Collaborative Proposal: Bridging and Coupling Particle to Continuum Length-Scale Mechanics for Simulating Deformation and Flow of Dense Dry Particulate Materials

颗粒材料仍然是一类尚未掌握的材料，无法以基于物理的方式在长度尺度上几个数量级对其机械行为谱进行计算建模。 颗粒材料可以瞬间从像固体一样变形转变为像流体或气体一样流动，反之亦然。 使用纯基于粒子的材料建模方法（例如 DEM）来计算模拟涉及颗粒材料的工程应用中的异质、局部变形和流动响应是不可行的。 智力价值：该项目旨在通过开发计算多尺度建模方法及其针对微观到宏观尺度实验的校准/验证来克服颗粒材料尺度表示的这一限制。 在此过程中，所提出的努力将1）提供对金属粉末沉积和压实成复杂模具形状的物理见解，以及导致压实后密度不均匀的潜在机制； 2）确定刚性穿透物体附近沙粒的重新分布状态。更广泛的影响包括（i）通过 CAVS 将创新的计算多尺度建模技术转移到汽车行业，以改善极其复杂的几何形状和各种不可预见的合金材料系统的近净形部件的制造； ㈡ 招聘工程学科中代表性不足的少数群体； (iii) 与技术和学生社区分享实验和计算进展以及物理见解。

Particulate materials remain a class of materials not mastered with regard to modeling computationally their spectrum of mechanical behavior in a physically-based manner across several orders of magnitude in length-scale. Particulate materials may transition in an instant from deforming like a solid to flowing like a fluid or gas and vice versa. It is not feasible to simulate computationally the heterogeneous, localized deformation, and flow response in the engineering application of interest involving particulate materials using a pure particle-based materials modeling approach (such as DEM).Intellectual merit: The project seeks to overcome this limitation in scale-representation of particulate materials by the development of a computational multiscale modeling approach and its calibration/ validation against micro to macro-scale experiments. In doing so, the proposed effort will 1) provide physical insight into the deposition and compaction of metallic powders into complex die shapes and the potential mechanisms leading to non-uniform density after compaction; and 2) determine the redistributed state of sand particles in the vicinity of a rigid penetrating object.Broader impacts include (i) transfer of innovative computational multiscale modeling technology to the automotive industry through CAVS for improving the manufacture of near net-shape components of extremely complex geometries and various unforeseen alloy material systems; (ii) recruitment of underrepresented minorities in the engineering disciplines; and (iii) sharing of experimental and computational advances and physical insight gained with the technical and student communities.