Investigation on vortex-induced vibrations of square-sectioned high-rise buildings with various structural eccentricities

Abstract

Structural eccentricities in a high-rise building can induce strong modal coupling, which therefore influences vortex-induced vibration (VIV) responses of the building and consequently affects human comfort within the building. This study investigates the VIV behaviour of square-sectioned high-rise buildings with different structural eccentricities, using both wind tunnel test and computational fluid dynamics (CFD) technique. Firstly, a novel method for constructing the multi-degree-of-freedom (MDOF) aeroelastic model of a high-rise building with specified structural eccentricities is introduced in detail. Seven MDOF aeroelastic models with different structural eccentricities are constructed. Wind tunnel test is then conducted to examine VIV responses of these high-rise building models. Effects of eccentricity ratio and direction on the models’ VIV responses are comprehensively investigated. In addition, CFD simulation is conducted to elucidate the aerodynamic mechanism of VIV responses of high-rise buildings with structural eccentricities. Results reveal that the direction of structural eccentricity influences the reattachment of vortex shedding over the building, which in turn affects the lift and, consequently, the building’ VIV responses. The maximum VIV response of the building models exhibits a negative correlation with the windward eccentricity ratio, while a positive correlation with the leeward eccentricity ratio. Results from CFD simulation demonstrate that the structural eccentricity tends to broaden the wake downstream, resulting in a reduction in the building’s vortex shedding frequency and, consequently, the Strouhal number. Findings of the present study can enhance the understanding of VIV behaviours of high-rise buildings with structural eccentricities, providing valuable insights for the wind design of such structures.