【作者】 李友遐；

【导师】 高诚辉；

【作者基本信息】 福州大学 ， 机械设计及理论， 2004， 硕士

【摘要】 工程实际中，相互接触的滑动摩擦表面是粗糙的，对粗糙表面的瞬时温升和热－机械应力分析有重要的理论意义。本文评述了粗糙表面的闪温以及摩擦接触算法的研究现状；建立粗糙表面接触模型并对其滑动摩擦界面的传热规律进行了研究。基于G-W接触模型，将两个粗糙表面简化为一个有规则排列的长方体微凸体的粗糙表面与一光滑表面，利用热－结构顺序耦合建立三维瞬态有限元计算模型，考虑两个物体摩擦接触的热弹性问题，采用非线性有限元多物理场来实现，对粗糙表面接触模型的瞬时摩擦温度场、压力场和应力场进行了计算分析。在数值计算过程中，着重考虑了温度变化与接触区域压力变化的耦合问题，接触压力与外加压力的关系，以及分别改变一些参数对结果的影响。对于相对滑动的粗糙表面，因实际接触面积小而导致接触压力很大，这样使得热流密度会很大，同时由于滑动时间很短，热来不及传导，最高温度发生在摩擦表面，在垂直于摩擦面的方向有很大的温度梯度，使得热应力很大，且最大应力发生在表面，同时产生热弹性变形，这种变形使得接触区域内的压力分布发生变化，这种变化又反过来影响了接触区域的温度分布。本文通过对粗糙表面接触模型的滑动摩擦的三维瞬态温度场、压力场和应力场的耦合计算分析，揭示了粗糙表面滑动摩擦副的温度和热应力分布规律，以及摩擦界面间的热流分配规律，分析了滑动过程中接触压力/温度/应力的分布及变化、最大等效应力位置的变化，探讨了实际接触面积、外加压力和滑动速度对结果的影响。本文的计算分析结果为进一步研究粗糙表面摩擦副的闪温和热－机械失效问题以及磨损机理，开发高性能摩擦材料打下了良好的基础。更多还原

【Abstract】 In real engineering, the two surfaces in sliding contact are rough. And it is an important theoretical part to calculate the coupled temperature and stress of sliding bodies having rough surfaces.At first the research current situation of the flash temperature field of rough surface and the algorithm of contact problems with friction were reviewed in this paper. And after the contact model of rough surfaces was created, the heat transfer between the sliding surfaces was studied. Based on G-W contact model, two rough surfaces in contact were simplified to a smooth one and a rough one which has regular rectangular asperities, and a three-dimensional transient thermal and stress coupled FEM model was established using thermal-structure sequential coupling. The course of the sliding with friction was simulated using the nonlinear multiphysics field FEM, meanwhile considering thermal-elastic problems of the two bodies, to calculate and analyze the temperature, contact pressure and stress of the sliding contact surfaces with frictional heating. The effect of the variation of temperature and contact pressure of the sliding contact surfaces with frictional heating on each other, particularly the relationship of the applied pressure and the contact pressure and the effect of the separate variation of some parameters on the simulation results were taken account into in the course of numerical simulation.The FEM results indicated that as to the rough surfaces in sliding contact, the value of the contact pressure was very high which coursed a high value of the heat flow rate, meanwhile the sliding time was not enough for the frictional heat to transfer, thus the highest value of the body temperature occurred just on the sliding surfaces, which possessed a sharp thermal gradient in direction perpendicular to the sliding surface. So the great thermal stress was caused just by the sharp gradient and the thermal elastic distortion with which the contact pressure changed occurred simultaneously, thus this change of the contact pressure would affect the temperature distribution in return.<WP=4>The regulation of distribution of temperature and stress fields and the division of heat between the sliding surfaces were showed, and the distribution and variation regulation of the temperature, contact pressure and stress field in the sliding process were also analyzed in this paper. The cause of the change of the greatest stress position, which possibly caused heat failure in sliding friction, and the separate effect of the real contact area, applied pressure and sliding velocity on the simulation results were discussed.The results of this paper are the basic for further research the flash temperature, thermal-mechanical problems and the wear mechanisms of the rough surfaces, also helps to develop the excellent frictional material.更多还原