Finite element modeling of Terfenol-D magneto-mechanical coupling: application to a direct micro-stepping rotary motor

Highly magnetostrictive materials such as Tb/sub 0.3/Dy/sub 0.7/Fe/sub 2/, commercially known as Terfenol-D, have been used to date in a variety of devices such as high power actuators and linear motors. The authors investigate a finite element model on a direct micro-stepping rotary motor. Such a motor would be a high torque micro-radian stepper, capable of precision movements and self-braking in the power off state. The thrust of this paper is to test the validity of the so-called "weak coupling" approach on a motor based on the proven inch worm technique. Comparison between numerical outputs from the model and test results on prototype hardware are presented.