A model for computational investigation of elasto-plastic normal and tangential contact considering adhesion effect

With the rapid development of Micro-Electro-Mechanical System (MEMS), we enter a field in which the surface effects have dominated many of the micro-scale phenomena, and the adhesive contact is one of the focuses. In this paper, a feasible model for finite element computation is presented via a macroscopic and microscopic combination approach, in which the adhesive forces are simulated by some non-linear spring elements considering the softening stage. Two basic problems concerning the adhesion effect were considered; through specific quantitative analysis, the results show a consistency with the current elastic continuum theories of adhesion and a brief investigation into the effects of adhesion on plastic deformation and tangential contact will be carried out as well. The project supported by the National Natural Science Foundation of China (10172050, 90205022) and Key Grant Project of Chinese MoE (0306)     

二维材料纳米尺度摩擦行为及其机制

二维材料是指厚度仅有单层或数层原子的晶体或非晶材料,其优异的物理、力学和化学性能给纳米尺度超薄固体润滑材料的设计和发展带来了新的契机.同时,二维材料独特而简单的拓扑结构也为深入了解摩擦的微观机制提供了一个理想的对象.论文综述了以石墨烯为主的二维材料纳米尺度摩擦和磨损研究的进展.根据相对运动形式的不同,分别介绍了二维材料的层间滑动和表面摩擦行为,并详细阐述了这些独特行为背后的微观物理机制;同时还重点介绍了若干种影响和调控二维材料表面摩擦性能的典型方法和策略,以及二维材料纳米尺度的磨损行为及其失效模式.最后,还对纳米尺度二维材料摩擦研究进行了小结,并展望了该领域尚待探索的若干研究方向.