Thermal wave imaging for defect depth measurement in composites

Thermal wave imaging has been becoming a more and mole powerful non-destruc tive evaluation technique. Ir is being used in the aerospace and automotive industries, in oil refineries, for corrosion detection and quantification, etc. In this paper, we describe the application of this technique to the m easurement of defect depths in composite structures in aircraft. Quantitati ve defect depth measurements are made by following the time evolution of th e surface temperature of the part after the flash heating. Results from lay ered structures in graphite and boron fiber as well as fiberglass composite samples are shown.