A method for locating embedded depth of the center of inner defect by magnetic flux leakage testing

Seeking the distribution of electromagnetism field and its source by superficial magnetic data belongs to the range of electromagnetism inverse, which is a focus problem on the research of the application of Magnetic flux leakage at present. Because the target function has multi-peak character, it may be have the same superficial magnetic testing data for defects with various embedded depth, which result in the uncertainty in seeking the embedded depth of defects. In this paper, we can obtain the dipole with the largest influential power by the simulated evolution optimization method. The position of the dipole with the largest value is the position of embedded depth of defects. Therefore, we can obtain the range of the depth of defects, which is the basis of quantification and visualization.