Coupled flutter analysis of long-span bridges using full set of flutter derivatives

A convenient and effective finite element-based method for coupled flutter analysis of long-span bridges is presented. The exact formulation of the aerodynamic self-excited forces with eighteen flutter derivatives utilized by complex notation is proposed. The predictions of the flutter wind speed and the critical frequency are compared with those either given by existing methods or the wind tunnel test showing the effectiveness and accuracy of the present approach. Numerical flutter analysis for an asymmetric bridge is the application for engineering practice, and its obtained results highlight the important role of the first lateral bending and torsional mode in generating the coupled flutter. Multi-mode analyses that are based on only the symmetrical modes can predict accurately the bridge flutter onset. The consistent self-excited aerodynamic force formulations produce the flutter velocity that is closer to the experimental one of full-bridge model in the wind tunnel.