Multiresolution, Coarse-Grained Modeling of 3D Dislocation Nucleation and Migration

3D 位错成核和迁移的多分辨率、粗粒度建模

• 批准号: 0758265
• 负责人: David McDowell
• 金额: $ 40万
• 依托单位: Georgia Tech Research Corporation
• 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: 2008-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0758265&HistoricalAwards=false
• 关键词: Multiresolution; Coarse; Grained; Modeling; 3D

CMMI 0758265Multiresolution, Coarse-Grained Modeling of 3D Dislocation Nucleation and MigrationPI: David L. McDowell, Co-PI: Ting ZhuNext generation models to support design of fracture-resistant materials must directly incorporate information related to interatomic bonding and structure of interfaces at nanoscales. The challenge is to develop methods that can address behavior at such small scales yet still account for aspects of average behavior at much higher length scales in structural applications such as automobiles, aircraft, tennis rackets, and so forth. This project will address behavior by linking defects analyzed at the nanoscale using atomistics (molecular dynamics) near the tips of cracks or at interfaces with long range fields that average effects of large numbers of atoms to achieve a so-called ?coarse grain? description. In this way, simulations can be undertaken at high enough length and time scales to provide meaningful information regarding behavior of structures, while the role of interfaces is treated with atomic-scale resolution.This research is expected to substantially impact the ability to tailor the structure of grain boundaries and fine scale microstructure to affect improved fatigue and fracture resistance of metal alloys. Fatigue is a failure mode in metals subjected to cyclic loading that is responsible for costly failures such as highway bridges, airplane tail sections, engine components, railway derailments, and many other examples. By developing more predictive tools to address the large gap in modeling and simulation tools between atomic scales and scales of grains in polycrystals (typically five orders of magnitude), the societal benefits in terms of energy savings and safety derived from more lightweight and durable materials can be substantial. Research results will be integrated into both an undergraduate course in computational materials science as well as graduate courses in defects and mechanical properties of materials taught by the PI and co-PI, accelerating the application of the technology developed in this project.

CMMI 07582653D 位错成核和迁移的多分辨率、粗粒度建模 PI：David L. McDowell，联合 PI：Ting Zhu 支持抗断裂材料设计的下一代模型必须直接纳入与纳米级原子间键合和界面结构相关的信息。 我们面临的挑战是开发一种方法，既能解决如此小尺度的行为，又能解释汽车、飞机、网球拍等结构应用中更高长度尺度的平均行为的各个方面。该项目将通过使用原子学（分子动力学）在裂纹尖端附近或与长程场的界面处连接在纳米级分析的缺陷来解决行为，这些长程场平均大量原子的影响以实现所谓的“粗晶粒”。描述。 通过这种方式，可以在足够高的长度和时间尺度上进行模拟，以提供有关结构行为的有意义的信息，同时以原子尺度分辨率处理界面的作用。这项研究预计将极大地影响定制结构的能力晶界和细尺度微观结构影响金属合金的疲劳和断裂抗力的提高。 疲劳是承受循环载荷的金属的一种失效模式，它会导致代价高昂的失效，例如公路桥梁、飞机尾部、发动机部件、铁路脱轨和许多其他例子。 通过开发更多的预测工具来解决原子尺度和多晶颗粒尺度之间的建模和模拟工具之间的巨大差距（通常是五个数量级），更轻质和耐用的材料在节能和安全方面的社会效益可以是实质性的。 研究成果将纳入PI和Co-PI教授的计算材料科学本科课程以及材料缺陷和力学性能研究生课程中，加速该项目开发的技术的应用。