基于分子动力学的PTFE材料摩擦磨损分析及试验研究

发布时间：2018-04-18 22:18

本文选题：分子动力学模拟 + PTFE　；参考：《燕山大学》2016年硕士论文

【摘要】：聚四氟乙烯(Polytetrafluoroethylene,PTFE)是织物自润滑关节轴承的润滑剂。在关节轴承工作时,织物衬垫中的部分PTFE转移到轴承内圈上,形成PTFE与PTFE的摩擦副,起到了降低轴承的摩擦系数和磨损率的作用,同时PTFE的磨损寿命又直接影响着轴承寿命,所以研究PTFE的摩擦磨损对织物衬垫关节轴承有着重要意义。前人对PTFE的摩擦学性能研究多采用宏观试验方法,本文从微观角度出发,应用分子动力学模拟方法对PTFE材料进行微观磨损分析以及宏观试验研究。主要内容有:应用Materials Studio软件建立PTFE模型,通过模拟PTFE模型的玻璃化转变过程、原子径向分布情况,验证了模型的可靠性;模型导入LAMMPS程序,模拟了PTFE体系的原子径向分布情况和弹性模量,验证了相关分子动力学参数设置的合理性。针对PTFE体系的微观摩擦磨损性能研究,建立了PTFE/PTFE的微观摩擦副模型,分析了模型的能量损耗形式,应用分子动力学模拟方法研究了法向载荷、滑行速度等工况对PTFE/PTFE摩擦副的摩擦系数和磨损深度的影响,根据相关数据和微观摩擦动画研究了PTFE摩擦磨损情况,得到随着PV值(P法向载荷、V滑行速度)增大微观摩擦过程更加剧烈,磨损深度增加;而摩擦系数随着法向载荷的增大而减小,随着摩擦速度的增大而增大。在与微观模拟相同的工况下,应用UMT摩擦磨损试验机对GCr15/PTFE摩擦副及PTFE/PTFE摩擦副的摩擦磨损性能进行了试验研究,得到了不同工况下的摩擦系数与磨损率情况,并应用相关试验表征设备进行了观察,分析了PTFE材料的宏观摩擦磨损机制。对比分析微观模拟结果和宏观试验结果,得出两种尺度下的摩擦系数数值接近且变化趋势一致的结论,验证了微观模拟结果的合理性。
[Abstract]:Polytetrafluoroethylene (Polytetrafluoroethylene, PTFE) is a fabric self lubricating joint bearing lubricant. In joint bearings, transfer part of PTFE fabric liner to the bearing inner ring, friction pair formation of PTFE and PTFE, to reduce the friction coefficient and wear rate of the bearing, and the wear life of PTFE directly affect the bearing life, so the study of friction and wear of PTFE fabric liner joint bearing has important significance. Study on the tribological properties of PTFE by the predecessor to the macro test method, this paper from the microscopic point of view, method of PTFE materials for micro wear analysis and macroscopic experimental study on Application of molecular dynamics simulation. The main contents are: Materials Studio software to establish the PTFE model, through the glass transition process of PTFE model simulation, atomic radial distribution, to verify the reliability of the model into the L model; AMMPS program, PTFE system of atomic radial distribution and elastic modulus were simulated, verified the rationality of setting the related molecular dynamics. The parameters of Micro Friction and wear properties for the PTFE system, the establishment of a micro friction model of PTFE/PTFE, analyzes the energy loss form of model, research the method to load the molecular dynamics simulation method is used. Effect of sliding speed conditions on PTFE/PTFE friction coefficient and the wear depth, according to the relevant data and Micro Friction animation on PTFE friction and wear, with PV value (P normal load, sliding speed increased V) micro friction process is more intense, the wear depth increases; while the friction coefficient with the normal load increases, increases with the increase of friction velocity. Under the same conditions and micro simulation, friction on GCr15/PTFE friction wear testing machine using UMT And the friction and wear properties of PTFE/PTFE friction pair were studied. The friction coefficient and wear rate under different working conditions are obtained, and the application of related test equipment characterization were observed, analyzed the macro friction material PTFE. The wear mechanism of micro and macro analysis of the simulation results comparison of test results, the friction coefficient of two numerical scales the close and consistent conclusion, verify the rationality of the microscopic simulation results.

【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O632.21

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