Time-Frequency Analysis of Earthquake Record Based on S Transform and Its Effect on Structural Seismic Response

The basic algorithm of the S transform is derived and the definitions of the time variable amplitude spectrum and the time variable energy spectrum which reflect the time-frequency characteristics of the earthquake record are given. The time-frequency characteristic of the EL-centro earthquake record is analyzed. The new conception of the time-frequency characteristic spectrum record is presented, which is able to reflect the concentration degree of the energy of the earthquake record in the time-frequency space. By the correlation analysis, the time-frequency characteristic spectrum shows a good linear correlation with the structural elastic acceleration response spectrum. Finally, the approximate relationship between the time-frequency characteristic spectrum and the elastic acceleration response spectrum is established.