Ultrasonic Imaging of Defects in Building Elements Made from Timber

Abstract:

There is a great demand for non-destructive testing methods for quality assurance and to assess the safety and durability of wooden structures. Ultrasonic echo technique with shear waves in the frequency range of 50 kHz is one of those promising methods and is already frequently applied for usual and glued laminated timber. The article describes the development and first results for an imaging method for this purpose. The highly anisotropic properties of the ultrasonic velocity have to be considered. A 3D-SAFT (Synthetic Aperture Focusing Technique) imaging scheme is developed initially for synthetic data resulting from modelling the elastic wave propagation. The main part of the paper describes the experimental validation of this evaluation technique by experimental studies applying automated ultrasonic scanning techniques. 3D ultrasonic imaging results are described for test specimens made from pine and spruce wood. Another object of investigation was a pedestrian bridge made from siberian larch.

• Periodical: Advanced Materials Research (Volume 778)
• Pages: 312-320
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.778.312
• Online since: September 2013
• Authors: Martin Krause, Klaus Mayer, Prashant Kumar Chinta, Ute Effner
• Keywords: Anisotropic Wave Propagation, EFIT Modelling, Glued-Laminated Timber (Glulam), Imaging, SAFT Reconstruction Calculation, Ultrasonic Echo

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