Non-contact nonlinear acoustic damage localization in plates. Part 1: Resonance of air between plates

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Full text:
Author(s): Claes Hedberg, Kristian Haller, Sven Arnoldsson
Title: Non-contact nonlinear acoustic damage localization in plates. Part 1: Resonance of air between plates
Translated title: Oberörande olinjär akustik skadelokalisering i plattor. Del 1: Luftresonans mellan plattor
Journal: Acta Acustica united with Acustica
Year: 2007
Volume: 93
Issue: 1
Pagination: 13-21
ISSN: 1610-1928
Publisher: S HIRZEL VERLAG
ISI number: 000244415600002
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Mechanical Engineering (Sektionen för teknik – avd. för maskinteknik)
School of Engineering S- 371 79 Karlskrona
+46 455 38 50 00
http://www.bth.se/ing/
Authors e-mail: claes.hedberg@bth.se
Language: English
Abstract: This is the first of three articles that deals with the goal of using non-contact nonlinear acoustic methods for the damage localization in plates. In this first part, the resonant air gap wave field between one active and one passive reflecting plate was investigated experimentally. Of particular interest is the wave field amplitude strength, and its distribution on the passive surface. The wave amplitude may be increased by choosing one plate to be concave, overcoming the nonlinear damping taking place for two flat plates.
Applications are connected with an increased wave field having advantages for processes taking place under open conditions and for a non-contact transducers' efficiency of transferring energy into an object.
A double resonance gives highest air pressure, while a triple provides most energy in the passive object. By choosing the gap distance, frequency and transducer width, the appearing resonant wave will have a considerably larger amplitude at the object surface. The work through the interface from air to object is investigated and the wave field in a resonant air-plate system is shown.
Subject: Mechanical Engineering\Structural Mechanics
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