Modeling, design, and control of embedded Terfenol-D actuator

Terfenol-D is a magnetostrictive material with properties such as large strain, high force, wide bandwidth, and high energy density. Terfenol-D actuator, with its unique characteristics, is therefore potentially a new class of actuator most suitable for embedded actuator applications. This paper deals with the modelling, design, and control of an embedded compact Terfenol-D actuator to suppress unwanted vibration in flexible structures, especially rotorcraft blades. Based on the two dimensional thermal analysis, the general form of the constitutive equation of magnetostrictive material is modified to include the effects of heating due to the current passing through the coil surrounding the Terfenol-D material. A new Terfenol-D actuator is designed with emphasis on compactness and embeddable properties. An accurate mathematical model based on the modified magnetostrictive constitutive equation is developed. Simulation results indicate good dynamic performance. Methodology of designing is also presented in this paper.