Wind tunnel tests on nonlinear energy sink for mitigating wind-induced responses of high-rise buildings

In order to study the control performance of Nonlinear Energy Sink (NES) on wind-induced vibration of high-rise buildings, including vortex-induced vibration (VIV) and buffeting, wind tunnel tests on the multi-degree-offreedom (MDOF) aeroelastic model of a high-rise building are conducted in the present work. The main mechanical components of NES include an auxiliary mass and a cubic nonlinear spring system built up by two linear springs. Four NESs having different auxiliary masses and stiffness coefficients are considered. Based on the windinduced acceleration of the scaled model measured in the wind tunnel tests, the vibration reduction effects of NES on VIV and buffeting are analyzed in the time and the time-frequency domains. Meanwhile, the influences of NES parameters on the vibration reduction effect are discussed. The test results show that both auxiliary mass and stiffness of NES have significant influences on its control performance. The maximum reduction ratios of 98.1 % and 34.1 % are achieved on the amplitude of acceleration responses on the top floor in VIV (at critical wind speed) and buffeting cases (at wind speed of 12 m/s), respectively.