Abstract：In recent years, the status of operational modal analysis in structural parameter identification is gradually rising.Here, aiming at low signal-to-noise ratio (SNR) of structural vibration response under environmental excitation, the auto-regressive (AR) power spectrum was introduced to improve the empirical Fourier decomposition, and a structural operational modal analysis method based on improved empirical Fourier decomposition (EFD) was proposed.In order to verify the feasibility and effectiveness of the proposed method, operational modal parameters of a 4-story simulated frame and a pedestrian cable-stayed bridge were recognized using this method, and the results were compared with those identified using the stochastic subspace identification (SSI).The results showed that modal parameters identified using the proposed method agree well with those identified using SSI; in case of dense modes, this method has certain advantages, so improving empirical Fourier decomposition can provide a reference for future structural modal identification.
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