Sage Journals: Discover world-class research

Abstract

This article is based on an existing model to describe mixed lubrication between parallel surfaces. This model uses a statistical description of the microgeometry and includes summit and radius distributions. Depending on these geometric parameters, each asperity works with one of the five following lubrication mechanisms: piezoviscous hydrodynamic, elastohydrodynamic, elastic, elastoplastic, and full plastic. By summing the normal load obtained for each asperity, we derived the normal load for the entire contact. Discussion in this article is based on the repartition of asperities into each of these five possible mechanisms. We first analyze the parameters that are able to significantly change the limit between two neighboring regimes. The number of asperities associated with each regime is also considered. We also analyze the fraction of normal load transmitted by all asperities of a given regime. Generally, only a maximum of four regimes can generate significant contributions for a given situation. Depending on the operating conditions of the contact, these significant regimes change. Consequently, it seems very difficult to suggest reducing the number of regimes for a general description of mixed lubrication between parallel surfaces.

Keywords

Asperity microgeometry coefficient of friction mixed lubrication

Get full access to this article

View all access options for this article.

References

Dobrica

Fillon

Maspeyrot

. Mixed elastohydrodynamic lubrication in a partial journal bearing—comparison between deterministic and stochastic models. J Tribol 2006; 128: 778–788.

Shi

Wang

. A mixed-TEHD model for journal-bearing conformal contacts – Part I: Model formulation and approximation of heat transfer considering asperity contact. J Tribol 1998; 120: 199–205.

Lee

Ren

. Behavior of elastic-plastic rough surface contacts as affected by surface topography, load, and material hardness. Tribol Trans 1996; 39: 74–76.

Khonsari

Gelinck

ERM

. The Stribeck curve: experimental results and theoretical prediction. J Tribol 2006; 128: 789–794.

Greenwood

Williamson

JBP

. Contact of nominally flat surfaces. Proc Roy Soc 1966; 295 A: 300–319.

Lebeck

. Parallel sliding load support in the mixed lubrication – Part 1: The experimental data. J Tribol 1987; 109: 189–195.

Lebeck

. Parallel sliding load support in the mixed lubrication – Part 2: Evaluation of the mechanisms. J Tribol 1987; 109: 196–205.

Emmens

. The influence of surface roughness on friction. Proceedings of the 15th biennial congress IDDRG. May 1988. Dearborn, MI, USA. 63–70.

Felder

Samper

. The generation by friction and plastic deformation on the restraining characteristics of draw beads in sheet metal forming. Proceedings of the 20th Leeds–Lyon symposium on tribology: dissipative processes in tribology. September 1993. Lyon. 361–372.

10.

Nogueira

Dias

Gras

. An experimental model for mixed friction during running-in. Wear 2002; 253/5-6: 541–549.

11.

Xiong

Salant

. A dynamic model of a contacting mechanical seal for down-hole tools. J Tribol 2003; 125: 391–402.

12.

de Kraker

van Ostayen

Rixen

. Calculation of strikec curves for water lubricated journal bearings. Tribol Int 2007; 40: 459–469.

13.

Robbe-Valloire

Paffoni

Progri

. Prediction of the amount of load transmitted by elastic, elastoplastic or plastic deformed asperities at a rough interface. Mech Mater 2001; 33: 617–633.

14.

Robbe-Valloire F, Paffoni B, Progri R, et al. An asperity based model for wear rate in mixed lubrication. In: Proceedings of the 31st Leeds–Lyon 2004, life cycle tribology, tribology and interface engineering series, vol. 48, pp.555–564. Elsevier.

15.

McCool

. Comparison of models for the contact of rough surfaces. Wear 1986; 107: 37–60.

16.

O'Callaghan

Robert

. Prediction and measurement of true area of contact between solids. Wear 1987; 120: 29–49.

17.

Nayak

. Random process model of rough surfaces. J Lubric Technol 1971; 93: 398–407.

18.

Whitehouse

Archard

. The properties of random surfaces of significance in their contact. Proc Roy Soc 1970; 316 A: 97–121.

19.

Robbe-Valloire

. Statistical analysis of asperities on a rough surface. Wear 2001; 249/5-6: 401–408.

20.

Hooke

. The effect of roughness in EHL contacts. Tribol Interf Eng Ser 2005; 48: 31–46.

21.

Kahraman

. A mixed EHL model with asymemetric integrated control volume discretization. Tribol Int 2009; 42: 1163–1172.

Mechanisms developed at the asperity scale for mixed lubrication between parallel surfaces

Abstract

Keywords

Get full access to this article

References