Anvar - Assistant Professor of Civil Engineering, Shiraz University, Shiraz, Iran
Hamtaei - Graduate student, Department of Civil Engineering, Shiraz University, Shiraz, Iran
Rahmatkhah - Graduate student, Department of Civil Engineering, Shiraz University, Shiraz, Iran

In this paper a methodology for identification of natural frequencies of structural systems using wavelet transform (WT), which is capable of yielding time-frequency representation of the structural responses, is proposed and a new framework for system identification is devised. The current work utilizes wavelet transform to identify structural dynamic characteristics from transient response of the system when subjected to ambient excitation. The effectiveness of this technique in determination of modal frequencies of buildings as applied to two buildings is presented. Finally, WT is then compared with NExT-ERA with regard to the number of identified modes and frequencies thus obtained.

Wavelet Transform; Natural Frequency Estimation; Time-Frequency Transform