Hysteresis analysis and reduction of giant magnetostrictive materials and their actuators

Hysteresis is the inherent characteristic of most smart materials, which quite challenges their effective use in many fields. In this paper, hysteresis of Giant magnetostrictive material (GMM) and their actuators are tested and analyzed and the corresponding reduction measures are presented. The studies show that hysteresis width of GMM is about 60Oe for the as-cast sample under zero stress and 110Oe for oriented rod under 10MPa in the linear magnetostriction. Hysteresis width of GMM actuator is about 130Oe. That indicates the feasibility of actuator design and still exist a little nonlinear effect. Moreover, the dynamic hysteresis loop of system is dependent on frequency and can be represented and compensated by phase lag between input and output signal.