Comparison of Damping Ratio Identification Methods for Buildings Using Seismic Responses

Identification of damping ratios of buildings using seismic response data has been a topic of significant research interest in recent years. However, extracting damping information from seismic records can be challenging due to the limited number of sensors and the presence of noise. Recent advancements in computer and sensing technologies have enabled the development of more effective damping identification techniques. In this paper, one technique and three mainstream damping ratio identification methods will be discussed: the random decrement technique, the logarithmic decrement method, the curve fitting method based on least squares, and the wavelet transform method. Numerical simulations of a single degree of freedom model subjected to seismic excitation are used to evaluate the performance of these methods. Additionally, the noise robustness of the methods is assessed by introducing noise to the signals. The results of this study demonstrate that the wavelet transform method performs well in terms of identification accuracy and noise robustness for the free decay part of the simulated data. However, the combination with the random decrement technique yields questionable identification results. In this study, the limitations of the tested identification method are analyzed and some ideas for future improvement are proposed.