Research On Vehicle-Bridge Coupling Vibration Of Long-Span Highway Bridge

With the the development of traffic and logistics, the bridge structures are always under a busy transportation condition. The traffic density, the load and moving speed increase day by day. Meanwhile, bridges are tending towards longer, lighter and more flexible for the development of bridge construction, which attracts much attention on the interaction of the vehicles and bridges. On one hand, the dynamic impact action which is produced by the high-speed running vehicle on the bridge that it passed,will affect the operating life and active state directly; On the other hand, the vibration of bridge will also affects the security and stationarity of running vehicle. Although the bridge-vehicle interaction does not normally cause major bridge failures. But the wheel loads induce vibration of the bridge components and contribute to fatigue,surface wear, and craeking which leads to corrosion.Therefore, discussion on the dynamic coupling system of vehicles and bridge, analysis on the dynamic performances of the structure and the balanced moving performance of the vehicles are very available demand for the rational design of the large-span bridges, which will contribute deeply to the theoretical and practical improvement of structural engineering field.Based on E-Huang-Changjiang Bridge, a dynamic simulation and research about the dynamic response of the bridge are made while a motorcade passing through. The contents of this paper are as the following:(1)Summary of the research of couple vibration at home and abroad on the history and at the present time, and discuss the necessity of the study on vehicle-bridge coupled vibration systems under motorcade.(2)The static analysis is carried out using the finite element method. Reasonable original stress condition of the bridge is established by regulating original cable stress, afterwards, the dynamic characteristics are discussed. The vehicle on the bridge is simulated as a vibration system with two axes, six freedom and three masses as a series. The motion equations of vehicle are derived using the d'Alembert Principle.(3)The vehicle's dynamic characteristics are studied. The dynamic equation of the coupled system is obtained. Vehicle-bridge vibration system be divided into two sub-systems at the interface of wheel and bridge,one for the bridge and the other for the vehicle. The vehicle-bridge coupling relationship,including the geometrical static equilibrium condition and compatibility condition the between vehicle and bridge is established. The coupling system including the vibration of vehicles and bridge structure is set up based on the vehicle-bridge coupling element due to pavement's stochastic irregulation, the motion equation is solved by numerical integration method.(4)The parameter analysis was conducted to analyze the effect of factors such as road surface roughness, different vehicle velocity, vehicle number and eccentric loading.