Effect of bulk stress and pit depth on calculated far and near-side magnetic flux leakage pit signals

3D finite element analysis was used to examine the effects of far and near-side pit depth and simulated bulk tensile stress on magnetic flux leakage (MFL) signals. Non-linear anisotropic Materials were used, and the effects of applied bulk tensile stress and the accompanying orthogonal Poisson stress were calculated. The radial MFL signals in both single and two-pit models was found to depend on far- and nearside pit depth and on the bulk stress. MFL signals increased with greater pit depth and applied bulk tensile stress. These calculated results help one understand measured stress-dependent and depth-dependent MFL signals.