A cohesive zone model for the electromechanical damage of piezoelectric/ferroelectric materials
A cohesive zone model for the electromechanical damage of piezoelectric/ferroelectric materials
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DOI：
10.1088/0964-1726/23/5/055024
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发表时间：
2014-04
影响因子：
4.1
通讯作者：
S. Kozinov;M. Kuna;S. Roth
中科院分区：
文献类型：
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作者：
S. Kozinov;M. Kuna;S. Roth
采用一种改进的指数循环粘结区模型，对压电和铁电材料进行了数值断裂分析。所实施的不可逆内聚律允许亚临界机电加载过程中的损伤积累。考虑了由于施加机电载荷而引起的极化方向的改变(作为铁电域转换的结果)。在内聚力定律中实现了一个表示晶界或粘结元素介电常数的广义电容模型。由于粘结元件的存在，试件可能会经历平衡响应路径的不稳定。因此，研究了峰值后应变软化本构关系，以处理突变效应。对3D基本试验模型以及铁电致动器进行了数值模拟。观察到的结果反映了电场以及电畴转换对试件断裂的真实影响。阐述了在循环电载荷作用下，压电/铁电介质中损伤的萌生和积累机制。
A numerical fracture analysis of piezoelectric and ferroelectric materials is conducted using an advanced exponential cyclic cohesive zone model. The implemented irreversible cohesive law allows for the damage accumulation during subcritical electromechanical loading. Change in polarization direction (as a result of ferroelectric domain switching) due to applied electromechanical loading is taken into account. A generalized capacitor model representing the permittivity of the grain boundaries or cohesive elements is implemented in the cohesive law. Due to the presence of cohesive elements, a specimen can experience instability of the equilibrium response path. Therefore, post-peak strain-softening constitutive relations are investigated to handle the snapback effect. Numerical simulations are performed for a 3D basic test model as well as for a ferroelectric actuator. The observed results reflect a realistic influence of the electric field as well as domain switching on the fracture of the specimen. Mechanisms of damage initiation and accumulation are illustrated in the piezoelectric/ferroelectric medium under cyclic electric loading.