中文摘要：

建立一具有三维分形特性的弹塑性粗糙表面与一理想刚性平面接触的热力耦合模型,充分考虑粗糙表面接触微凸体间的相互作用及接触界面摩擦热流耦合等的影响。运用大型有限元软件ANSYS中的非线性有限元多物理场方法,数值模拟并分析了滑动摩擦过程粗糙实体的热、力分布规律。发现由于速度的突变,滑动初始摩擦表面最高温度急剧升高,而匀速滑动中温升缓慢;整个滑动摩擦过程中粗糙表面的VonMises等效应力分布极其不均,且在接触凸点后方距表面一定深度处存在一拉应力区;在滑动瞬间及其闪点温度形成时,粗糙实体表面的VonMises等效应力发生明显变化,且最大拉应力值及其拉应力层厚度明显增大,此结果为材料裂纹萌生及扩展提供了一定的理论依据。

英文摘要：

A thermo-mechanical coupling model for a rigid flat plane and an elastic-plastic rough surface based on three-dimensional fractal theory is established.The model considers the interaction between asperities,and integrates the heat flux coupling on the contact interface.To obtain the transient stress/temperature distribution of the rough solid,the thermo-mechanical problem under this 3D model is solved by using the nonlinear multiphysics field of the ANSYS software.The numerical results from the analysis and simulation show that the maximum contact temperature of the rough surface increases quickly in the initial sliding due to the velocity mutation,but the temperature rises slowly during the constant sliding process.The results also show that the VonMises equivalent stress distribution of the rough surface is very uneven.And a tension stress zone exists at a certain depth from the contact surface in the rear of the contact asperity.The results demonstrate that the VonMises equivalent stress of the contact surface,the maximum tensile stress and the layer thickness of the tensile stress increase obviously in transient sliding contact and forming of instantaneous flash temperature.These results provide a theoretical basis for crack initiation and propagation.