Baseline-free defect evaluation of complex-microstructure composites using frequency-dependent ultrasound reflections - ScienceDirect
In this study, baseline-free defect characterization for both flat and ply-drop composites were proposed using frequency dependence of ultrasound reflections. This frequency dependence of ultrasound interaction with delamination and resin layers in composites were investigated through CIVA® simulation and experimental investigation. To extract quantitative data of frequency dependence of ultrasonic reflections in composites with a single test, synchro squeezed wavelet transform was adopted to decompose the acquired wide-band raw signals into narrow-band frequencies. ....
