Discriminating porosity in composites using thermal depth imaging

Abstract

Porosity evaluation in composites has been extensively studied with ultrasonics. There are far fewer examples of porosity evaluation using thermal imaging. One reason for this dearth of work has been the qualitative nature of most thermal characterization. In this paper we use quantitative thermal depth imaging to identify, for the first time, the characteristic signature of planes of dense porosity in composites. The observations are compared with results from thermal theory and modeling of porosity and with ultrasonic characterization. This approach should eventually lead to a quantitative thermal evaluation of volume % porosity in composites.