Numerical analysis of the aerodynamic stability of bridges

This paper presents a numerical technique to analyse the aerodynamic stability of bridges. The self-excited forces developed on the deck are assumed to depend linearly upon its displacements and velocities and the structural behavior is analysed by a modal approach, based on a finite element model of the structure. The formulation leads to a linear eigenvalue problem, with the critical situation (either aerodynamic flutter or aerostatic divergence) being identified by a zero-condition on the eigenvalues. The technique described herein may easily be incorporated in finite-element computer codes and may become routine practice (in the format shown or in other equivalent variant) in the design of long-span bridges.