Moving window techniques to model shock wave propagation using the concurrent atomistic–continuum method
Moving window techniques to model shock wave propagation using the concurrent atomistic–continuum method
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DOI：
10.1016/j.cma.2021.114360
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发表时间：
2021-08
影响因子：
7.2
通讯作者：
Alexander S. Davis;J. Lloyd;V. Agrawal
中科院分区：
文献类型：
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作者：
Alexander S. Davis;J. Lloyd;V. Agrawal
在过去的几十年里，原子论方法已经成功地模拟了冲击波在材料中传播的不同方面，但它们受到了限制总运行时间和系统规模的限制。多尺度方法已经能够增加可建模的长度和时间尺度，但使用这种方法来模拟工程尺度域中的波的传播和演化是一个活跃的研究领域。在这项工作中，我们在并行原子-连续介质(CAC)框架内发展了两种不同的移动窗口方法来模拟冲击波通过一维单原子链的传播。在第一种方法中，整个CAC系统以传送带的方式与激波一起移动，并将激波前沿保持在整个区域的中间。在第二种方法中，原子区通过同时粗化和细化连续体区来跟随激波。通过色散关系研究和声子波包测试对CAC框架和移动窗口框架进行了验证。我们用传送带技术模拟的激波速度与理论值符合得很好，而粗化-细化技术使我们能够在大尺度区域内跟踪传播的波前。这项工作展示了CAC方法精确模拟激波传播的能力，并演示了如何在多尺度框架中使用移动窗口技术来研究高度非线性的瞬变现象。
Atomistic methods have successfully modeled different aspects of shock wave propagation in materials over the past several decades, but they suffer from limitations which restrict the total runtime and system size. Multiscale methods have been able to increase the length and time scales that can be modeled but employing such schemes to simulate wave propagation and evolution through engineering-scale domains is an active area of research. In this work, we develop two distinct moving window approaches within a Concurrent Atomistic–Continuum (CAC) framework to model shock wave propagation through a one-dimensional monatomic chain. In the first method, the entire CAC system travels with the shock in a conveyor fashion and maintains the shock front in the middle of the overall domain. In the second method, the atomistic region follows the shock by the simultaneous coarsening and refinement of the continuum regions. The CAC and moving window frameworks are verified through dispersion relation studies and phonon wave packet tests. We achieve good agreement between the simulated shock velocities and the values obtained from theory with the conveyor technique, while the coarsen-refine technique allows us to follow the propagating wave front through a large-scale domain. This work showcases the ability of the CAC method to accurately simulate propagating shocks and also demonstrates how a moving window technique can be used in a multiscale framework to study highly nonlinear, transient phenomena.