Anisotropic Magnetostriction of Nonoriented Silicon Steel Sheet and Its Frequency Dependence

The nonoriented (NO) silicon steel sheet´s deformation caused by magnetostriction is one of the main reasons for the vibration and noise of electrical machine, and the presence of higher harmonics of magnetic field may make vibration and noise more serious. In this paper, in order to improve the measurement accuracy of the in-plane magnetostriction of the NO silicon steel sheets, a device with a single yoke and a laser vibrometer is proposed to investigate the principal strain behavior under different alternating magnetization directions. In addition, the effect of higher harmonic of magnetic field on the magnetostrictive behavior is measured and analyzed. The vector magnetostrictive property determined by measured principal strain vector and magnetic flux density vector is described as a 2-D interpolation surface and combined into a simplified magnetoelastic coupling course. The effectiveness of the proposed method is verified by comparing the simulation data and the measured ones.