Decomposition of mechanical stress effect on the magnetic property of silicon steel sheet

A principal stress decomposition method was examined and compared with the equivalent stress theory to evaluate the stress-dependent magnetic properties of nonoriented silicon steel. A physical magnetization model, the multidomain particle model, was used to simulate the stress dependence of the magnetic properties by applying mechanical stress in different directions relative to the magnetic field direction. Experimental and computational tests show that even though the principal stress decomposition method provides a reasonable evaluation of the stress-dependent properties in the stress direction, it fails to accurately predict the properties in the perpendicular direction. To improve the prediction accuracy, a modified decomposition method is proposed, which gives a reasonable evaluation of the stress dependence of BH loops, permeability and hysteresis loss even when the magnetization direction is different from the stress direction.