窗型超磁致伸缩换能器的设计与试验研究

Design and experimental study of window-type giant magnetostrictive transducer

该研究研制了一种窗型结构(双棒结构)超磁致伸缩换能器。等效电路法设计了换能器,以输出端振幅最大、稀土棒内磁场均匀和棒内小峰值应力为目标,有限元方法优化了其结构尺寸,并仿真计算了阻抗圆、输出端振幅随激励电流变化的规律,以及工作频率点处温升与时间的关系。测试了换能器样品,结果表明:测试频率为19.64 kHz,设计值为19.45 kHz;1 A激励电流的位移振幅测试值为6.1μm,计算值为6.3μm;电声效率测试值为52.58%,计算值为41.51%;试验测试1 A电流工作15 min后温度升为45.5℃,仿真计算的温度升为47.8℃。试验测试与理论计算基本吻合。

A window structure(double rare earth rods structure)giant magnetostrictive transducer was developed.The transducer was designed by the equivalent circuit method.In order to get the maximum amplitude of the vibration output end,the uniformity of the magnetic field in the rare earth rod and the small peak stress rare earth rods,the structure size of the transducer was optimized by the finite element method.The impedance circle and the amplitude of the output end of the transducer were simulated and calculated with the increase of the excitation current,and the relationship between the temperature rise and time at the operating frequency was also calculated.The test results of the fabricated transducer show that the measured value is 19.64 kHz,the design frequency is 19.45 kHz;the experimental test displacement amplitude is 6.1μm at 1 A excitation current,and the calculated value is 6.3μm;the tested value of electro-acoustic efficiency is 52.58%,and the calculated value is 41.51%.After 15 min of transducer operation under 1 A excitation current,the temperature rises to 45.5°C by tested,while the simulation calculation temperature rise is 47.8°C.The experimental test is in good agreement with simulation.