Vehicle-bridge Coupled Vibration Analysis Of Simply Supported Steel Truss Bridge On High Speed Railway

With the rapid improvement of China's economy,high-speed rail transportation has become the backbone of China's modern transportation system.In order to meet the needs of high-speed railway trains for high-speed and smooth operation,bridges occupy a high proportion.Therefore,the safety and stability of high-speed trains running on bridges deserves our careful study.In this paper,based on the relevant theory,a four-axis 42-degree-of-freedom vehicle vibration analysis model and a kinematics equation of the vehicle are established.The wheel-rail effect and the track source irregularity of the axle system are analyzed.Then the bridge motion equation is established based on the 96 m simple-supported steel truss bridge of Yinchuan Yellow River Bridge of Yinwu Railway.The space model and vehicle model of simply supported steel truss bridge are established according to finite element software and multi-body dynamics software.A comparative analysis of dynamic characteristics was performed.Finally,the balance equation of the axle system is established and the solution method is introduced.Co-simulation was implemented in the general finite element software ANSYS and UM using data exchange.According to the vibration performance evaluation standards of vehicles and bridges at home and abroad,combined with the engineering background of this paper,the data analysis basis is provided for the results of subsequent analysis.At the same time,the simulation results of the simply supported steel truss bridge were analyzed in detail and the vibration performance evaluation of the axle system was carried out.Finally,different factors of the axle coupling system are studied and analyzed.The factors and conclusions of vehicle-bridge coupling vibration are obtained by data processing:(1)When the vehicle passes the steel truss bridge,the vibration performance of the axle meets the requirements;the lateral vibration of the upper chord is larger than that of the lower chord,but the vertical vibration of the lower chord is larger;the vertical displacement of the vertical rod at the middle The lateral displacement is greater than the vertical rod at 3L/8.(2)The vibration response of vehicle-bridge increases with the increase of speed,but it does not increase linearly.There will be a peak at the critical speed: with the increase of speed,the vibration of bridge members will become more intense.(3)When the vehicle is not full of bridges,as the number of vehicles increases,the vibration response of the bridge increases and increases rapidly: when the vehicle is covered with bridge spans,the influence of the vehicle increases slowly with the increase of the number of vehicles;In the regrouping,the vibration performance evaluation values of different vehicles(trailers and motor trains)are relatively small(derailment coefficient,sperling,wheel load shedding rate,acceleration),safety and stability are better,but the wheel and rail force of heavy vehicles More than an empty car.(4)When the bridge is subjected to eccentric load,the transverse displacement and acceleration in the middle of the span of the bridge at different speeds are larger than that in the center;the vertical displacement in the middle of the span of the bridge basically does not change much with the eccentricity of the load.The trough appears at 350 km/h and the resonance phenomenon occurs at 300 km/h.(5)When the degree of track irregularity increases,all the vibration response indexes of the vehicle increase relatively,and the acceleration and displacement of the bridge and the dynamic coefficient also increase.It can be concluded that the vehicle body is large when the track irregularity is large.The vibration of the bridge is more severe,and the ride comfort and safety are poor.(6)When the damping ratio of the bridge changes,the vibration of the bridge itself has an influence,which will indirectly affect the vibration of the vehicle.The change of the damping factor of the bridge has a relatively small impact on the vibration response of the vehicle,mainly affecting the vibration response of the bridge.Damping can improve the shock absorption effect and increase the safety of vehicle driving to a certain extent.