Analysis Of Aerodynamic Characteristics And Coupling Vibration Of Wind-Vehicle-Bridge System Of Trains Passing Each Other On A Simply Supported Box Girder Bridge

Nowadays,a big amount of high-speed railways are already accomplished or under construction.The public have higher requirement on security and comfortable capability of trains.The dynamic response of train is mainly affected by the excitation of track irregularity,the vibration of bridge and the wind load on train and bridge,among which the wind load is an important factor.Because the wind load acting on the leeward side of the train will change abruptly in the whole process of two trains intersection,which is very unfavorable to the safety and comfort of the train,it is necessary to study the aerodynamic characteristics and the dynamic response analysis of the train in the process of intersection.In this thesis,the aerodynamic characteristics during trains intersection are analyzed by wind tunnel test,CFD numerical simulation method.The dynamic response is analyzed by MATLAB program based on the theory of wind-vehicle-bridge coupling vibration.1.Through the wind tunnel test,it was chosen to compare the differences of the test data between the static and dynamic model.For the lift coefficient,the data of static model is less than that of the dynamic model.For the side force coefficient and rolling moment coefficient,the data of static model are bigger than that of the dynamic test.2.The wind tunnel test results show that the length of the intersection affected area is more affected by the train speed rather than the wind speed.For aerodynamic force,with the increment of the wind velocity,the change variable values of aerodynamic force becomes larger.For aerodynamic coefficient,with the increment of the yaw angle,the change variable values of lift coefficient becomes larger.The side force coefficient and rolling moment coefficient are contrary to the law of lift coefficient.For the convenience of engineering application,the fitting curves and certain formulas of the three-component aerodynamic coefficient changing with the yaw angle were obtained through curve fitting.3.By using the computational fluid dynamics(CFD)numerical simulation method and overlapping grid technology,the pressure distributed around the car body surface is studied,and the time series of aerodynamic force and coefficients in the process of two trains rendezvous are explained.4.Based on the theory of wind-vehicle-bridge coupling vibration analysis,the change law of train dynamic response in the process of two vehicle rendezvous is explored by MATLAB calculation program.It reflects that with the increment of the wind velocity,the dynamic response of train(including transverse and vertical wheel contact force,transverse and vertical acceleration,transverse and vertical Sperling index and derailment coefficient)increase;With the increment of vehicle velocity,the transverse dynamic response of train and derailment coefficient increase,but the vertical dynamic response decrease.