Analysis of Vehicle–Bridge Coupling System Under the Wind and Waves Combined Condition During Two Trains’ Meeting

Based on the theories of computational fluid dynamics, aerodynamics, bridge dynamics and vehicle dynamics, a sea-crossing cable-stayed bridge with a main span of 532[Formula: see text]m is taken as the research object in this study to explore the characteristics of dynamic response when two CRH3 high-speed trains pass each other under the context of wind–wave combination. Firstly, the CFD method is used to construct an aerodynamic calculation model of the vehicle–bridge system under the context of wind–wave combination. Also, the first wind tunnel and wave flume tests are conducted to verify the numerical results of aerodynamic coefficients. Then, the bridge dynamics model and vehicle dynamics model are established by using both the finite element method and the multi-body dynamics method. Finally, a three-dimension vehicle–bridge coupled model is constructed by using the multi-body dynamic software SIMPACK to explore the effects of average wind and regular waves. It is demonstrated that the dynamic characteristics of the vehicle–bridge coupling system under the condition of wind–wave combination are different than under the context of average wind alone. According to the research result, wave effect can affect or make a difference to the aerodynamic characteristics of the vehicle–bridge coupling system. In general, there is only a slight increase in the dynamic responses of bridge structure including mid-span displacement when compared with the condition of average wind alone, including mid-span displacement. Meanwhile, the wind and waves combined condition also has a negative effect on the dynamic responses and running safety of high-speed trains. Especially for the leeward vehicle, the dynamic responses of the leeward train change more abruptly than under the single static wind condition with the increase of running speed.