Three-dimensional stress-induced magnetic anisotropic constitutive model for ferromagnetic material in low intensity magnetic field

Le Sun,Dong Jia,Hongpan Niu,Xin’En Liu

doi:10.1063/1.4964359

Abstract

Metal magnetic memory (MMM) technique is a promising tool for inspecting early damage in ferromagnetic components due to its high sensitivity to stress in weak geomagnetic field. However, the quantitative analysis methods for the MMM haven’t been sufficiently studied yet for absence of a reasonable constitutive model. A three-dimensional stress-induced magnetic anisotropic constitutive model is proposed in this paper to study magneto-mechanical coupling effect of the MMM. The model is developed in principal stress space and a linear relation between magnetization and magnetic field is employed for low intensity magnetic field. As a result, stress-induced magnetic anisotropy is represented by stress dependence of magnetic permeability in different directions, which is simple and convenient for applications in the MMM technique. Based on the model, the effect of stress on magnetic permeability and surface magnetic field is computed and compared with experimental data for a tensioned ferromagnetic specimen in low intensity magnetic field. The good consistency implies the validity of the proposed model.

Highlights

Metal magnetic memory (MMM)[1] is a kind of passive magnetic nondestructive testing technique, which works in weak geomagnetic field of about 40A/m
The effect of stress on magnetic property is represented by variations of magnetic parameters with stress, such as magnetic susceptibility or permeability, which makes it convenient to combine the model with commercial FEM software for magneto-mechanical coupling analysis
An Instron5988 testing machine was used to perform a tensile test in geomagnetic field, and the surface magnetic field signals were measured by Bartington Mag-01 instrument

Summary

INTRODUCTION

Metal magnetic memory (MMM)[1] is a kind of passive magnetic nondestructive testing technique, which works in weak geomagnetic field of about 40A/m. The authors developed a one-dimensional constitutive model[6] for ferromagnetic materials, and extended it to a three-dimensional model,[7] i.e., Liu-Zheng model. It is useful in characterizing the magneto-mechanical coupling effect of the ferromagnetic materials over a broad range of field, especially in moderate and intense magnetic field. The model is improved for special condition of the MMM technique, and a more simple and feasible model than Liu-Zheng model is obtained to describe stress-induced magnetic anisotropy effect of ferromagnetic materials in low intensity magnetic field. The validity of the proposed model is verified by comparing computed results with experimental data

MODEL FORMULATION

RESULTS AND DISCUSSION

CONCLUSIONS