In this research, the relationship between the degree of stress concentration and the sponta-neous magnetic signals of metal magnetic memory (MMM) was investigated by tensile tests. Sheet specimens of Q235 steel were machined into standard bars with rectangular holes to obtain various stress concentration factors. The variations of the MMM signal and its gradient with the applied loads were studied. It was found that both the tangential component, Hp(x), and the normal component, Hp(y), are sensitive to the local stress concentration caused by the discontinuity. The maximum magnetic gradient in the discontinuity area, kmax, was found to increase as the tension or the stress concentration factor increases. The kmax of the Hp(y) signal is effective in characterizing the degree of stress concentration. The magnetic stress concentration factor, αmHp(y), can be used as an indicator of the stress concentration degree. This research is useful for promoting the metal magnetic memory testing (MMMT) to a quantita-tive nondestructive technique for assessing the degree of stress concentration.
Dong, L.H., B.S. Xu, S.Y. Dong, L. Song, Q.Z. Chen, and D. Wang, “Stress Dependence of the Spontaneous Stray Field Signals of Ferromagnetic Steel,” NDT & E International, Vol. 42, 2009, pp. 323–327.
Doubov, A.A., “Screening of Weld Quality using the Magnetic Metal Memory Effect,” Welding in the World, Vol. 41, 1998, pp. 196–199.
Doubov, A.A., “Diagnostics of Equipment and Constructions Strength with Usage of Magnetic Memory, Inspection Diagnostics,” Inspection Diagnostics, Vol. 6, 2001, pp. 19–29.
Huang, H.H., S.L. Jiang, Y. Cheng, and Z.F. Liu, “Stress Concentration Impact on the Magnetic Memory Signal of Ferromagnetic Structural Steel,” Nondestructive Testing and Evaluation, Vol. 29, 2014a, pp. 377–390.
Huang, H.H., S.L. Jiang, R.J. Liu, and Z.F. Liu, “Investigation of Magnetic Memory Signals Induced by Dynamic Bending Load in Fatigue Crack Propagation Process of Structural Steel,” Journal of Nondestructive Evalua-tion, Vol. 33, 2014a, pp. 407–412.
Hwu, C., and Y.C. Liang, “Evaluation of Stress Concentration Factors and Stress Intensity Factors from Remote Boundary Data,” International Journal of Solids and Structures, Vol. 37, 2000, pp. 5957–5972.
Jiles, D.C., “Theory of the Magnetomechanical Effect,” Journal of Physics D: Applied Physics, Vol. 28, No. 8, 1995.
Leng, J.C., M.Q. Xu, M.X. Xu, and J.Z. Zhang, “Magnetic Field Variation Induced by Cyclic Bending Stress,” NDT& E International, Vol. 42, 2009, pp. 410–414.
Pal’a, J., J. Bydžovský, and P. Švec, “Influence of Magnetizing Frequency and Construction of Pick-up Coil on Barkhausen Noise,” Journal of Electrical Engineering, Vol. 55, 2004, pp. 38–40.
Shi, C.L., S.Y. Dong, B.S. Xu, and P. He, “Stress Concentration Degree Affects Spontaneous Magnetic Signals of Ferromagnetic Steel Under Dynamic Tension Load,” NDT& E International, Vol. 43, 2010, pp. 8–12.
Wang, Z.D., K. Yao, B. Deng, and K.Q. Ding, “Quantitative Study of Metal Magnetic Memory Signal Versus Local Stress Concentration,” NDT& E International, Vol. 43, 2010, pp. 513–518.
Wilson, J.W., G.Y. Tian, and S. Barrans, “Residual Magnetic Field Sensing for Stress Measurement,” Sensors and Actuators A: Physical, Vol. 135, 2007, pp. 381–387.
Yang, E., L.M. Li, and X. Chen, “Magnetic Field Aberration Induced by Cycle Stress,” Journal of Magnetism and Magnetic Materials, Vol. 312, 2007, pp. 72–77.
Yao, K., Z.D. Wang, B. Deng, and K. Shen,“Experimental Research on Metal Magnetic Memory Method,” Experimental Mechanics, Vol. 52, 2012a, pp. 305–314.
Yao, K., B. Deng, and Z.D. Wang, “Numerical Studies to Signal Character-istics with the Metal Magnetic Memory-effect in Plastically Deformed Samples,” NDT& E International, Vol. 47, 2012b, pp. 7–17.
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