An extended magnetic-stress coupling model of ferromagnetic materials based on energy conservation law and its application in metal magnetic memory technique

An extended magnetic-stress coupling model based on energy conservation law was established for ferromagnetic materials in low-intensity magnetic fields to develop the metal magnetic memory (MMM) technique, and its application was quantitatively analyzed using the finite element method. Firstly, the verification of the proposed model was given by comparing the influences of stress on relative permeability and residual magnetic field (RMF) signals with experimental data and other theoretical model. Then, the effect of the defect type, size, load magnitude, and lift-off value on the RMF signals was respectively discussed, and their sensitivities on the total characteristic parameter of RMF gradients were compared. In addition, the combined influence of the lift-off value and the defect depth was analyzed. The results indicate that the proposed magneto-stress coupling model is feasible to predict the stress state and structure damage using the MMM technique.