独立矩形截面超高层建筑的顺风向气动阻尼风洞试验研究

Along-wind aerodynamic damping of isolated rectangular high-rise buildings

通过37个超高层建筑气动弹性模型的风洞试验,利用随机减量法从模型的风致加速度响应中识别了气动阻尼,并通过与前人相关研究成果及基于准定常理论的计算结果的比较验证了识别结果的正确性。在此基础上,研究了独立矩形截面超高层建筑顺风向气动阻尼的变化规律,考察了质量密度比、广义刚度、结构阻尼比、高宽比、宽厚比及风场类型对建筑结构气动阻尼比的影响。研究结果表明:超高层建筑顺风向气动阻尼比随折减风速变化的曲线近似一条单调增加的直线;结构阻尼比、质量密度比、宽厚比、折减风速、高宽比是影响顺风气动阻尼的比较重要的参数;广义刚度、风场类型相对影响较小。基于这些研究数据,拟合了超高层建筑顺风向气动阻尼比的经验公式。

Along-wind aerodynamic damping ratios were identified from wind-induced acceleration responses of 37 aeroelastic models in a simulated turbulence wind environment using the random decrement technique （RDT）. Their validity was examined through comparing them with previous research achievements and the results evaluated with quasi- steady theory. Based on them, the characteristics of the along-wind aerodynamic damping of isolated rectangular high-rise buildings were studied. The effects of mass density ratio, generalized stiffness, structural damping ratio, aspect ratio, side ratio and terrain category on the aerodynamic damping ratio of rectangular high-rise buildings were investigated. Results indicated that aerodynamic damping ratio increases monotonically with reduced wind velocity; structural damping ratio, mass density ratio, side ratio, reduced wind velocity and aspect ratio are very important parameters for along-wind aerodynamic damping, while no obvious effect of generalized stiffness and terrain category on aerodynamic damping ratio is observed. According to these results, an empirical aerodynamic damping ratio formula for high-rise buildings was proposed.