Simplified evaluation of mechanical instability in large-scale atomic structures
Simplified evaluation of mechanical instability in large-scale atomic structures
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DOI：
10.1016/j.msea.2009.01.058
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发表时间：
2009-07
期刊：
影响因子：
6.4
通讯作者：
T. Shimada;S. Okawa;Shinichiro Minami;T. Kitamura
中科院分区：
文献类型：
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作者：
T. Shimada;S. Okawa;Shinichiro Minami;T. Kitamura
为了研究大尺度原子结构中的力学不稳定性，提出了一种通过引入线性元素来描述自由度降低的不稳定变形的简化方法。将该方法应用于拉伸作用下的裂纹原子结构，成功地再现了位错发射前势能的Hessian矩阵最小特征值及其在裂纹尖端附近的变形模式。与原来的精确方法相比，计算量大大减少，这使我们能够解决大尺度原子系统的机械不稳定性问题。此外，该方法还可以确定主要主导不稳定变形的临界区域。
For the investigation of mechanical instability in a large-scale atomic structure, a simplified method is presented that can describe unstable deformation with reduced degrees of freedom by introducing linear elements. The proposed method is applied to a cracked atomic structure under tension, and it can successfully reproduce the minimum eigenvalue of the Hessian matrix of the potential energy before the dislocation emission and its deformation mode near the crack-tip. The computational load is considerably reduced in comparison with the original precise method, and this enables us to address the mechanical instability in a large-scale atomic system. Moreover, the critical area that mainly dominates unstable deformation can be determined using the proposed method.