超磁致伸缩换能器的声辐射特性

对超磁致伸缩大功率换能器的声辐射振动特性进行了理论分析与实验研究,将在一定预压应力下处于阶跃段的磁致伸缩棒简化为磁场强度与磁致伸缩应变的单输入单输出的线性系统·以静态试验数据为基础,建立等效的动态磁致伸缩模型·对指数形变幅杆的设计进行了理论分析和讨论,着重计算与设计了相关的振速分布、应力分布、振幅放大系数及节面位置等参数,测试中发现超磁致伸缩换能器频率范围较宽·试验得到了影响换能器发射声波主频率和最大振幅的若干参数·提高换能器的电声转换效率,增大换能器的发射功率的有效途径是选择合理辐射面质量和配重质量之间的比值,使能量流向辐射面一侧·所得结果可以为进一步优化超磁致伸缩换能器提供设计参考·

Acoustic Properties of Giant Magnetostrictive Transducer

Terfenol-D bar is used in actuator and simplified as one-to-one linear input/output system for the equivalent dynamic magnetic-mechanical model. Based on test data of magnetostrictive material under compression, an exponent type horn of the magnetostrictive transducer is designed. the geometric size based on actual resonance, magnifying coefficient of amplitude, distributing functions of vibration speed and stress and position of nodal section are calculated and a natural frequency equation of the exponent type horn of magnetotrictive transducer is derived designing the magnetostrictive transducer. With the alloy TeDyFe as giant magnetostrictive material tested including its static mechanical properties, a new kind of giant magnetostrictive transducer was made with its dynamic properties tested as well. In such tests the transducer was proved that it has a wide frequency range with wave shape prominent apex and higher launching power and that a proper attached weight ratio can increase the conversion efficiency between electric and acoustic energies.