Sagasta, Francisco ORCID: 0000-0003-3202-873X, Tee, Kong Fah ORCID: 0000-0003-3202-873X and Piotrkowski, Rosa (2019) Lamb modes detection using cumulative Shannon Entropy with improved estimation of arrival time. Journal of Nondestructive Evaluation, 38:27. ISSN 0195-9298 (Print), 1573-4862 (Online) (doi:https://doi.org/10.1007/s10921-019-0561-1)

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Abstract

Non-destructive testing techniques for damage localization constitute a key aspect of structural health monitoring (SHM) systems. The acoustic emission (AE) method can be used for SHM and its location capability is considered as one of the most powerful qualities. This paper presents a novel method for distinguishing between AE transient and noise signals and this proposes a very promising procedure to detect the Lamb modes of AE signals, which provides an improvement in the localization of AE sources. The AE signals were generated on an aluminium flat bar and a plate using the normalised Hsu-Nielsen source. For a successful localisation of the AE sources, both the noise signal discrimination and detection of the beginning of the signal are crucial. The source locations were determined using the conventional Time of Arrival technique and a novel approach based on Shannon entropy of each AE signal. A sharp and substantial change in the cumulative Shannon entropy (CSE) at the instant of arrival of the A0 and S0 Lamb modes was observed. In addition, a comparison of the results using the first Threshold crossing and CSE of the AE signals illustrated that the new proposed method detects more accurately the location of AE sources and reduces the ambiguity introduced by arrival times of noisy signals in both studied specimens.

Item Type:	Article
Additional Information:	© The Author(s) 2019. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Uncontrolled Keywords:	Acoustic emission; Source location; Time of arrival; Entropy; Lamb waves; Noise signals
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Faculty / School / Research Centre / Research Group:	Faculty of Engineering & Science Faculty of Engineering & Science > School of Engineering (ENG)
Last Modified:	23 Mar 2019 01:39
URI:	http://gala.gre.ac.uk/id/eprint/23137

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