A 3-D analysis of the sheared cross-section of electrical steel plates

Abstract

Most rotators and stators of motors or generators as well as the cores of transformers are produced by laminated plates of electric steel to reduce the energy loss caused by eddy current. Therefore, it is essential to predict as well as improve the shearing quality of the electric steel plates and thus help increase the efficiency of the machines. Most investigations overlook the planar anisotropy in the numerical analysis of the shearing process. The simplified 2-D analysis was adopted instead of the 3-D analysis. In this work, DEFORM 3D analysis is used which takes into account the anisotropy of the plate material. Normalized Cockcroft & Latham damage criterion is used in determining the occurrence of fracture during the shearing. The result shows that the 3-D analysis predicts well in the burnish depth while roughly in rollover due to insufficient resolution of the element size. The 2-D analysis tends to underestimate the burnish depth attributed to the improper selection of lower critical damage values and predicts scattered rollover.