Non-linear frequency-modulated infrared thermal wave detection of debonding defects in CFRP laminates

Abstract

NLFM infrared thermal wave detection system was established to detect and analyze debonding defects of different sizes of CFRP laminates. Principal component analysis, thermal signal reconstruction and total harmonic distortion are used to process the infrared image sequence collected by thermal imager, and the processing effect is evaluated by signal-to-noise ratio. Compared with the other two image sequence processing algorithms, PCA has better effect, can effectively improve the signal-to-noise ratio, and the defect edge in the processed image is clearer.