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，我们旨在将脱位 - 脱位相互作用和脱位反应纳入连续性脱位动力学（CDD）的组成方程。 CDD的本构定律定义了平均位错速度对当前应力和错位状态的依赖性。本构建模应在双重策略中实现，该策略结合了自上而下的变分方法和基于离散脱位数据的自下而上的方法。变分方法用于得出弹性相互作用的表达式，这些弹性相互作用捕获例如应变梯度效应。自下而上的方法在经典应变硬化中的目标目标，并使用离散脱位模拟的脱位反应和连接形成的统计数据。此外，构成定律应纳入脱位反应产生的脱位乘以。派生的脱位磁通方程应在有限元代码中纳入，以将预测与微观示例和离散脱位模拟进行比较。