Impact damages detection on composite materials by THz imaging

International audienceThis paper presents a Non-Destructive Testing (NDT) method based on the penetration properties of terahertz (THz) waves. A CW raster-scanning THz imaging setup, using a 3.8 THz Quantum Cascade Laser as a source, is used to perform NDT of polypropylene/polypropylene composite samples. Results from transmission and reflection THz imaging are compared to ultrasound C-scan. THz images in reflection give similar results to C-scan whereas THz transmission images provide more information about delaminations and cracks in the fiber fabrics