粗糙面变形特性对摩擦温度与接触压力的影响

在考虑微凸体间的相互作用及摩擦界面摩擦热流耦合等影响基础上,建立一具有三维分形特性粗糙表面/理想平面接触的热力耦合模型,运用有限元软件ANSYS中的非线性有限元多物理场方法,数值模拟并分析了弹性粗糙实体/理想平面刚性体(E/R)、弹塑性粗糙实体/理想平面刚性体(P/R)的摩擦滑动过程,揭示了粗糙表面不同变形特性下粗糙实体摩擦热、接触压力与接触面积的变化规律。发现在匀速滑动过程中,摩擦表面最高接触温度在波动中缓慢上升,而最大接触压力和接触面积则在一定范围内波动。弹性接触(E/R)中接触压力、摩擦温度比弹塑性接触(P/R)大,而接触面积则小很多。在分析摩擦过程中粗糙实体热、力问题时,考虑粗糙接触体的弹塑性变形对结果有较大的影响。

Influence of Deformation Characteristic of Rough Surface on Frictional Temperature and Contact Pressure

A thermo-mechanical coupling model for a flat plane and a rough surface based on 3-D fractal theory was established.The model considered the interaction between asperities,and integrated the heat flux coupling between the sliding surfaces.By using the nonlinear multiphysics field of the ANSYS software,the frictional sliding process of the elastic rough surface and the rigid flat plane(E/R model),and that of the elasto-plastic rough surface and the rigid flat plane(P/R model) were simulated.The frictional temperature,the contact pressure and the contact area under two different deformation characteristic of the rough solid during the sliding process were analyzed.The numerical results from the analysis and simulation showed that the maximum contact temperature of the rough surface rose slowly during the constant sliding.The maximum contact pressure and the contact area fluctuated within a certain range.The contact pressure and the frictional temperature of the elastic contact(E/R model) were larger than those of the elasto-plastic contact(P/R model),but the contact area was much smaller.The results demonstrated that the elasto-plastic deformation of the rough body had significant influence on the result during the thermo-mechanical analysis of the rough solid in the friction.