Investigation of bulk material property changes and fatigue strength determination of relaxor-PT piezoelectric materials

固溶体弛豫-PT压电单晶自20世纪90年代首次成功生长以来，由于机电耦合接近理论最大值和压电电压-应变系数远高于传统PZT陶瓷，引起了人们极大的兴趣。虽然大量的研究工作集中在这些不同的组合物和晶体取向的几个弛豫PT材料的整体性能值，一直缺乏系统的调查，这些属性如何在不同的边界条件和输入，以及疲劳数据的变化。拟议的研究项目有两个主要目标。第一个是调查的弛豫PT单晶在各种边界条件和循环加载下使用逆方法的材料属性值。第二个目标是使用实验数据和标称应力状态确定来确定疲劳强度值。这两个结果，即改变材料性能值下的服务和材料强度特性，将有助于设计人员在设计更持久的压电器件与改进的性能。**

Solid solution relaxor-PT piezoelectric single crystals have generated considerable interest since first being successfully grown in the 1990s due to electromechanical coupling close to the theoretical maximum and piezoelectric voltage-strain coefficients much higher than traditional PZT ceramics. While significant research effort has focused on these bulk property values for different compositions and crystal orientations of several relaxor-PT materials, there has been a lack of systematic investigation of how these properties change under different boundary conditions and inputs, as well as fatigue data. The proposed research project has two main goals. The first is to investigate the material property values for relaxor-PT single crystals under various boundary conditions and cyclic loading using the inverse method. The second goal is to determine fatigue strength values using experimental data and nominal stress state determinations. The two outcomes, namely changing material property values under service and material strength characteristics, will aid designers in designing longer lasting piezoelectric devices with improved performance. **