超磁致伸缩材料高频磁能损耗特性测试与分析

Test and Analysis of High Frequency Magnetic Energy Losses Characteristics for Giant Magnetostrictive Materials

为进一步研究超磁致伸缩材料磁能损耗特性,将棒状Terfenol-D材料沿着不同磁化方向进行切片,制成多个方形环状薄片样品,对比分析了材料磁化方向以及样品尺寸对磁能损耗的影响。在不同驱动磁场频率和磁密幅值下,对磁能损耗进行测试,分析损耗实测数值变化趋势。基于损耗分离法,结合实测数据,考虑了材料内部涡流集肤效应及动态磁滞特性等影响,对高频磁能损耗进行了数值模拟,研究各项损耗系数变化规律。结果表明,Terfenol-D材料高频磁能损耗随着频率及磁密幅值增加,整体呈数值增大、增速加快趋势。在高频下,损耗系数为随着频率和磁密幅值变化的变量。当频率大于5 k Hz、磁密幅值大于0. 05 T时,数值模拟方法所得计算值与实测值的平均误差为3%。

Experimental and calculating analysis of magnetic losses for giant magnetostrictive materials is necessary steps for the design of high power magnetostrictive transducer.In order to further research the magnetic energy losses characteristics,a Terfenol-D rod was sectioned along different directions,and these slices were made into several square annular sheet samples.The influences of magnetization direction and dimension parameter on the magnetic losses were compared and analyzed.Under different frequency and magnetic density of driving magnetic field,the magnetic energy losses were measured to analyze the variation trends of the losses.Based on the loss separation formula and measured data,the effects of eddy current skin effect and dynamic hysteresis characteristics were taken into consideration.The variation trends of the losses coefficients were investigated with numerical simulation.The results showed that the high frequency magnetic energy losses for Terfenol-D were increased rapidly in both value and growth rate with the increase of frequency and magnetic density.When the frequency was 5 kHz,the losses were increased from 2.742 W/kg to 153.890 W/kg as the flux density was varied from 0.01 T to 0.09 T.The losses were increased by 55.12 times.When the flux density was 0.05 T,the losses were increased from 8.138 W/kg to 319.428 W/kg as the frequency was increased from 1 kHz to 20 kHz.The losses were increased by 38.25 times.The losses coefficients varied with high frequency and magnetic density.When the frequency was above 5 kHz and the magnetic density was higher than 0.05 T,the average error of the model between the calculated value and the measured value was 3%.The numerical model was suitable for calculating high magnetic energy losses of Terfenol D.It can provide a theoretical and experimental guidance for the high frequency applications of magnetostrictive materials.