A hierarchical dislocation-grain boundary interaction model based on 3D discrete dislocation dynamics and molecular dynamics

作     者：GAO Yuan ZHUANG Zhuo YOU XiaoChuan 

作者机构：Applied Mechanics Lab School of Aerospace Tsinghua University Beijing 100084 China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2011年第54卷第4期

页      面：625-632页

核心收录：

学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grant No. 10772096) the National Basic Research Program of China(Grand No. 2010CB631005) 

主　　题：Grain boundary Multiscale simulation Discrete dislocation dynamics Bi-crystal compression 

摘      要：We develop a new hierarchical dislocation-grain boundary （GB） interaction model to predict the mechanical behavior of poly- crystalline metals at micro and submicro scales by coupling 3D Discrete Dislocation Dynamics （DDD） simulation with the Molecular Dynamics （MD） simulation. At the microscales, the DDD simulations are responsible for capturing the evolution of dislocation structures; at the nanoscales, the MD simulations are responsible for obtaining the GB energy and ISF energy which are then transferred hierarchically to the DDD level. In the present model, four kinds of dislocafion-GB interactions, i.e. transmission, absorption, re-emission and reflection, are all considered. By this methodology, the compression of a Cu mi- cro-sized bi-crystal pillar is studied. We investigate the characteristic mechanical behavior of the bi-crystal compared with that of the single-crystal. Moreover, the comparison between the present penetrable model of GB and the conventional impenetrable model also shows the accuracy and efficiency of the present model.