The elastic-plastic contact of a single asperity of a rough surface

Peter Ogar,Denis Gorokhov,Sergey Belokobylsky,S Bratan,S Roshchupkin,S Leonov,S Gorbatyuk

doi:10.1051/matecconf/201712906017

Abstract

A penetration of spherical asperity into the elastic-plastic hardening half-space is described. The elastic-plastic material properties correspond to Hollomon´s power law. In this case the empirical Meyer law relating a spherical indentation load with an indentation diameter d is used. Initially, the Meyer law is not related to the mechanical characteristics of the test material. The study used the relations between the strain hardening exponent n and the Meyer law constant obtained by S.I. Bulychev. The effects relating to elastic punching and plastic displacement of material are taked into account. It is shown that there is no need to define Meyer law constants. Expressions relating the value of the relative load magnitude to the relative indenter penetration magnitude are presented. The scope of application of the proposed equations is defined. A comparison of the obtained results with the experimental data and published data of the finite element analysis is given.

Highlights

Widespread use in tribology finds a discrete model of roughness, in which the asperities are presented as a set of bodies of regular geometric shapes, for which solutions of contact problems are available [1, 2]
The method consists in the use of the kinetic indentation load-displacement diagram and the similarity method of deformation characteristics
The proposed approach suggests an alternative to a more complex method for describing elastoplastic penetration of a sphere on the basis of the kinetic indentation diagram [5], which was used in solving problems of elastoplastic contacting of rough surfaces

Summary

Introduction

Widespread use in tribology finds a discrete model of roughness, in which the asperities are presented as a set of bodies of regular geometric shapes, for which solutions of contact problems are available [1, 2]. In this case, the asperity model in the form of a spherical segment is considered to be optimal. The method consists in the use of the kinetic indentation load-displacement diagram and the similarity method of deformation characteristics In this case, the notion “plastic hardness” is used as characteristics of material resistance to contact plastic strain. The aim of this work is to use the above mentioned hardened material characteristics in the Meyer law application

Problem solution

Conclusions