Search for Constitutive Relations for Micromechanics Modeling of Model Nanocrystalline Materials: A Multiscale Approach

寻找模型纳米晶材料微力学建模的本构关系：多尺度方法

• 批准号: 0411227
• 负责人: Mo Li
• 金额: $ 24万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0411227&HistoricalAwards=false
• 关键词: Search; Constitutive; Relations; Micromechanics; Modeling

===========================ABSTRACT=============================Nanocrystalline materials with characteristic grain size of 1-100 nanometers have been synthesized and investigated extensively in the last decade. Small sized grains and large volume fraction of atoms sitting on grain or interface boundaries characterize these materials. They exhibit many unusual mechanical properties, making them by far one of only a few nanoscale material systems that have potential to be used as large-scale structural material in civil, mechanical, transport, and industrial applications. However, as the dimensions of the grain size are pushed down to nanometer scale, the degrees of difficulty multiply in determining and understanding the mechanical properties and their relations with microstructures. As a result, quantitative constitutive relations for various mechanical properties and their relation with microstructures have not been fully established. This work aims at filling this gap by searching for micromechanical constitutive relations in nanocrystalline materials using large-scale atomistic simulations. To achieve this goal, we plan to perform large-scale atomistic modeling of various detailed microstructures and their contributions to constitutive relations in nanoscale environment. And to perform continuum modeling of deformation process in model nanocrystalline samples. The detailed constitutive relation and microstructure-property relation obtained from atomistic simulations will be used in corse-grained modeling. The proposed topics are timely and answers to these questions are urgently needed for materials and mechanics community. Successful execution of this proposed work is expected to contribute to establishing systematic approaches for modeling microstructures and laying a solid foundation for constitutive modeling of mechanical deformation in nanoscale polycrystalline materials.

========================== 摘要============================== 在过去十年中，特征晶粒尺寸为 1-100 纳米的纳米晶材料已被合成和广泛研究。这些材料的特点是晶粒尺寸小，晶粒或界面边界上的原子体积分数大。它们表现出许多不寻常的机械性能，使它们成为迄今为止仅有的少数有可能在土木、机械、运输和工业应用中用作大型结构材料的纳米级材料系统之一。然而，随着晶粒尺寸被缩小到纳米尺度，确定和理解机械性能及其与微观结构的关系的难度成倍增加。因此，各种力学性能的定量本构关系及其与微观结构的关系尚未完全建立。这项工作旨在通过使用大规模原子模拟寻找纳米晶体材料中的微机械本构关系来填补这一空白。为了实现这一目标，我们计划对各种详细的微观结构及其对纳米级环境中本构关系的贡献进行大规模原子建模。并对模型纳米晶样品的变形过程进行连续建模。从原子模拟中获得的详细本构关系和微观结构-性能关系将用于科西嘉粒度建模。提出的主题是及时的，材料和力学界迫切需要这些问题的答案。这项工作的成功执行预计将有助于建立微结构建模的系统方法，并为纳米级多晶材料机械变形的本构建模奠定坚实的基础。