Simulation Study On Coupled Vibration Of Cross-sea Bridge Train-Bridge System Under The Effect Of Wind And Wave

Cross-sea bridges are different from inland bridges in that they not only have to bear dead load of superstructure and moving load,but also the challenges brought by different ocean conditions,the most significant in them is the effect of across-wind and wave load.Wind and wave are two interrelated environmental loads,especially long-span bridges are wind-sensitive structures,and wave action is the main load on the understructure of the cross-sea high-speed railway bridges.For the high-speed railway bridges built in the offshore area,the combined action of wind and wave not only affects the vibration response of the bridge structure,but also adversely affects the track regularity of the high-speed railway bridge structure,which will directly threaten the operation and traffic safety of the cross-sea high-speed railway bridge structure.This paper is based on the wave environment elements of PingTan channel bridge site,using numerical simulation method to study the influence of undulating sea surface on the wind field of train-bridge,and take the wind speed,wave parameters and vehicle speed as the control objects,the refined simulation model is used to study the coupled vibration of the train-bridge system under the interaction of wind and waves.The Reynolds time-averaged method is used to calculate the aerodynamic loads of train and bridge under different wave return period,different wind speeds and different vehicle speeds according to the wind and wave elements in PingTan channel bridge site.Based on the wave mechanics of ocean engineering,the wave loads under different wave elements in the bridge site are calculated by a self-programming program.The vehicle model is established by multi-body dynamics software SIMPACK,adequately consider train wheel-rail contact is nonlinearity,creep force is nonlinearity and suspension parameter is nonlinearity.Utilizing finite element method to establish the dynamic analysis model to obtain the mass matrix,stiffness matrix,node coordinates and other information of the bridge.Based on the method of elastomers are coupled and integrated in a multi-body system,call the basic information of the bridge by fore treatment program of multi-body dynamic model,data exchange is carried out on discrete information points of the wheel-rail contact surface,take wind-wave load as external random excitation,and establish high-speed railway train-bridge coupling vibration refined co-simulation model under the action of wind and wave.Analyze the effects of aerodynamic loads affected by the wave-shaped bottom surface on the dynamic response of trains and bridges when wave loads,wind loads and vehicle speeds are constant.The derailment coefficient,rate of wheel load reduction,transverse force of wheelset,lateral vibration acceleration of the car body and train comfort of the limit value standard for safe operation of cross-sea bridge high-speed train under the combined action of wind and wave and the limit value standard of bridge vibration acceleration,lateral amplitude,vertical deflection and other evaluation indicators are described,analyze influence low of each parameter on train safety comfort and bridge safety to systematically evaluate dynamic responses of high-speed railway bridges under the combined action of wind and wave.