Journal of Institute of Control, Robotics and Systems (제어로봇시스템학회논문지)

Institute of Control, Robotics and Systems (제어로봇시스템학회)
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A Measurement of Size of the Open Crack using Ultrasound Thermography

초음파 서모그라피를 이용한 개방 균열의 크기 측정

  • 조재완 (한국원자력연구소 원자력로봇LAB.) ;
  • 서용칠 (한국원자력연구소 원자력로봇LAB.) ;
  • 정승호 (한국원자력연구소 원자력로봇LAB.) ;
  • 정현규 (한국원자력연구소 원자력로봇LAB.) ;
  • 김승호 (한국원자력연구소 원자력로봇LAB.)
  • Published : 2007.03.01
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Abstract

The dissipation of high-power ultrasonic energy at the faces of the defect causes an increase in temperature. It is resulted from localized selective heating in the vicinity of cracks because of the friction effect. In this paper the measurement of size and direction of crack using UET(Ultrasound Excitation Thermography) is described. The ultrasonic pulse energy is injected into the sample in one side. The hot spot, which is a small area around the crack tip and heated up highly, is observed. The hot spot, which is estimated as the starting point of the crack, is seen in the nearest position from the ultrasonic excitation point. Another ultrasonic pulse energy is injected into the sample in the opposite side. The hot spot, the ending point of the crack, is seen in the closest distance from the injection point also. From the calculation of the coordinates of both the first hot spot and the second hot spot observed, the size and slope of the crack is estimated. In the experiment of STS fatigue crack specimen(thickness 14mm), the size and the direction of the crack was measured.

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References

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