The Research On Vehicle-Bridge Coupling And Vibration Response Of High-speed Railway Curved Bridge

For the curve is always the weak link in the rail structures, the track maintenance, the wear and tear of steel rail, and the train derailment of the curved bridge have come the serious problems .In the respect of academic value and engineering practice, it is necessary to develop the study on the vehicle-bridge coupling dynamic problem to ensure the running safety and riding comfort and design the proper curve parameters of the bridge.Based on the summery of others'experience of studies, a deeper research has been conducted in this thesis on the vehicle-bridge coupling dynamic stimulation on the curved bridge .The key points are shown as follows:1. The introduction has been made of how to set up the analysis model of the vehicle subsystem and bridge subsystem for the vehicle-bridge coupling dynamic program. Besides, how to solve the lateral centrifugal force when the vehicle travels along a curved path is also offered.2. According to the balanced relationship between the geometric harmony and the force, the formula of displacement compatibility condition has been deduced under the condition of single or double vehicles' running ,as well as the amount of the relative compression between the wheel and track .The calculate formations of the interactional force between the wheel set and the bridge is proposed ,which acts as the coupled relation between wheel and track to solve problem of the dynamic response between the vehicle and bridge.3. The stimulation of different speeds and accelerations of different irregularities of track has been offered. The stimulated results of the German displacement , speed and acceleration of the track spectrum is also displayed. To some extent, we can take the track gauge widening while the vehicles passing through the curved path and the superelevation of outer rail as the rail irregularities resulting in its changes of track geometry. Then we can solve the geometrical contact problem between the wheel and track by modifying the ordinate values of the discrete points of the wheel sets and track profiles. 4. Through the vehicle-bridge coupling stimulated dynamic process and engineering cases ,it analyses the influence of the curve track superelevation, the radius, the running speed of vehicle and the bridge span on the vehicle-bridge coupling dynamic response on the curved bridge .The results indicate:the setting up of superelevation on curve will enlarge the contact angle and comparative displacement between the wheel set and outside track .The situation of two point contact may probably appear ,making the geometric contact relation between the wheel and track more complicated ;As the curvature radius increasing ,the lateral force and displacement of the wheel set will decrease in different degrees .The survey shows when the curvature radius is relatively small, the outside wheel will inevitably come near to the outside track.The lateral interaction will be more fierce ,so it is very important to set the curvature radius properly for the vehicle-bridge coupling response. The higher the running speed ,the bigger the all kinds of the response index .When the speed has reached a certain degree ,the lateral force and displacement of the wheel set will increase noticeably .The influence of speed on the bridge vertical vibration response is comparatively obvious and the lateral displacement is comparatively small. In the circumstances of bigger radius of curve, the maxima and minima of the vertical and lateral displacement of bridge midspan vary reversely with the bridge span, like the straight bridge's.