Affiliations: [a] State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, China | [b] School of Electric and Automation Engineering, Nanjing Normal University, Nanjing, Jiangsu, China | [c] Institute of Fluid Science, Tohoku University, Miyagi, Japan
Correspondence:
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Corresponding author: Jinhao Qiu, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao Street, Nanjing 210016, Jiangsu, China. Tel./Fax: +86 25 84891123; E-mail:qiu@nuaa.edu.cn
Abstract: In this article, two novel NDT methods for composite
structures are presented. First, the laser ultrasonic method for
visualization of impact damage is introduced. A laser ultrasonic scanning
system was developed, and the anomalous incident wave (AIW) energy was
obtained from the wave-field data to image the artificial and impact
damages. Next, a mid-frequency ECT (eddy current testing) system with the
working frequency up to 250 kHz developed by the authors' lab for CFRP
inspection is presented. The main features of the system include the
weak-signal extraction method using the lock-in amplifier and the C-scan
imaging techniques. The location and size of different damages were
visualized in the scan image. With the developed system, the direction of
different fiber plies could also be successfully detected.
