Debris Denting Effects on Elastohydrodynamic Lubricated Contacts

Abstract

A finite element model was developed to investigate the effects of a spherical debris on elastohydrodynamically lubricated rolling/sliding contacts. Three dimensional dent profiles were obtained using finite element method showing horseshoe shape material pile-up along the rolling direction. The dent profiles obtained from the finite element analysis (FEA) were compared with the experimental results. There is good qualitative agreement between FEA and experimental dent profiles. The FEA dent profiles were then used in a time dependent thermal elastohydrodynamic lubrication (EHL) point contact model to analyze the dent effects on the pressure, film thickness and temperature profiles. The presence of a dent in lubricated contacts generates high pressure spikes and increases the peak temperature. The internal stresses were calculated based on the pressure and traction data obtained from the EHL analysis. The results indicate that a dent created by a debris will cause the internal maximum Von Mises stress to occur near the surface, which contributes to surface initiated failures.