采用阶梯形弹性基底的磁致伸缩/压电复合结构磁电响应研究

利用阶梯形变幅杆的应变放大作用，构造了磁致伸缩/阶梯形弹性基底/压电复合结构. 采用等效电路法分析了沿长度方向振动复合结构的一阶磁电响应. 计算了Terfenol-D/阶梯形铍青铜基底/PZT-5H复合结构的磁电响应，并与实际结构的磁电响应进行了比较，由于理论分析中忽略了胶层产生的损耗，理论值和实验结果的变化规律相似，但是谐振频率点和磁电电压转换系数有一定的差异. 同时比较了阶梯形基底和等截面杆基底复合结构，分析表明前者具有更高的磁电电压转换系数. 研究了阶梯形弹性基底长度比及层厚比对复合结构纵振动一阶模 关键词： 磁电效应 磁致伸缩/压电复合结构 磁电响应

Magnetoelectric response of magnetostrictive/piezoelectric composite on a trapezoidal elastic substrate

A magnetostrictive /elastic substrate /piezoelectric composite has been developed where the elastic substrate takes the form of trapezium to amplify the strain. By using the equivalent circuit, the magnetoelectric response of the composite in the longitudinal vibration has been analyzed. The magnetoelectric response of a Terfenol-D/trapezoidal Be-bronze/PZT-5H composite is calculated and is compared with the experiment. It is indicated that the theoretical response shows a similar variation tendency as the experimental in spite of the difference in resonant frequencies and the values of the magnetoelectric voltage coefficients, which is the result of neglecting the glue behavior. At the same time, the composite on a trapezoidal substrate and the composite on a rectangular substrate are compared, which indicates that the former has higher magnetoelectric voltage coefficient. The length ratio of the trapezoidal elastic substrate and the thickness ratio of the composite are further analyzed. It is found that the composite will have maximum magnetoelectric voltage coefficient when: (1) the ratio of the length of wide section to the total length of a trapezoidal elastic substrate is 0.45; (2) the thickness of a trapezoidal elastic substrate is one fourth that of Terfenol-D layer.