Coupled Vibration Simulation Analysis Of High Speed Train-simply Supported Beam Bridge

With the vigorous construction and development of high-speed railway,more and more vehicle-bridge vibration problems are accompanied.In order to solve the vibration problems and ensure the safe operation of trains,it is need to study the influencing factors of vehicle-bridge coupling vibration response.Firstly,the development history and research status of vehicle-bridge coupled vibration theory at home and abroad,as well as the influencing factors and research methods of vehicle-bridge coupled vibration system are summarized.Then it introduces the classification of track irregularities and typical track spectra,as well as the evaluation criteria and limits of vehicle-bridge dynamic indices.Then the basic assumptions of the vehicle model and the determination of the degree of freedom,the vehicle motion equation,the wheel-rail interaction relationship and the bridge motion equation are described in detail,and the methods to solve the system motion equation are given,which are the mode superposition method and Newmark-beta integration method.Secondly,the vehicle-track model and the finite element software ANSYS are used to establish the simply supported beam model of Shihe No.2 super bridge,and the vibration mode and natural frequency of the bridge are analyzed.Using UM and ANSYS establishes model.Then the simulation results of vehicles and bridges are obtained through the joint simulation.Comparing the computed results with the measured results,The error is within the allowable range,and verifies the rationality and accuracy of the axle model.Meanwhile,the change trend of vehicle and bridge dynamic index under different speeds is analyzed.The result shows that the dynamic index of vehicle and bridge increases with the train speed.The increase of train speed can increase the vibration response of vehicle and bridge.Finally,the influence factors of vehicle-bridge coupling vibration of railway simply supported girder bridge are studied,including pier lateral stiffness,rail bottom slope,track irregularity,vehicle tread and track model.By analyzing the simulation results of vehicle and bridge dynamic indices,the following conclusions are drawn: the dynamic indices of vehicle and Bridge increase with the decrease of pier lateral stiffness ratio,and when the ratio is less than 0.65,the dynamic indices of vehicle and bridge increase rapidly.When pier lateral stiffness decrease continuously,the transverse displacement in the middle of the span increases exponentially,so the safety and stability of the train can not be guaranteed when it crosses the bridge;for the rail bottom slope,the dynamic response of the vehicle and the bridge is smaller than that of the rail bottom slope at 0.025,which indicates that the rail bottom slope is 0.025 more reasonable than that of 0.05;the dynamic index of the vehicle and the bridge varies bigger with the track smoothness.For the vehicle tread,the vibration response of the bridge with LMA tread is smaller,which indicates that the matching of LMA tread and track is more reasonable and suitable.In addition,the transverse power of the bridge is increased by different vehicle treads,but the vertical power is not affected much.For the track model,the maximum dynamic indices of vehicles and bridges under the mass-less track are larger than those under the moving mass track,which indicates that the moving mass track can more truly reflect the dynamic response of vehicles and bridges than that under the mass-less track.