Thermally Stable Magnetostrictive Device

Abstract

An extremely small magnetostrictive actuator has been designed for a precision application. This paper outlines the procedure utilized to insure that the device remains thermally stable during operation. A differential constitutive relation, suitable for describing magnetostrictive materials, is used to formulate the design constraints. Using this vector constitutive relation in conjunction with finite element and lumpedparameter (circuit) models, conditions on the design parameters may be derived to insure thermally stable operation. To achieve robustness to parameter uncertainty, it is further shown that thermal stability may be achieved through the use of a properly selected thermal control bias current.