Mechanisms of Rolling Contact Fatigue in Lubricated Rolling Contacts

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.