Huang Wenmei

Numerical Dynamic Strong Coupled Model of Linear Magnetostrictive Actuators

A numerical dynamic and magneto-mechanical strong coupled model of linear magnetostrictive actuators was found. The model includes the magneto-mechanical coupling term, which reflects the strong coupling characteristic of magnetostrictive actuators. With this model, the dynamic magnetic and the mechanical problems can be solved simultaneously. According to the proposed model and the measured magnetic characteristic of magnetostrictive material, the relation between the magnet field and the output displacement of the actuator was calculated based on the finite element method. A comparison between the calculated results and the experimental ones for a actuator was carried out and it was found that they were in agreement well. This indicates that the numerical dynamic magneto-mechanical strong coupled model can be used for the design and control of linear magnetostrictive actuators.

Investigation of current dependencies of displacement under variable load for giant magnetostrictive actuators

The dependencies of displacement on current under different variable loads for giant magnetostrictive actuators are computed by using the finite-element method and measured. It is found that the computed result is in agreement with the measured one. This indicates that the finite-element model is valid for computing the displacement for actuators under variable load, and it can be used to design actuators.

Frequency-dependent complex magnetic permeability and magnetic losses of Fe-Ga alloy

The amplitude of magnetic permeability and electromagnetic losses are the basis of application of Fe-Ga alloy. Different magnetic hysteresis curves of Fe-Ga alloy are measured using AMH-1M-S dynamic testing system under different conditions, which are the same saturated magnetic field and the same maximum saturation flux density under different frequencies. The complex magnetic permeability, medium energy storage and magnetic losses are analyzed. Electromagnetic loss increases and energy storage of material reduces with increasing of frequency. Hysteresis loss increases linearly with increasing of frequency, the eddy current loss increases dramatically, and the residual loss increases rapidly. The experimental results of this paper can provide guidance for the design of high frequency Fe-Ga ultrasonic transducers.