纳米级粗糙峰法向接触特性研究  

Normal contact characteristics of nanoscale asperities

作　　者：涂福泉[1] 韦俊伟 魏斯佳 石理 陈超 苏子豪 Tu Fuquan;Wei Junwei;Wei Sijia;Shi Li;Chen Chao;Su Zihao(Key Laboratory of Metallurgical Equipment and Control of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学冶金装备及其控制教育部重点实验室,湖北武汉430081

出　　处：《武汉科技大学学报》2023年第4期281-288,共8页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金面上项目(51975425).

摘　　要：为了突破有限元法在微观尺度下界面接触特性分析中的局限性,采用分子动力学方法研究纳米级粗糙峰的法向接触行为。利用大规模原子/分子并行模拟器(LAMMPS)建立3种不同半径的Cu单粗糙峰与金刚石刚性平面法向接触的分子动力学模型,从原子尺度模拟纳米级粗糙峰法向接触动态过程,分析法向接触力、实际接触面积、接触应力等参量的动态变化特性。结果表明:粗糙峰半径一定时,法向接触力、接触应力、实际接触面积与接触变形率正相关;接触变形率一定时,法向接触力、接触应力、实际接触面积均随粗糙峰半径的增大而递增;不同于宏观接触行为,由于原子间相互作用力,纳米级粗糙峰在法向初始接触阶段出现负的法向接触力以及非零的实际接触面积;粗糙峰的接触变形过程伴随着原子位错以及应力集中。To break through the limitations of finite element method in the analysis of interfacial contact characteristics at microscopic scale,the normal contact behavior of nanoscale asperities was studied by using molecular dynamics method.Molecular dynamics models of normal contact between copper single asperities with three different radii and diamond rigid plane were established via Large-scale Atomic/Molecular Massively Parallel Simulator(LAMMPS).The normal contact process of nanoscale asperities was simulated from atomic scale.Dynamic characteristics of normal contact force,actual contact area and contact stress were analyzed.The results show that,when the asperity radius is constant,the normal contact force,contact stress and the actual contact area are positively correlated with the contact deformation rate.When the contact deformation rate is constant,the normal contact force,contact stress and the actual contact area increase with the rising asperity radius.Different from the macroscopic contact behavior,negative normal contact force and non-zero actual contact area appear in the initial normal contact stage of nanoscale asperities due to the interatomic force.The contact deformation of nanoscale asperities comes with atomic dislocation and stress concentration.

关 键 词：纳米级粗糙峰 单粗糙峰 分子动力学 法向接触特性 

分 类 号：O313.5[理学—一般力学与力学基础] TH117.1[理学—力学]