The Analysis On Vehicle-bridge Coupled Vibration For Railway Large-span Simply Supported Steel Truss Bridge

When the vehicles passes through the bridges will cause the vibration of the bridge structure, and the vibration of bridges structure, in turn, will affect the vibration of the vehicles, it is called vehicle- bridge coupled vibration problem. With the constant improvement of the vehicle speed and load, and the extensive use of bridge structure on the railway line,in order to evaluate the steel truss for effective operation state and comfort, safety and stability of the vehicle, as well as provide reference for optimization design of similar bridges for future, the paper need to analysis the vehicle of railway long-span steel truss bridge coupled vibration research.In this paper, taking a 156 m simply supported steel truss beam bridge of Huang Han hou New Yellow River railway bridge as the engineering background to make vehicle-bridge coupled vibration. Firstly, according to the dynamic equations of the principle of Lagrange, the vehicle dynamic model which has four-sxis and vehicle dynamic vibration equation are established by selecting the 27 degrees of freedom. The bridge subsystem model and the dynamics equations are established by modal synthesis method. The interaction between the wheel and rail were analyzed and summarized, establishing the general equations of vehicle-bridge coupled vibration system uses the artificial crawl wave function and the track irregularity as the excitation of the system, and introduces the method for solving the dynamic equations of the coupled vibration of vehicle bridge and co-simulation technology. Then, the performance evaluation criteria of many countries vehicle-bridge coupled vibration was compared and summarized. At the same time, according to the project background of this paper and the related parameters, establishing the steel truss bridge finite element model of New Yellow River bridge, which was used to calculate its dynamic characteristics through ANSYS and MIDAS/CIVIL softwares, and its natural frequency was assessed by a lot of national standards. Finally, when a single locomotive, marshalling buses and trucks pass the bridge by the design speed, the co-simulation technology of ANSYS and UM softwares was used to achieve the vehicle-bridge coupled vibration of long span simply supported steel truss bridge. Moreover, the dynamic response parameters of vehicle and bridge are analyzed and summarized, and calculate the resonance speed.. Last but not means least, influence of the bridge structure of portal frame, wide span ratio, curve of steel truss and vehicle systems track irregularity and marshalling angles of trucks on the vehicle-bridge coupled vibration system of the large span simply supported steel truss are discussed.Through calculation and analysis found:(1)The lateral stiffness of the large span steel truss bridge is relatively small;(2)the dynamic response parameters of vehicle and bridge are all within the allowable range when the different marshallings of using design speed passed the bridge;(3) the gantry of steel truss girder bridge has great influence on the acceleration;(4)With the line radius of the curved steel truss bridge increasing,the vehicle dynamic response parameters becomes smaller, and wheel-rail force affected;(5)Increasing wide span ratio of steel truss girder bridge makes lateral stiffness of wide steel truss bridge increases, and bridge lateral vibration smaller;(6)with the track conditions becoming worse,the dynamic responses of the vehicle showed a gradual increase while the overall trend, and vehicle safety, comfort and stability became gradually worse;(7)The full empty mixed grouping and empty weight mixed grouping form is harmful to the coupled system of steel truss bridge- vehicle, which should be avoided in practice.