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http://dx.doi.org/10.5762/KAIS.2014.15.11.6432

Internal Defection Evaluation of Spot Weld Part and Carbon Composite using the Non-contact Air-coupled Ultrasonic Transducer Method  

Kwak, Nam-Su (Dept. of Advanced parts & materials Engineering, Chosun University)
Lee, Seung-Chul (Dept. of Applied & Computational Mechanics, Chosun College of Science & Technology)
Publication Information
Journal of the Korea Academia-Industrial cooperation Society / v.15, no.11, 2014 , pp. 6432-6439 More about this Journal
Abstract
The NAUT (Non-contact Air coupled Ultrasonic Testing) technique is one of the ultrasonic testing methods that enables non-contact ultrasonic testing by compensating for the energy loss caused by the difference in acoustic impedance of air with an ultrasonic pulser receiver, PRE-AMP and high-sensitivity transducer. As the NAUT is performed in a state of steady ultrasonic transmission and reception, testing can be performed on materials of high or low temperatures or specimens with a rough surface or narrow part, which could not have been tested using the conventional contact-type testing technique. For this study, the internal defects of spot weld, which are often applied to auto parts, and CFRP parts, were tested to determine if it is practical to make the NAUT technique commercial. As the spot welded part had a high ultrasonic transmissivity, the result was shown as red. On the other hand, the part with an internal defect had a layer of air and low transmissivity, which was shown as blue. In addition, depending on the PRF (Pulse Repetition Frequency), an important factor that determines the measurement speed, the color sharpness showed differences. With the images obtained from CFRP specimens or an imaging device, it was possible to identify the shape, size and position of the internal defect within a short period of time. In this paper, it was confirmed in the above-described experiment that both internal defect detection and image processing of the defect could be possible using the NAUT technique. Moreover, it was possible to apply NAUT to the detection of internal defects in the spot welded parts or in CFRP parts, and commercialize its practical application to various fields.
Keywords
CFRP; Lamella Tearing; NAUT; NDE; Spot Welding Part;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 M.W. Nam, Y.S. Lee, O. Y. Yang, "Development of 3D Image Processing Software using EMD Ultrasonic NDE", Journal of the Korea Academia-Industrial cooperation Society, Vol. 15, No. 6, pp. 1569, 2008 DOI: http://dx.doi.org/10.5762/KAIS.2008.9.6.1569
2 Sadayuki, Takahashi, "Ultrasonic imaging using air-coupled P(VDF/TrFE) transducers at 2 MHz" Ultrasonic Vol. 49, pp 495-498, 2009 DOI: http://dx.doi.org/10.1016/j.ultras.2008.10.020   DOI
3 Y.G. Kim, B.Y. Ahn, S.S. Lee, "Automatic Noncontact Ultrasonic Inspection Technique" Journal of the Korean Society for Nondestructive Testing. Vol. 13, No. 4, pp.25-31, 1994.   과학기술학회마을
4 S.W. Choi, J.H. Lee, Y.H. Cho, "Application of Laser - based Ultrasonic Technique for Evaluation of Corrosion and Defects in Pipeline" ournal of the Korean Society for Nondestructive Testing. Vol. 25, No. 2, pp.95-102, 2005.   과학기술학회마을
5 T.Masakazu, T.Osamu, H.Hidekazu, O.Yukio, N.Hideo, K.Koichiro, "Characteristics of Probes for Non Contact Air coupled Ultrasonic Testing," Proceedings of the 17th Symposium on Ultrasonic Testing of Japanese Society for Non-Destructive Inspection, 6-3, pp.81-86, 2010.
6 J.H. Lee, S.W. Choi, J. H. Byun, "A Study on Non - contacting Ultrasonic Testing for Inspecting Delamination in CFRP" Journal of the Korean Society for Nondestructive Testing. Vol. 24, No.3, pp.23-30, 2007.
7 I. K. Park, "Ultrasonic C-scan Technique for Nondestructive Evaluation of Spot Weld Quality" Journal of the Korean Society for Nondestructive Testing. Vol. 14, No. 2, pp. 112, 1994.   과학기술학회마을