Data-driven exploration and continuum modeling of dislocation networks
Data-driven exploration and continuum modeling of dislocation networks
复制标题
位错网络的数据驱动探索和连续介质建模
DOI：
10.1088/1361-651x/ab97ef
复制
发表时间：
2020
影响因子：
1.8
通讯作者：
K. Schulz
中科院分区：
文献类型：
--
作者：
Markus Sudmanns;J. Bach;D. Weygand;K. Schulz
面心立方（fcc）金属塑性变形阶段应变硬化的显微组织成因可以归结为位错密度的增加导致位错网络的形成。虽然这是一个众所周知的关系，但最近通过离散位错动力学（DDD）模拟揭示了位错增殖过程的复杂性和位错网络形成的细节。观察到位错在由倍增机制产生后，在其滑移面内表现出有限的扩展，然后被位错反应困在网络中。这种机制涉及多个滑移系统，并导致非均质位错网络，这在大多数基于位错的连续体模型中没有反映出来。我们通过使用数据科学方法来接近位错网络的连续统建模，以提供离散位错和连续统水平之间的联系。为此，我们确定了在基于位错的塑性连续体理论中输入位错网络模型的相关相关性。该模型的一个关键特征是通过形成稳定的位错结，将位错的增殖与位错传播距离的限制结合起来。网络的有效迁移率由位错间距的范围决定，该范围再现了在DDD中观察到的产生的位错的散射传播距离。将该模型应用于高对称fcc加载情况，并与DDD仿真进行了比较。结果显示了物理上有意义的微观结构演变，其中由乘法机制产生的新位错被稳定位错网络的形成所抵消。结合DDD，我们观察到不同机制的稳态相互作用。
The microstructural origin of strain hardening during plastic deformation in stage II deformation of face-centered cubic (fcc) metals can be attributed to the increase in dislocation density resulting in a formation of dislocation networks. Although this is a well known relation, the complexity of dislocation multiplication processes and details about the formation of dislocation networks have recently been revealed by discrete dislocation dynamics (DDD) simulations. It has been observed that dislocations, after being generated by multiplication mechanisms, show a limited expansion within their slip plane before they get trapped in the network by dislocation reactions. This mechanism involves multiple slip systems and results in a heterogeneous dislocation network, which is not reflected in most dislocation-based continuum models. We approach the continuum modeling of dislocation networks by using data science methods to provide a link between discrete dislocations and the continuum level. For this purpose, we identify relevant correlations that feed into a model for dislocation networks in a dislocation-based continuum theory of plasticity. As a key feature, the model combines the dislocation multiplication with the limitation of the travel distance of dislocations by formation of stable dislocation junctions. The effective mobility of the network is determined by a range of dislocation spacings which reproduces the scattering travel distances of generated dislocation as observed in DDD. The model is applied to a high-symmetry fcc loading case and compared to DDD simulations. The results show a physically meaningful microstructural evolution, where the generation of new dislocations by multiplication mechanisms is counteracted by a formation of a stable dislocation network. In conjunction with DDD, we observe a steady state interplay of the different mechanisms.
登录
查看更多内容
单晶镍中楔形凹痕周围的位错密度分布：将非局部晶体塑性有限元预测与实验进行比较
DOI：
10.1016/j.actamat.2014.03.012
发表时间：
2014
期刊：
影响因子：
--
作者：
C. Reuber;P. Eisenlohr;F. Roters;D. Raabe
通讯作者：
D. Raabe
影响因子：
1.6
作者：
T. Hochrainer
通讯作者：
T. Hochrainer
影响因子：
9.4
作者：
M. Stricker;D. Weygand
通讯作者：
M. Stricker;D. Weygand
影响因子：
3.3
作者：
Roters, F.;Diehl, M.;Raabe, D.
通讯作者：
Raabe, D.