Modeling of a Scan Type Magnetic Camera Image Using the Improved Dipole Model

  • Hwang Ji-Seong (Graduate School, Chosun University) ;
  • Lee Jin-Yi (Department of Control and Instrument Engineering, Chosun University)
  • 발행 : 2006.10.01

초록

The scan type magnetic camera is proposed to improve the limited spatial resolution due to the size of the packaged magnetic sensor. An image of the scan type magnetic camera, ${\partial}B/{\partial}x$ image, is useful for extracting the crack information of a specimen under a large inclined mag netic field distribution due to the poles of magnetizer. The ${\partial}B/{\partial}x$ images of the cracks of different shapes and sizes are calculated by using the improved dipole model proposed in this paper. The improved dipole model uses small divided dipole models, the rotation and relocation of each dipole model and the principle of superposition. Also for a low carbon steel specimen, the experimental results of nondestructive testing obtained by using multiple cracks are compared with the modeling results to verify the effectiveness of ${\partial}B/{\partial}x$ modeling. The improved dipole model can be used to simulate the LMF and ${\partial}B/{\partial}x$ image of a specimen with complex cracks, and to evaluate the cracks quantitatively using magnetic flux leakage testing.

키워드

참고문헌

  1. Lee, J. et al., 1998a, 'Novel NDI by Use of Magneto-Optical Film,' Transactions of the Japan Society of Mechanical Engineers, Vol. 64, No. 619, pp. 825-830
  2. Lee, J. et al., 1998b, 'Nondestructive Inspection for the Paramagnetic Materials Using the Magneto-Optical NDI System,' Journal of the Japan Society of Applied Electromagnetics and Mechanics, Vol. 6, No.4, pp. 337-342
  3. Lee, J. et al., 2000, 'An Algorithm for the Characterization of Surface Crack by Use of Dipole Model and Magneto-Optical Non-Destructive Inspection System,' KSME International Journal, Vol. 14, No. 10, pp. 1072~ 1080 https://doi.org/10.1007/BF03185061
  4. Lee, J. et al., 2001, 'Development of Magnetic Camera Using 2-D Arrayed Hall Elements,' Proc. APCFS & ATEM'01, pp. 222-227
  5. Lee, J. et al., 2004a, 'Magnetic Flux Density Apparatus for, E.G., Detecting an Internal Crack of a Metal or a Shape of the Metal,' US patents 6,683,452 B2
  6. Lee, J. et al., 2004b, 'Theoretical Consideration of Nondestructive Testing by Use of Vertical Magnetization and Magneto-Optical Sensor,' KSME International Journal, Vol. 18, No. 4, pp. 640-648
  7. Lee, J. et al., 2004c, 'Numerical Consideration of Magnetic Camera for Quantitative Nondestructive Evaluation,' Key Engineering Materials, Vols. 270-273, pp.630-635 https://doi.org/10.4028/www.scientific.net/KEM.270-273.630
  8. Lee, J. et al., 2005, 'Modeling of Characteristics of Magneto-Optical Sensor Using FEM and Dipole Model for Nondestructive Evaluation,' Key Engineering Materials, Vols. 297 -300, pp. 2022-2027 https://doi.org/10.4028/www.scientific.net/KEM.297-300.2022
  9. Lee, J. et al., 2006a, 'The QNDE Using Image Processing of the Magnetic Camera,' International Journal of Modern Physics B, in press
  10. Lee, J. et al., 2006b, 'Detection Probability Improvement for Nondestructive Evaluation Using a Magnetic Camera,' Key Engineering Materials, Vols. 306-308, pp. 241-246 https://doi.org/10.4028/www.scientific.net/KEM.306-308.241
  11. Lee, J. et al., 2006c, 'A Study of Leakage Magnetic Flux Detector Using Hall Sensors Array,' Key Engineering Materials, Vols. 306-308, pp.235-240 https://doi.org/10.4028/www.scientific.net/KEM.306-308.235
  12. Lee, J. et aI., 2006d, 'The Detection Probability Improvement of the Far-Side Crack on the High Lift-off Using the Magnetic Camera,' International Journal of Modern Physics B, in press
  13. Lee, J. and Hwang, J., 2006e, 'A Study of the Quantitative Nondestructive Evaluation Using the Cross Type Magnetic Source and the Magnetic Camera,' Key Engineering Materials, Vol. 321-323, pp. 1447-1450 https://doi.org/10.4028/www.scientific.net/KEM.321-323.1447
  14. Minkov, D. et al., 2000, 'Improvement of the Dipole Model of a Surface Crack,' Materials Evaluation, Vol. 58, No.5, pp. 661-666
  15. Mukae, S., 1988, 'Investigation of Quantification for Defect and Effect of Factors Affecting Leakage Flux Density in Magnetic Leakage Flux Testing Method,' Journal of the Japanese Society for Non-Destructive Inspection, Vol. 37, No. 11, pp.885-894
  16. Yamada, K. et al., 2001, 'Magnetic and Optical Nondestructive Evaluations for Iron-based Materials,' Nondestructive Characterization of Materials X, Elsevier, pp. 330- 340