Vibration-Based Damage Detection and Evaluation of Sheet Materials using a Remote Acoustic Excitation

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Full text:
Author(s): Etienne Mfoumou, Claes Hedberg, Sharon Kao-Walter
Title: Vibration-Based Damage Detection and Evaluation of Sheet Materials using a Remote Acoustic Excitation
Journal: Acoustical Physics
Year: 2008
Volume: 54
Issue: 1
Pagination: 127-134
ISSN: 1063-7710 (print) 1562-6865 (online)
Publisher: Pleiades Publishing, Ltd.
URI/DOI: 10.1134/S1063771008010181
ISI number: 000252805800018
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: emf@bth.se, che@bth.se, skw@bth.se
Language: English
Abstract: A simple method of damage severity assessment on sheet materials is suggested and proved by theory
and experiment. The investigated defect types are in forms of added mass and crack. The method is based
on the frequency shift measurement of a material vibrating as a membrane subjected to static tension and irradiated
by an acoustic wave. It is shown both theoretically and experimentally that the natural frequency of the
damaged membrane is shifted relative to its position in the ideal material. A local increase in thickness (or addition
of mass) shifts the natural frequency down, while a crack shifts the frequency up. The method can be considered
as acoustic weighting through the frequency shift. The sensitivity of this method can be high because
frequency measurement is one of the most accurate measurements in physics and metrology.
Subject: Mechanical Engineering\Structural Dynamics
Mechanical Engineering\Structural Mechanics
Mechanical Engineering\General
Keywords: Vibration-Based, Damage Detection, natural frequency, nondestructive testing
Note: The original publication is available at www.springerlink.com
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