Wavelet transform-based modal parameter identification considering uncertainty

• Published in: Journal of sound and vibration Vol. 291; no. 1; pp. 285 - 301
• Main Authors: Yan, B.F., Miyamoto, A., Brühwiler, E.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 21.03.2006; Elsevier
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Measurement and testing methods; Physics; Solid mechanics; Structural and continuum mechanics; End effect; Measurement; Statistical analysis; Modal analysis; Statistical distribution; Time frequency domain method; Entropy; Vibration test; Experimental study; Shannon theory; Modeling; Interval arithmetic; Confidence interval; Bridges; Frequency characteristic; Uncertain system; Wavelet transformation; Bootstrap; Interval matrix; System identification
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2005.06.005

This paper presents an integrated identification method to consider the uncertainty effect on modal parameters for output-only system. The method is based on the time–frequency characteristics of the wavelet transform (WT) and the capabilities of the bootstrap distribution in statistical estimation. For the WT-only based identification method, the important issues related to identification accuracy such as modal separation, end-effect, associated with the parameter selection of wavelet function based on Shannon entropy, are given detailed investigations. The bootstrap procedure is then employed to evaluate the uncertainty effects by providing confidence interval of the modal parameter statistically. The effectiveness of the integrated method has been confirmed through numerical simulation and experimental test on a bridge model.