The Study Of Post-Derailment Dynamic Behaviors Of The Bogie Based On Bench Tests

The rapid development of high-speed brings new challenges for the running safety of trains. On the one hand, if a high-speed train derailed, a catastrophe may be brought. And on the other hand, the running principles, performance, and dynamical environment of high speed train are essentially different from those of the ordinary train. However, due to the complexity of derailment problem, the knowledge on the post-derailment dynamic behaviors of railway vehicle still stays at elementary stage.In order to investigate the factors influencing the post-derailment dynamic behaviors of railway vehicle, the derailment safety protection device is installed on axle box, and the derailment experiment for a bogie is conducted in the laboratory. The experimental results show that after derailment the wheel set comes into contact with the fasteners and sleepers again and again, meanwhile the derailment safety protection device and gearbox will contact with the rail, and then affect the post-derailment dynamic behaviors of the bogie.To understand the dynamic behaviors of the bogie after derailment, a post-derailment dynamic model for the bogie is put forward in this paper. The model is composed of three parts:which are dynamic model of derailment test bench; the three-dimensional entity model and contact force model. Based on the contact force model, the post-derailment dynamic model considers a variety of contacts which may occur during the derailment, such as the contacts between wheels and fasteners and sleepers, the collision of gearboxes and rails, and the impact of the derailment safety protection device and rails.According to the comparison analysis of tests and simulation results, the post-derailment dynamic model is consistent with the experiments, and can reflect the dynamic behaviors of railway vehicle after derailment. The results indicate that the lateral displacement of the bogie is limited when the derailment safety protection device and gearbox contact with the rail, which affects the post-derailment dynamic behaviors of the bogie. Therefore a suitable design of vehicle component may play an active role in the derailment.