Experimental analysis and multiscale modelling of the anisotropic mechanical and magnetostrictive behaviours of electrical steels

Non-Oriented (NO) iron-silicon laminations are commonly used in electrical engineering. Although these materials are assumed to exhibit a quasi-isotropic behaviour in the sheet plane, some specific coupled properties such as magnetostriction are very sensitive to a weak crystallographic texture. Magnetristriction is the strain mechanism that is induced by a magnetic field. This deformation contributes to the noise emitted by electrical machines. An experimental study of the process-induced anisotropy is presented, for both elastic and magnetostrictive behaviours. A multi-scale approach is then proposed, taking into account two sources of anisotropy: the usual cubic anisotropy at the grain scale, and the heterogeneous orientation of the grains (crystallographic texture) at the macro scale. It is shown that specific surface effects must be taken into account in the description of the anisotropy of industrial iron-silicon laminations.