一类准方形截面超高层建筑顺风向气动阻尼

Along-wind aerodynamic damping of high-rise buildings with aerodynamically modified square cross-sections

利用随机减量法从湍流风场下10个高层建筑气动弹性模型的风致加速度响应中识别气动阻尼,通过与已有研究成果及基于准定常理论计算结果比较,验证识别结果的正确性。在此基础上,研究方形截面超高层建筑四个角沿不同尺寸的削角、凹角处理及截面沿高收缩率对作用在建筑上的气动阻尼比影响。研究结果发现:气动阻尼比随截面削角率、凹角率及截面沿高收缩率的增大而增大;较小的截面削角率和凹角率使顺风向气动阻尼比显著减小;但截面削角率、凹角率及截面沿高收缩率对超高层建筑气动效应的减小效应并非总有效。基于方形截面超高层建筑顺风向气动阻尼特性研究,结合截面修角及沿高收缩率影响,给出相应的经验公式,供工程设计人员参考。

Along-wind aerodynamic damping ratios were identified from wind-induced responses of ten aeroelastic models in a simulated turbulence flow using the random decrement technique （RDT）. Their validity was examined through comparison with previous research achievements and the results calculated with the quasi-steady theory. Based on them, the effects of aerodynamically modified cross-sections, such as, chamfered corner and slotted corner, and tapering on aerodynamic damping of square high-rise buildings were investigated. Results indicated that aerodynamic damping ratio increases with increasing corner-cut ratio or taper ratio; low corner-cut ratios significantly decrease aerodynamic damping; however, modifications of building corners and tapering are not always effective to reduce the aerodynamic damping of tall buildings. According to the study on aerodynamic damping of square high-rise buildings, combining with the effect of corner-cut and tapering, an empirical aerodynamic damping formula for high-rise buildings was proposed.