矩形截面超高层建筑风致脉动扭矩的基本特征

利用刚性模型的同步测压风洞试验,研究了矩形截面超高层建筑脉动扭矩的基本特征。研究内容包括扭矩系数的根方差、功率谱密度、竖向相关性以及横风向脉动风力-扭矩相干函数,另外还考察了厚宽比和风场类别这两个参数对脉动扭矩的影响。研究结果表明,脉动扭矩系数随高度增加递减,随厚宽比增加而增加;脉动扭矩谱具有两个谱峰,谱峰形状随厚宽比改变发生很大变化;相对横风向风力,扭矩的竖向相关系数随距离衰减更快;脉动扭矩与横风向风力具有较强的相关性。

Basic characteristics of torsional fluctuating wind force on rectangular super-tall buildings

Wind pressure distribution acting on typical rectangular building models was measured in a wind tunnel test.Based on the wind pressure data,the characteristics of torsional fluctuating wind forces,including RMS of torque coefficients,power spectral densities and vertical correlation coefficients,were investigated.The coherence functions between crosswind forces and torques were also studied.The effects of wind terrain and side ratio of the building models on the torques were then discussed.The results indicate that RMS of torque coefficients decrease slightly along the elevation and increase with the side ratio.Generally,power spectral densities of torques have two distinct peaks which are greatly influenced by the side ratio.Vertical correlation coefficient of torques along the elevation decrease faster with increasing separation than those of crosswind.The crosswind forces and torques are highly correlated.