Numerical Simulation Of Aerodynamic Characteristics Of Vehicle-Bridge System And Analysis Of The Traffic Safety Near The Bridge Tower

The tower is usually quite large for the cable-stayed bridge and suspension bridge which has bridge tower. The aerodynamic coefficients of vehicle running near the bridge tower will have a quite complex change, when the bridge tower has a strongly impact on the flow field of strong wind which blows to it, and traffic safety will be also affected. The vehicle is attacked by the wind suddenly when it is driven away from the bridge tower or the wind action on the vehicle disappears suddenly when the vehicle is driven into the bridge tower, which will cause the aerodynamic force of vehicle changing rapidly, and traffic accident will happen easily if the driver dose not adjust moving state in time. It is necessary to study the aerodynamic characteristics of vehicle near the bridge tower.In this thesis, the Xiangshangang bridge in Ningbo is selected as an example. The aerodynamic characteristics of vehicle and main girder are investigated near the bridge tower, and preliminary research is performed on traffic safety.1. The aerodynamic characteristics of vehicle are studied near the bridge tower. With the influence of the bridge tower, the aerodynamic coefficients of vehicle are changed obviously, and the effects of attack angle, yaw angle, longitudinal position, traffic lane and vehicle type on those coefficients are discussed.2. The aerodynamic characteristics of main girder are investigated near the bridge tower. The aerodynamic coefficients of main girder decrease when the position is close to the bridge tower. The aerodynamic coefficients of main girder increase when the position is a short distance away from the bridge tower. The rule of the aerodynamic coefficients of main girder is studied with variation of attack angle or yaw angle.3. The critical wind speed of traffic safety of four kind of typical vehicle near the bridge tower is obtained through preliminary computation, the results show that it is an effective way to improve traffic safety with crosswind to limit vehicle speed and increase friction coefficient between tire and surface of the bridge.