Improving the critical flutter wind speed of long-span bridges by installing flaps on one side of the hangers

Abstract

 Improving the critical flutter wind speed for long-span bridges through aerodynamic methods has attracted significant research interest. Unlike mechanical methods, aerodynamic solutions aim to modify the wind forces acting on the bridge, thereby enhancing its aerodynamic stability. These modifications can be achieved by installing flaps either on the bridge deck or on the hangers. This article focuses on improving the aerodynamic stability of the bridge deck by installing flaps on the hangers, considering installation on the upstream and downstream sides relative to the wind direction. The number of flaps installed on a suspender is also investigated. The revised step-by-step method is used to calculate the critical flutter wind speed. Numerical simulation results show that installing the flaps on the downstream side of the wind flow yields a significant improvement. The efficiency of enhancing the critical flutter wind speed increases as the number of flaps on the suspender increases. The computational approach presented in this article can be extended to full-bridge models. The research direction of the paper can be applied to bridges in practice in Vietnam.