On the estimation of structural admittances from acoustic measurement using a dynamic substructuring approach

Ocepek, Domen (author), Kodrič, Miha (author), Čepon, Gregor (author), Boltežar, Miha (author)

A reconstructed displacement field using near-field acoustic holography (NAH) serves as an alternative to conventional measurement methods when it comes to obtaining the high-resolution vibration response of a structure. The method is highly applicable as it enables direct, non-contact measurement of the 3D structural response based on a single acoustic measurement. Although useful, the method's ill-posed nature limits its use in the field of structural dynamics. This problem can be effectively addressed by using regularization and/or field-separation techniques that can attenuate the noise and the presence of external acoustic sources. All these methods rely on the measurement of acoustic quantities; therefore, the reconstruction of structural admittances is based solely on the evaluation of the hologram(s). This article proposes an alternative approach to improving the accuracy of NAH-based structural admittances by integrating them with a few discrete response measurement on the structure itself. The formulation relies on the mixing of the high-resolution NAH measurement with accurate discrete measurements (e.g., accelerometer or laser vibrometer) using dynamic substructuring techniques. The proposed hybrid approach is a very powerful modeling methodology that can integrate high-resolution spatial measurements using NAH with the accuracy and consistency provided by precise translation discrete measurements. In order to mix two experimental response models System Equivalent Model Mixing (SEMM) method is proposed. An experimental case study on a T-shaped structure demonstrates the robustness and improved accuracy of the estimated structural admittances compared to the plain NAH formulation.

• Language: English
• Keywords: acoustic measurement, near-field acoustic holography, dynamic substructuring, system equivalent model mixing, hybrid model
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Submitted for review: 18.02.2021
• Article acceptance date: 08.04.2021
• Publication date: 01.09.2021
• Year: 2021
• Number of pages: Str. 1-10
• Numbering: Vol. 180, art. 108115
• PID: 20.500.12556/RUL-126915
• UDC: 534.6(045)
• ISSN on article: 0003-682X
• DOI: 10.1016/j.apacoust.2021.108115
• COBISS.SI-ID: 62006531
• Publication date in RUL: 10.05.2021

Record is a part of a journal

• Title: Applied acoustics
• Shortened title: Appl. Acoust.
• Publisher: Elsevier Science
• ISSN: 0003-682X
• COBISS.SI-ID: 24982016

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
• Licensing start date: 01.09.2021

Secondary language

• Language: Slovenian
• Keywords: akustična meritev, akustična holografija v bližnjem polju, dinamsko podstrukturiranje, mešanje ekvivalentnih modelov, hibridni model

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0263
• Name: Mehanika v tehniki

• Funder: ARRS - Slovenian Research Agency
• Project number: L2-1837
• Name: Hibridne metode dinamičnega podstrukturiranja v industriji bele tehnike