Crack growth in ferroelectrics driven by cyclic electric loading

循环电负载驱动的铁电体裂纹扩展

• 批准号: 5397373
• 负责人: Professor Dr.-Ing. Jürgen Rödel
• 金额: --
• 依托单位: Fachgebiet Nichtmetallisch-Anorganische Werkstoffe
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2005-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5397373?language=en
• 关键词: Crack; growth; ferroelectrics; driven; cyclic

Prior work from the literature of non-conducting cracks indicates that ferroelectrics can exhibit crack growth due to electrical cycling only with the electrical field perpendicular to the crack propagation direction. A clear quantitative and mechanistic understanding about the influences of prior poling, polarity and frequency of the cyclic electric field, however, is still missing. In the experimental part of this project, crack propagation of through thickness cracks in DCB specimens in PZT due to electrical cycling will be investigated with and without a mechanical preload. Switchable strain and macroscopic material characterization will also be performed. The theoretical part of the project will provide switching zones for 90° switching, for 180° switching and will include the piezoelectric effect in order to compute the stress intensity factor at the crack tip via an evaluation of the tractions along a contour integral around the crack tip. A further consistency check of the model is afforded by calculating the specimen geometries where a stable crack path is obtained under mixed mechanical and cyclic electrical loading.

非导电裂纹的文献中的先前工作表明，仅与垂直于裂纹传播方向的电场循环，铁电裂解可以杀死裂纹的生长。然而，仍然缺少对先前的极性，极性和频率的影响的明确定量和机械理解。在该项目的实验部分中，将在有没有机械预加载的情况下研究PZT中DCB标本中通过厚度裂纹的裂纹传播。还将执行可切换应变和宏观材料表征。该项目的理论部分将为90°开关提供开关区域，以进行180°开关，并包括压电效应，以通过沿裂纹尖端的轮廓积分对牵引力的评估来计算裂纹尖端处的应力强度因子。通过计算样品几何形状，在混合机械和环状电载荷下获得稳定的裂纹路径，可以对模型进行进一步的一致性检查。