Efficient and Reliable Nanoindentation Simulation by Dislocation Loop Erasing Method

作     者：Fei Shuang Pan Xiao Yilong Bai Fei Shuang;Pan Xiao;Yilong Bai

作者机构：LNMInstitute of MechanicsChinese Academy of SciencesBeijing100190China Department of Mechanical and Aerospace EngineeringUniversity of FloridaGainesvilleFL32611USA 

出 版 物：《Acta Mechanica Solida Sinica》 (固体力学学报（英文版）)

年 卷 期：2020年第33卷第5期

页      面：586-599页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：Supports from the National Natural Science Foundation of China(Grant Nos.11790292,11672298,and 11432014) the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB22040501) are gratefully acknowledged.Computations are performed on the ScGrid of Supercomputing Center,Computer Network Information Center of Chinese Academy of Sciences and LNMGrid of the State Key Laboratory of Nonlinear Mechanics. 

主　　题：Nanoindentation Dislocation loops Boundary effects Molecular statics 

摘      要：Nanoindentation is a useful technique to measure material properties at microscopic level.However,the intrinsically multiscale nature makes it challenging for large-scale simulations to be carried out.It is shown that in molecular statics simulations of nanoindentation,the separated dislocation loops(SDLs)are trapped in simulation box which detrimentally affects the plastic behavior in the plastic zone(PZ);and the long-distance propagation of SDLs consumes much computational cost yet with little contribution to the variation of tip force.To tackle the problem,the dislocation loop erasing(DLE)method is proposed in the work to alleviate the influence of artificial boundary conditions on the SDL–PZ interaction and improve simulation efficiency.Simulation results indicate that the force–depth curves obtained from simulations with and without DLE are consistent with each other,while the method with DLE yields more reasonable results of microstructural evolution and shows better efficiency.The new method provides an alternative approach for large-scale molecular simulation of nanoindentation with reliable results and higher efficiency and also sheds lights on improving existing multiscale methods.