APPLICATION OF HHT METHOD TO SYSTEM IDENTIFICATION OF DI WANG BUILDING DURING TYPHOON YORK

摘要

The wind and structural monitoring system installed in the Di Wang Building timely recorded wind and structural response data during Typhoon York in September 1999. The newly emerged Hilbert-Huang transform (HHT) method together with the random decrement technique (RDT) is applied in this paper to the measured data to identify dynamic characteristics of the building. A series of natural frequencies and modal damping ratios of the building under different wind speeds in different directions are identified and compared with those from the fast Fourier transform (FFT)-based method. The results show that the natural frequencies identified by the HHT method and the FFT method are almost the same, but the modal damping ratios identified by the two methods are different to some extent. The results also show that the total modal damping ratios increase with increasing wind speed and vibration amplitude but the situation is reversed for the natural frequency.