Optimum design of the magnetostrictive actuator

Based on the electromagnetism principles, the relationship between the actuator s output and Terfenol-D rod as well as the top and bottom end plate was deduced. Then optimization was made to minimize the size of the actuator without losing performance. The distribution of magnetic field in the magnetic coils have improved attributing to the closed magnetic flux path, which is composed by the Terfenol-D rod, the top end plate, the bottom end plate and the internal wall of actuator. Similarly, the affection of the temperature was eliminated by the compensation of the thermal expansion, so that the nonlinearity of the actuator s output was minimized. At last a non-magnetizer shield was introduced to house the actuator which can protect other equipments from the effect of the actuator s magnetic field. The finite element analysis simulation with the software of ansys showed that the internal magnetic field of the actuator was uniform and the out magnet leakage was almost zero.