Author(s)

G. Diogo, A. V. Lopes & L. M. C. Simões

Abstract

The aerodynamic instability of bridges should be one of the biggest concerns for bridge designers. From all the aerodynamic studies, only a few are related to improvements of bridge cross sections. Among them, strategies such as grating, edge plates, edge fairing plates, side plates, baffle plates or flaps have been tested. The aim of this study is associated with the efficiency of using baffle plates with the purpose of improving the aerodynamic characteristics of a π cross section (B/D=6). The limit will be the use of a rectangular cross section. The Scanlan model, namely the * 2 A coefficient, is considered with the aim of evaluating the aerodynamic efficiency of the cross section. In order to determine the fluid flow around the obstacle, a numerical algorithm of Computational Fluid Dynamics (CFD) based on the Finite Volume Method (FVM) is used. Additionally, the Forced Oscillation Method (FOM) is adopted for evaluating aeroelastic coefficients. Keywords: CFD, FVM, FOM, bridges, Scanlan model, aerodynamic coefficients, flutter, improving cross section. 1 Introduction Wind action is one of the most determining factors for the safety of large and flexible structures. As it is well known, since the famous Tacoma Narrows Bridge failure, in 1940, the design of long span cable-stayed and suspension bridges requires careful study of their aerodynamic behaviour under wind loads.

Keywords

CFD, FVM, FOM, bridges, Scanlan model, aerodynamic coefficients, flutter, improving cross section.