Analysis Of Vehicle-bridge Coupling Vibration Response Of Long Span Continuous Bridge

When the car passes over the bridge,it will produce huge vibration to the bridge,which will cause structural changes and stress increase,and even more serious will cause damage to the bridge components.Therefore,it is very important to discuss the influence of structural vibration caused by vehicle load on the bridge to improve the safe operation of the bridge design.The vehicle-bridge coupling vibration problem generally does not lead to the overall damage of the bridge structure,but the vibration caused by a long time of vehicle passing through the bridge structure will accelerate the fatigue,aging,cracking and other problems of the bridge components,and then increase the maintenance cost of the bridge.Therefore,the study of vehicle-induced bridge vibration of long-span continuous beam Bridges will help people to improve the bridge structure design,standardize the vehicle load,control the vehicle speed and so on to improve the service life of the bridge,which has positive theoretical and practical significance for the development of bridge engineering.In this paper,Hongshengli Bridge as the engineering background,the dynamic response of the bridge under the action of typical vehicle load simulation research and calculation.The main research contents include:(1)According to the principle of the modern automobile dynamics related mechanics,built a two degree of freedom under uniaxial two-axis vehicle plane model,four degree of freedom model and five axis pull-type car space model,and then all of the above model of car is deduced kinetics equation,using auto tire structure and pavement structure of lateral force and geometry car mechanics of balance between the vertical geometrical stress conditions,The differential equations of coupling and vibration of vehicle-bridge are derived.It lays a foundation for vibration and response analysis of vehicle-bridge coupling system.(2)In this paper,a three-dimensional finite element model of the bridge is established with the Hong Shengli Bridge as the research object,and the modal information of each order is extracted.Meanwhile,the author adopts the method of finite element nonlinear theory to carry out static analysis of the bridge structure of the large span continuous girder bridge,and based on this,the structural dynamic characteristics are studied.(3)The vibration response of a vehicle to a typical section of a continuous girder bridge is studied.The influence of vehicle loading position,vehicle speed,vehicle weight,deck smoothness and damping coefficient on the vibration response of typical sections of long-span continuous girder Bridges is studied.(4)On the basis of the traditional nonlinear analysis theory of single-vehicle vehicle-bridge coupling,a new nonlinear analysis model of multi-vehicle vehicle-bridge coupling is formed to explore the state of multi-vehicle operating and its dynamic response to the bridge.Under the condition that only the vehicles in the same lane are running at a constant speed,the changes of the dynamic response values of different vehicles in the fleet,the distance between cars and the fleet’s driving speed to the bridge are comprehensively considered,so as to determine the worst driving conditions under different working conditions.The results can be used as a reference for the design,construction and operation of long span continuous girder Bridges.