The Research Of Vehicle-bridge Coupling Dynamic Calculation Method Based On ANSYS

The bridge vibrates when the vehicle crosses bridge and the vibration of bridge also affects the vibration of vehicle,so the relation of impact on each other is called the vehicle-bridge coupling vibration.At present,our country is in the peak period of railway construction.A large number of railways need to be evaluated and optimized by vehicle-bridge coupling dynamic analysis.The traditional method of vehicle-bridge coupling dynamic calculation is relatively complex and has higher requirements to researchers.Therefore,it is of great significance to select a widely applied and general structural analysis software to solve the vehicle bridge coupling vibration problem.On this account,the vehicle-bridge coupling dynamic calculation method based on ANSYS is established in this paper.The main work is as follows:(1)Based on 27 degrees of freedom vehicle theoretical model and the Lagrange motion equation,finally,stiffness matrix,damping matrix of the vehicle system and the dynamic balance equations of vehicle-bridge system are derived.In addition,this chapter also introduces a method of solving the vehicle-bridge coupling system which is easy to use and has clear physical meaning—Inter-system iteration method.(2)With the vehicle body,bogies and wheels simulated by MASS21 unit,the springs and dampers simulated by COMBIN14 unit and the rigid connections simulated by MASS21,finally,the finite element model of the vehicle based on ANSYS is established.Through the ANSYS modal analysis,the first 15 natural frequencies of the finite element model of vehicle are obtained,which are consistent with the theoretical natural frequencies.Based on the calculation example of CRH2 vehicle through the 32m simply supported beam bridge of railway,vehicle-bridge coupling dynamic calculation method based on ANSYS is established,and the dynamic responses of the vehicle-bridge system are obtained.Compared with the dynamic responses of the vehicle-bridge system solved by the method based on the MATLAB programming,the results of the two methods are basically consistent,which proves the feasibility and accuracy of the vehicle-bridge coupling dynamic calculation method based on ANSYS.(3)Through the method of vehicle-bridge coupling dynamic calculation method based on ANSYS,the main bridge of Wei Fen River Bridge is analyzed and solved.This bridge is 5 spans(70+3×120+70)m rigid frame bridge,and its length is 500m;the train is a marshaling of 40 trucks whose axle load is 25t,and its length is 479m.Through calculation,in the range of 75-150km/h speed,the vehicle safety,vehicle stability and the dynamic performance of main bridge of the Wei Fen River Bridge is satisfied with the limit value.At the speed of 125km/h,the main bridge of the Wei Fen River Bridge appears the phenomenon of beat vibration,and the vertical dynamic response of the bridge reaches peak value.The results of this study show that the vehicle-bridge coupling dynamic calculation method based on ANSYS is feasible and accurate.This method avoids the programming,and does not need a variety of software.So it is conducive to the majority of engineering personnel to master and has certain significance to the practical application of the vehicle-bridge coupling theory.