Wavelet-based analysis of time-variant adaptive structures

Kajetan Dziedziech; Alexander Nowak; Alexander Hasse; Tadeusz Uhl; Wiesław J Staszewski

doi:10.1098/rsta.2017.0245

Wavelet-based analysis of time-variant adaptive structures

Philos Trans A Math Phys Eng Sci. 2018 Aug 13;376(2126):20170245. doi: 10.1098/rsta.2017.0245.

Authors

Kajetan Dziedziech¹, Alexander Nowak², Alexander Hasse², Tadeusz Uhl¹, Wiesław J Staszewski³

Affiliations

¹ Department of Robotics and Mechatronics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland.
² Chemnitz University of Technology, Professorship of Machine Elements and Product Development, Reichenhainer Strasse 70, 09126 Chemnitz, Germany.
³ Department of Robotics and Mechatronics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland w.j.staszewski@agh.edu.pl.

Abstract

Wavelet analysis is applied to identify the time-variant dynamics of adaptive structures. The wavelet-based power spectrum of the structural response, wavelet-based frequency response function (FRF) and wavelet-based coherence are used to identify continuously and abruptly varying natural frequencies. A cantilever plate with surface-bonded macro fibre composite-which alters the structural stiffness-is used to demonstrate the application of the methods. The results show that the wavelet-based input-output characteristics-i.e. the FRF and coherence-can identify correctly the dynamics of the analysed time-variant system and reveal the varying natural frequency. The wavelet-based coherence can be used not only for the assessment of the quality of the wavelet-based FRF but also for the identification.This article is part of the theme issue 'Redundancy rules: the continuous wavelet transform comes of age'.

Keywords: adaptive structures; time-variant systems; wavelet-based coherence; wavelet-based frequency response function; wavelets.