A new magnetic dipole model for evaluating the local stress concentration effects on metal magnetic memory signals

Abstract Metal magnetic memory technology (MMMT), which is based on the force–magnetic effect, is widely used to evaluate the stress concentration state of ferromagnetic materials. Previous studies employed a linear stress distribution model to explain the influence of stress concentration on the normal component of the metal magnetic memory (MMM) signal (Hp(y) signal). However, this approach led to lower accuracy. To address this limitation, this study proposes a nonlinear stress distribution model and evaluates its accuracy. The effects of probe lift-off and stress concentration parameters, including the depth and burial depth of the stress concentration region, on the Hp(y) signal are analyzed theoretically. The results show that as the probe lift-off and burial depth of the stress concentration region increase, the Hp(y) signal amplitude decreases gradually, whereas an increase in the depth of the stress concentration region enhances the signal amplitude. The significance of these factors is further analyzed using response surface analysis. Finally, a comparison between experimental and theoretical Hp(y) signals reveal nearly identical variation patterns, confirming the improved suitability of the proposed model for evaluating stress concentration in ferromagnetic materials. The proposed model enhances the accuracy of stress concentration assessment in ferromagnetic materials, improving the reliability of MMMT for various engineering applications.