Multimode flutter of long-span cable-stayed bridge based on 18 experimental aeroelastic derivatives

This paper presents flutter analysis of a super-long span (central span 1020 m) cable-stayed bridge based on experimentally extracted 18 flutter derivatives. In the analysis, the aeroelastic forces to be used in the equation of motion utilize rational function approximation of flutter derivatives. The equation of motion is finally recast into aeroelastically modified modal state space form, which yields an unsymmetric eigenvalue problem. The complex eigenvalues thus obtained are used to identify the critical flutter condition. The numerical analysis is performed on a three-dimensional (3D) finite element model of the bridge. The results show that critical flutter velocity based on theoretical flutter derivatives is exceptionally higher than that based on experimental flutter derivatives.