Finite-element and complete quadratic combination analysis of coupled buffeting for long-span bridges

A finite-element and CQC method for analyzing the coupled buffeting responses of long-span bridges is proposed based on the modal coordinates of structure. The formula of nodal equivalent aerodynamic buffeting forces is derived based on a reasonable hypothesis. The methodology for computing the power spectrum density and square deviation of nodal displacements and elemental internal forces of bridge structures is presented by using the finite-element method and the random vibration theory. The method presented is very efficient and can consider the arbitrary spectrum and spatial coherence of natural winds and the multimode and intermode effects on the buffeting responses of bridge structures.