Effect of spectral shaping on defect detection in frequency modulated thermal wave imaging

Abstract

This manuscript highlights a novel data processing approach for active infrared non-destructive testing and evaluation of carbon fibre reinforced polymers (CFRP). This is accomplished by performing spectral reshaping on a captured pre-processed linear frequency modulated thermal profile over the specimen. Results obtained from the Gaussian windowed frequency modulated thermal wave imaging (GWFMTWI) clearly shows better detection capabilities with improved test resolution and sensitivity. Further multi-transform techniques have been introduced both in time and frequency in order to test subsurface defect capabilities of the proposed approach.