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http://dx.doi.org/10.4283/JKMS.2013.23.1.018

A Study on Determining the Shape of Small Axial Cracks by using Magnetic Flux Leakage in NDT System for Underground Pipe  

Kim, Hui Min (Dept. of Electrical Engineering, Pusan National University)
Park, Gwan Soo (Dept. of Electrical Engineering, Pusan National University)
Abstract
MFL PIG (Magnetic Flux Leakage Pipeline Inspection Gauge) is called the system which detects the defect for underground pipelines by using magnetic flux leakage method in nondestructive testing. This method is very suitable for testing pipelines because pipeline has high magnetic permeability. MFL PIG generates the magnetic fields to the pipe axially oriented, and detect the signal of leakage flux by using hall sensor. However, MFL PIG is hard to detect the axially oriented crack with small size because the magnetic flux leakage is not enough to be occurred. To detect the small size and axially oriented crack, the circumferential MFL (CMFL) PIG is being proposed and it can maximize the leakage flux for the axial crack by performing magnetic fields circumferentially on the pipe. In this paper, CMFL PIG is applied to detect the axially oriented crack with small size and the analysis for the distribution and the amplitude of the leakage flux signal is performed by using three dimensional finite element method. From sensing signals, the method how to determine the shape of axially oriented cracks is proposed and verified with experiment.
Keywords
MFL; NDT (nondestructive testing); axially oriented crack; CMFL PIG;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 K. K. Tandon, Materials Selection & Design 36, 75 (1997).
2 H. Haines, P. C. Porter, and L. Barkdull, Pipeline & Gas Industry 82, 49 (1999).
3 Vijay Babbar, James Bryne and Lynann Clapham, NDT & E Int. 38, 471 (2005).   DOI   ScienceOn
4 Muhammad Afzal and Satish Udpa, NDT & E Int. 35, 449 (2002).   DOI   ScienceOn
5 J. B. Nestleroth, Battelle Report (2003).
6 J. Grimes and A. N. de Alvarez, Proceedings of the 7th International Pipeline Conference, IPC2008-64275 (2008).
7 R. C. Ireland and C. R. Torres, Sensors and Actuators 129, 197 (2006).   DOI   ScienceOn
8 김희민, 노용우, 유휘룡, 조성호, 김동규, 구성자, 박관수, 한국 자기학회지 22, 49 (2012).