Magnetostriction characteristics of 3.1% grain-oriented silicon-iron transformer steel

Recent developments in conventional soft magnetic materials

“…A number of methods have been used to measure the magnetostriction of laminations. On large transformers, vibration transducers are comparatively simple and convenient to use, but for laboratory work, where Epstein samples (30.5 cm x 3 cm) of convenient size are usually available, a technique employing ceramic displacement transducers as developed by Brownsey and Maples (1966) is often used. The technique, however, is not free from complications (Simmons and Thompson 1968).…”

“…In alloys in which the anisotropy is very small, rotational processes could take precedence over wall movements. Chikazumi (1964) points out that, using a model based on coherent rotation magnetization, for a permeability of 10 000 the anisotropy needs to be as low as about 300 erg cm-3, from which he concludes that coherent rotation is hardly likely to occur. It is more probable that displacement of broad walls, or incoherent rotation, is involved when the magnetization changes.…”

Magnetic properties of grain-oriented silicon iron. Part 1: Use of ceramic displacement transducers for the measurement of magnetostriction

“…Perhaps the most potentially useful apparatus has been developed by Brownsey,5 which uses ceramic displacement transducers to measure the change of length along the length of a sample from one end, which is clamped. The magnetostriction is given by the slope of the resulting graph of change in length against distance from the clamp.…”

Influence of structural constraints on open-circuit losses of simple transformer structure

“…It would thus seem that, for the same magnetostriction type, a small overall magnetostrictive strain on the unconstrained strips does not in itself ensure low structural sensitivity to change of constraints. As regards the prime causes of the observed effect, it is suggested that the differing behaviour of the three kinds of laminations when the end conditions of the stacks are changed from free to clamped may be attributable to their different magnetostriction and stress sensitivity [2][3][4][5][6][7][8][9][10][11]. The laminations are of course loaded by forces due to electromagnetic attraction and to magnetostriction.…”