中文摘要：

采用Stillinger-Weber（SW）势函数描述硅纳米杆中硅原子间的相互作用，通过分子动力学方法对几种硅纳米杆进行轴向拉伸研究，发现硅纳米杆拉伸时表现出来的特性与宏观脆性材料基本一致：拉伸曲线没有明显的直线部分和屈服变形部分；进一步研究发现硅纳米杆的杨氏模量和强度极限随着尺寸增大而增大，尺寸效应随尺寸增大而逐渐减弱．

英文摘要：

Molecular dynamics （MD） simulations have been performed to simulate the stretching process of Silicon nano-rods with the use of Stillinger-Weber potential to describe the interactions of atoms in silicon nano-rods. The results show that the tension properties of silicon nano-rods are similar to that of macroscopic brittle material： there are no linear elastic stages and ductile yield stages; The influence of size effects is observed： The Young＇s modulus and tensile strength for silicon nano-rods found increase with the section area sizes, respectively,the size effects is becoming feeble with the increase of section area sizes.