Research On Bridge Structure Dynamic Performance Under High-Speed Train

High-speed railway is a systematic engineering which refers to a wide range of professions and high technique.With the development of our country's economy and the pursuing of a society which saves energy sources,high-speed railway springs up.In the construction of high-speed railway,bridge occupies large proportion.As the bridge deformation are restricted strictly by high-speed railway,whereas the design of bridge structure adopts the static method which can not reflect the dynamic interaction among the railway and bridge at present.This problem will become more and more obvious with the improve of the train speed.Take use of the large common finite element program ANSYS,found proper model which considers the dynamic interaction among the railway and bridge,pay attentionon to the high-speed railway bridge, mainly study as follows:(1) Taking use of the APDL (ANSYS Parametric Design Language) in ANSYS, found dynamic model of vehicle-bridge system, simulations the vehiele by means of moving load,moving mass,moving spring mass system and four-degree-of freedom vehicle model respectively. Through the analysis of dynamic deflection variation curve under moving load,point out dead weight and inertia force plays an important role in bridge dynamic deflection. Obtained that compared with moving spring mass system and four-degree-of freedom vehicle model, moving load and moving mass model calculation results are somewhat conservative.(2) Analysis and research simply supported beam and continuous beam dynamic performance under high-speed trains, obtained dynamic deflection and vertical acceleration of bridge structures are nonlinear relationship between speed, the dynamic deflection and vertical acceleration of bridge structures are linear relationship between load mass, the dynamic deflection and vertical acceleration of bridge structures are nonlinear relationship between structural damping and stiffness. Increase the structure damping ratio and stiffness in appropriate range can effectively restrain bridge vibration.(3) By analysis continuous beam bearings force and deformation under the action of high-speed trains, obtained that support reactions and rotation at the corner are irregular changed with the velocity curve;support reactions and rotation at the corner increase in proportion to the moving load. Structural damping ratio hardly influenced on support reactions, but can be a good control of support rotation at the corner.