Analyzing Vehicle-bridge Coupled Vibration Of Simple Beam Bridge Subjected To Moving Loads

Dynamic effects will happen on the bridge, when vehicles pass through the bridge with a certain speed, such as vibration and impact, etc. The vibration of bridge also has a reverse effect on vehicles moving. This interaction problem between vehicles and bridge is called vehicle-bridge coupled vibration. The upper structure vibration of bridge caused by the vehicles driving force may lead the structural component fatigue or reduction of the strength and stability. Largely vibration of bridge will influence the safety and stability of vehicles on it. With the rapid development of the China economy, speed of vehicles is increasing heavily and bridge structures have tended to become long-span and light. Both of that make the problem of the coupled vibration of vehicle-bridge system become more serious increasingly. Therefore, more and more attention are paid on the studies of the coupled vibration of the vehicle-bridge system in the engineering field.This paper studied the coupled vibration of vehicle-bridge system,based on summarizing and absorbing the achievement of pioneer works. The main research work is as follows:1. Based on the finite element theory, the mathematic model of the coupled vibration of vehicle-bridge system are established. The dynamic equation of vehicle and the expression of the interaction force between vehicle and bridge are derived as well as the mass, damping, stiffness matrices considering the interaction between the vehicle and the bridge.2. The dynamic performance of simply supported beam and continuous beam subjected to the vehicles loads are analyzed and researched. Also the influence inducing by vehicle speed change on dynamic response of vehicle-bridges is considered. The higher the speed, the greater impact on the bridge.3. In this paper, on the base of commercial software ANSYS, taking full advantage of its strong pre-and post-processing, multi-user activity tools, the dynamic response of bridge with moving vehicles is analyzed.4. A calculating program is made with MATLAB,and obtained numerical solution. A set of response figures are drawn according to solutions;By comparing to ANSYS solution, the difference is very little . This prove that the analysis of the coupled vibration of vehicle-bridge with ANSYS is possible. 5. Take MaAnShan cable stayed bridge as an example, considering of nolineer effect(large deformation,beam-pillar,cable vertical effect).6. Then coupled vibration of vehicle-bridge is analyzed . The results show that when consider nolinear effect ,the lagerest displacement response of bridge cross is smaller than the linear condition,and appears earlier,also the displacement fluctaated rapidly.