Study on safety boundary for high-speed train running in severe environments

This article reviews some important published papers regarding the discussions on the mechanism and the modelling of trains operating in severe environments which are originally defined. A few important derailment criteria are briefly discussed. A study strategy of the safety operation boundaries of high-speed trains operating in the severe environments is first put forward. In the strategy, the safety operation boundaries are defined as a number of separatrices which clearly indicate the safety operation area, warning area and derailment occurring area of a high-speed vehicle in operation. The defined separatrices are the limit surface functions of the key factors influencing the vehicle dynamic behaviour and its derailment. They are found through numerical simulation by using an advanced dynamics model for vehicle/track interaction and the derailment criteria. In order to fully understand the present strategy, a detailed numerical example of a high-speed vehicle passing over a buckled track is discussed. The given results clearly indicate the effects of the key factors on the wheel/rail normal forces, the derailment criteria limits and the vehicle derailment boundary.