Nonlinear Wave Modulation and Time Reversal Tomography of Structural Defects

0351999 - ÚT 2011 RIV FR eng C - Conference Paper (international conference)
Převorovský, Zdeněk - Vejvodová, Šárka - Dos Santos, S.
Nonlinear Wave Modulation and Time Reversal Tomography of Structural Defects.
CFA 10. Lyon: IntellAgence Technologies, 2010, s. 1-4. ISBN 978-2-9521105-7-0.
[10éme Congrés Francais d´Acoustique. Lyon (FR), 12.04.2010-16.04.2010]
R&D Projects: GA MPO(CZ) FR-TI1/274; GA ČR GA106/07/1393
Institutional research plan: CEZ:AV0Z20760514
Keywords : NDT * acoustic emission * ESAM * DORT
Subject RIV: BI - Acoustics
http://cfa.sfa.asso.fr/

Classical ultrasonic tomography generally uses source signals of constant amplitude. Mostly linear characteristics like ultrasonic amplitude, attenuation or time of flight are used to structural defects imaging. On the other hand, more complex and nonlinear characteristics of elastic wave propagation provide more sensitive indicators of body changes and irregularities. Nonlinear Elastic Wave Spectroscopy (NEWS) techniques give us better information about damage with higher sensitivity and also the ability to detect defects smaller than the ultrasonic wavelength. Two NEWS methods are considered: Nonlinear Wave Modulation Spectroscopy (NWMS) and Nonlinear Time Reversal Mirrors (NLTRM) with ESAM and DORT signal processing. Testing results, obtained on metallic and concrete parts illustrate performance of both procedures.
Permanent Link: http://hdl.handle.net/11104/0191613