Spatial Dynamic Response Of Hinge Joint Voided Slab Bridge Due To Moving Vehicles

Bridge vibration under moving vehicle loads is a complex dynamic problem. It has many influence factors. Analysis of the factors that affect the vehicle-bridge coupled vibration has been a pressing concern of the engineering. With the rapid development of road transport, the number of new bridges is increasing, and slab bridges of small and medium span still occupy a large proportion. Thus spatial dynamic response and its effect in research of this type of bridges are particularly important.By the actual project as an example, Lagrange equation is used to derive three-axis plane vehicle model of five degrees of freedom and triaxial spatial vehicle model of nine degrees of freedom. Spatial model of finite element analysis of hinge joint voided slab bridge is established by ANSYS software. The interaction between vehicle and bridge is treated as two vibration systems. Establish the equations of motion of vehicle and bridge respectively. And get the relationship of the two models by displacement compatibility conditions and force equilibrium condition of the contact point between the vehicle and the bridge. Using ANSYS software, we analyze dynamic characteristics of established bridge model, obtain dynamic analysis model of bridge, and compile the program of vehicle-bridge interaction to solve dynamic response of bridge due to moving vehicles. And analyze the impact of vehicle speed, flatness, vehicle weight, deck pavement, bridge width and other factors on the dynamic response of hinge joint voided slab bridge. The results show that vehicle speed has a little influence on bridge vibration but flatness has great impact on bridge vibration, and the level of road is lower, bridge vibration will be more intense. When weight of vehicle increases, the deflection value of bridge has a rapid growth, but the growth of dynamic part is essentially the same, and impact coefficient decreases with weight increasing. When vehicle is eccentric driving, the maximum dynamic deflection of bridge is large. Dynamic deflection of bridge is larger under multi- vehicle driving in the same direction than under single- vehicle driving. The bridge spatial dynamic response curves of plane three-axis vehicle model and that of spatial three-axis vehicle model are almost close, the accuracy of calculation is also little difference. So using plane three-axis vehicle model to analyze spatial dynamic response is appropriate. The dynamic deflection value of no bridge deck pavement is greater than that of bridge deck pavement. Each plate dynamic response of bridge is different with different bridge widths. Under the same condition, bridge width is more narrow, dynamic response of bridge will be greater. Impact coefficient changes with vehicle speed, but not a linear increasing. Whether to consider the role of pavement has little effect on the calculation results of impact coefficient of hinge joint voided slab wide bridge, but bridge deck flatness has a great effect on impact coefficient, and level of road is lower, impact coefficient will be greater.Using beam model to solve dynamic response of bridge due to moving vehicles does not consider the spatial effect of bridge, and the dynamic response obtained is obviously too small, which is unsafe. But using spatial model to solve dynamic response of bridge obtains similar results with experiment.