Evaluation of aerodynamic admittance for buffeting analysis

Abstract In the wind resistant design of flexible civil engineering structures such as suspension bridges and cable-stayed bridges, it is very important to investigate the actual behavior of structures in natural winds. This study focuses on the buffeting response among the various aerodynamic phenomena, which causes the fatigue and serviceability problems of flexible structures. The aerodynamic forces on structures in natural winds are evaluated in terms of aerodynamic admittance and self-excited aerodynamic coefficients. An efficient method is presented to obtain the admittance using an active gust generator. The aerodynamic response of rectangular cylinders with aspect ratios of 2 and 5 is investigated. The estimated response from power spectra of turbulent flow and the admittance is compared with the measured response in wind tunnel tests. The effects of turbulence characteristics on buffeting response are also investigated.