| Abstract: | ![]()
Alternating magnetic flux leakage testing has been applied in the inspection process for detecting cracks on the surface of steel. To develop a precise inspection method, the flux and eddy current distribution should be investigated taking into account the nonlinearity of steel. This paper describes 3D numerical analysis and experiment for this testing. The property of leakage flux from the crack of steel under ac excitation is investigated using the 3D edge‐based hexahedral finite element method. It is shown that the 3D analysis is obligatory in the precise analysis of magnetic phenomena of this testing. The effect of crack width and depth of leakage flux is clarified, and the relationship between the lift off and the amplitude of leakage flux is also illustrated. The characteristic of leakage flux is confirmed by a verification experiment. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 8–15, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10085 |
