纳米金属材料宏观弹性模量的数值模拟研究

COMPUTATIONAL SIMULATION OF THE ELASTIC MODULUS OF NANOCRYSTALLINE MATERIALS

将分子动力学模拟方法与连续体的有限元模拟技术相结合,进行“复合有限元”方法的探索与研究。首先,将纳米金属材料看作由晶粒、晶界、三叉晶界组成的复合材料,基体是具有不规则原子结构的界面相,夹杂是具有理想晶格的晶粒相,用有限元源程序自动生成系统fepg软件模拟材料的宏观弹性模量,并进一步调整晶粒尺寸,研究晶粒尺寸对材料宏观弹性模量的影响。研究结果表明,随着晶粒尺寸的减小,晶界、孔洞等所占的体积比增大,材料的弹性模量也随之下降。

The traditional finite element analysis method in conjunction with the atomic simulation technology was applied to study the mechanical properties of nanostructure materials. A phase mixture model in which nanocrystalline material is regarded as a mixture of crystalline phases and intercrystalline phases （grain-boundary, triple line junction and quadratic node） is presented. The elastic modulus of nanoerystalline（NC） materials were simulated by means of finite element program automatic generate system-FEPG. The effects of grain size were investigated in the literature. With a decrease of grain size and a increase volume fraction of grain boundary and porosity, it was found that, the macro elastic modulus declined step by step. The calculated results were compared with previously published experimental data.