A numerical slipline field for the sliding cylinder problem

This paper presents a slipline field solution for a rigid cylindrical asper ity sliding across an initially plane surface of a softer material. The num erical development of the model is described. The friction and strain patte rn predictions of the model an tested against the results of experiments an d finite element analysis. It is shown that the friction predictions of the model developed an in good agreement with the chord approximation model pr oposed by Challen and Oxley [J.M. Challen, P.L.B. Oxley, Slipline fields fo r explaining the mechanics of polishing and related processes, Int. J. Mech . Sci. 26 (6-8) (1983), 403-418]. Thus, it can predict well the friction co efficients measured from tests when a cylinder, whose trailing edge has bee n removed, slides across an aluminium alloy, as shown experimentally in Bus quet and Torrance [M. Busquet, A.A. Torrance, Investigation of surface defo rmation and damage when hard cylindrical asperity slides over a soft smooth surface, Proc. 25th. Leeds-Lyon Symp. Tribol. (1998)]. However, this model is not suitable for predicting the friction coefficients when a full cylin der slides on aluminium. This has already been explained partly by the fact that the slipline field theory neglects elastic effects and also by the pr esence of detached particles trapped in the contact. The strain pattern cal culated by the model presented here is much closer than the chord model of Challen and Oxley [J.M. Challen, P.L.B, Oxley, Slipline fields for explaini ng the mechanics of polishing and related processes, Int. J. Mech. Sci. 26 (6-8) (1983) 403-418] to visioplastic measurements of strain patterns produ ced by wedge-shaped asperities [Y. Yang, The prediction of the wear rates o f ductile materials through their surface strains, PN) thesis, Trinity Coll ege, University of Dublin, September 1997], and this without strain-hardeni ng. Furthermore, the morphology of the debris produced during wedge experim ents has been explained to some extent by the model presented hen without i nvolving elastic effects. (C) 2000 Elsevier Science S.A. All rights reserve d.