Coupling Vibration Study Of Vehicle-Bridge Under Special Running State

In recent years, with the rapid development of national highway transportation, the continuously increasing of traffic volume and axle load, the loading of highway bridges becomes aggravating. At the same time, high-strength materials are widely used in the bridge projects to fulfill the demands of the bridge structure and aesthetics. It makes the structure of the bridge lighter, thinner and longer. The vehicle moving loads would lead to complex dynamical coupling effect. It also produces more deformation and stress for bridge structures than the static loads. So, the dynamic response of highway bridges becomes one of the most important subjects in bridge dynamics when subjected to vehicle moving loads.By synthesizing a great deal of related literature, the author has summarized the typical research theory, the methods of computing and analysis and the elementary findings of the dynamics of the coupling vibration of vehicle-bridge. The job on the base of the above work has been done as follows:The thesis introduces two modals of the vehicle, a quarter vehicle modal with two degrees of freedom and a half vehicle modal with four degrees of freedom. The bridge is simplified as a uniform Euler-Bernoulli beam.In this thesis, bridge and vehicle are taken as two separate systems, and then the discrete equations are established. Secondly, they are connected by the condition of geometric coordination conditions and static force equilibrium, and the coupling equation of bridge-vehicle vibration is established. At last, NEWMARK method is used in the MATLAB procedures to solve the equation.The thesis focuses on the coupling vibration of vehicle-bridge under the special running state. Considering the typical road surface roughness, the author chooses two special running states such as vehicle pitching and braking, and then, puts the dynamic behavior of the coupling vibration of vehicle-bridge and the impact effect of bridge into research and discussion. On the basis of the research, we can get some elementary findings about the dynamic response of vehicle-bridge system, and it offers the reference and theoretical basis to the further study of the vehicle-bridge coupling vibration and engineering practice.