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Variation of Eddy Current Signal According to the Defect Shape, Defect Depth and Radial Load in CFRP Tube

CFRP 튜브의 결함형상.결함깊이.레이디얼 하중에 따른 와전류 신호의 변화

  • 송삼홍 (고려대학교 기계공학과) ;
  • 안형근 (세안기술(주)기술연구소) ;
  • 이정순 (세안기술(주)기술연구소) ;
  • 오동준 (안동대학교 기계교육과) ;
  • 송일 (세안기술(주)기술연구소) ;
  • 김철웅 (고려대학교 공학기술연구소)
  • Published : 2004.12.01

Abstract

The applicability of the ultrasonic C-scan inspection is restricted due to the deterioration of mechanical properties of specimen during the test. Therefore, the aim of this research is applied to Eddy Current (EC) test substitute for the C-scan inspection in CFRP tube containing defects. This research is to evaluate the EC signals for the inspection of CFRP tube containing various circular hole defects (20% to 100% depth to the specimen thickness) using the unloading specimen and radial loading specimen. This study was considered the following points; 1) Analysis of EC signals for the inspection of saw-cut defect and circular hole defect, 2) The evaluation of defect depths and EC signals relationship. 3) Variation of EC signal owing to the radial load. In conclusions, the high frequency such as 300∼500 kHz made it possible to the inspection of 40% to 100% defects. Particularly, in case of 20% defect, the EC signal was not detected due to the noise of micro-crack and delamination. While the depth of the hole defects were decreasing, the difference of the phase angle between unloading specimen and radial loading specimen was gradually increasing.

Keywords

Eddy Current Signal;CFRP Tube;MRPC Probe;Saw-cut Defect;Circular Hole Defect;Signal to Noise Ratio;Phase Angle;Lissajous Figure;Radial Load;Delamination

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