Study of the dipole model of a crack

摘要

Magnetic flux applied within a magnetic specimen redistributes in the proximity of a surface crack and a part of it named leakage magnetic flux leaves the specimen in the vicinity of the crack. The intensity of the magnetic field around the crack can be expressed mathematically using the dipole model of a crack (DMC). In DMC, the crack is considered to be filled by dipoles with dipole moments oriented opposite to the direction of the applied field. Respectively, the intensity of the leakage magnetic field (ILMF) in a particular point outside the specimen is represented as a sum of the intensities of the magnetic fields generated by these dipoles in the same point.