Dynamic performance analysis of intercity trains under strong crosswinds

This paper focused on analyzing the influence of unsteady aerodynamic forces on the stability and safety of a specific intercity electric multiple unit (EMU) model subjected to strong crosswinds of 25 m/s on level open tracks. Based on their actual geometric and dynamic parameters, aerodynamic and multi-body dynamic models were respectively established for the 8-car configuration. The <italic>k</italic>-<italic>ω</italic> SST turbulence model was used to calculate the unsteady aerodynamic forces acting on each car. These calculation results were then incorporated into the multi-body dynamic model as external excitations, leading to the development of a fluid-solid coupling simulation model for subsequent calculations related to wind-induced carbody vibrations and safety. The results showed that the aerodynamic forces acting on each car under steady strong crosswinds exhibited obvious unsteady behaviors, with main frequencies varying from 0.5 to 7.0 Hz. The influence of these unsteady aerodynamic forces led to an increase in both the lateral and vertical Sperling indexes of each car, with the lateral Sperling index of the head car reaching 3.3, indicating a considerable deterioration in ride comfort. The collisions between the bodies of the head and tail cars and the lateral stops, under the action of large lateral forces and yaw torques, exacerbated lateral vibrations. Compared with scenarios without aerodynamic loads, the safety indexes of both the head car and tail car under strong crosswinds of 25 m/s were significantly increased, but still remained within safety limits. The wind-induced lateral vibrations of the head car could be mitigated to some extent by increasing the lateral stop clearance and increasing the damping coefficient of both the anti-yaw damper and the secondary lateral damper.