CAREER: Bridging Experiments and Multiscale Modeling of Size- and Temperature-dependent Phenomena in Polycrystalline Plasticity

职业：多晶塑性中尺寸和温度相关现象的桥接实验和多尺度建模

• 批准号: 0748187
• 负责人: Ahmed-Amine Benzerga
• 金额: $ 40.23万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0748187&HistoricalAwards=false
• 关键词: CAREER; Bridging; Experiments; Multiscale; Modeling

This Faculty Early Career Development Plan (CAREER) proposes a new multiscale modeling and simulation methodology, integrated with experiments, in fundamental studies of defect-mediated deformation and fracture in crystalline solids at small length scales. The objectives are to investigate the combined effects of material length scales (e.g. grain size) and structural length scales (e.g. device dimensions) on temperature-dependent fracture transitions and creep. Brittleness and creep are important reliability issues in small-scale devices and nanostructured metallic materials. Central to modeling is a mesoscale framework based on the dynamics of defects, which will deliver: (i) scale- and temperature-dependent mechanical response; and (ii) microcrack nucleation criteria for use in continuum modeling of fracture transitions. This mesoscale framework will serve as the hyphen in information passing from the atomic scale, with on-demand calls to molecular dynamics simulations for targeted dislocation-interface interactions, all theway to the continuum scale, where model predictions can be validated with experiments.Societal benefits of small-scale devices, such as micro/nano-electro-mechanical systems and electronic devices, stem from their pervasiveness in the emerging technologies that are affecting the ways in which we work, communicate, learn, treat diseases, and are even entertained. The proposed activities will help improve our understanding of plasticity at nano- and micro-scales, which has direct applications to structural components in small-scale devices. Multiscale modeling of plasticity will play a key role to reduce development costs and manufacturing times of new devices and materials and to assess their reliability and mechanical integrity. Integration of research and education is achieved through the development of a materials nanomechanics graduate course, involvement of undergraduates in research, an international exchange program with universities in North-Africa and use of visualization in outreach activities to help students with different backgrounds and learning paths retain a physically intuitive comprehension of crystal defects.

该教师早期职业发展计划（CAREER）提出了一种新的多尺度建模和模拟方法，与实验相结合，在晶体固体中缺陷介导的变形和断裂的基础研究中，以小的长度尺度。目的是研究材料长度尺度（例如晶粒尺寸）和结构长度尺度（例如器械尺寸）对温度依赖性断裂转变和蠕变的综合影响。脆性和蠕变是小型器件和纳米结构金属材料的重要可靠性问题。建模的核心是基于缺陷动力学的中尺度框架，它将提供：（i）尺度和温度相关的机械响应;和（ii）用于断裂过渡连续建模的微裂纹成核标准。这个中尺度框架将作为信息传递的连接符，从原子尺度，到针对目标位错-界面相互作用的分子动力学模拟，一直到连续尺度，模型预测可以通过实验验证。小尺度设备的社会效益，如微/纳米机电系统和电子设备，源于它们在新兴技术中的普遍存在，这些技术正在影响我们工作、交流、学习、治疗疾病甚至娱乐的方式。拟议的活动将有助于提高我们对纳米和微米尺度塑性的理解，这些塑性直接应用于小型设备中的结构部件。塑性的多尺度建模将在降低新设备和材料的开发成本和制造时间以及评估其可靠性和机械完整性方面发挥关键作用。研究和教育的整合是通过开发材料纳米力学研究生课程，参与研究的本科生，与北非大学的国际交流计划，并在推广活动中使用可视化来帮助不同背景和学习路径的学生保持对晶体缺陷的物理直观理解。