ABSTRACT
A device for preventing bridge flutter is presented. It consists of wings running parallel to the bridge deck. In contrast to similar devices proposed in the past, the wings are positioned far outside the bridge deck to achieve a large lateral eccentricity with regard to the bridge axis. This is accomplished by attaching the wings to the bridge deck by means of lateral cantilever structures. The wings do not move relative to the bridge deck. Hence they constitute a passive aerodynamic damping device without moving parts. This is an advantage over devices with moving parts as these meet resistance with bridge owners due to reliability and maintenance concerns. The results of finite element flutter analyses are presented. Furthermore, a simplified approach for the analysis of torsional flutter of a bridge equipped with this device is presented. It leads to a simple equation for determining the flutter speed, in which the influence of all relevant parameters becomes apparent. The simplified approach is applied to the first Tacoma Narrows Bridge. All analyses and tests confirm a high flutter-suppression effectiveness of the wings provided their lateral eccentricity is large. The main findings concerning flutter analysis, flutter-suppression effectiveness, and cost-efficiency of the eccentric-wing flutter stabilizer are outlined.
