Time reversal localization of continuous and burst acoustic emission under noise background

0484034 - ÚT 2018 RIV SI eng C - Konferenční příspěvek (zahraniční konf.)
Převorovský, Zdeněk - Krofta, Josef - Kober, Jan - Chlada, Milan
Time reversal localization of continuous and burst acoustic emission under noise background.
Application of contemporary non-destructive testing in engineering. Ljubljana, Slovenia: Slovenian Society for Non-Destructive Testing, 2017 - (Grum, J.; Kek, T.), s. 3-13. ISBN 978-961-93537-2-1.
[INTERNATIONAL CONFERENCE OF THE SLOVENIAN SOCIETY FOR NON-DESTRUCTIVE TESTING / 14./. St. Bernardin / Portorož (SI), 04.09.2017-06.09.2017]
Grant CEP: GA ČR GA17-22615S
Institucionální podpora: RVO:61388998
Klíčová slova: continuous acoustic emission * source location * time reversal * leakage noise
Obor OECD: Acoustics

Time reversal (TR) processing of acoustic and ultrasonic signals becomes very effective tool for complicated problems solution in many fields of NDT/E and SHM. TR enables wave focusing in time and space and then location and partial reconstruction of acoustic emission (AE) sources in complex structures. However, the burst AE e.g. from cracks is often completely buried in a high background structural noise. Example of that may be cracking in pipes with streaming or leaking out fluid medium, which is detected as continuous AE. In such situation is location of burst AE and/or leaks extremely difficult. TR is used to enhance signal
to noise ratio (S/N)and to suppress unwanted disturbing background noise. It allows localization of both continuous and burst signal sources at TR focus. In this paper we used TR to localize point-like bounded leakage source and localize burst source buried in leakage noise background. New TR localization procedure is illustrated using artificial AE sources on a steel plate: a) Continuous AE source simulated by sampled leakage noise is precisely located using only two transducers and cross-correlation of TR signals, and b) burst AE events simulated by pen-test are localized under high leakage noise with only one transducer on the plate. Experimental results show new possibilities of TR signal processing in practical engineering applications.
Trvalý link: http://hdl.handle.net/11104/0279577