Signal and image processing techniques for digitized frequency modulated thermal-wave imaging for characterization of fiber-reinforced plastics

摘要

Active infrared nondestructive evaluation (AIRNDE) involves mapping of surface temperatures over the test object, for a known imposed incident heat flux, to detect surface and subsurface defects (voids, disbands, cracks etc.). It is a fast, whole field and remote inspection method for defect detection. Since most of the solids conduct heat, AIRNDE has the potential for wide use in non destructive testing of variety of solid materials. It is achieved by observing, recording and analyzing the thermal response over the material surface to a heat stimulus and is broadly known as active thermography in contrast to passive thermography where no heat stimulus is applied. This paper highlights the defect detection capabilities of digitized frequency modulated thermal wave imaging for carbon and glass fiber reinforced plastic materials