Constitutive laws for continuum dislocation dynamics

连续体位错动力学的本构定律

• 批准号: 273907642
• 负责人: Professor Dr.-Ing. Thomas Hochrainer
• 金额: --
• 依托单位: Institut für Festigkeitslehre
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/273907642?language=en
• 关键词: Constitutive; laws; continuum; dislocation; dynamics

In this project we aim at incorporating dislocation--dislocation interactions and dislocation reactions in the constitutive equations for continuum dislocation dynamics (CDD). A constitutive law for CDD defines the dependence of the average dislocation velocity on the current stress and dislocation state. The constitutive modeling shall be achieved in a double strategy combining a top down variational approach and bottom up methods built on discrete dislocation data. The variational methods are used to derive expressions for elastic interactions which capture, for example, strain gradient effects. The bottom up approach targets at classical strain hardening and uses statistical data on dislocation reactions and junction formation from discrete dislocation simulations. Moreover, dislocation multiplication resulting from dislocation reactions shall be incorporated in the constitutive law. The derived dislocation flux equations shall be incorporated in a finite-element code in order to compare the predictions to micro-experiments and discrete dislocation simulations.

在这个项目中，我们的目标是将位错-位错相互作用和位错反应纳入连续体位错动力学（CDD）的本构方程中。 CDD 的本构定律定义了平均位错速度对当前应力和位错状态的依赖性。本构建模应通过结合自上而下变分方法和基于离散位错数据的自下而上方法的双重策略来实现。变分方法用于导出弹性相互作用的表达式，例如捕捉应变梯度效应。自下而上的方法针对经典应变硬化，并使用来自离散位错模拟的位错反应和结形成的统计数据。此外，位错反应引起的位错增殖应纳入本构律中。导出的位错通量方程应纳入有限元代码中，以便将预测与微实验和离散位错模拟进行比较。