A theory of magnetostriction oriented towards applications

A simplified theory of magnetostriction, derived from micromagnetics, is presented. The theory is designed to provide a systematic, yet manageable, quantitative tool in the design of magnetostrictive actuators, by making the “calculation” of the overall response of magnetostrictive specimens subjected to applied magnetic fields and loads a feasible task. Indeed, for simple geometries, the computation of energy minimizing domain patterns is reduced to a finite dimensional problem. As an application of the theory, a mechanism explaining the anisotropic magnetostriction observed in Terfenol-D rods, based on computed energetically optimal domain arrangements, is proposed.