Investigation on modal coupling–aeroelastic effect of a super tall building by MDOF aeroelastic model test

Abstract

The prototype buildings in existing wind tunnel tests on the aeroelastic effect of super tall building are mostly hypothetical and not consider the modal coupling. In this paper, a multi-degree-of-freedom aeroelastic model was designed and wind tunnel tests were performed to research the modal coupling–aeroelastic effect of a super tall building, which exhibited significant aeroelastic effects and modal coupling during typhoon. The characteristics of wind-induced response of the model during different wind speeds were discussed. Complex mode decoupling technique and Bayesian approach were used to identify and analyze the variation of the first two modal parameters of the model with reduced wind velocity. Finally, wind tunnel test results were compared with field measurements. Results show that compared with the narrow-side windward, the cross-wind vortex-induced resonance of the model is more obvious when the model is wide-side windward. The along-wind modal frequency and damping ratio show similar variation with reduced wind velocity as cross-wind modal frequency and damping ratio. Moreover, the along-wind mode shape approaches the cross-wind mode shape at the reduced wind velocity of resonance. The peak accelerations predicted from the aeroelastic model test are in good agreement with the field measurements.