Vehicle-bridge Coupled Dynamical Numerical Analysis For Long Span Self-anchored Suspension Bridge

In recent years, with bridges getting lighter and more flexible, meanwhile the speed and weight of vehicles growing greater, the problem of coupled 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. But, little documents on theories and methods of coupling vibration of vehicle-bridge for complex highway bridges can be found either in homeland or abroad.The self-anchored suspension bridge has good mechanical properties, the beautiful appearance, good ability to adapt to the topography of the advantages. So, engineers pay more and more attention to self-anchored suspension bridge. Over the past 20 years, dozens of self-anchored suspension bridges had been built. However, the vehicle-bridge vibration interaction of self-anchored suspension bridge is still blank at homeland and abroad. With widely application of finite element technique and large-scale structure analysis software, 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 self-anchored suspension bridge).Taking some self-anchored suspension bridge as engineering background. The paper establishes two models of 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 is obtained by programming analysis software with precise time-integration method for vehicles vibration in MATLAB language. Compared with Wilson-θmethod, the precise time-integration method excludes the effect of algorithmic damping. The numerical results show that this method is more efficient. 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. With this method, the paper also analyzes the coupling vibration of vehicle-bridge for self-anchored suspension bridge under conditions of different vehicle models, different vehicle velocities, and the bridge deck roughness, studying the main influencing parameters and response rule.In this paper, coupled vibration analysis of vehicle-bridge is realized by the general finite element software, and a kind of reliable numerical method is supported for evaluation of self-anchored suspension bridges in vibration performance.