TIME DOMAIN BUFFETING ANALYSIS OF SUSPENSION BRIDGES SUBJECTED TO TURBULENT WIND WITH EFFECTIVE ATTACK ANGLE

Suspension bridges are long-span flexible structures susceptible to various types of wind-induced vibrations such as buffeting actions. In this paper, a three-dimensional finite element model formulated to deal with suspension bridges under turbulent wind with effective attack angle is presented. In this model, all sources of geometric non-linearity such as cable sag, force-bending moment interaction in the bridge deck and towers as well as changes in bridge geometry due to large displacements are fully considered. The wind loads which include buffeting loads and self-excited loads are converted into the time domain by using a computer simulation technique to form aerodynamic damping and stiffness matrices as well as element loading vectors. Furthermore, a more refined model of wind loads is constructed in order to investigate the effect of an instantaneous change in effective attack angle of turbulent wind on bridge buffeting response. By comparing the results with those obtained by classic buffeting theory through an example bridge, the validity of the presented method is verified.