Mechanical responses of high-speed train derailment due to collision with deformable obstacles

The collision phenomenon of high-speed trains colliding with obstacles is prone to resulting in derailment. This study focuses on analyzing the mechanical responses of a high-speed train when colliding with a deformable obstacle at different angles and speeds. The results show that the derailment initiation speed decreases with the increase in angle. Overall, as the angle increased from 0 to 45°, derailment risk increased. Specifically, when the speed was 110 km h−1 and the angle was 45°, the wheels of the front bogie of the head train derailed; by contrast, no derailment occurred for collision angles ranging from 0 to 40°. When the angle was lower than 5°, derailment did not occur even when the speed increased up to the train's design speed of 250 km h−1. Jumping derailment and climbing derailment were observed, respectively, when the collision angle ranged from 10 to 25° and from 30 to 45°. It was revealed that derailment occurred due to the combined effect of lateral and vertical forces acting on the contact interface. By establishing a derailment boundary incorporating both collision angle and speed parameters, the research provides valuable insights for railway infrastructure design and safety speed limit determination in high-speed rail operations.