考虑摩擦生热的扭动微动热力耦合数值分析

Numerical analysis of thermomechanical torsional fretting behavior considering frictional heat generation

摩擦产生的表面温升和热传导,是微动接触中导致接触材料磨损损伤的重要因素,但摩擦生热引起的温升对扭动微动磨损的影响机制尚未揭示。本文基于摩擦耗散能建立了扭动微动磨损的热力耦合数值模型,将退化后的模型数值结果与Johnson解析解进行了对比,验证了模型的正确性。在此基础上,本文对接触表面的Von Mises应力分布、温升与塑性变形进行了预测和讨论,并对表面塑性变形与温升之间的关系进行了分析。结果表明:在完全滑移状态下,接触表面有明显的温升,发生了较大的塑性变形;且随着温度升高,表面塑性变形显著增加。因此,在扭动微动中,摩擦产生的温升会显著扩大接触表面的塑性变形,致使材料在完全滑移状态下发生严重磨损。

Heat conduction and temperature rise because friction are identified as significant factors in both the wear behavior and mechanism of damage in fretting contact.However,the influence of the temperature rise caused by the frictional heat on torsional fretting wear has been unrevealed.In this work,taking into account frictional power dissipation,numerical model is developed to analyze the thermomechanical behavior in torsional fretting wear,also provides a further understanding and the fundamental study on the torsional fretting wear mechanism.The contact solutions degenerated from the proposed model are verified with analytical solutions from Johnson.And then,the von Mises stress distribution,the temperature rise,and the link between surface plastic deformation and the temperature rise are predicted and discussed.The fact is that obvious surface temperature rise are observed in the full slip regime,where large plastic deformation occurred in the contact surface.And it is found that surface plastic deformation has a remarkable increase with the increase of the temperature rise.In consequence,it can be deduced that the temperature rise can significantly enlarge surface plastic deformation in torsional fretting,and hence induce serious wear occurring in the full slip regime.