Abstract We present a multi-material cell model (closure model) for demanding arbitrary Lagrangian-Eulerian (ALE) simulations of fluids and solids. It is based on the interface-aware sub-scale dynamics (IASSD) approach which utilizes the exact material interface geometry within the computational cell to calculate internal material interactions. Our formulation of the closure model also aims to improve the accuracy in low-speed impact events. Voids are used to represent ambient vacuum and internal free boundaries of the distinct materials. Void regions can close and open at contact surfaces, allowing a transition from contact physics to free motion in vacuum. The coupling of void closure and opening with a new formulation of the IASSD model for solids is tested on several one- and two-dimensional numerical examples, ranging from gas expansion in vacuum to planar and round object impacts at various speeds.

中文翻译：

---

界面感知亚尺度动力学多材料单元模型，适用于在所有速度下均具有空隙闭合和开口的固体

摘要 我们提出了一种多材料单元模型（闭合模型），用于流体和固体的任意拉格朗日-欧拉 (ALE) 模拟。它基于界面感知子尺度动力学 (IASSD) 方法，该方法利用计算单元内的精确材料界面几何形状来计算内部材料相互作用。我们制定的闭合模型还旨在提高低速撞击事件的准确性。空隙用于表示不同材料的环境真空和内部自由边界。空隙区域可以在接触表面关闭和打开，允许从接触物理过渡到真空中的自由运动。在几个一维和二维数值例子中测试了空隙闭合和开口与固体 IASSD 模型的新公式的耦合，