasing transportation demands, the operating safety of railway systems, especially the risk management and safety measures to prevent train derailments, has become critically important. This study investigates the post-derailment dynamic behavior of railway vehicles and its self-protection mechanism. In order to understand the post-derailment dynamic behavior of railway vehicle, a half-car full-scale derailment experiment was conducted in the laboratory. Subsequently, a post-derailment contact collision dynamic model of a half-car was developed through integrating a polygonal contact model. This model accounts for the actual geometric shapes of various components in the vehicle and track system, and its validity was demonstrated through comparing the numerical results with those obtained through the derailment experiments. Subsequently, a full-scale post-derailment dynamic model for railway vehicle was developed, and further used to investigate the safety zone of motor installation for the self-protection of railway vehicle. In addition, a comparative analysis of self-protection of railway vehicle operating on different slab types was carried out. The results indicated that the CRTS II slab track, with its inclusion of shoulder blocks, shows better protective capabilities compared to the CRTS I slab track.