Multiscale modeling of the magneto-mechanical behavior of grain-oriented silicon steels

The prediction of the magnetic and magnetostrictive behavior of grain-oriented (GO) silicon steels is discussed. An experimental procedure for the measurement of the magneto-mechanical quantities is first detailed. Experimental measurements of the anhysteretic magnetization and magnetostriction are compared to results from the literature. A multiscale model, based on an energetic approach and infinite medium hypothesis, is used. Significant discrepancies between experiments and predictions are highlighted. The specimen shape combined to large grain size induces some strong boundary (surface) conditions leading to a change in the definition of the local potential energy. A specific demagnetizing term is introduced in the definition of the potential energy, creating an initial heterogeneous distribution of the magnetic domains and saturating the magnetostriction along the rolling direction. This modification strongly increases the ability of the model to predict the magneto-mechanical behavior of GO steels.