Research On Dynamic Performance Of Train On Bridge Under Unsteady Aerodynamic Load Based On Rigid Flexible Coupling Method

With the rapid development of high-speed railway,it is particularly important to keep the lines straight and smooth,and Bridges have unique advantages,so that the proportion of high-speed railway Bridges is rising.The design of speeding up and lighting the train puts forward higher requirements for the safety and comfort of the train running on the bridge.The dynamic performance of bogie is the key factor affecting the stability and safety of vehicle.Influenced by different climate and geological conditions along the route,the safety of high-speed trains crossing the bridge is very complicated,especially the safety and comfort of high-speed trains crossing the bridge under transverse wind conditions.This paper focuses on the safety and comfort of running trains on the bridge under cross wind,and the main work is as follows:(1)Based on multi-body dynamics software SIMPACK joint simulation with finite element analysis software ANSYS,established 50 degrees of freedom vehicle multi-body dynamics analysis model of four axis,as well as 3 across 32 m of simply supported box of railway bridge and 96 m UIC60 steel rail of the finite element substructure models,using the improved simulation method to establish fine train/track coupled vibration of train-bridge system model,and preliminary verified by an example analysis in this paper to establish the train-track-bridge modeling analysis method is feasible and the correctness of the simulation results.(2)Aiming at the dynamic performance of bogie of high-speed train on the bridge,to high-speed train safe and comfortable operation demand as the goal,the concrete analysis type wheel tread secondary suspension system,a system and main influencing factors,are analyzed to study the driving safety and stability of the train running on the bridge,and the dynamics of high-speed train bogie for the bridge design and optimization of support.It also provides optimized vehicle parameters for the follow-up wind-train-track-bridge coupling vibration analysis model.(3)Through CFD numerical simulation,calculates the 10 m/s combine wind speed,the three-component force coefficients of vehicles under different wind yaw angles are obtained for the three-dimensional numerical model of train-simply supported beam bridge,fitting the steady aerodynamic load coefficient and the relationship between the wind yaw angle curve,and by considering the flow pulsation characteristics of wind speed,established the train under different wind speed and the speed of aerodynamic load model,which lays a foundation for the calculation of wind-train-railway-bridge model.(4)Based on the train-track-bridge coupling model,the unsteady aerodynamic load model of the train is introduced to calculate the dynamic response of the wind-train-track-bridge coupling system.The running safety and comfort of the train on the bridge under the action of steady and unsteady aerodynamic loads are compared,and the influence of different transverse wind speed on the running safety of the train under the action of unsteady aerodynamic loads is studied.The results show that the aerodynamic load of simple supported box girder bridge has little influence on the dynamic response of train on the bridge;considering the influence of unsteady aerodynamic load will not only make the evaluation results safer,but also make the evaluation results of train comfort more conservative,and give the control speed of train on the bridge under the action of unsteady aerodynamic load.