偏置电压对磁致伸缩/压电层合换能结构磁电性能影响

Effect of adjustable bias voltage on magnetoelectric properties of magnetostrictive/piezoelectric laminated transducer structure

分析和测试了偏置电压调整时PZT5/Terfenol-D/PZT8层合换能结构磁电性能.提出了一种磁致伸缩/压电层合磁电换能结构的一阶谐振频率控制方法.通过改变压电驱动层的直流电压对磁电层合结构的预应变进行改变,从而调整谐振频率.分析偏置电压、应变、弹性模量、谐振频率和谐振磁电电压系数之间关系.分析表明:在较小应变情况下,控制电压几乎可以线性调节谐振频率,而层合结构谐振磁电电压系数几乎与偏置电压无关.实验研究验证:理论与实验结果较好吻合.在-170 V—+170 V的偏置电压时,谐振频率可以几乎线性调整.最大频率调整量达到1 kHz,偏置电压对一阶纵振频率的控制率达到:2.94 Hz/V.在偏置磁场为0—225 Oe时,谐振频率调整量与偏置磁场无关.偏置磁场会改变谐振磁电电压系数,在大于178 Oe静态磁场偏置时,磁电电压系数最大,达到1.65 V/Oe.

The magnetoelectric properties of PZT5/Terfenol-D/PZT8 laminated transducer structure are analyzed and detected for adjusting the bias voltage across PZT5. A control method of one-order resonant frequency for a magnetostrictive/piezoelectric laminated magnetoelectric transducer structure is proposed. The resonant frequency and the prestrain of the magnetoelectric laminated structure can be adjusted by changing the bias voltage across PZT5. The relationships between the control voltage, the strain, the Young＇s modulus, the resonant frequencies and the resonant magnetoelectric coefficient are analyzed. Theoretical analyses show that the resonant frequency of the laminated structure is almost a linear function of the applied dc bias voltage at a small strain. The magnetoelectric coefficient is hardly related to the control voltage. The experimental results verify the theoretical analyses. For a control voltage of -170 V to ＋170 V, the resonant frequency can be linearly adjusted. The adjusted maximum of the resonant frequency is 1 kHz. The ratio of the adjusted value to the bias control voltage is 2.94 Hz/V. For a bias magnetic field from 00e to 225 Oe, the resonant frequency is almost unrelated to the bias magnetic field. The magnetoelectric voltage coefficient changes with the bias magnetic field. A maximum magnetoelectric voltage coefficient of 1.65 WOe is obtained at a bias magnetic field of 〉 178 Oe.