Heizler Shay I, Kessler David A, Levine Herbert
Department of Physics, Bar-Ilan University, Ramat-Gan, IL52900 Israel.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Aug;84(2 Pt 2):026102. doi: 10.1103/PhysRevE.84.026102. Epub 2011 Aug 3.
We study propagating mode-I fracture in two-dimensional amorphous materials using atomistic simulations. We use the continuous random network model of an amorphous material, creating samples using a two-dimensional analog of the Wooten-Winer-Weaire Monte Carlo algorithm. For modeling fracture, molecular-dynamics simulations were run on the resulting samples. The results of our simulations reproduce the main experimental features. In addition to achieving a steady-state crack under a constant driving displacement (which has not yet been achieved by other atomistic models for amorphous materials), the runs show microbranching, which increases with driving, transitioning to macrobranching for the largest drivings. In addition to the qualitative visual similarity of the simulated cracks to experiment, the simulation also succeeds in reproducing qualitatively the experimentally observed oscillations of the crack velocity.
我们使用原子模拟研究二维非晶材料中的扩展I型断裂。我们采用非晶材料的连续随机网络模型，利用伍滕 - 维纳 - 韦尔蒙特卡罗算法的二维类似方法创建样本。为了对断裂进行建模，对所得样本进行了分子动力学模拟。我们的模拟结果再现了主要的实验特征。除了在恒定驱动位移下实现稳态裂纹（这是其他非晶材料原子模型尚未实现的）之外，模拟还显示出微分支，其随着驱动而增加，在最大驱动时转变为宏分支。除了模拟裂纹与实验在定性视觉上的相似性之外，模拟还成功地定性再现了实验观察到的裂纹速度振荡。
