Effects of torsion on domains of coated Si-Fe sheets

The paper discusses consequences of twisting a grain oriented transformer sheet of conventional type and HI-B type, respectively, around an axis parallel to the rolling direction; a situation which (in a less defined way) will occur in regions close to core bands, for example. Mechanically, apart from shear stress, there results tension at the sheet´s peripheral regions which is counterbalanced by compression in the central region. Here, torsion leads to domain widening and, in the case of higher twist angles, to extensive domain reconstructions connected with increases of iron losses. Quantitatively, the effectiveness of a given twist angle increases strongly with increasing sheet width.