风场类型对方形超高层建筑顺风向气动阻尼的影响研究

Effect of roughness exposure on aerodynamic damping of square high-rise buildings

通过8个典型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,研究了典型超高层建筑顺风向气动阻尼比的变化规律,考察了风场类型对建筑结构顺风向气动阻尼比的影响。研究结果表明:在Ⅰ～Ⅳ类风场下,建筑结构的气动阻尼比随折减风速增长的速度渐缓;在Ⅴ～Ⅷ类风场下,风场对顺风向气动阻尼比的影响不是很显著。基于大量矩形截面超高层建筑顺风向气动阻尼特性研究,并结合风场类型的影响,给出相应的经验公式,供工程设计人员参考。

The aerodynamic damping ratio was identified from wind-induced response data of 8 aeroelastic models in a simulated turbulence wind environment using the random decrement technique （RDT）. Their validity was examined through comparison with the previous research achievements and the results evaluated by quasi-steady theory. On this basis, the characteristics of along-wind aerodynamic damping of isolated square high-rise buildings were studied. The effect of roughness exposure on aerodynamic damping ratio of square high-rise buildings was investigated. The results indicate that： under roughness exposure of Ⅰto Ⅳ type, aerodynamic damping ratio increases gradually and slowly with reduced wind velocity, while no clear effect of roughness exposure on aerodynamic damping ratio is observed under roughness exposure of Ⅴ to Ⅷ type. According to numerous studies results of aerodynamic damping of rectangular high- rise buildings and considering the effect of roughness exposure, an empirical aerodynamic damping function for high-rise buildings was proposed.