Pulse compression approach to digitized frequency modulated infrared imaging for non-destructive testing of carbon fibre reinforced polymers

Abstract

InfraRed Thermal Wave Imaging (IRTWI) is one of the promising non-contact and full field inspection technique for non-destructive characterization. This technique relies on the mapping of surface temperature distribution to visualize the presence of surface and subsurface anomalies in the test material. Due to its fast and quantitative evaluation capabilities, IRTWI has gained significant importance in the characterization of Carbon Fiber Reinforced Polymers (CFRP). A CFRP specimen having flat bottom holes is considered for inspection using non-stationary Digitized Frequency Modulated Thermal Wave Imaging (DFMTWI) technique. Further depth scanning performance by using frequency domain based phase approach has been compared with recently proposed time domain phase approach.