Non-linear Constitutive Thermo-Electro-Mechanical Behavior of Piezocermics: Experimental Investigation

相对较差的可靠性已成为阻碍压电陶瓷材料向广泛应用领域突破的主要障碍。现代传感器通常具有复杂的结构并且在严重的负载条件下工作，这一事实加剧了该问题。由于压电陶瓷固有的铁电和铁弹特性，其在大信号载荷下的真实的响应主要表现为显著的非线性行为。本课题的主要目的是对压电陶瓷在不同温度水平下的单轴和多轴机电加载条件下的大信号非线性本构特性进行实验研究。为了进一步理解所观察到的现象所造成的潜在的微观机制，宏观测量将补充微观分析的域结构和相态。在这个项目中获得的系统的热-电-机械实验数据的基础上，开发合适的本构模型作为基础的压电陶瓷元件的可靠性评估。

Relatively poor reliability has become the main obstacle in preventing the breakthrough of piezoceramic materials into a broad field of applications. This problem is intensified by the fact that modern transducers normally have complicated structures and work under severe loading conditions. Due to their inherent ferroelectric and ferroelastic properties, the real response of piezoceramics under large signal loading is dominated by significantly non-linear behavior. The main objective of this project proposed here is to experimentally investigate the large signal non-linear constitutive properties of piezoceramics under uni-axial and multi-axial electromechanical loading conditions at different temperature levels. To further the understanding of the observed phenomena caused by underlying microscopic mechanisms, macroscopic measurements will be supplemented by microscopic analysis of the domain structure and phase state. The systematic thermo-electro-mechanical experimental data obtained in this project are the foundation for the development of suitable constitutive models serving as a basis for the reliability assessment of piezoceramic components.