Dynamic performance improvement for high-speed trains under strong crosswind and tunnel passage using semi-active dampers

High-speed trains traversing tunnels under strong crosswinds are subjected to unsteady aerodynamic loads that induce significant carbody vibrations, compromising both ride performance and operational safety. This study proposes a semi-active control strategy for secondary lateral dampers to mitigate carbody vibrations and improve ride performance and safety. A coupled 3-car aerodynamic model and multi-body dynamic model are established to analyse aerodynamic loads and vehicle dynamic responses. Additionally, the influence of aerodynamic loads on dynamic performance is investigated under different operating speeds. The results indicate that the headcar experiences the highest aerodynamic loads, with the greatest derailment risk occurring at the leeward wheel of the first wheelset. The application of semi-active control can significantly mitigate carbody vibrations, with the mixed continuous skyhook and acceleration-driven damping method demonstrating superior performance. This method improves the Sperling index of the headcar by 33.8% (15 m/s) and 28.8% (20 m/s), and reduces the derailment coefficient by 21.3% (15 m/s) and 13.8% (20 m/s). Moreover, the ride performance and safety of the train are more sensitive to wind speed than to train speed.