Applying Time-Frequency Analysis on Earthquake Inputs and Structure Responses

This work presents the use of a short time Fourier transform to identify the modal parameters (such as natural frequencies, damping ratios and mode shapes) of a structure from its earthquake responses data. The short time Fourier transform is applied to the measured acceleration responses of a structural system, and to reconstruct the autoregressive with exogenous input (ARX) model in time-frequency domain. The accuracy of this procedure is numerically confirmed, the effects of the remove frequency band and noise on the ability to accurately estimate the dynamic characteristics are also investigated.