Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Effect of Ear and Near-side Single Circular Pit Depth and Bulk Stress on Magnetic Flux Leakage at ferromagnetic Pipeline

강자성 배관 외.내부 면의 단일 원형 홈의 깊이와 부피응력이 누설자속에 미치는 영향

  • 유권상 (한국표준과학연구원 전기자기그룹) ;
  • 박영태 (한국표준과학연구원) ;
  • ;
  • Published : 2003.06.30
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Abstract

Magnetic flux leakage (MFL) signals were used for corrosion inspection of buried oil and gas pipeline. 3D finite element analysis was used to examine the effects of far and near-side pit depth and tensile stress on MFL signals. Anisotropci materials were used, and the effects of simulated tensile stress on MFL were investigated. The axial and radial MFL signals depended on far and near-side single pit depth and on the bulk stress, but the circumferential MFL signal did not depend on them. The axial and radial MFL signals increased with increasing pit depth and the bulk stress, but the circumferential MFL signal was scarcely changed.

누설자속 (magnetic flux leakage: MFL) 신호는 매설된 송유관이나 가스관에 생성된 부식결함의 검사에 이용된다. 배관의 외 내부 면의 단일 원형 홈 (pit) 깊이와 부피응력 (bulk stress)이 축 (x) 방향, 원주 (y) 방향 및 방사상 (z) 방향의 누설자속에 미치는 영향을 3차원 유한요소법을 이용하여 계산하였다. 자기이방성 물질을 이용하여 부피인장응력 (bulk tensile stress)과 수직 응력에 의한 MFL 신호변화를 계산하였다. 배관의 축 및 방사상 방향의 MFL 신호는 배관 외 내부 면의 결함 길이가 깊어질수록, 부피인장응력이 커질수록 MFL 신호는 증가하였다 그러나 원주 방향의 MFL 신호는 결함 깊이와 부피인장응력에 영향을 거의 받지 않았다.

Keywords

References

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