中文摘要：

索穹顶是一种具有很强风振敏感性的大跨柔性结构．风振问题在设计中应予以高度重视，这其中气动阻尼有至关重要的影响，而如何有效地识别气动阻尼则是问题的关键。利用肋环型索穹顶结构气弹模型风洞实验的数据，先由经验模态分解法提取信号的低频分量，并在此基础上采用改进的随机减量法及Hilbert变换得到结构的气动阻尼，结果证明该方法是稳定而有效的。最后在计算分析的基础上总结了索穹顶结构中气动阻尼随风速及风向角的变化规律。

英文摘要：

The cable dome is a kind of long-span structure which is sensitive to wind vibration, the problem of wind vibration should be paid high attention and in this regard, the aerodynamic damping is of vital importance. Hence, the key to the problem is how to identify the aerodynamic damping. Based on the data of wind tunnel test of aeroelastic Geiger cable dome model, the method of empirical mode decomposition is used to distill the intrinsic mode function, then the improved random decrement technique and Hilbert transformation are used to get the aerodynamic damping ratio, and the result shows that this kind of method is stable and effctive. Some conclusions based on computation are drawn about the relationship among aerodynamic damping, windspeed and excitation direction.