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Deformation, Strength, Fatigue and Fracture of Gradient Nanostructured Metals

梯度纳米结构金属的变形、强度、疲劳和断裂

基本信息

批准号：
1709318
负责人：
Huajian Gao
金额：
$ 47.92万
依托单位：
Brown University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2021-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709318&HistoricalAwards=false
关键词：
Deformation Strength Fatigue Fracture Gradient

项目摘要

Non-technical Abstract:Metals play essential roles in infrastructural and overall economic developments of our society, as reflected by the fact that the annual global market value of metals is close to a trillion US dollars. During the last five years, a new class of nano materials called gradient nanostructured metals have emerged as a material class which exhibits an unusual combination of ultrahigh strength, good tensile ductility, enhanced strain hardening, superior fracture toughness and fatigue resistance. However, the current lack of understanding of the underlying mechanisms that control the properties of these materials severely limits our ability to tailor or optimize their properties for specific applications. On the other hand, recent advances in computational modeling and simulation capabilities are providing unprecedented opportunities to advance the knowledge frontier in our understanding of mechanical properties of materials at micro- and nano-scales. The proposed research will take advantage of the cutting-edge multiscale modeling and simulation methods to address the fundamental issues with regard to the mechanical properties and behavior of gradient nanostructured metals. The project will train graduate and undergraduate students in state of the art computational techniques. Technical AbstractThe proposed research will address the following questions: What are the deformation mechanisms that control the mechanical properties of gradient nanostructured metals? How to design the gradient micro- and nanostructures to optimize the mechanical responses of gradient nanostructured metals? The problems under study will be tackled via a multiscale modeling approach that combines finite element method, strain gradient plasticity, cohesive modeling, crystal plasticity, dislocation dynamics and molecular dynamics simulations will be used to investigate the deformation and failure mechanisms of gradient nanostructured metals. The technical approach will be based on the experience and theoretical/simulation capabilities developed by the PI. The proposed work will clarify the controlling deformation mechanisms through ultra-large-scale and high-resolution atomistic and dislocation dynamics simulations, interpret the experimental data and phenomena through continuum strain gradient plasticity and cohesive modeling of fatigue and fracture behavior, and guide further research in structural optimization and processing. The ultra-large scale simulations in the proposed work will be performed on the National Institute for Computational Sciences, and the rest of the proposed computational work will be performed at the Center for Computing and Visualization at Brown University. The project will train graduate and undergraduate students in state of the art computational techniques.

摘要：金属在我们社会的基础设施和整体经济发展中发挥着至关重要的作用，这反映在每年全球金属市场价值接近一万亿美元这一事实上。在过去的五年中，一种被称为梯度纳米结构金属的新型纳米材料已经出现，这种材料具有超高强度、良好的拉伸延展性、增强的应变硬化、优异的断裂韧性和抗疲劳性。然而，目前对控制这些材料性能的潜在机制缺乏了解，严重限制了我们为特定应用量身定制或优化其性能的能力。另一方面，计算建模和模拟能力的最新进展为我们在微观和纳米尺度上对材料力学性能的理解提供了前所未有的机会。本研究将利用尖端的多尺度建模和仿真方法来解决有关梯度纳米结构金属的力学性能和行为的基本问题。该项目将培养研究生和本科生掌握最先进的计算技术。技术摘要：本研究将解决以下问题：控制梯度纳米结构金属力学性能的变形机制是什么？如何设计梯度微纳米结构以优化梯度纳米结构金属的力学响应？本文将采用多尺度建模方法，结合有限元法、应变梯度塑性、内聚模型、晶体塑性、位错动力学和分子动力学模拟，研究梯度纳米结构金属的变形和破坏机制。技术方法将以PI开发的经验和理论/模拟能力为基础。通过超大尺度、高分辨率的原子和位错动力学模拟来阐明控制变形机制，通过连续应变梯度塑性和疲劳断裂行为的内聚建模来解释实验数据和现象，并指导进一步的结构优化和加工研究。所提议工作中的超大规模模拟将在美国国家计算科学研究所进行，其余的计算工作将在布朗大学计算与可视化中心进行。该项目将培养研究生和本科生掌握最先进的计算技术。