Local defect resonance (LDR) makes use of high frequency vibrations to get a localized resonant activation of a defective region. In this study, the LDR behavior of carbon fiber reinforced polymer (CFRP) coupons with three different types of damages is investigated using broadband measurements obtained with a scanning laser Doppler vibrometer (SLDV). First, the LDR response of flat bottom holes of different depths and sizes is evaluated using a signal-to-noise ratio. Next, results are obtained for ETFE inserts where the difference between (artificial) delaminations and inserts is outlined. At last, the vibrational response of a CFRP coupon with barely visible impact damage is investigated. This type of damage has a more complex structure, and it is shown that frequency band data (an alternative to the single frequency LDR) performs well in identifying such complex damage.
134 Investigation to Local Defect Resonance for Non-Destructive Testing of Composites
Published: 27 May 2018 by MDPI AG in Proceedings of The Eighteenth International Conference of Experimental Mechanics in The Eighteenth International Conference of Experimental Mechanics
MDPI AG, Volume 2; 10.3390/ICEM18-05273
Keywords: Composite materials, Non-destructive Testing (ndt), Laser Doppler Vibrometry (ldv), Local defect resonance (LDR), Frequency Band Data (FBD)