基于位移连接的单晶银板Ⅰ型边裂纹扩展过程跨连续介质/原子尺度数值模拟研究

THE NUMERICAL SIMULATIONSTUDY SPANNING THE CONTINUUM/ATOMS SCALEON THE TYPE Ⅰ EDGE CRACK PROPAGATION PROCESS IN SINGLE CRYSTAL SILVERBASED ON THEDISPLACEMENT CONNECTION

材料变形破坏机理的研究,以及NEMS/MEMS技术与生物技术的进步推动了多尺度分析方法的发展。然而,多尺度连接是多尺度建模的关键。本文采用有限元与分子动力学相结合的方法,采用应力强度因子和位移等力学参量连接和转换连续介质区域和离散分子动力学区域的力学信息,建立了二维单晶银板裂纹扩展的跨三区多尺度模型,得到了裂纹尖端坐标轨迹和微观尺度下的裂纹扩展过程,结果与理论和实验相符,证明了该方法的合理性。

The study on deformation and failure mechanism of materials,and the progressof NEMS/MEMStechnology and biotechnologypromote the development of multi-scale analysis method. However,Multi-scale connectionisthe key of multi-scale model. The finite element method（ FEM） and molecular dynamics simulation（ MD） were combined to simulate the multi-scale models,and the stress intensity factors（ SIF） and displacement mechanics parameters were adopted to connect and convertthecontinuum region and discrete molecular dynamics region,then three multi-scale model of two-dimensional silver crack propagationwasestablished to obtain the crack tip trajectory and the micro-scale crackpropagationprocess. The result is in good agreement with theory and experiment,and proves the rationality of the method.