The Effects of Surface Irregularities on the Elastohydrodynamic Lubrication of Sliding Line Contacts. Part I—Single Irregularities

Abstract

A full line contact solution, under isothermal conditions, is obtained in which the effects of single stationary surface irregularities on the EHD lubrication process are studied under pure sliding conditions. The irregularities studied are furrows, furrows with built-up edges, and asperities. The effects of these irregularities on film thickness, pressure, and subsurface octahedral shear stress are presented. The pressure and film thickness resulting from such surface irregularities are significantly changed from their smooth surface values. These changes alter the state of stress in the subsurface region by increasing the maximum value of octahedral shear stress and bringing the location of this maximum stress closer to the surface. The film thickness in the contact is significantly changed from the smooth surface value only when the irregularities are located in the inlet region while the maximum value of the octahedral shear stress increases to the greatest extent when the irregularities are located in the outlet half of the contact.