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Analysis of effects of diffraction and interference on detection by microwave thermography

  • Sam-Ang KeoEmail author
  • Chan-Young Yune
  • R. G. Dragan
  • Didier Defer
  • Florin Breaban
Original Paper
  • 42 Downloads

Abstract

In this paper, the effects of diffraction and interference on thermograms of steel bars in a reinforced concrete wall using microwave thermography are discussed. Three series of microwave thermography tests were conducted. Transmission approach was used for the first series of tests. The tests were carried out with a single rebar (12 mm diameter) vertically placed against a concrete wall of 1 m × 1 m × 6.5 cm. The sample was heated with an average power of 600 W for 3 min. The second and the last series of tests were carried out with a reinforced concrete wall using transmission and reflection approaches, with five angles of incident waves (0°, 15°, 30°, 45°, and 60°), and a heating power of 600 W for 5 min. The test results were analyzed based on the Snell–Descartes theory and data interpretation by multiple approaches. Detailed discussion clarifies how diffraction and interference affected the thermograms. In the reflection approach, the incident waves guided by the antenna were refracted after reaching the surface of the concrete wall, then transmitted into the concrete. The fractions of transmitted waves that reached the steel bars were reflected to the surface of the concrete wall, which made those parts of concrete hotter than the other parts without reflected waves. In the transmission approach, the interference of the diffracted waves made the concrete in the areas of wave superposition hotter than other areas and mainly affected the thermograms of the rear surface of the detected wall.

Keywords

Diffraction Interference Detection Steel Microwave Thermography 

Notes

Acknowledgements

This work was carried out at Laboratoire de Génie Civil et GéoEnvironnement (LGCgE). The authors would like to acknowledge Nord-Pas-Calais Regional Council and Université d’Artois for their financial support. The authors also express their gratitude to the Mechanical and Productive Department of Institut Universitaire de Technologie de Béthune (IUT Béthune) for providing space to carry out the tests. Special thanks to Franck Brachelet, research engineer of Université d’Artois, for having facilitated the preparation of the necessary materials for the tests.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

References

  1. 1.
    Keo S-A, Defer D, Breaban F, Brachelet F (2013) Comparison between microwave infrared thermography and CO2 laser infrared thermography in defect detection in applications with CFRP. Mater Sci Appl 4(10):600–605Google Scholar
  2. 2.
    Keo S-A, Defer D, Breaban F, Brachelet F (2013) Development of an infrared thermography method with CO2 laser excitation, applied to defect detection in CFRP. Int J Civ Environ Eng 7(8):580–584Google Scholar
  3. 3.
    Dragan RG, Rosca I-C, Keo S-A, Breaban F (2013) Active thermography method using an CO2 laser for thermal excitation, applied to defect detection in bioceramic materials. In: The 4th IEEE international conference on e-health and bioengineering (EHB2013). Iaşi, RomaniaGoogle Scholar
  4. 4.
    Keo SA (2013) Développement d’une Méthode de Thermographie Infrarouge Active par Excitation Micro-ondes appliquée au Contrôle Non Destructif. PhD thesis. Lille Nord de France, Artois University, FranceGoogle Scholar
  5. 5.
    Keo SA (2014) Nouvelles Méthodes de Contrôle Non Destructif (CND) en Génie Civil. Presses Académiques Francophones, SaarbrückenGoogle Scholar
  6. 6.
    Keo SA, Brachelet F, Breaban F, Defer D (2015) Defect detection in CFRP by infrared thermography with CO2 laser excitation compared to conventional lock-in infrared thermography. Compos B Eng 69:1–5CrossRefGoogle Scholar
  7. 7.
    Keo SA, Brachelet F, Defer D, Breaban F (2014) Defects detection by infrared thermography with a new microwave excitation system. Mech Ind 15:509–516CrossRefGoogle Scholar
  8. 8.
    Keo SA, Brachelet F, Defer D, Breaban F (2014) Détection de Défauts par Thermographie Infrarouge avec un Nouveau Système d’Excitation Micro-ondes. Spectra Anal 297:44–51Google Scholar
  9. 9.
    Keo SA, Brachelet F, Breaban F, Defer D (2014) Steel detection in reinforced concrete wall by microwave infrared thermography. NDT E Int 62:172–177CrossRefGoogle Scholar
  10. 10.
    Brachelet F, Keo S, Defer D, Breaban F (2014) Detection of reinforcement bars in concrete slab by infrared thermography and microwaves excitation. In: The 12th international conference on quantitative infrared thermography (QIRT). Bordeaux, FranceGoogle Scholar
  11. 11.
    Henry M (1982) Optique ondulatoire, Interférences. Diffraction. Polarisation. Techniques Ingénieur. A191Google Scholar
  12. 12.
    Labarthe J-J (2004) COURS OPTIQUE ONDULATOIRE. Université Paris-Sud Orsay, FranceGoogle Scholar
  13. 13.
    Moussa A, Ponsonnet P (1988) Cours de Physiques Tome I - Optique, ed. n. 718. Impressions Dumas, Saint-Etienne (Loire)Google Scholar
  14. 14.
    Rhim HC, Büyüköztürk O (1998) Electromagnetic properties of concrete at microwave frequency range. ACI Mater J 95:265–271Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Sam-Ang Keo
    • 1
    Email author
  • Chan-Young Yune
    • 1
  • R. G. Dragan
    • 2
    • 5
  • Didier Defer
    • 2
    • 3
  • Florin Breaban
    • 2
    • 4
  1. 1.Department of Civil EngineeringGangneung-Wonju National UniversityGangneungRepublic of Korea
  2. 2.Laboratoire de Génie Civil et GéoEnvironnementPRES Lille Nord de FranceLilleFrance
  3. 3.Faculté des Sciences Appliquées (FSA)BéthuneFrance
  4. 4.Institut Universitaire de Technologie (IUT)BéthuneFrance
  5. 5.DPMM DepartmentTransylvania UniversityBrasovRomania

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