Preliminary Studies On Coupling Vibration Of Wind-Vehicle-Bridge System

In order to cross over rivers or valleys the mankind has constructed lots of long-span continuous rigid frame bridges, and thanks to magnification effect the wind velocity in valleys are usually higher than that in flat areas. And with the increase of bridge span, the stiffness and the damper of bridges become lower and lower, that cause bridges are more sensitive to the wind. The comfort and safety of vehicle on the bridge under turbulent wind is a important issue that should be studied seriously.so the study on coupling vibration system of wind-vehicle-bridge has profound impact on theories and utility. My dissertation bases on the dynamic responses of the vehicle and bridge of the coupling vibration of wind-vehicle-bridge system. This research is focused mainly on the following aspects:1,The dissertation has analyzed several classic theories on the coupling vibration of vehicle-bridge system through calculation and results comparison.2,The turbulent wind velocity sample is simulated by improved WAWS method by utilizing measured turbulence wind spectrums. The aerostatic factors of some representative section are simulated by fluid software FLUENT. The 13 DOF dynamic equations of two axle vehicle model are set up. The road roughness sample has already been simulated. The comfort of vehicle running on the road under various road roughness,wind velocity and vehicle speed is investigated by using wind-vehicle program.3,Coupling vehicle-bridge vibration system can be assumed as two different independent subsystems, one for bridge and another for vehicle, the geometric and mechanical coupling relation between bridge and vehicle are introduced, and a separated iterative method is utilized to solve the dynamic equations of the coupling vibration system.4,A model of coupling vibration system of vehicle and bridge under lateral turbulent wind is established. The impacts of vehicle running on the bridge under lateral wind or without lateral wind are investigated. The influences of vehicle speed, wind velocity and road roughness on comfort of vehicle moving on the bridge are discussed in detail. At last the influenced of crosswind and vehicles on vibration of bridge are studied.