Frequency-modulated thermal wave imaging (FMTWI) is an emerging thermal non-destructive testing and evaluation (TNDT&E) technique widely used for damage monitoring of various structural materials. The present paper discusses the theoretical aspects of a three-dimensional simulated mild steel model for FMTWI to predict the detection of air defects. In this paper, a comparative evaluation of the results has been carried out by the conventional frequency-domain-based post-processing scheme and is compared with the recently proposed correlation-based time-domain data processing approach. Results show the merits of the time-domain-based post-processing scheme over the frequency-domain-based analysis schemes for improved defect detection capability.
Keywords
- Defect estimation
- Fast-Fourier transform
- Frequency modulated
- Non-destructive testing
- Pulse compression