Influence of shear stress on vector magnetic properties of non-oriented electrical steel sheets

Electrical steel sheet that is used as a core in electrical machines deteriorates due to residual stress and external stress. The magnetic properties and stress need to be clarified in order to effectively utilize electrical steel sheet in electrical machines. We have measured the residual stress distribution in a motor core using an X-ray stress measurement device and clarified not only the tensile and compressive stress distributions, but also the shear stress distribution. In this study, a new measurement system is developed for determining vector magnetic properties under shear stress. The vector magnetic properties of the non-oriented electrical steel sheets under the alternating magnetic flux and rotating magnetic flux conditions were measured with the developed system. As the result, it was clear that the magnitude of the magnetic field strength vector and the magnetic power loss along the direction of about 135 degrees increased by applying the shear stress.