论文标题
剪切无定形固体中雪崩期间的机械激发和边缘触发
Mechanical excitation and marginal triggering during avalanches in sheared amorphous solids
论文作者
论文摘要
我们研究了在过度阻尼的粒子尺度分子动力学（MD）和中尺度弹性模型（EPM）中，研究塑料应变，用于在achermal quasi static限制中剪切的非定形固体。我们表明，塑料活动的空间相关性表现出短长的尺度，在MD中的$ t^{3/4} $增长，并在EPM中在爆炸中生长，并且通过机械激发附近站点的机械激发而产生，不一定要接近其稳定性阈值，并且在两个模型中的长度范围都与两个模型相关联，并且与远程偏远的偏远地区相关联。空间相关性中的这些相似性解释了为什么简单的EPM准确地捕获了MD中观察到的雪崩的尺寸分布，尽管时间概况和动态临界指数截然不同。
We study plastic strain during individual avalanches in overdamped particle-scale molecular dynamics (MD) and meso-scale elasto-plastic models (EPM) for amorphous solids sheared in the athermal quasi-static limit. We show that the spatial correlations in plastic activity exhibit a short lengthscale that grows as $t^{3/4}$ in MD and ballistically in EPM, and is generated by mechanical excitation of nearby sites not necessarily close to their stability thresholds, and a longer lengthscale that grows diffusively for both models and is associated with remote marginally stable sites. These similarities in spatial correlations explain why simple EPMs accurately capture the size distribution of avalanches observed in MD, though the temporal profiles and dynamical critical exponents are quite different.
