Research on the Magnetomechanical Coupling Effect of Ferromagnetic Cavity Based on Improved Jiles-Atherton Theory

Magnetic field generated by ferromagnetic materials of underwater detectors varies with seawater pressure, which affects the accuracy of deep-sea resource exploration. Therefore, to precisely simulate the influence of deep-sea pressure on the magnetic field around the underwater detectors, a magnetomechanical numerical model must be developed. In this article, a magnetomechanical coupling model of an oxygen tank was developed in COMSOL Multiphysics. Hysteresis curves of 37Mn-type steel were measured with superconducting quantum interference device (SQUID), on which Jiles-Atherton parameters were identified. Initial magnetization of the oxygen tank was calculated according to the obtained conversion matrix and flux density matrix measured by sensors. Furthermore, the concept of equivalent mean field parameter was introduced to describe the magnetomechanical coupling effect of ferromagnets by improving Jiles-Atherton theory, and three equivalent mean field parameters of 37Mn-type steel were obtained. The irreversibility of magnetization and relationship between the pressure and the spatial magnetic field were experimentally obtained and verified. With the escalation of inner pressure and the augmentation of the stress cycle number, reduction in the spatial magnetic field components occurred. The spatial magnetic field components demonstrated an approximate quadratic relationship with the pressure, while exhibiting an approximately linear association with the stress cycle number.

Automated summary

The magnetic field generated by ferromagnetic materials of underwater detectors is affected by seawater pressure, impacting the accuracy of deep-sea resource exploration. A magnetomechanical numerical model must be developed to simulate the influence of deep-sea pressure on the magnetic field. This article presents a magnetomechanical coupling model of an oxygen tank developed in COMSOL Multiphysics. The experimental results show the relationship between magnetization irreversibility, pressure, and the spatial magnetic field.