A statistical model of elastic-plastic contact between rough surfaces

Abstract

In a mechanical interface, the contact surface topography has an important influence on the contact stiffness. In the contact processes of asperities, elastic-plastic change can lead to discontinuity and lack of smoothness at a critical contact point. The result is a large difference between the elastic-plastic deformation and the actual asperity deformation. Based on Hertz contact theory, the heights of asperities on a rough surface obey a Gaussian distribution. To take into consideration the continuity of elastic-plastic asperity deformation, we divide the elastic-plastic deformation into three stages: pre-elastic-plastic, mid-elastic-plastic, and post-elastic-plastic deformation. This establishes an elastic-plastic contact model of asperity at a continuous critical point. The contact model of a single asperity fits well with the Kogut–Etsion model and the Zhao–Maietta–Chang model, and the variation trend is consistent. At a lower plastic index, the present model coincides with classical models of contact area and contact load. At a higher plastic index, the simulation results of the present model differ from the Greenwood–Williamson model and the Chang–Etsion–Bogy model but are similar to results from the Kogut–Etsion and Zhao–Maietta–Chang models. This study provides a more accurate microscopic contact model for rough surfaces and a theoretical framework for interface design and analysis.

A fractal model of rough surfaces based on ellipsoidal asperities

“…Generally, the elastoplastic deformation stages of existing models differ markedly from actual deformation. To enhance the contact model, by synthesizing the research of Zhao et al (2019) factoring in friction, the elastoplastic stage is segmented into three distinct phases: First elastoplastic deformation stage: This stage occurs when ωecμ≤ω≤6ωecμ. Second elastoplastic deformation stage: This stage is defined for 6ωecμ≤ω≤76.8ωecμ. Third elastoplastic deformation stage: This stage occurs when 76.8ωecμ≤ω≤110ωecμ. …”

“…Generally, the elastoplastic deformation stages of existing models differ markedly from actual deformation. To enhance the contact model, by synthesizing the research of Zhao et al (2019) epc1 , the contact load and area of a single asperity are detailed as follows (Wen and Tang, 2018):…”

A Fractal Contact Model for Rough Surfaces considering the Variation of Critical Asperity Levels

“…Statistical contact models use statistical parameters to characterize the rough surfaces. e GW contact model proposed by Greenwood [26] in 1966 is a typical representative of the statistical contact models, and subsequent scholars have improved the GW model from different aspects [27,28]. e advantage of statistical contact models is that their expressions are simple and clear, which greatly simplifies the derivation of the contact equation between rough surfaces and is conducive to rapid contact analysis between rough surfaces.…”

How to Select 2D and 3D Roughness Parameters at Their Relevant Scales by the Analysis of Covariance

“…Many tribology studies have used surface topography to analyze and quantify the behavior of a system (wear, friction) [1,2]. In numerous cases, the study of a tribological process involves the continuous (or progressive) monitoring of the morphological change of the surface over time [3] or during the continuous evolution of a mechanical request: for example, monitoring surface damage on a tribometer [4], surface wear [5][6][7][8], changes in the tribo-chemical process [9,10], plastic deformation [11] of roughness asperities through an increase in macroscopic contact pressure [4,12], etc. In other words, the monitoring of surface morphology constitutes the basic analysis of the tribological process.…”