Load combination and response combination of wind-excited tall buildings and the effects of structural eccentricity

摘要

Wind tunnel aeroelastic model tests of the CAARC standard tall building with coupled translationa-torsional motion, using a three-degree-of-freedom base hinged aeroelastic (BHA) model, were con-ducted. Experimental investigation on the effects of cross-wind/torsional frequency ratio and the presence of eccentricity between centre of mass and centre of stiffness on wind-induced response characteristics and wind excitation mechanisms, were carried out. The results indicated significant impacts of cross-wind/torsional frequency ratio on the normalised along-wind, cross-wind and torsional rms responses. In addition, cross-wind/torsional frequency ratio and eccentricity between centre of mass and centre of stiffness demonstrated significant impacts on the transfer of vibrational energy between each response components. It was also found that the torsional response of the building model could be greatly amplified by the resonance mechanism, which occurs when the torsional frequency of the building model coincides with either the frequency of the periodic twisting moment or the shed vortices.