Constitutive modelling of magnetostrictive and soft ferromagnetic materials

Phenomenological constitutive models are desirable in order to guide the processing and development of ferromagnetism and for use in the design of ferromagnetic devices. In this paper, both experimental and theoretical work performed on non-linear constitutive modelling of ferromagnets are presented, which involve in three aspects: (1) The experimental set-up and measured techniques by which the non-linear deformation of both magnetostrictive and soft ferromagnetic materials subjected to coupled magnetomechanical loading are introduced. And the experimental results will be illustrated and analysed; (2) Non-linear deformation behaviour of magnetostrictive materials is studied and three magneto elastic coupling constitutive models such as the Standard Square constitutive model (SS model), the Hyperbolic Tangent model (TH model) and the domain-switching density-model (DSD model) are developed; (3) A phenomenological constitutive model of ferromagnets is developed for general magneto-mechanical loading histories. The state of materials is described in terms of the remnant strain and the remnant magnetization that are introduced as internal variables besides stress, strain, magnetic field and magnetization. The one-dimensional model will be verified by means of the experimental results.