Effect of Compressive Stress in Thickness Direction on Iron Losses of Nonoriented Electrical Steel Sheet

The electrical steel sheet is widely used in iron cores of motors, etc. The magnetic properties of a motor core are affected by the distortion due to the compressive stress in the thickness direction caused by bolt bundles, etc. There have been few reports of magnetic properties being investigated systematically, although the detailed examination of the behavior of magnetic properties is important for the precise design of motor, etc. In this paper, the correlation between the compressive stress and its magnetic properties of a nonoriented electrical steel sheet is measured, using a single sheet compressed in the thickness direction. Moreover, the behavior of hysteresis loss and the eddy current loss under the compressive stress in the thickness direction is examined.