Atomic Effects on Brittle Fracture

该奖项支持固体材料断裂和塑性变形的原子尺度理论建模。这项提议的目标是学习原子间作用力和材料在脆性断裂过程中的行为之间的联系。项目的大部分工作将集中在硅作为测试用例。分析和数值方法将与正在进行的实验计划密切配合使用。分析方法包括求解裂隙的动态晶格模型的技术，而数值方法包括为高性能计算系统编写的、用于研究裂隙的分子动力学代码。这一领域的实验工作得到了陶瓷计划中DMR的支持。%该奖项支持固体材料断裂和塑性变形的原子尺度理论建模。材料物理学的中心目标之一是将原子之间的纳米尺度相互作用与宏观尺度上观察到的物理性质联系起来。固体中的断裂和塑性变形是特别难模拟的物理效应之一，因为它们涉及到非常复杂的缺陷的动力学--快速移动的结构，其特征尺寸大到几米，但受原子尺度的过程控制。这一努力的目标是表明原子和宏观尺度之间的定量联系是可能的，并且原子尺度的模拟可以用于对可实现的实验室实验的详细预测。该项目将专注于脆性断裂，并在延性断裂和塑性变形方面进行额外工作。这方面的实验工作由DMR在陶瓷项目中提供支持。*

9877044MarderThis award supports theoretical atomic-scale modeling of fracture and plastic deformation of solid materials. The goal of this proposal is to learn the connection between interatomic forces and the behavior of materials during brittle fracture. Most of the project effort will be focused on silicon as a test case. Analytic and numerical methods will be used in close coordination with an ongoing experimental program. The analytical methods include techniques for solving dynamical lattice models of fracture, while the numerical methods include molecular dynamics code written for high-performance computing systems and designed to study fracture. Experimental work in this area is supported by DMR in the Ceramics Program.%%%This award supports theoretical atomic-scale modeling of fracture and plastic deformation of solid materials. One of the central goals of materials physics is to relate the nanometer-scale interactions between atoms to observed physical properties at the macroscopic scale. Fracture and plastic deformation in solids is one of the particularly difficult physical effects to model because they involve dynamics of defects of great complexity-rapidly moving structures with characteristic dimensions as large as meters but controlled by atomic-scale processes. The goal of this effort is to show that a quantitative connection between atomic and macro scales is possible, and that atomic-scale simulations can be used for detailed predictions of realizable laboratory experiments. The project will focus on brittle fracture, with additional work on ductile fracture and plastic deformation. Experimental work in this area is supported by DMR in the Ceramics Program.***