Continuum Dislocation Dynamics

位错运动作为晶体材料塑性变形过程的基本物理机制已经被广泛接受，并在不同的长度尺度上引入了各种基于位错的模型。虽然平均公式引入了不同的简化和近似来表示宏观材料行为，但离散位错动力学结合了每个位错的应力场，从而引入了基于物理的模拟模型。在接近离散模型的情况下，本文采用了基于位错的连续介质方法，该方法基于离散位错运动的直接均匀化。它的目标是位错运动的连续表示，它直接由位错系综的物理平均产生。因此，一个中心目标是在没有唯象拟合参数的情况下，用一般的连续统方法来表示3D位错相互作用和反应。我们的下一个目标是在描述中包括关键的微结构元素，如晶界和沉淀物。

Dislocation motion as the fundamental physical mechanism of plastic deformation processes in crystalline materials is well accepted and various dislocation based models have been introduced on different length scales. Whereas averaged formulations introduce different simplifications and approximations to represent the macroscopical material behavior, discrete dislocation dynamics incorporates the stress field of each dislocation and thereby introduces a physically based simulation model. In close proximity to the discrete model a dislocation based continuum approach is followed here which is based on a direct homogenization of discrete dislocation motion. It aims at a continuum representation of dislocation motion, which results directly from physical averages of dislocation ensembles. Therefore, a central objective is to represent 3D dislocation interactions and reactions in a general continuum approach without phenomenological fitting parameters. One of our next goals is to include crucial microstructural elements in the description like grain boundaries and precipitates.