Continuum Dislocation Dynamics Modeling of Mesoscale Crystal Plasticity at Finite Deformation

有限变形下介观晶体塑性的连续体位错动力学建模

基本信息

批准号：
1663311
负责人：
Anter El-Azab
金额：
$ 43万
依托单位：
Purdue University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2022-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1663311&HistoricalAwards=false
关键词：
Continuum Dislocation Dynamics Modeling Mesoscale

项目摘要

Mechanical deformation of crystalline metals is caused by motion and interactions of defects called dislocations under applied forces or stresses. As the individual crystals deform, dislocation interactions lead to the formation of self-organized dislocation microstructures or patterns. These patterns are believed to control the mechanical strength and failure of metals. They are also important in metal manufacturing as they provide the way to refine the material behavior through combined mechanical deformation and heating. Although dislocation patterns were observed long ago, there is currently no theoretical or computational framework for predicting their formation in metals under arbitrary deformation. This research aims to bridge this critical gap by implementing a computational modeling framework that explicitly represents dislocations and their interactions at the mesoscale based on the continuum dislocation dynamics method. Such a generalization will enable accurate prediction of material behavior in crystalline materials, and it will eventually lead to realistic models of the manufacturing processes of structural alloys. Scientific knowledge obtained in this research will be incorporated into graduate curriculum and the developed tools will be disseminated to the wider research community. A particular focus will be given to the training of female and underrepresented students through graduate research assistantships.The collective dislocation mechanisms that induce various dislocation microstructures in metal single crystals under deformation will be investigated by computational modeling. A recently developed computational framework based on continuum dislocation dynamics will be used as the method of investigation after generalization to finite crystal deformation. This modeling framework is theoretically founded to capture the full mesoscale deformation response of single crystals from dislocation properties, which includes the dislocation patterns, plastic slip distribution and crystal distortion, internal elastic fields, as well as the overall stress-strain response and average dislocation density evolution. The investigation includes the following research tasks: formulating the governing continuum dislocation dynamics equations at finite deformation and coupling these equations with the stress equilibrium and deformation kinematics of crystals, solving the coupled system of dislocation dynamics and crystal mechanics equations using the finite element approach, building a community available code for mesoscale deformation of crystals based on the above, and simulating the dislocation microstructures of interest and validating the predictions using open literature microstructure data obtained by Transmission Electron Microscopy and X-ray techniques.

晶体金属的机械变形是由运动或应力下称为脱位的缺陷的运动和相互作用引起的。随着个体晶体的变形，位错相互作用会导致形成自组织的脱位微结构或模式。这些模式被认为可以控制金属的机械强度和故障。它们在金属制造中也很重要，因为它们为通过机械变形和加热结合的方式提供了改善材料行为的方法。尽管很久以前观察到了位错模式，但目前尚无理论或计算框架来预测其在任意变形下的金属中形成。这项研究的目的是通过实施一个基于连续脱位动力学方法明确表示位错及其相互作用的计算建模框架来弥合这一关键差距。这样的概括将能够准确预测晶体材料中的材料行为，并最终导致结构合金制造过程的现实模型。在这项研究中获得的科学知识将纳入研究生课程中，并将开发的工具传播到更广泛的研究社区。通过研究生研究助理的培训将特别关注女性和代表性不足的学生的培训。将通过计算建模来研究诱导金属单晶中各种脱位微结构的集体错位机制。最近开发的基于连续脱位动力学的计算框架将用作有限晶体变形后的研究方法。从理论上讲，该建模框架是为了捕获单个晶体的整个中尺度变形响应的理论而建立的，其中包括位错模式，塑料滑动分布和晶体失真，内部弹性场以及整体应力 - 应变响应以及总体压力 - 响应和平均脱位密度进化。调查包括以下研究任务：在有限变形时制定控制连续性脱位动力学方程，并将这些方程与压力平衡和晶体的变形运动学结合，以求解脱位动力学和晶体力学方程式的耦合系统基于上述晶体的中尺度变形的社区可用代码，并模拟感兴趣的错位微观结构，并使用通过传输电子显微镜和X射线技术获得的开放文献微观结构数据验证预测。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

On the computational solution of vector-density based continuum dislocation dynamics models: A comparison of two plastic distortion and stress update algorithms

DOI：
10.1016/j.ijplas.2021.102943
发表时间：
2021-02
期刊：
影响因子：
0
作者：
P. Lin;Vignesh Vivekanandan;K. Starkey;B. Anglin;C. Geller;A. El-Azab
通讯作者：
P. Lin;Vignesh Vivekanandan;K. Starkey;B. Anglin;C. Geller;A. El-Azab

Theoretical development of continuum dislocation dynamics for finite-deformation crystal plasticity at the mesoscale

DOI：
10.1016/j.jmps.2020.103926
发表时间：
2020-06
期刊：
Journal of The Mechanics and Physics of Solids
影响因子：
5.3
作者：
K. Starkey;G. Winther;A. El-Azab
通讯作者：
K. Starkey;G. Winther;A. El-Azab

Situating the Vector Density Approach Among Contemporary Continuum Theories of Dislocation Dynamics

将矢量密度方法置于当代位错动力学连续体理论中

DOI：
10.1115/1.4052066
发表时间：
2022
期刊：
Journal of engineering materials and technology
影响因子：
0
作者：
Anderson, Joseph Pierre;Vivekanandan, Vignesh;Lin, Peng;Starkey, Kyle;Pachaury, Yash;El-Azab, Anter
通讯作者：
El-Azab, Anter

Development of mean-field continuum dislocation kinematics with junction reactions using de Rham currents and graph theory

使用德拉姆电流和图论开发具有结反应的平均场连续位错运动学