A Lamb wave-based damage identification method called damage imaging method for composite shells is presented. A damage index (DI) is generated from the delay matrix of the Lamb wave response signals, and it is used to indicate the location and approximate area of the damage. A piezoelectric actuator is employed to generate the Lamb waves that are subsequently captured by a fiber Bragg grating (FBG) sensor element array multiplexed in a single fiber connected to a high-speed fiber-optic sensor system. The high-speed sensing is enabled by an innovative parallel-architecture optical interrogation system. The viability of this method is demonstrated by analyzing the numerical and experimental Lamb wave response signals from laminated composite shells. The technique only requires the response signals from the plate after damage, and it is capable of performing near real-time damage identification. This study sheds some light on the application of a Lamb wave-based damage detection algorithm for curved plate/shell-type structures by using the relatively low frequency (around 100 kHz) Lamb wave response and the high-speed FBG sensor system.

Date Published: 17 April 2014
PDF: 12 pages
Proc. SPIE 9062, Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2014, 906214 (17 April 2014); doi: 10.1117/12.2058142

Published in SPIE Proceedings Vol. 9062:
Smart Sensor Phenomena, Technology, Networks, and Systems Integration 2014
Wolfgang Ecke; Kara J. Peters; Norbert G. Meyendorf; Theodoros E. Matikas, Editor(s)