Impact damages detection on composite materials by THz imaging

- An imaging setup uses terahertz (THz) waves from a Quantum Cascade Laser.
- NDE of impact damages on polypropylene/polypropylene composite samples is performed.
- THz images are compared with results from a commercial ultrasonic C-scan instrument.
- THz images in reflection and ultrasound C-scan give similar results.
- Delaminations and crack in the fiber fabrics are shown in THz transmission images.

This 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.