Open AccessJournal Article
Digitized Frequency Modulated Thermal Wave Imaging for Nondestructive Testing
Ravibabu Mulaveesala,Suneet Tuli +1 more
TLDR
In this article, a pulse compression approach is used to detect subsurface discontinuities using linear frequency modulated thermal wave imaging and digitized LFMI thermal wave image. But the proposed technique is limited by the limited depth resolution due to the fixed driving frequency of the excited heat sources.Abstract:
This paper proposes novel techniques for thermal nondestructive testing based on frequency modulated thermal waves. A mild steel sample having discontinuities at different depths is taken as a test sample. The limited depth resolution of the lock in thermography due to the fixed driving frequency of the excited heat sources is overcome by the proposed new technique. A pulse compression approach is used to detect subsurface discontinuities using linear frequency modulated thermal wave imaging and digitized linear frequency modulated thermal wave imaging. In this way, the peak power for probing the specimen can be decreased markedly by increasing the average transmitted energy, which is proportional to the length of the modulated excitation signal. Comparison between the techniques based on the analog frequency modulated signal and its digital form are presented.read more
Citations
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Journal ArticleDOI
Pulse compression approach to infrared nondestructive characterization
TL;DR: The technique of pulse compression offers a means of increasing the average power available to illuminate test specimen without any loss of the depth resolution needed for the tactical requirements.
Journal ArticleDOI
Coded excitation for infrared non-destructive testing of carbon fiber reinforced plastics
TL;DR: Capability of the proposed excitation scheme is highlighted with recently introduced correlation based post processing approach and compared with the existing phase based analysis by taking the signal to noise ratio into consideration.
Journal ArticleDOI
Investigation of carbon fiber reinforced polymer (CFRP) sheet with subsurface defects inspection using thermal-wave radar imaging (TWRI) based on the multi-transform technique
TL;DR: A combined theoretical and experimental approach using thermal-wave radar imaging (TRWI) for carbon fiber reinforced polymer (CFRP) with subsurface defects inspection is reported in this article.
Journal ArticleDOI
Frequency-modulated thermal wave imaging for non-destructive testing of carbon fiber-reinforced plastic materials
TL;DR: In this article, a comparative analysis of different thermographic schemes on the basis of supplying equal energy to the chosen frequency used for the analysis of a given carbon fiber-reinforced plastic sample used in experimentation is presented.
Journal ArticleDOI
The use of pulse-compression thermography for detecting defects in paintings
Stefano Laureti,Stefano Sfarra,Hamed Malekmohammadi,Pietro Burrascano,David A. Hutchins,Luca Senni,Giuseppe Silipigni,Xavier Maldague,Marco Ricci +8 more
TL;DR: In this paper, a pulse-compression infrared thermography technique was used to detect buried defects in paintings while minimising the level of thermal stimulus, and the experimental results show that the proposed signal processing procedure is able to detect defects using a low temperature contrast.
References
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BookDOI
Review of Progress in Quantitative Nondestructive Evaluation
TL;DR: The Review of Progress in Quantitative NDE (ROPQN) as mentioned in this paper is the world's leading conference in reporting annually new research and development results in quantitative NDE and promotes communication between the research and engineering communities and emphasize current reporting of work in progress.
Book
High Resolution Radar
TL;DR: In this paper, the authors apply the radar range equation to high-resolution radar high resolution radar design high range resolution waveforms and processing synthetic high-range resolution radar synthetic aperture radar inverse synthetic aperture Radar (ISAR) three dimensional imaging with monopulse radar target imaging with non-coherent radar systems applications for surveillance.
Journal ArticleDOI
Coded excitation system for improving the penetration of real-time phased-array imaging systems
TL;DR: A very simple coded excitation for phased arrays based on the principles of 'pseudochirp' excitation and equalization filtering is described, capable of SNR improvements of about 15 dB with range sidelobe levels acceptable for many medical imaging applications.
Journal ArticleDOI
Lock-in thermography for nondestructive evaluation of materials
Datong Wu,Gerd Busse +1 more
TL;DR: In this paper, the phase sensitive modulation thermography (or "lock-in thermography") combines the advantages of photothermal radiometry with the fast technique of infrared imaging thereby revealing hidden defects in a short time.
Journal ArticleDOI
Advances in pulsed phase thermography
TL;DR: In this article, the fundamental theory of pulsed phase thermography (PPT) processing method is presented including notes on thermal waves, pulsed thermography and lockin thermography.
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Theory of frequency modulated thermal wave imaging for nondestructive subsurface defect detection
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