Residual Stresses Due to Debris Effects in EHL Contacts

Abstract

Debris in lubricated contacts significantly reduces the contact fatigue life. The life reduction is due to the surface damage caused by debris denting and the subsequent overrolling of the dent in the EHL contact. High pressure spikes are generated due to the dent which will modify the contact stress profiles, leading to stress concentration at or near the surface. In this paper, the residual stresses caused by debris effects are investigated. The residual stresses originate from the debris denting process and from the overrolling process of the dent in EHL contacts. The finite element method was used to investigate the residual stresses due to each process and their combined effects on the internal stress distribution of an EHL contact. It was found that the residual stress from debris denting will increase the internal stresses in an EHL contact. However, the residual stresses from overrolling of dent will reduce the internal stresses. The residual stresses are largely dependent on the plastic modulus of the contacting materials and need to be considered when investigating the internal stresses in heavily loaded lubricated contacts.

Presented at the 52nd Annual Meeting in Kansas City, Missouri May 18–22, 1997

KEY WORDS:

• Rolling-Element Bearings
• Engineering Analysis and Computing
• Elastohydrodynamic Lubrication
• Wear and Failure

Notes

Presented at the 52nd Annual Meeting in Kansas City, Missouri May 18–22, 1997