Analytical Study of Suspension Bridge Flutter

A systematic procedure for investigating suspension bridge flutter is presented. As a prerequisite for flutter analysis the free vibration problem is considered first. The bridge is idealized as an initially stressed space structure and the natural frequencies and modes of oscillation are obtained as the solution to the eigenvalue problem associated with the system. The results of the free vibration problem are then used in connection with the results of recent wind tunnel techniques to investigate the flutter problem. The flutter equations of motion are formulated in terms of the flutter derivatives and the normal modes method is used to solve the resulting eigenvalue problem. The effect on the bridge stability of changing the major design parameters is investigated and the critical flutter velocity is plotted against the variation in the parameter investigated for each case.