EFFECTS OF FRICTION ON CONTACT OF TRANSVERSE GROUND SURFACES

The two-dimensional plane-strain sliding contact of a smooth rigid rol ler on a transverse ground rough surface is analyzed. The rough surfac e is idealized as an elastic half-space with periodic roughness modele d as cylindrical ridges oriented transverse to the sliding direction. The contact problem is solved using a numerical iterative method in wh ich each asperity contact is treated as a micro-Hertz contact, and the exact treatment of asperity interaction is included. The subsurface s tress field is calculated using Westergaard stress functions. The subs equent analysis compares the rough surface stress fields with the corr esponding smooth Hertz contact to evaluate the influence of surface ro ughness and friction on the subsurface stress distributions. The resul ts show that the real area of contact is less than the corresponding s mooth surface Hertz contact area, and the magnitude of the actual loca lized maximum contact pressure is always greater than the correspondin g smooth surface contact pressure. The asperity level subsurface effec tive stresses are greater in magnitude than the maximum subsurface str ess due to the macro-Hertz contact for low coefficients of friction, a nd for high coefficients of friction the maximum effective stresses oc cur on the bulk material surface.