杨晓京,詹胜鹏,迟毅林.纳米尺度接触过程分子动力学模拟[J].农业机械学报,2012,43(11):250-255.
Yang Xiaojing,Zhan Shengpeng,Chi Yilin.Molecular Dynamics Simulation of Nanoscale Contact Process[J].Transactions of the Chinese Society for Agricultural Machinery,2012,43(11):250-255.
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纳米尺度接触过程分子动力学模拟   [下载全文]
Molecular Dynamics Simulation of Nanoscale Contact Process   [Download Pdf][in English]
  
DOI:10.6041/j.issn.1000-1298.2012.11.046
中文关键词:  纳米尺度  接触  分子动力学模拟  原子力显微镜
基金项目:国家自然科学基金资助项目(11062003);云南省应用基础研究计划资助项目(2009ZC042M)
作者单位
杨晓京 昆明理工大学 
詹胜鹏 昆明理工大学 
迟毅林 昆明理工大学 
中文摘要:为研究纳米尺度接触过程力学行为,以刚性半球体接触压入单晶硅表面为分析对象,建立分子动力学模型并求解仿真,得到纳米尺度接触过程中微观接触区域的状态变化和接触作用力变化规律。由于粘附力作用,两表面尚未完全接触时,基体原子发生纳米尺度接触所特有的“突跳”现象。随着接触深度增加,基体原子位错和滑移带相继出现,接触区域的硅材料由初期弹性变形转向后期塑性变形。在脱离接触过程中,基体材料有部分弹性恢复,接触完全脱离时,球面仍粘附着部分硅原子。然后利用原子力显微镜,对应分子动力学模拟时的参数条件和接触过程,进行实验对比分析,实验结果表明:分子动力学模拟不但对纳米尺度接触过程力学行为的分析是可行和有效的,而且可以观察到实验无法反映的微观细节。
Yang Xiaojing  Zhan Shengpeng  Chi Yilin
Kunming University of Science and Technology;Kunming University of Science and Technology;Kunming University of Science and Technology
Key Words:Nanoscale  Contact  Molecular dynamics simulation  Atomic force microscopy
Abstract:In order to study nanoscale contact mechanics behavior, taking the rigid hemispherical surface contacted on and pressed in the silicon surface as the research object, the molecular dynamics model of nanoscale contact process was established. State changing of microscopic contact area and variation law of contact force was acquired. Results showed that the adhesion force caused the hemispherical surface and monocrystalline silicon surface to jump-to-contact when the hemispherical surface has not fully contact with monocrystalline silicon substrate surface. With the increase of contact depth, dislocations and sliding of matrix atoms appeared successively. The initial stage of contact was mainly elastic deformation with some dislocations. The later stage of contact was plastic deformation with lots of dislocation accumulation. In the process of disengagement, the substrate material generated some extent elastic recovery. When the hemispherical surface and the matrix surface were completely out of touch, the contact surface still contacted with some matrix atoms due to adhesion phenomenon. Finally, atomic force microscopy was used to finish comparative analysis of the experiment according to the parameter conditions and the contact process of molecular dynamics. The experimental results showed that molecular dynamics simulation was practicable and effective for analysis of the nanoscale contact mechanics behavior. Moreover, molecular dynamics simulation could acquire the microscopic details that not be observed through the experiment.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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