TY - JOUR T1 - Boundary Condition for Dislocation Dynamic Simulation in BCC Crystal AU - Dai , Shuyang AU - Wang , Fengru AU - Xiang , Yang AU - Zhijian Yang , Jerry AU - Yuan , Cheng JO - CSIAM Transactions on Applied Mathematics VL - 1 SP - 175 EP - 194 PY - 2021 DA - 2021/02 SN - 2 DO - http://doi.org/10.4208/csiam-am.SO-2020-0003 UR - https://global-sci.org/intro/article_detail/csiam-am/18659.html KW - Dislocation, dislocation dynamics, boundary conditions, analytical model, Onsager's variational principle. AB -

The movement of dislocations and the corresponding crystal plastic deformation are highly influenced by the interaction between dislocations and nearby free surfaces. The boundary condition for inclination angle $θ$inc which indicates the relation between a dislocation line and the surface is one of the key ingredients in the dislocation dynamic simulations. In this paper, we first present a systematical study on $θ$inc by molecular static simulations in BCC-irons samples. We also study the inclination angle by using molecular dynamic simulations. A continuum description of inclination angle in both static and dynamic cases is derived based on Onsager's variational principle. We show that the results obtained from continuum description are in good agreement with the molecular simulations. These results can serve as boundary conditions for dislocation dynamics simulations.