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Evaluation of Detectable Defect Size for Inner Defect of Pressure Vessel Using Laser Speckle Shearing Interferometry

레이저 스페클 전단간섭법을 이용한 압력용기 내부결함의 측정 가능한 결함 크기의 평가

  • 김경석 (조선대학교 기계설계공학과) ;
  • 선상우 (조선대학교 대학원 첨단부품소재공학과) ;
  • 최태호 (조선대학교 대학원 첨단부품소재공학과) ;
  • 강찬근 (조선대학교 대학원 첨단부품소재공학과) ;
  • 나만균 (조선대학교 원자력공학과) ;
  • 정현철 (조선대학교 기계설계공학과)
  • Received : 2013.10.08
  • Accepted : 2014.03.12
  • Published : 2014.04.30

Abstract

Pressure vessels are used in various industrial fields. If a defect occurs on the inner or outer surface of a pressure vessel, it may cause a massive accident. A defect on the outer surface can be detected by visual inspection. However, a defect on the inner surface is generally impossible to detect with visual inspection. Nondestructive testing can be used to detect this type of defect. Laser speckle shearing interferometry is one nondestructive testing method that can optically detect a defect; its advantages include noncontact, full field, and real time inspection. This study evaluated the detectable size for an internal defect of a pressure vessel. The material of the pressure vessel was ASTM A53 Gr.B. The internal defect was detected when the pressure vessel was loaded by internal pressure controlled by a pneumatic system. The internal pressure was controlled from 0.2 MPa to 0.6 MPa in increments of 0.2 MPa. The results confirmed that an internal defect with a 25 % defect depth could be detected even at 0.2 MPa pressure variation.

Acknowledgement

Supported by : 한국연구재단

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