Thermal Wave Imaging of Disbonding and Corrosion on Aircraft

Abstract

Thermal wave imaging is emerging as a strong competitor to conventional nondestructive aircraft inspection techniques. Its strengths are in its ability to do rapid, wide-area, contactless imaging to detect corrosion and disbonding. It readily lends itself to the inspection of both metallic and composite aircraft structures. Recently [1], we have described the evolution of thermal wave hardware, and the role of the FAA’s NDI Validation Center in that evolution. In this report, we provide illustrative thermal wave images which show corrosion and disbonding on the B737 testbed aircraft at the NDI Validation Center. By showing sequences of images at successive times after the pulse-heating of the aircraft surface, we show that the greatest detail of subsurface corrosion occurs at very early times, thus mandating the use of rapid imaging techniques. More detailed laboratory studies confirming this conclusion are provided in a separate study by some of the authors [2].