Morlet-wave-based modal identification in the time domain

Tomac, Ivan (author), Slavič, Janko (author)

This research focuses on the time-domain identification of modal parameters using impact response excitation from signals with a relatively small dynamic range and high noise contamination (e.g., from high-speed cameras). The information required to identify the modal parameters is limited and is contained mostly at the beginning of the signal. In order to perform an identification from such a response, the following challenges have to be overcome: a good frequency-domain separation (for close modes), a good localization in the time domain and an over-determination (to reduce uncertainty). To overcome these challenges this research introduces the Morlet-wave modal identification method as an extension of the Morlet-wave damping identification method, which has already proven capable of identifying the damping of short signals. Here, the method is extended to the modal parameters and an over-determination approach is proposed to reduce the uncertainty. The method identifies each mode shape separately from 10 to a maximum of 400 oscillations and at damping levels from 0.02% to 2% with a strong presence of noise in the signal. The method is tested on an experimental example and the results are compared to the classical modal identification methodology.

• Language: English
• Keywords: Morlet-wave, modal identification, modal parameters, over-determination, noise
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 11 str.
• Numbering: Vol. 192, art. 110243
• PID: 20.500.12556/RUL-144640
• UDC: 519.677:510.643
• ISSN on article: 1096-1216
• DOI: 10.1016/j.ymssp.2023.110243
• COBISS.SI-ID: 144036355
• Publication date in RUL: 06.03.2023

Record is a part of a journal

• Title: Mechanical systems and signal processing
• Shortened title: Mech. syst. signal process.
• Publisher: Elsevier
• ISSN: 1096-1216
• COBISS.SI-ID: 15296283

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: Morletov valček, modalna identifikacija, modalni parametri, predoločen sistem, šum