Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Laser Lock-in Thermal Wave Imaging for Nondestructive Evaluation

  • An, Yun-Kyu (Department of Civil and Environmental Engineering, KAIST) ;
  • Sohn, Hoon (Department of Civil and Environmental Engineering, KAIST) ;
  • Kim, Ji Min (Department of Civil and Environmental Engineering, KAIST)
  • Received : 2013.06.20
  • Accepted : 2013.08.12
  • Published : 2013.08.30
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Abstract

This paper presents a new laser lock-in thermography (LLT) technique for nondestructive evaluation. LLT utilizes a modulated continuous wave laser beam as a heat source to obtain high fidelity thermal wave images even at the presence of background heat disturbances. The thermal waves propagating along the surface and through-the-thickness directions of a structure are visualized using newly developed laser lock-in amplitude and phase images, enhancing the detectability of surface and subsurface defects. The LLT technique is numerically investigated and experimentally validated using thermal images obtained from a steel specimen with low emissivity.

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References

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