Perturbed magnetic field of an infinite plate with a centered crack

• Published in: Acta mechanica Sinica 2011-04, Vol.27 (2), p.259-265
• Main Authors: Qin, Fei, Zhang, Yang, Liu, Ya-Nan
• Format: Article
• Language: English
• Subjects: Boundaries; Classical and Continuum Physics; Computational Intelligence; Cracks; Deformation; Engineering; Engineering Fluid Dynamics; Fourier transforms; Magnetic fields; Mathematical analysis; Nondestructive testing; Research Paper; Tensile stress; Theoretical and Applied Mechanics; 中心裂纹板; 外部磁场; 对称分布; 形变诱导; 拉伸应力; 无损检测技术; 磁场强度
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-011-0418-z

Deforming a cracked magnetoelastic body in a magnetic field induces a perturbed magnetic field around the crack. The quantitative relationship between this perturbed field and the stress around the crack is crucial in developing a new generation of magnetism-based nondestructive testing technologies. In this paper, an analytical expression of the perturbed magnetic field induced by structural deforma- tion of an infinite ferromagnetic elastic plate containing a centered crack in a weak external magnetic field is obtained by using the linearized magnetoelastic theory and Fourier transform methods. The main finding is that the perturbed magnetic field intensity is proportional to the applied tensile stress, and is dominated by the displacement gradient on the boundary of the magnetoelastic solid. The tangential component of the perturbed magnetic-field intensity near the crack exhibits an antisymmetric distribution along the crack that reverses its direction sharply across its two faces, while the normal component shows a symmetric distribution along the crack with singular points at the crack tips.