DocumentCode :
2688624
Title :
Leakage and scattering of a leaky lamb wave by a structural discontinuity: Acousto-optics and FEM
Author :
Kersemans, Mathias ; Van Paepegem, Wim ; Van Den Abeele, Koen ; Degrieck, Joris
Author_Institution :
Dept. of Mater. Sci. & Eng., Ghent Univ., Zwijnaarde, Belgium
fYear :
2012
fDate :
7-10 Oct. 2012
Firstpage :
735
Lastpage :
738
Abstract :
This study focuses on the leakage and scattering phenomena of Lamb waves in liquids as the result of the insonification of the end of an immersed solid plate by means of a bounded ultrasonic beam at the Lamb angle. Both acousto-optics measurements and FEM simulations are presented and discussed. It is shown that the observed complex scattered field is composed of the leaking fields of mode-converted backward propagating Lamb waves. The geometrical position of the leakage indicates that the conversion process is completed very locally. On the other hand, it is observed that large zones of the immersion liquid become ´polluted´ with scattered ultrasound. An analysis performed in the spatial frequency domain furthermore revealed the presence of a nonlinear interaction between multiple overlapping acoustic fields. Since real structures have limited spatial dimensions, the current results indicate a possible source of misinterpretation during water-coupled non-destructive testing (NDT).
Keywords :
acousto-optical effects; finite element analysis; surface acoustic waves; ultrasonic materials testing; ultrasonic scattering; FEM simulations; Lamb angle; acousto-optics measurements; immersed solid plate; insonification; leaking fields; leaky lamb wave; mode-converted backward propagating Lamb waves; multiple overlapping acoustic fields; nonlinear interaction; spatial frequency domain; structural discontinuity; ultrasonic beam; ultrasound scattering; water-coupled nondestructive testing; Acoustic beams; Acoustics; Finite element analysis; Fluids; Frequency-domain analysis; Scattering; Solids; Acousto-optics; FEM; NDT; leaky Lamb wave; vertical edge;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium (IUS), 2012 IEEE International
Conference_Location :
Dresden
ISSN :
1948-5719
Print_ISBN :
978-1-4673-4561-3
Type :
conf
DOI :
10.1109/ULTSYM.2012.0183
Filename :
6562059
Link To Document :
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