【作者】 邓莎莎；

【导师】 沈火明；

【作者基本信息】 西南交通大学 ， 工程力学， 2012， 硕士

【摘要】 扭动微动是指接触副在承受交变载荷作用下在接触界面间发生的扭动幅度很小的相对运动,其在航空航天业、汽车制造业等领域均广泛存在,是一种不容忽视的失效行为。根据受载情形,微动的失效形式表现为磨损和疲劳两种形式。由于微动损伤的危害日益凸显,因此对其研究显的越发重要。目前,针对微动磨损的研究已十分活跃,在实验和有限元模拟方面均取得了很多成果,尤其是清华大学和西南交通大学等在实验研究方面已进行了大量的探索并形成了较完整的体系,这些成果相互印证,更好的从机理上对微动磨损进行了分析,但有限元研究方面依然有所欠缺。本文采用工程软件对GCr15钢球／PMMA平板扭动微动时磨损接触区的力学行为进行分析,并与实验结果进行对比分析。1.采用有限元软件MARC建立GCr15钢球与PMMA有机玻璃平板扭动微动计算模型,对其在不同角位移和不同摩擦系数情况下进行有限元分析。结果表明：角位移和摩擦系数均对接触区的应力应变分布有着很大影响。2.对GCr15钢球与PMMA有机玻璃的扭动微动实验所获得的摩擦力矩-角位移曲线、磨痕形貌图和磨痕轮廓曲线进行定性分析。结果表明：随着角位移的增大,相同循环下所对应的摩擦力矩越大,且磨损深度和磨损范围也越大。3.将GCr15／PMMA扭动微动时的模拟计算结果与实验结果进行对比分析,结果表明,它们在一定程度上能较好的吻合,说明有限元结果与实验结果可相互预测验证。更多还原

【Abstract】 Torsional fretting is the relative motion with a tiny amplitude between the contact interfaces induced by reciprocating torsion under alternate load. It is one kind of failure behavior which is not allowed to be neglected, as a result of wildly existing in many fields such as aerospace industry and automotive industry. The damages forms of fretting can be defined as wear and fatigue according to the loading cases. There is great significance in the research of fretting damage whose harm becoming gradually obvious. The current research on fretting damage is very active. Lots of achievements in the experiment were obtained, especially experimental research for Tsinghua University and Southwest Jiaotong University etc, which developed a completed system of experiment after a lots of exploration. Those achievements confirmed reciprocally and further analyzed fretting damage mechanism. However, little research has been made in FEM simulation. In this paper, a ball-plate contact geometry of GCrl5/PMMA was studied, and mechanical behavior on the contact surface was analyzed by a finite element code. The simulation results were compared to the results of experiments.(1)The finite model of GCr15/PMMA was established by FEM software MARC, and the stress-strain distribution was analyzed under different angular displacement and fiction coefficient. Results showed that angular displacement and friction coefficient had great influence on the stress and strain of the contact area.(2)The analyses in quality were taken to friction torque-angular displacement curves, worn scars micrographs and wear scars profiles of GCrl5ball and PMMA which were obtained by torsional fretting experiments. Results showed that the friction torque of the same cycle was bigger with the increasing angular displacement, and the corresponding wear depth and range were also bigger.(3) The simulation results and the test results were compared under the torsional fretting, and good consistency was obtained between the two kinds of results. It indicated that the FEM method could be used to predict the torsional fretting of GCrl5/PMMA.更多还原