Coupling Vibration Study Of Automobile And Girder Bridge Of Continuous System Of Time-varying System Based On Separated Iterative Method

With the increasing of the traffic,improving of driving speed and loading of the freight vehicle recently,the problem of mutual coupling between vehicle and bridge is increasingly outstanding.Meanwhile,girder bridge of continuous system(including continuous beam bridge and simple-supported to continuous beam bridge)is applied widely in highway bridge,further study of dynamic response and influencing factors of vehicle-bridge coupling is required.In addition,because of special construction technology,the stress and stiffness distribution of simple-supported to continuous beam bridge are constantly changing during the process of system transformation,and the final completion state is difference from corresponding continuous beam bridge,so it is worthy of further research of dynamic response and influencing factors of vehicle-bridge coupling of continuous beam bridge and simple-supported to continuous beam bridge.Therefore,according to separate-alternate method of vehicle-bridge coupling vibration analysis theory,by using APDL language of finite element program ANSYS to compile vehicle-girder bridge of continuous system coupling vibration analysis program,this paper compared and analyzed the dynamic response and influencing factors of vehicle-bridge coupling of continuous beam bridge and simple-supported to continuous beam bridge based on girder bridge of continuous system.The main research contents are as follows:1.Establishment of automobile-girder bridge of continuous system dynamic analysis modelThis paper established dynamic analysis model of girder bridge of continuous system(including continuous beam bridge and simple-supported to continuous beam bridge)by using ANSYS;discretized the automobile in system of muti-rigid-body connected by spring and damper,and introduced main parameters of automobile spatial vibration analysis model based on three axle vehicle with six wheels,nine degrees of freedom were considered in this vehicle model;the surface irregularity of bridge was regarded as stable stochastic process,after the selection of power spectral density function,it compiled program to simulate sample values by using trigonometric series method through MATLAB.2.Derivation of vibration equation of vehicle-girder bridge of continuous system coupling systemThis paper divided vehicle and bridge into two subsystems taking the contact point of wheel and bridge deck as separatrix based on separate-alternate method of vehicle-bridge coupling vibration analysis theory,and through the displacement compatibility of contact point of wheel and bridge deck,and equilibrium condition of interaction force,it established vibration equation of vehicle and bridge respectively.3.Compilation of vehicle-girder bridge of continuous system coupling vibration analysis programBased on separate-alternate method of vehicle-bridge coupling vibration analysis theory,this paper compiled vehicle-girder bridge of continuous system coupling vibration analysis program by using APDL language of ANSYS,and then verified the reliability of this program through calculation example.In this example,vehicle was discretized as muti-rigid-body model connected by spring and damper,the method of Newmark-? was adopted to solve motion equation of vehicle and bridge,and through cyclic iteraton this paper obtained dynamic response of vehicle and bridge.4.Vibration analysis of vehicle-bridge coupling system of continuous beam bridgeBy taking a continuous beam bridge as research object,this paper calculated dynamic response of vehicle-bridge coupling system of continuous beam bridge by using self-compiling program,and studied the influence of some factors to dynamic response of vehicle-bridge coupling system,such as vehicle number,vehicle spacing,different lanes,running speed the grade of bridge deck and so on based on threee axle vehicle model,then analyzed and evaluated vibration response of bridge and safety of vehicle.5.Vibration analysis of vehicle-bridge coupling system of simple-supported to continuous beam bridgeBy taking simple-supported to continuous beam bridge that has the same sectional characteristic with continuous beam bridge mentioned above as the research object,this paper proposed the dynamic analysis model of simple-supported to continuous beam bridge.This model can take the difference of stress characteristics and finished bridge state between simple-supported to continuous beam bridge and continuous beam bridge into consideration.This paper analyzed the dynamic response and influencing factors of vehicle-bridge coupling of this simple-supported to continuous beam bridge,and then compared with dynamic response of continuous beam bridge.