Reconstruction of damage-induced magnetization with leakage magnetic field signals

Abstract

The phenomenon of damage-induced magnetization possesses good application prospects in nondestructive testing and material evaluation purpose, once the relationship between the mechanical damage and the induced magnetization can be quantitatively established. As the magnetization can not be measured directly, it is vital to reconstruct the distribution of the magnetization within the materials from the measured magnetic field signals in order to find the correlation. In this paper, an approach has been studied to realize the reconstruction of damage-induced magnetization in a flat plate from the magnetic field signals measured nearby the plate. A deterministic optimization scheme of the steepest descent method has been developed for the inversion in addition with a strategy dealing with the border-effect. Reconstructions with both simulated and measured signals verified the validity and efficiency of the proposed approach.