Dislocation based Gradient Plasticity Theory

基于位错的梯度塑性理论

• 批准号: 206429275
• 负责人: Professor Dr.-Ing. Thomas Böhlke
• 金额: --
• 依托单位: Bereich Kontinuumsmechanik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/206429275?language=en
• 关键词: Dislocation; based; Gradient; Plasticity; Theory

This project aims at the extension of the small strain gradient crystal plasticity framework, which has been developed through the first funding period, to large deformations. Similar to the smallstrain framework, the large-strain framework is then coupled to CDD-theory which incorporates dislocation transport terms. By such an approach a gradient crystal plasticity theory is linked to CDD thereby closing the latter constitutively. This extended type of gradient theory is expected to reproduce size effects in oligocrystals induced by both a size-dependent bulk behavior and grain boundary effects. Additionally, the second period aims at extension of the developed elastic-plastic grain boundary model by introducing an orientation dependence of the plastic grain boundary terms (like the resistance against plastic flow) on e.g. the orientation of the grain boundary and the crystal orientations of the adjacent grains. Here, also a geometrically nonlinear efficient extension of the developed elastic-plastic grain boundary model for finite deformations is planned. A broad variety of applications is intended by comparing the simulation results to experiments (bending of micro-beams, torsion of thin wires, tensile tests) as well as benchmark simulations, e.g. from DDD.

该项目旨在将第一个供资期开发的小应变梯度晶体塑性框架扩展到大变形。类似的smallstrain框架，大应变框架，然后耦合到CDD理论，其中包括位错输运条款。通过这种方法，一个梯度晶体塑性理论是联系在一起的CDD，从而关闭后者组成。这种扩展类型的梯度理论，预计将重现尺寸效应在oligocrystals引起的尺寸依赖的散装行为和晶界效应。此外，第二阶段旨在通过引入塑性晶界项（如对塑性流动的阻力）对例如晶界取向和相邻晶粒的晶体取向的取向依赖性来扩展所开发的弹塑性晶界模型。在这里，也是一个几何非线性有效扩展的有限变形的弹塑性晶界模型的计划。通过将模拟结果与实验（微梁弯曲、细线扭转、拉伸测试）以及基准模拟（例如DDD）进行比较，可以实现广泛的应用。