Applying Time-Frequency Analysis on Earthquake Inputs and Structure Responses

Abstract

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.