Developing rigorous boundary conditions to simulations of discrete dislocation dynamics
Developing rigorous boundary conditions to simulations of discrete dislocation dynamics
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DOI：
10.1088/0965-0393/7/5/308
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发表时间：
1999-09
影响因子：
1.8
通讯作者：
M. Fivel;G. Canova
中科院分区：
文献类型：
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作者：
M. Fivel;G. Canova
为了更好地理解位错的集体行为及其对力学响应的影响，最近发展了中尺度模拟。这些模拟处理离散成片段的位错，这些片段允许在三维(3D)离散网络中移动。该网络是原始晶格网络的子晶格。两点之间的最小距离由两个刃位错的湮灭距离定义，即两个刃位错共存而不瞬间崩塌的最小距离。弹性理论仍然适用于模拟的体积，因为与位错核半径相比，最小距离较大，在此范围内位错-位错相互作用应考虑非线性表达式。这一性质允许我们使用叠加原理在模拟框上强制边界条件。本文详细介绍了当模拟盒被假定为块体晶体、自由支撑膜或承受复杂载荷的有限晶体时，所应用的严格边界条件。
Mesoscale simulations have recently been developed in order to better understand the collective behaviour of dislocations and their effects on the mechanical response. Those simulations deal with dislocations discretized into segments which are allowed to move in a three-dimensional (3D) discrete network. This network is a sublattice of the original crystalline lattice network. The minimum distance between two points is defined by the annihilation distance for two edge dislocations, i.e. the minimum distance for which two edge dislocations can coexist without instantaneous collapse. The elastic theory can still be applied in the simulated volume, since the minimum distance is large compared to the dislocation core radius within which nonlinear expressions should be taken into account in the dislocation-dislocation interaction. This property allows us to use the superposition principle to enforce boundary conditions on the simulation box. This paper details the rigorous boundary conditions applied when the simulation box is supposed to be either a bulk crystal, a free standing film or a finite crystal submitted to a complex loading.