Holian BL, Lomdahl PS
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Science. 1998 Jun 26;280(5372):2085-8. doi: 10.1126/science.280.5372.2085.
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.
对横截面尺寸为100×100个晶胞的三维1000万个原子面心立方晶体中的冲击波进行的非平衡分子动力学模拟表明，该系统沿着所有可用的111滑移面滑动，在非平面冲击波前沿的不同位置。将这些模拟与早期较小规模的模拟进行比较，不仅消除了观察到的滑移是横向周期性边界条件假象的可能性，还揭示了留下的纳米结构的丰富性。通过引入不再完全平坦的活塞面，模拟未受冲击材料中的线或面不均匀性，结果表明，对于较弱的冲击波（低于完美晶体屈服强度），堆垛层错可以由预先存在的扩展缺陷形核。
