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广泛应用的主要障碍。现代换能器通常具有复杂的结构并在恶劣的负载条件下工作，这一事实加剧了这个问题。由于其固有的铁电和铁弹性性质，在大信号载荷作用下，压电陶瓷的实际响应主要是由显著的非线性行为主导的。本课题的主要目的是通过实验研究不同温度水平下单轴和多轴机电加载条件下压电陶瓷的大信号非线性本构特性。为了进一步理解由潜在的微观机制引起的观察到的现象，宏观测量将得到对结构域结构和相态的微观分析的补充。本项目所获得的系统的热电-机械实验数据是建立合适的本构模型的基础，而本构模型是对压电陶瓷元件进行可靠性评估的基础。

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.