Journal of the Korean Society of Manufacturing Technology Engineers (한국생산제조학회지)

The Korean Society of Manufacturing Technology Engineers (한국생산제조학회)
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Nondestructive Evaluation in the Defects of FRP Composites By Using Terahertz Waves

테라헤르츠파를 이용한 FRP 복합재료의 비파괴결함평가

  • 임광희 (우석대학교 기계자동차공학과) ;
  • 김지훈 (조선대학교 기계설계공학과) ;
  • Received : 2011.10.17
  • Accepted : 2012.02.15
  • Published : 2012.04.15
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Abstract

A study of terahertz waves was made for the nondestructive evaluation of FRP (Fiber reinforced plastics) composite materials. The terahertz systems were consisted of time domain spectroscopy (TDS) and continuous wave (CW). The composite materials investigated include both non-conducting polymeric composites and conducting carbon fiber composites. Terahertz signals in the TDS mode resembles that of ultrasound; however, unlike ultrasound, a terahertz pulse was not able to detect a material with conductivity. The CFRP (Carbon fiber reinforced plastics) laminates were utilized for confirming the experimentation in the terahertz NDE. In carbon composites the penetration of terahertz waves is quite limited and the detection of flaws is strongly affected by the angle between the electric field direction of the terahertz waves and the intervening fiber directions. A refractive index (n) was defined as one of mechanical properties; so a method was obtained in order solve the "n" in the material with non-conductivity. The usefulness and limitations of terahertz radiation are investigated for the NDE of FRP composites.

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References

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  1. Characterization of Fiber Direction Influence in CFRP Composites Using Advanced NDE Techniques vol.21, pp.6, 2012, https://doi.org/10.7735/ksmte.2012.21.6.1003