Experimental study on the aeroelastic response of a square supertall building considering twisted wind effect

For high-slenderness supertall buildings, the aeroelastic effect has been carefully addressed, as the ignorance of aeroelastic response may significantly affect the serviceability of the building. Several state-of-the-art researches have analyzed the influence of twisted wind field (TWF) on aerodynamic wind loads on tall buildings. In this study, the influence of TWF on the aeroelastic response of buildings is studied experimentally. The displacement time histories, trajectories and correlation coefficients of wind-induced responses, statistical characteristics, probability density functions and power spectra of across-wind displacement under various levels of reduced wind speeds are examined. The experimental results show that TWF greatly affects the aeroelastic behaviors of buildings. When reduced wind speed is lower than the critical vortex-resonance wind speed, TWF strengthens the coupling effect between the along-wind and across-wind responses, while for reduced wind speed beyond the critical vortex-resonance wind speed, TWF weakens the coupling effect, and weakens more for the case of larger structural damping level. Also, it is found in this study that TWF strengthens stochastic buffeting and suppresses the vortex-resonance vibration. Furthermore, TWF may modify the lock-in region of vortex-resonance. Overall, it is crucial to reproduce TWF when reduced wind speed is lower than the critical vortex-resonance wind speed, as the TWF-induced across-wind responses can be increased by 89 % in this wind speed region, while for larger wind speeds (i.e., Ur > 10), the across-wind responses are generally weakened in the presence of twisted wind and the wind-resistance design can be accomplished based on the experimental results obtained under CWF. This study contributes to a better understanding for the aeroelastic characteristics of buildings under twisted wind.