Aeroelastic complex mode analysis for coupled gust response of the Akashi Kaikyo bridge model

An analytical approach for the coupled gust response of long-span bridges is presented. The calculation scheme is based on the direct complex eigenanalysis of the integrated system of three-dimensional FEM model of a long-span bridge and the aeroelastic forces. Actual vibration modes of the bridge in wind flow, which are called aeroelastic complex modes, are appropriately determined at each mean wind speed. A complex modal analysis scheme is then formulated for gust response analysis in either time or frequency domains. By using the aeroelastic complex modes, the aeroelastic coupled gust responses are effectively captured and interpreted. A numerical example is given for the Akashi Kaikyo Bridge model. The calculated results agree very well with the experimental ones. Parameter studies on the effect turbulence properties and the advantages of using the aeroelastic complex modes are then addressed.