Influence of hole geometry on magnetic flux density distribution in lasercut non-oriented electrical steels at power frequencies

Abstract

A mechanical strain caused by shearing, drilling, and punching stresses that occur during the processing of the electrical steel sheets will cause a deterioration of the magnetic characteristics/properties of the material. The variation of localized magnetic flux density distribution is measured and monitored with the help of a search coil located at 45 (ay) angle with respect to the center of different hole shapes such as circular, elliptical, triangular, and square. The localized flux density and magnetic field strength, in laser-cut non-oriented electrical steels, were measured at different peak flux densities with values between 0 and 0.5 T in a frequency range from 50 to 400 Hz. The maximum flux density was obtained in the case of the sample, which has an ellipsoidal hole at the same value of the field strength, whereas the minimum flux density was measured for the triangular hole at 50 Hz.