Título:
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Laser Ultrasound Inspection Based on Wavelet Transform and Data Clustering for Defect Estimation in Metallic Samples
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Autor/a:
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Mohamed Selim, Hossameldin; Delgado Prieto, Miquel; Trull Silvestre, José Francisco; Romeral Martínez, José Luis; Cojocaru, Crina
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Otros autores:
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Universitat Politècnica de Catalunya. Departament de Física; Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica; Universitat Politècnica de Catalunya. MCIA - Motion Control and Industrial Applications Research Group; Universitat Politècnica de Catalunya. DONLL - Dinàmica no Lineal, Òptica no Lineal i Làsers |
Abstract:
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Laser-generated ultrasound is a modern non-destructive testing technique. It has been investigated over recent years as an alternative to classical ultrasonic methods, mainly in industrial maintenance and quality control procedures. In this study, the detection and reconstruction of internal defects in a metallic sample is performed by means of a time-frequency analysis of ultrasonic waves generated by a laser-induced thermal mechanism. In the proposed methodology, we used wavelet transform due to its multi-resolution time frequency characteristics. In order to isolate and estimate the corresponding time of flight of eventual ultrasonic echoes related to internal defects, a density-based spatial clustering was applied to the resulting time frequency maps. Using the laser scan beam’s position, the ultrasonic transducer’s location and the echoes’ arrival times were determined, the estimation of the defect’s position was carried out afterwards. Finally, clustering algorithms were applied to the resulting geometric solutions from the set of the laser scan points which was proposed to obtain a two-dimensional projection of the defect outline over the scan plane. The study demonstrates that the proposed method of wavelet transform ultrasonic imaging can be effectively applied to detect and size internal defects without any reference information, which represents a valuable outcome for various applications in the industry. View Full-Text |
Abstract:
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Peer Reviewed |
Materia(s):
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-Àrees temàtiques de la UPC::Física -Lasers -Signal processing -Laser ultrasound -damage visualization -spectral signal processing -ultrasound propagation -time of flight -wavelet transform -non-destructive testing -Làsers -Tractament del senyal |
Derechos:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Tipo de documento:
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Artículo - Versión publicada Artículo |
Editor:
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Multidisciplinary Digital Publishing Institute (MDPI)
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