Mechanisms of Rolling Contact Fatigue in Lubricated Rolling Contacts

该项目旨在提高对滚动/滑动润滑接触中表面引发的滚动接触疲劳(RCF)损伤的了解。它可广泛应用于各种机械部件，包括滚动元件、轴承和齿轮。RCF本身表现为点蚀或微点蚀表面失效。随着当前使用低粘度润滑油的趋势和机械功率密度的增加，工程应用中的摩擦学接触不得不在相对较薄的润滑膜下运行，这导致金属与金属之间的接触量增加，从而导致更多的表面引发疲劳损伤。因此，本文研究的重点是表面引发的RCF裂纹，这些裂纹发生在粗糙接触层面，而不是宏观接触层面，通常会导致微观点蚀损伤。该项目利用三圆盘RCF试验机产生表面疲劳损伤，并在受控接触条件下研究材料、表面光洁度、滑滚比和接触压力等参数对疲劳损伤的影响。这反过来将提供所需的理解，以改进我们对这种类型的损伤的预测工具，该项目的后期阶段将尝试利用我们现有的接触力学模型和在这些实验中产生的知识来提供裂纹萌生和随后的表面疲劳损伤发展的数字预测。

The project aims to provide improved understanding of surface initiated rolling contact fatigue (RCF) damage in rolling/sliding lubricated contacts. This has applications to a wide range of mechanical components including rolling element bearing and gears. RCF manifests itself as pitting or micropitting surface failures. With current trends for use of lower viscosity lubricating oils and increased power density of machines, tribological contacts in engineering applications are having to operate under relatively thin lubricant films leading to increased amount of metal-to-metal contact and hence more surface initiated fatigue damage. Therefore, the focus of this research is on surface initiated RCF cracks which occur at asperity contact level, as opposed to macro-contact level, and commonly lead to microptting damage. The project utilises a triple-disc RCF test machine to generate surface fatigue damage and study the influence of parameters including material, surface finish, slide-roll ratio and contact pressure under controlled contact conditions. This will in turn provide the understanding needed to improve our predictive tools of this type of damage, and the later stages of the project will attempt to utilise our exiting contact mechanics models and the knowledge generated in these experiments to provide numerical predictions of crack initiation and subsequent progression of surface fatigue damage.