Combined ESAM and DORT method in nonlinear ultrasonic spectroscopy

0334351 - ÚT 2010 RIV CZ eng C - Conference Paper (international conference)
Vejvodová, Šárka - Převorovský, Zdeněk - Dos Santos, S.
Combined ESAM and DORT method in nonlinear ultrasonic spectroscopy.
NDT in PROGRESS. Brno: University of Technology Brno, 2009 - (Mazal, P.), s. 311-320. ISBN 978-80-214-3968-9.
[NDT in Progress /5./. Praha (CZ), 12.10.2009-14.10.2009]
R&D Projects: GA ČR GA106/07/1393; GA ČR GA101/07/1518
Institutional research plan: CEZ:AV0Z20760514
Keywords : nonlinear elastic wave spectroscopy (NEWS) * ESAM * time reversal (TR) * TR-NEWS imaging * DORT
Subject RIV: BI - Acoustics

Combination of ESAM (Excitation Symmetry Analysis Method) and DORT (Décomposition de l’Opérateur du Retournement Temporel) provides a powerful tool for detection and localization of defects by analysis of their nonlinear signature. Piezoelectric transducers are used for both excitation and data acquisition. Transmitters consequently emit the excitation signals and corresponding responses are measured by the array of receivers. The amplitude of excitation signals is variable as to separate the nonlinear parts of the measured signal. ESAM signal pre-processing is used for nonlinear parts extraction. Separated signal records form linear and nonlinear multistatic data matrices. DORT method is applied on data matrices to separate echoes of defects in the tested medium. Obtained data are used for evaluation of nonlinear parameters corresponding to separated defects and also for their localization. The procedure is completed by visualization of nonlinear signatures of detected defects.
Permanent Link: http://hdl.handle.net/11104/0179111