基于HHT和WT识别高层建筑模态参数的比较研究

A Comparative Study of Identifying Model Parameters of Tall Buildings Based on HHT and WT

现役高层建筑动力响应的实测与参数识别对结构动态数据资料的补充和设计准确性的校验是十分必要的.首先回顾了基于HHT和WT识别结构动力参数的基本原理;接着,基于高层建筑动力响应的实测数据进行了结构固有频率和阻尼比的识别.结果表明,对结构固有频率和低阶阻尼比的识别两者都具有较高的准确性;而对于高阶阻尼比的识别,两者有较大差别.对于固有频率呈密集分布结构的动力参数识别,WT方法通过调整小波中心频率而实现频率分离,因而WT方法更为简单有效.

Both full-scale measurement of dynamic responses and identification of dynamic parameters of tall buildings can certainly supplement the structural dynamic data and evaluate the accuracy of structural design.In this paper,the fundamental principles of both HHT and WT applications to the identification of structural model parameters are first reviewed.Then,the identification of both the natural frequencies and damping ratios is carried out by using the full-scale measurement of dynamic responses of a tall building.The results show that both HHT and WT can identify the natural frequencies and lower damping ratios of the tall buildings quite accurately,but the difference consists in the identification of higher damping ratios.The WT separates the closely-spaced natural frequencies by adjusting the central frequency of the wavelets.As a result,the WT approach is simpler and more effective compared with the HHT approach when the natural frequencies of structures are close to each other.