Simulation Approach To The Main Factors Of Vehicle-bridge Coupled Vibration

In recent years, with bridges getting lighter and more flexible, meanwhile the speed and weight of vehicles growing greater, the problem for coupling vibration of vehicle-bridge becomes further outstanding. For the styles of highway bridges are diversified and the weight of vehicles is complex and uncertain, the bridge vibration analysis caused by moving vehicles becomes even more complex.At present, these researches are mainly focused on railway bridges. Little documents on theories and methods of coupling vibration of vehicle-bridge can be found either in homeland or abroad. It is important to find a method based on existing finite element to solve the coupling vibration of vehicle-bridge for complex bridges (such as bridge deck roughness, non-linear suspension and vehicle acceleration and so on).This paper, as an important constituent of foundation research project of communication application by Traffic Ministry《Analysis of evaluation and methods on the dynamic properties for curved bridge》,performs a model experimentation of vehicle-bridge coupled vibration and analyzes the rule of coupling vibration properties between them. The paper establishes a four degree of freedom models of linear suspension and non-linear suspension vehicle-bridge coupled vibrations, in which the bridge and the vehicles are separated into two systems. Dynamic equations have been deduced with virtual work principle and finite element method, providing geometrical compatibility equations and equilibrium equations of the interaction forces between the bridge and vehicle. The vehicle vibration response was obtained by programming analysis software with Wilson-θmethod for non-linear suspension vehicles vibration in MATLAB language. Being based on existing software ANSYS, the paper studies a finite element iterative method of vehicle-bridge coupled system in conditions of geometrical compatibility and equilibrium of the interaction forces between the bridge and vehicle. The paper studies the value of different pavement roughness by Fourier reverse transform according to the power spectral density function advised by GB7031-1986, and they were applied to bridge deck roughness. The paper also establishes uniformly variable speeds vehicle-bridge couple vibrations model.Aimed at simply supported beam and continuous beam, the paper analyzes the coupling vibration of vehicle-bridge under conditions of different bridge deck roughness,different vehicle velocities,different non-linear suspension vehicle model and different acceleration of vehicle to study the influent rule of dynamic factor caused by main factors. The results show that brideg deck roughness,vehicel velocities,vehicle acceleration and so on have a salient effect on vehicle-bridge coupled vibration. The acheievements can serve as basic references for vehicle-bridge coupled vibration in the complex structure bridges.