Optimal design of magnetic circuit for a magnetostrictive actuator

Magnetostrictive actuators have many advantages such as friction free, powerful output force, resolution of μm or nm scale, and low stiffness than piezoelectric actuators. The objectives of this research are to identify the design parameters and to estimate an optimal value for each parameter through the mathematical modeling and finite element analysis (FEA), respectively. A typical magnetic circuit was also shown, which consists of a magnetostrictive rod, coil, and flux return path. Usually, it is classified into two types according to the existence of the permanent magnet (PM). The magnetic circuit having optimal performances transfer magnetic field which is obtained by providing input current at coil without energy loss. Mathematical model of magnetic circuit is obtained from the relations between flux and reluctance of the magnetic equivalent circuit for identifying the design parameters.