Stress concentration near a surface step and shear localization
Stress concentration near a surface step and shear localization
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DOI：
10.1103/physrevb.61.8707
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发表时间：
2000-04-01
影响因子：
3.7
通讯作者：
Grilhé, J
中科院分区：
文献类型：
--
作者：
Brochard, S;Beauchamp, P;Grilhé, J
在以前的静态原子模拟，它已被明确地表明，表面台阶是位错成核的特权网站。在位错成核之前，观察到弹性剪切，该剪切位于具有将发生成核的台阶的区域的平面中。当这种局部剪切达到最大值时，真实的位错形成，在该值处晶体变得机械不稳定。讨论了应力集中对剪切局部化所起的作用：虽然应力集中不涉及台阶区滑移面中的任何剪切，但它产生了面间距的变化，使剪切变得容易。基于Frenkel模型的计算被开发来分析面间距变化的影响，并且计算使应变能最小化的剪切分布。然后将得到的解析解与原子模拟的结果进行比较。
In a previous static atomistic simulation, it has been shown unambiguously that a surface step is a privileged site for dislocation nucleation. Before dislocation nucleation, an elastic shear, localized in the plane in zone with the step where nucleation will occur, is observed. The real dislocation forms when this localized shear reaches, at its maximum, the value where the crystal gets mechanically unstable. The part played by the stress concentration on the shear localization is discussed: although the stress concentration does not involve any shear in the glide planes in zone with the step, it is shown that it produces a variation of the interplanar distance, which can make shear easier. A calculation based on the Frenkel model is developed to analyze the effect of an interplanar distance variation, and the shear distribution that minimizes the strain energy is calculated. The analytical solution obtained is then compared to the results of an atomistic simulation.