考虑铁镓磁特性的换能器输出位移模型与试验

Output displacement model and experiment of transducer considering Galfenol magnetic characteristics

磁致伸缩换能器的换能机制与外加驱动磁场、材料的磁致伸缩特性有不可分割的关系,换能器的输出位移取决于磁致伸缩材料的磁特性、外加磁场、变幅杆等方面。根据等效电路法和平方近似模型,结合材料磁特性和变幅杆振动方程,建立了换能器的输出位移模型,设计了一种无偏置磁场的窗式铁镓磁致伸缩换能器。对铁镓合金材料进行了静态、动态磁特性测量。搭建了试验测试系统,对换能器样机进行了试验测试,完成了模型验证。结果表明:换能器的输出位移幅值理论曲线和试验曲线基本吻合,验证了模型的准确性;在激励电流为2 A、谐振频率为12.4 kHz时,换能器的输出位移幅值为8.22μm。该研究建立的模型和所得结论对换能器的优化设计和输出特性分析具有一定的指导意义。

The energy exchange mechanism of magnetostrictive transducer has an inseparable relationship with the external driving magnetic field and the magnetostrictive characteristics of the material.The output displacement of the transducer depends on the magnetic characteristics of the magnetostrictive material,the external magnetic field,the amplitude transformer and so on.Based on the equivalent circuit method and a square approximation model,the displacement output model of the transducer was established by combining the magnetic properties of the material and the vibration equation of the horn,and a window type Galfenol magnetostrictive transducer with unbiased magnetic field was designed.The static and dynamic magnetic characteristics of Galfenol were measured.An experimental test system was built to test the transducer prototype and verify the model.Results show that the theoretical curve of the output displacement amplitude of the transducer is basically consistent with the experimental curve,which verifies the accuracy of the model.When the excitation current is 2 A and the resonant frequency is 12.4 kHz,the output displacement amplitude is 8.22μm.The model and conclusion are useful for the optimization design and the analysis of the output characteristics of the transducer.