Wavelet-based modal analysis for time-variant systems. (January 2015)

• Record Type: Journal Article
• Authors: Dziedziech, K.; Staszewski, W.J.; Uhl, T.
• Is Part Of: Mechanical systems and signal processing. Volume 50/51(2015)
• Page Start: 323
• Page End: 337
• Publication Date: 2015-01
• Subjects: Vibration time-variant systems -- Wavelet analysis -- Modal analysis -- Wavelet-based frequency response function -- System identification; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2014.05.003
• Languages: English
• ISSNs: 0888-3270

Abstract

Abstract: The paper presents algorithms for modal identification of time-variant systems. These algorithms utilise the wavelet-based Frequency Response Function, and lead to estimation of all three modal parameters, i.e. natural frequencies, damping and mode shapes. The method presented utilises random impact excitation and signal post-processing based on the crazy climbers Algorithm. The method is validated using simulated and experimental data from vibration time-variant systems. The results show that the method captures correctly the dynamics of the analysed systems, leading to correct modal parameter identification. Highlights: A new method for the analysis and identification of time-variant vibration systems is proposed. The method utilises the wavelet-based Frequency Response Function (FRF). Random impact excitation is used to obtain the wavelet-based FRF. Signal post-processing – based on ridge extraction and the crazy climbers Algorithm – is applied to identify modal parameters, i.e. natural frequencies, damping and mode shapes. The method captures the dynamics of the analysed simulated and experimental time-variant vibration systems. All modal parameters - and their evolution in time - are identified correctly.