Matched filtering with gaussian windowed frequency modulated thermal wave imaging for Non-destructive testing and evaluation of mild steel sample

Abstract

InfraRed Thermography (IRT) is a safe, remote, whole field and quantitative Non-Destructive Testing and Evaluation (NDTE) technique to obtain subsurface information. In this paper, depth resolvability using matched filtering approach has been explored for Frequency Modulated Thermal Wave Imaging (FMTWI) technique. Further, the spectral reshaping has been performed using Gaussian windowing function to study and compare the variations obtained in the thermal response. The present paper explores proposed techniques on a mild steel sample having six Flat Bottom Hole (FBH) defects using finite element modeling and analysis technique. Results shows high defect detection performance of frequency modulated approach by considering correlation coefficient and time delay as a figure of merit.