Methodology to Establish a Scuffing Limit for Ultra-Smooth Lubricated Contacts Subject to Sliding

This is a hybrid seminar.

Seminar Speaker: Michael Handschuh, PhD Research Scientist The Ohio State University

Abstract: Scuffing is a heat-induced failure mode of lubricated contacts. Any contact subjected to high pressures and sliding velocities is susceptible to scuffing failures. Scuffing causes a sudden permanent damage to the surfaces which leads to catastrophic failure of the product. Likelihood of scuffing further increases when lubrication temperatures are elevated, which is often the case in aerospace applications. As such, most gear contacts in aerospace and automotive electric vehicle (EV) applications are prone to scuffing. Conventional design practices that employ crude surface-temperature based scuffing limits, primarily based on field experience are typically unreliable and inaccurate under high-speed conditions with ultra-smooth contact surfaces. In this presentation, a novel hybrid methodology is presented which combines the results of an extensive experimental study with a refined physics-based model to establish a material-lubricant specific scuffing limit. As the surface roughness decreases, rheological properties of the lubricant become more important because the lubricant carries the entire load between the contacting surfaces. An existing thermal elastohydrodynamic lubrication model is refined to accurately predict the surface traction of ultra-smooth surfaces and validated through comparisons of measured traction data. Validated model is employed to simulate multiple scuffing experiments to establish a multi-parameter scuffing limit based on fluid temperature and pressure. At the end of the presentation, future research areas, potential proposals and funding agencies are presented.

Bio: Dr. Michael Handschuh is currently a Research Scientist in the MAE Department of the Ohio State University. He received his PhD in Mechanical Engineering from Ohio State in 2018. His research envelops issues in power transmission and gearing mainly in aerospace and automotive industries with some research extending into the industrial and renewable energy gearbox sectors. His specific research focuses on high-speed lubricated contact tribology, heat-induced scuffing failure modes, gear dynamics and vibrations, and engineered surface technologies impact on gear performance.