An Element-Combination Method for Arbitrary Defect Reconstruction from MFL Signals

A solution to the inverse problem of reconstructing the defect from a detected Magnetic flux leakage (MFL) signal is important in MFL testing. This paper proposes an element-combination method to solve the inverse problem efficiently. This method obtains sets of element MFL signals of different defects from a finite element model in advance. By conducting the interpolation and combination operations of the selected element signals based on the deduced combination-invariance property, the defect profile is updated to approach the optimal result. The presented inverse procedure is tested using arbitrary defects, and the results show a good agreement between the target and reconstructed defect profiles with a high calculation speed.