Dynamic Interaction Analysis and Running Safety Assessment of the Wind–Train–Bridge System Considering the Moving Train’s Aerodynamic Coupling with Crosswind

Trains tend to be faster and lighter to meet the increasing public travel needs and interact with crosswind to produce a strong aerodynamic interaction, leaving a safety hazard for the operation. This paper presents a study into the dynamic response and running safety of the train–bridge system accounting for this aerodynamic interaction. The threedimensional flow features of a moving train in crosswinds are first investigated by a computational fluid dynamics method, and then an aerodynamic model for simulating unsteady crosswind force is developed. Furthermore, the dynamic responses of the train and bridge are calculated by using a wind–train–bridge dynamic interaction equation, and finally, the characteristic wind curve and surface are defined to evaluate the train’s running safety. The results show that the lateral response of the train–bridge system significantly increases as the crosswind increases, and the head car can experience a high derailment risk and determine the running safety of the train due to the aerodynamic coupling effect of a moving train and crosswind. Variations in the wind direction need to be factored into the safety assessment for low train speeds, and the train is at greater danger when the crosswind appears perpendicular to the car body.