Plasticity induced by shock waves in nonequilibrium molecular-dynamics simulations
Plasticity induced by shock waves in nonequilibrium molecular-dynamics simulations
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DOI：
10.1126/science.280.5372.2085
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发表时间：
1998-06-26
期刊：
影响因子：
56.9
通讯作者：
Lomdahl, PS
中科院分区：
文献类型：
--
作者：
Holian, BL;Lomdahl, PS
非平衡分子动力学模拟的冲击波在三维1000万个原子的面心立方晶体的横截面尺寸为100 × 100的晶胞表明，该系统的滑移沿着所有可用的{111}滑移面，在不同的地方沿着非平面冲击波阵面。这些模拟与早期的小规模的比较不仅消除了观察到的滑移是横向周期性边界条件的伪影的可能性，而且还揭示了留下的纳米结构的丰富性。通过引入一个活塞面，不再是完全平坦的，模仿线或表面的不均匀性在未受冲击的材料，它示出，对于较弱的冲击波（低于完美的晶体屈服强度），堆垛层错可以成核预先存在的扩展缺陷。
Nonequilibrium molecular-dynamics simulations of shock waves in three-dimensional 10-million atom face-centered cubic crystals with cross-sectional dimensions of 100 by 100 unit cells show that the system slips along all of the available {111} slip planes, in different places along the nonplanar shock front. Comparison of these simulations with earlier ones on a smaller scale not only eliminates the possibility that the observed slippage is an artifact of transverse periodic boundary conditions, but also reveals the richness of the nanostructure left behind. By introducing a piston face that is no longer perfectly flat, mimicking a line or surface inhomogeneity in the unshocked material, it is shown that for weaker shock waves (below the perfect-crystal yield strength), stacking faults can be nucleated by preexisting extended defects.