A magnetoelastic model of nonlinear behaviors of Tb-Dy-Fe alloys based on domain rotation

A magnetoelastic constitutive theory of nonlinear anhysteretic behaviors based on domain rotation is presented in this paper for giant magnetostrictive materials (GMMs). For a Tb-Dy-Fe polycrystal with preferred orientations, the magnetic moments of domains are constrained by the anisotropy to lie along the <111> easy magnetization directions. Thus, the fractional occupancies of only the eight <111> directions and the field direction are calculated using an inverse exponential distribution function for simplicity. The linear fitting of the potential distribution parameter with the pre-stress is obtained from the magnetization curves under different compressive stresses for a [110] oriented Tb-Dy-Fe rod, which is used to predict the magnetostriction behaviors. It shows good quantitative agreement with the experimental results under a range of constant uniaxial compressive stresses.