Residual Leakage Field Modeling

  • Y. S. Sun
  • S. S. Udpa
  • W. Lord
Conference paper
Part of the Review of Progress in Quantitative Nondestructive Evaluation book series (RPQN, volume 6 A)


Residual leakage fields are set up around defects in ferromagnetic materials after the active source of d. c. excitation has been removed [1]. Defect detection and characterization then occur by using any flux density sensitive transducer such as magnetic particles, magnetic tape, a moving coil or a Hall element [2]. Past analytical attempts at modeling these phenomena have largely been based on representing simple defect shapes by an equivalent dipole or magnetic charge distribution [3]. In order to examine the effects of realistic defect shapes and material B/H properties, finite element analysis techniques have been used [4,5] to model both active and residual leakage field effects. This paper discusses alternative B/H representations and their impact on the numerical modeling of defect residual leakage fields.


Field Equation Defect Detection Ferromagnetic Material Magnetic Tape Defect Width 
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  1. 1.
    W. Lord, Applications of Numerical Field Modeling to Electromagnetic Methods of Nondestructive Testing, IEEE Trans. Mag. 19, 2437 (1983).CrossRefGoogle Scholar
  2. 2.
    W. Lord and D. J. Oswald, Leakage Field Methods of Defect Detection, Int. J. NDT, 4, 249 (1972).Google Scholar
  3. 3.
    N. N. Zatsepin and V. E. Shcherbinin, Calculation of the Magnetostatic Field of Surface Defects, Defektoskopiya, 5, 50 (1966).Google Scholar
  4. 4.
    W. Lord, J. M. Bridges, W. Yen and R. Palanisamy, “Residual and Active Leakage Fields Around Defects in Ferromagnetic Material,” Mat. Eval., 36, 47 (1978).Google Scholar
  5. 5.
    S. S. Udpa, W. Lord and Y. Sun, “Numerical Modeling of Residual Magnetic Phenomena,” IEEE Trans. Mag., 21, 2165 (1985).CrossRefGoogle Scholar
  6. 6.
    Yu-shi Sun, “On the Calculating Models of Permanent Magnets,” Acta Electronica, 10, 86 (1982).Google Scholar
  7. 7.
    S. R. Satish, “Finite Element Modeling of Residual Magnetic Phenomena,” Master of Science Thesis, Dept. of Elec. Engr., Colorado State University, Fall (1980).Google Scholar
  8. 8.
    D. J. Binns, M. A. Jabbar and W. R. Barnard, “Computation of the Magnetic Field of Permanent Magnets in Iron Cores,” Proc. IEE, 122, 1377 (1975).Google Scholar

Copyright information

© Springer Science+Business Media New York 1987

Authors and Affiliations

  • Y. S. Sun
    • 1
    • 2
  • S. S. Udpa
    • 1
  • W. Lord
    • 1
  1. 1.Electrical Engineering DepartmentColorado State UniversityFort CollinsUSA
  2. 2.Nanjing Aeronautical InstituteChina

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