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材料，在以物理为基础的方式在长度尺度上跨几个数量级计算其机械行为谱方面尚未掌握。颗粒材料可以在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。在涉及颗粒材料的工程应用中，使用纯基于颗粒的材料建模方法（如DEM）来模拟非均质、局部变形和流动响应是不可行的。智力优势：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在尺度表示方面的这一限制。在此过程中，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以及导致压实后密度不均匀的潜在机制的物理见解；2)确定刚性穿透物附近砂粒的再分布状态。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，以改善极端复杂几何形状和各种不可预见的合金材料系统的近净形状部件的制造；（ii）在工程学科中征聘代表性不足的少数民族；（三）与技术和学生社区分享实验和计算方面的进展以及对物理的见解。

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.