Abstract: In order to investigate the running safety and derailment boundary of high-speed train subjected to strong gusts, a coupled vehicle/track dynamic model considering the gust environment is developed. In the model, the vehicle is modeled as a multi-body system with 35 degrees of freedom, the ballast track is assumed as a three layers discrete elastic support model. A bi-exponential gust model adopted by the TSI standard is used to simulate the dynamic wind field and the dynamic aerodynamic forces caused by gusts are modeled as the external forces exerted on the mass center of vehicle body. The wheel/rail normal forces and creep forces are calculated by using Hertz nonlinear contact theory and SHEN’s nonlinear creep theory respectively. Based on the numerical calculation, the dynamic responses and derailment mechanism of the high-speed vehicles in the gust environment are discussed in detail. The main factors that affect the safe operation of the vehicles are investigated. Finally, the derailment boundary and safety operational area of high-speed train considering several key factors and derailment criteria are calculated. The numerical results could provide theoretical guidance for the operational control of high-speed train under gust.

Key words: Derailment boundary, Derailment criteria, Gust, High-speed train, Running safety