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Shock and Vibration
Volume 2014, Article ID 725030, 14 pages
http://dx.doi.org/10.1155/2014/725030
Research Article

Flaw Imaging Technique for Plate-Like Structures Using Scanning Laser Source Actuation

Department of Civil and Environmental Engineering, Sungkyunkwan University, Cheoncheon-Dong, Jangan-Gu, Suwon, Gyunggi-do 440-746, Republic of Korea

Received 6 December 2012; Accepted 14 March 2013; Published 27 April 2014

Academic Editor: Gyuhae Park

Copyright © 2014 Changgil Lee and Seunghee Park. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Recently, the longitudinal, shear, and surface waves have been very widely used as ultrasonic wave-based exploration methods to identify internal defects of host structures. In this context, a noncontact nondestructive testing (NDT) method is proposed to detect the damage of plate-like structures and to identify the location of the damage. To achieve this goal, a scanning laser source actuation technique is utilized to generate a guided wave and scans a specific area to find damage location more precisely. The ND:YAG pulsed laser is used to generate Lamb wave and a piezoelectric sensor is installed to measure the structural responses. The measured responses are analyzed using 3-dimensional Fourier transformation (3D FT). The damage-sensitive features are extracted by wavenumber filtering based on the 3D FT. Then, flaw imaging techniques of a plate-like structure are conducted using the damage-sensitive features. Finally, the plates with notches are investigated to verify the effectiveness and the robustness of the proposed NDT approach.