Analysis on eddy current effect in giant magnetostriction with finite element method

To compensate the nonlinear displacement of the giant magnetostrictive micro-displacement actuator caused by temperature and eddy current induced reverse magnetic field, a mathematic model used to describe the distributing and magnitude of eddy current in the giant magnetostrictive micro-displacement actuator was derived based on electromagnetic theory. Galerkin method and Newton-Laphson iteration were used to analyze the mathematic model of eddy current. The electromagnetic-field distributing of cross-section in the giant magnetostriction micro-displacement was calculated by this mathematic model to gain the corresponding relation of eddy current and frequency of input current in actuator. When the frequency of input current is greater than 1 kHz, the difference of the dissipation of eddy current induced magnetic field calculated by eddy current model of finite element with magnetic field intensity measured actually is 4.6 mT, which shows that the model can effectively compensate the dissipation of the giant magnetostriction micro-displacement actuator caused by eddy current.