Switching induced heating at the crack tip in ferroelectric ceramics
Switching induced heating at the crack tip in ferroelectric ceramics
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DOI：
10.1007/s10704-019-00415-4
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发表时间：
2019-12
影响因子：
2.5
通讯作者：
Omar El Khatib;M. Kuna;S. Kozinov
中科院分区：
文献类型：
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作者：
Omar El Khatib;M. Kuna;S. Kozinov
采用边界层方法研究了铁电材料在周期电场作用下的断裂行为。利用铁电材料细观力学模型，分析了裂纹尖端的热-电-力耦合场。除了外部负载，内部的热生成由于耗散域切换过程被认为是。结果，在正向和反向加载期间形成的切换区的形状和尺寸与温度分布一起被阐明。用位形力和机电J积分描述了各种内外因素对裂纹驱动能的影响。数值结果表明，在外加电场作用下，由于畴变而对裂纹尖端产生屏蔽效应。然而，裂纹在卸载时更容易断裂，因为裂纹尖端的残余场。裂纹尖端附近的温度增加，由于域切换确定假设一个绝热过程。较高的温度会导致铁电性能的退化，作为施加循环加载的结果。它降低了屏蔽效应，从而促进了断裂。
The fracture behavior of ferroelectric materials is investigated under cyclic electric fields using a boundary layer approach for small scale switching conditions. By means of a micromechanical ferroelectric material model the coupled thermo-electro-mechanical fields at the crack tip are analyzed. Besides external loading, the internal heat generation due to dissipative domain switching processes is considered. As a result, the shape and size of the formed switching zones during forward and reverse loading are elucidated together with the temperature distribution. The effect of all the internal and external factors on the crack driving energy is described by means of the configurational forces and the electromechanicalJ-integral. The numerical results show that, under the application of the electric field a shielding effect for the crack tip due to domain switching occurs. However, the crack is more vulnerable to fracture while unloading, because of the residual fields at the crack tip. The temperature increase around the crack tip due to domain switching is determined assuming an adiabatic process. A higher temperature leads to the degeneration of the ferroelectric properties as a result of applied cyclic loading. It is reducing the shielding effect, thus promoting fracture.