3D finite element method(FEM) was adopted to analyze the magnetic leakage fields(MLF) because of the drawbacks of magnetic dipole model and 2D FEM.The mathematical models for MLF were established based on the Maxwell's equations and 3D finite element theory.The models were used for simulating and analyzing MLF data sets.The vector plot of 3D magnetic flux and the surface plot for the radial component of magnetic flux density were obtained,which could show the feature of the MLF near defect expressly.The eff...