论文标题
使用并发的原子 - 孔子法在长度尺度上传输多个高频波
Transmitting multiple high-frequency waves across length scales using the concurrent atomistic-continuum method
论文作者
论文摘要
与传统原子技术相比，耦合的原子 - 抗孔子方法可以描述大型域和模型动态材料行为的计算成本要低得多。但是，由于精细尺度和粗尺度模型之间的数值差异，这些多尺寸框架在原子 - 孔子界面处遭受了波浪反射。这种反射是非物理的，可能导致不利的结果，例如原子区域的人工加热。在这项工作中，我们开发了一种技术，以使整个声子都可以合并到周期性并发原子 - 基因图（CAC）框架的粗尺度区域中。该方案跟踪在各个时间步骤生成的声子，因此允许多个高频波数据包在原子和连续区域之间传播。用这种方法进行的模拟证明了该技术在通过域传播时保持波浪与一系列波形的相干性的能力。这项工作具有针对具有定义边界条件的系统的应用，可以扩展到涉及从多尺度框架内的影响随机成核的波浪的更复杂的问题。
Coupled atomistic-continuum methods can describe large domains and model dynamic material behavior for a much lower computational cost than traditional atomistic techniques. However, these multiscale frameworks suffer from wave reflections at the atomistic-continuum interfaces due to the numerical discrepancy between the fine-scaled and coarse-scaled models. Such reflections are non-physical and may lead to unfavorable outcomes such as artificial heating in the atomistic region. In this work, we develop a technique to allow the full spectrum of phonons to be incorporated into the coarse-scaled regions of a periodic concurrent atomistic-continuum (CAC) framework. This scheme tracks phonons generated at various time steps and thus allows multiple high-frequency wave packets to travel between the atomistic and continuum regions. Simulations performed with this method demonstrate the ability of the technique to preserve the coherency of waves with a range of wavevectors as they propagate through the domain. This work has applications for systems with defined boundary conditions and may be extended to more complex problems involving waves randomly nucleated from an impact within a multiscale framework.
