冲击波加载下单晶铜动态破坏微观过程的分子动力学研究

发布时间：2018-03-16 15:17

本文选题：分子动力学　切入点：空洞成核及生长　出处：《原子能科学技术》2016年05期 　论文类型：期刊论文

【摘要】：采用嵌入原子势模型和分子动力学方法,模拟研究了冲击波加载下单晶铜动态破坏的微观过程和空洞成核及生长过程。根据原子中心对称参数变化给出了单晶铜动态破坏的微观过程,通过不同碰撞速度的模拟,讨论了冲击波加载下破碎区内物质形态分布的变化,给出了材料破坏深度的变化规律。研究发现纳米空洞在完整单晶铜中随机成核,空洞成核后,空洞表面的应力集中和原子活化易形成位错源,各种不同类型的位错的生长使空洞逐渐长大,空洞长大到一定尺寸后,邻近空洞相互作用贯通形成更大尺寸的空洞,这种空洞贯通效应造成了材料内部的宏观层裂及失效。
[Abstract]:The embedded atomic potential model and molecular dynamics method are used. The microscopic process and cavity nucleation and growth process of single crystal copper under shock wave loading are simulated. According to the change of atomic centrosymmetric parameters, the microscopic process of dynamic failure of single crystal copper is given, and the simulation of different collision velocities is carried out. The variation of material morphology distribution in the cracked zone under shock wave loading is discussed, and the variation law of the material failure depth is given. It is found that the nano-cavity is nucleated randomly in the intact single crystal copper, and the cavity nucleates after the cavity nucleation. The stress concentration on the surface of the cavity and the activation of atoms are easy to form the dislocation source. The growth of different types of dislocation makes the cavity grow up gradually, and when the cavity grows to a certain size, the interaction between the adjacent voids becomes a larger size cavity. This hollow-through effect causes macroscopic spallation and failure within the material.
【作者单位】：中国工程物理研究院激光聚变研究中心;西华师范大学物理与电子信息学院;
【基金】：中国博士后科学基金资助项目(2014M562510XB) 四川省教育厅青年项目资助(11ZB033) 西华师范大学重大探索性项目资助(14C005)
【分类号】：O347.3

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