Establishment and visualization of wind-vehicle-bridge analysis system for the large-span steel truss suspension bridge

The existing wind-vehicle-bridge coupling vibration system is improved and refined from the aspects of wind loading and vehicle loading on the section of steel truss girder. Firstly, the truss rod is taken as the analysis unit based on the structural characteristics of steel truss girder. The static and buffeting force are obtained by equivalence principle of resultant force, which implies that the resultant force of the static force and buffeting force of all the nodes within each section are equal to the equivalent static wind pressure and buffeting force at centroid of each section at any time. The relation of motion states between the nodes and the corresponding centroid of section is deduced based on the kinematics theory of rigid body, and the self-excited force at each node is acquired by the principle of invariant response. Secondly, the proposed improving or refining method is applied to the existing analysis system which is suitable for single beam model, and the wind-vehicle-bridge analysis system for large-span steel truss suspension bridge is established. Based on the OpenGL technology, the dynamic visualization functions of the random traffic flow across the bridge under wind load are developed. Finally, based on a large-span steel truss suspension bridge, the responses of the bridge under different wind speeds and traffic densities are analyzed with the established analysis system. The results show that the vertical displacement of the bridge shall bemainly controlled by the vehicle load, and the lateral displacement shall be controlled by the wind load and the traffic flow density, but the wind load shall play a major role. With the increase of wind speed and the traffic flow density, the maximum internal force and displacement response at the mid-span may increase remarkably. © 2018, Editorial Office of China Civil Engineering Journal. All right reserved.