Design of a giant magnetostrictive motor driven by elliptical motion

Recently, rare earth giant magnetostrictive materials (GMM) have drawn a lot of attention. Their applications are developing quickly owing to their unique features, especially at room temperature, such as giant strain coefficient, efficient electric(magnetic)-mechanical transformation ability, and so on. In this paper, a design model for magnetic and mechanical energy coupling and transformation, so-called coupled field iteration, is firstly described through the finite element method (FEM), including the calculation of magnetostrictive force, which is analyzed through the local application of the virtual work principle. Then a prototype of single GMM actuator is designed and comparison between the calculated deformations and experiment measurements is exhibited. Based on these results, a new motor is designed and fabricated by combining two single actuators with a metallic annulus. The metallic annulus is vibrated in elliptical motion mode, which is driven by the two actuators with specific input current pattern. Finally the elliptical motion is validated by the experiments.