Numerical Treatment of Seismic Accelerograms and of Inelastic Seismic Structural Responses Using Harmonic Wavelets

The harmonic wavelet transform is used to analyze various kinds of nonstationary signals common in aseismic design. In this paper, the effectiveness of harmonic wavelets for capturing temporal evolution of the frequency content of strong ground motions is shown. A detailed study of important earthquake accelerograms is undertaken and smooth joint time-frequency spectra are provided for 2 near-field and 2 far-field records; inherent is the concept of the mean instantaneous frequency. Furthermore, as a paradigm of usefulness for aseismic structural purposes, a similar analysis is conducted for the response of a steel frame benchmark structure considering 1 of the 4 accelerograms scaled by such factors as excitation to simulate undamaged and severely damaged conditions for the structure. The resulting joint time-frequency representation of the response time histories captures the influence of nonlinearity on variation of the effective natural frequencies of a structural system during evolution of a seismic event. In this context, potential of the harmonic wavelet transform as a detection tool for global structural damage is explored in conjunction with the concept of monitoring the mean instantaneous frequency of records of critical structural responses.

  • Availability:
  • Authors:
    • Spanos, Pol D
    • Giaralis, Agathoklis
    • Politis, Nikolaos P
  • Publication Date: 2007-5

Language

  • English

Media Info

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Filing Info

  • Accession Number: 01049780
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 1 2007 1:18PM