根据作者早期研究中提出的一种新型功能梯度驱动器,设计并制备了该驱动器,建立了理论模型,并对驱动器的性能进行了测试。这种新型功能梯度驱动器由4种基于Pb(Ni1/3Nb2/3)O3-PbZrO3-PbTiO3系列的材料复合而成,且4层材料的压电常数和介电常数在厚度方向上的梯度变化相反,这种梯度结构能使驱动器结构内部的应力分布优于传统弯曲驱动器。为了对驱动器进行优化设计,利用经典复合材料力学和压电方程建立了功能梯度压电驱动器的理论模型,并计算了不同厚度配比的驱动器受电压和自由端集中力单独作用时的准静态变形和应力分布,通过分析驱动器的内部应力,确定了各层最优厚度配比为1∶1∶1∶1。根据优化结果成功制备了功能梯度压电驱动器,并测量了驱动器自由端输出位移与输出力的关系。测量结果表明,功能梯度压电弯曲驱动器的输出位移和输出力呈线性关系,并且频率越低,输出位移和力就越大。

On the basis of a new type of functionally gradient (FG) piezoelectric actuator proposed by the authors in their former study,the new actuator is designed, fabricated, modeled and experimentally studied. The material compositions are selected from Pb(Ni1/3Nb2/3)O3-PbZrO3-PbTiO3 family and they are used as the four layers in the new FG piezoelectric actuator.The piezoelectric constants and dielectric constants of the materials are gradated oppositely in the thickness direction, because this special structure of the FG piezoelectric actuator has an advantage over the traditional actuators in internal stress distribution. To optimize the structure of the FG piezoelectric actuator, an electromechanic model is derived from Classical Lamination Theory (CLT) and piezoelectric equation, and the static distortion and stress distribution of the actuator with different thickness ratios are computed when the voltage or concentrated force effects on it independently.The optimum thickness ratio is 1∶1∶1∶1, which is determined by optimizing the internal stress distribution.According to the optimizing result,the FG piezoelectric actuator is fabricated successfully,also the relation between the output displacement and output force at the free end of the actuator is measured. The experimental results indicate that there is a linear relation between the output displacement and output force of the actuator, moreover, the lower vibration frequency is, the greater output displacement and output force are.