论文标题
使用移动窗口并发原子 - 孔子框架研究冲击波传播,进化和各向异性
Investigating shock wave propagation, evolution, and anisotropy using a moving window concurrent atomistic-continuum framework
论文作者
论文摘要
尽管它们在材料的微观模型中取得了成功,但原子能方法仍然受到短时尺度,小域大小和高应变速率的限制。多尺度配方可以在较长的时间内捕获固体的连续响应,但是使用此类方案来对高度动态的非线性现象进行建模非常具有挑战性,并且是一个积极的研究领域。在这项工作中,我们在同时的原子 - 孔子多尺度框架中开发了新技术,以通过二维单晶格晶格模拟冲击波传播。详细描述了该技术,并合并了两种移动的窗户方法,以通过域跟踪冲击前线,从而防止在原子 - 孔口接口处的伪造波反射。我们将模拟结果与分析模型以及先前的原子和CAC数据进行比较,并讨论了晶格方向对FCC晶体冲击响应的明显影响。然后,我们使用移动窗口技术进行参数研究,以分析冲击锋的结构和平面性。最后,我们将模型的效率与分子动力学模拟进行了比较。这项工作展示了使用移动窗口并发多尺度框架在长期运行时模拟动态冲击的力量,并为更复杂的研究打开了涉及通过复合材料和高素质合金冲击传播的更复杂研究的大门。
Despite their success in microscale modeling of materials, atomistic methods are still limited by short time scales, small domain sizes, and high strain rates. Multiscale formulations can capture the continuum-level response of solids over longer runtimes, but using such schemes to model highly dynamic, nonlinear phenomena is very challenging and an active area of research. In this work, we develop novel techniques within the concurrent atomistic-continuum multiscale framework to simulate shock wave propagation through a two-dimensional, single-crystal lattice. The technique is described in detail, and two moving window methods are incorporated to track the shock front through the domain and thus prevent spurious wave reflections at the atomistic-continuum interfaces. We compare our simulation results to analytical models as well as previous atomistic and CAC data and discuss the apparent effects of lattice orientation on the shock response of FCC crystals. We then use the moving window techniques to perform parametric studies which analyze the shock front's structure and planarity. Finally we compare the efficiency of our model to molecular dynamics simulations. This work showcases the power of using a moving window concurrent multiscale framework to simulate dynamic shock evolution over long runtimes and opens the door to more complex studies involving shock propagation through composites and high-entropy alloys.