Inspection of defects in CFRP based on principal components

Abstract

Recent advances in thermal non-destructive testing (TNDT) witnessed improved defect detection capabilities in various fields. Active thermography enables fast and easy inspection of products made of composites. A number of post processing techniques are being developed with an aim to enhance the subsurface defects from the thermographic data. This paper explores the idea of applying principal component analysis (PCA) to thermal wave imaging for possible enhancement of subsurface defects in carbon fibre reinforced plastic (CFRP) material. The experimentation is carried over CFRP sample using quadrature frequency modulated thermal wave imaging (QFMTWI) excitation scheme and results are compared with conventional phase based methods. The results demonstrate the potential of this approach for detecting subsurface defects in CFRP.