A novel, concurrent multiscale approach to meso/macroscale plasticity is demonstrated. It utilizes a carefully designed coupling of a partial differential equation (pde) based theory of dislocation mediated crystal plasticity with time-averaged inputs from microscopic Dislocation Dynamics (DD), adapting a state-of-the-art mathematical coarse-graining scheme. The stress-strain response of mesoscopic samples at realistic, slow, loading rates up to appreciable values of strain is obtained, with significant speed-up in compute time compared to conventional DD. Effects of crystal orientation, loading rate, and the ratio of the initial mobile to sessile dislocation density on the macroscopic response, for both load and displacement controlled simulations are demonstrated. These results are obtained without using any phenomenological constitutive assumption, except for thermal activation which is not a part of microscopic DD. The results also demonstrate the effect of the internal stresses on the collective behavior of dislocations, manifesting, in a set of examples, as a Stage I to Stage II hardening transition.

演示了一种新颖的并发多尺度方法，用于介观/宏观尺度可塑性。它利用精心设计的基于偏微分方程（pde）的位错介导的晶体可塑性理论与微观位错动力学（DD）的时间平均输入进行耦合，从而适应了最新的数学粗粒度方案。与常规DD相比，获得了介观样品在逼真的，缓慢的加载速率下达到可观的应变值时的应力应变响应，并且计算时间显着加快。晶体的取向，加载速率和初始移动与无柄位错密度的比率对宏观响应的影响进行了演示，无论是负载和位移控制的模拟。获得这些结果不使用任何现象学的构成假设，但不属于微观DD的热激活除外。结果还证明了内部应力对位错集体行为的影响，在一组示例中显示为第一阶段到第二阶段的硬化过渡。