0
Research Papers: Elastohydrodynamic Lubrication

Experimental and Numerical Investigations of the Stribeck Curves for Lubricated Counterformal Contacts

[+] Author and Article Information
Tao He

School of Aeronautics and Astronautics,
Sichuan University,
Chengdu 610065, China

Dong Zhu

School of Aeronautics and Astronautics,
Sichuan University,
Chengdu 610065, China
e-mail: DongZhu@Mail.com

Jiaxu Wang

School of Aeronautics and Astronautics,
Sichuan University,
Chengdu 610065, China;
State Key Laboratory of Mechanical Transmissions,
Chongqing University,
Chongqing 400044, China

Q. Jane Wang

Department of Mechanical Engineering,
Northwestern University,
Evanston, IL 60208;
State Key Laboratory of Mechanical Transmissions,
Chongqing University,
Chongqing 400044, China

1Corresponding author.

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received April 7, 2016; final manuscript received June 26, 2016; published online August 24, 2016. Assoc. Editor: Xiaolan Ai.

J. Tribol 139(2), 021505 (Aug 24, 2016) (13 pages) Paper No: TRIB-16-1117; doi: 10.1115/1.4034051 History: Received April 07, 2016; Revised June 26, 2016

The Stribeck curve is an important means to demonstrate the frictional behavior of a lubricated interface during the entire transition from boundary and mixed to full-film lubrication. In the present study, a new test apparatus has been built that can operate under rolling–sliding conditions at a continuously variable speed in an extremely wide range, approximately from 0.00006 to 60 m/s, covering six orders of magnitude. Hence, a complete Stribeck curve can be measured to reveal its basic characteristics for lubricated counterformal contacts. The measured curves are compared with numerical simulation results obtained from an available unified mixed elastohydrodynamic lubrication (EHL) model that is also capable of handling cases during the entire transition. A modified empirical model for the limiting shear stress of lubricant is obtained, and a good agreement between the measured and calculated Stribeck curves is achieved for the tested base oils in all the three lubrication regimes, which thus well validates the simulation methods employed. Both the experimental and numerical results indicate that the Stribeck curves for counterformal contact interfaces behave differently from those for conformal contacts. When the rolling speed increases at a fixed slide-to-roll ratio, the friction continuously decreases even in the full-film lubrication regime due to the reduction of the lubricant limiting shear stress caused mainly by the rise of the surface flash temperature. In addition, the test results indicate that the boundary additives in a commodity lubricant may have considerable influence on the boundary lubrication friction but that on the friction in the mixed and full-film lubrication appears to be limited.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Stribeck, R. , 1902, “ Die Wesentlichen Eigenschaften der Gleit und Rollenlager, Part 1,” Z. Ver. Dtsch. Ing., 46(37), pp. 1341–1348.
Stribeck, R. , 1902, “ Die Wesentlichen Eigenschaften der Gleit und Rollenlager, Part 2,” Z. Ver. Dtsch. Ing., 46(38), pp. 1432–1438.
Stribeck, R. , 1902, “ Die Wesentlichen Eigenschaften der Gleit und Rollenlager, Part 3,” Z. Ver. Dtsch. Ing., 46(39), pp. 1463–1470.
Hersey, M. D. , 1914, “ The Laws of Lubrication of Horizontal Journal Bearings,” J. Wash. Acad. Sci., 4, pp. 542–552.
Luengo, G. , Israelachvili, J. , and Granick, S. , 2002, “ Generalized Effects in Confined Fluids: New Friction Map for Boundary Lubrication,” Wear, 200(1–2)., pp. 328–335.
Wang, Y. S. , Wang, Q. , Lin, C. , and Shi, F. H. , 2006, “ Development of a Set of Stribeck Curves for Conformal Contacts of Rough Surfaces,” Tribol. Trans., 49(4), pp. 526–535. [CrossRef]
Crook, A. W. , 1963, “ The Lubrication of Rollers—IV. Measurements of Friction and Effective Viscosity,” Philos. Trans. R. Soc., London A, 255(1056), pp. 281–312. [CrossRef]
Plint, M. A. , 1967–1968, “ Traction in Elastohydrodynamic Contacts,” Proc. Inst. Mech. Eng., 182(1967), pp. 300–306. [CrossRef]
Johnson, K. L. , and Cameron, R. , 1967–1968, “ Shear Behavior of Elastohydrodynamic Oil Films at High Rolling Contact Pressures,” Proc. Inst. Mech. Eng., 182(1967), pp. 307–319. [CrossRef]
Johnson, K. L. , and Tevaarwerk, J. L. , 1977, “ Shear Behavior of EHD Oil Films,” Proc. R. Soc. London, Ser. A, 356(1685), pp. 215–236. [CrossRef]
Bair, S. , and Winer, W. O. , 1978, “ Rheological Response of Lubricants in EHD Contacts,” 5th Leeds-Lyon Symposium on Tribology, pp. 162–169.
Zhu, D. , 2013, “ Elastohydrodynamic Lubrication (EHL),” Encyclopedia of Tribology, Q. J. Wang and Y. W. Chung , eds., Springer Science+Business Media, New York, pp. 874–889.
Lu, X. B. , Khonsari, M. M. , and Gelinck, E. R. M. , 2006, “ The Stribeck Curve: Experimental Results and Theoretical Prediction,” ASME J. Tribol., 128(4), pp. 789–794. [CrossRef]
de Kraker, A. , van Ostayen, R. A. J. , and Rixen, D. J. , 2007, “ Calculation of Stribeck Curves for (Water) Lubricated Journal Bearings,” Tribol. Int., 40(3), pp. 459–469. [CrossRef]
Guangteng, G. , and Spikes, H. A. , 1997, “ The Control of Friction by Molecular Fractionation of Base Fluid Mixtures at Metal Surfaces,” Tribol. Trans., 40(3), pp. 461–469. [CrossRef]
Zhu, D. , and Wang, Q. , 2012, “ On the λ Ratio Range of Mixed Lubrication,” Proc. Inst. Mech. Eng., Part J, 226(12), pp. 1010–1022. [CrossRef]
Gelinck, E. R. M. , and Schipper, D. J. , 2000, “ Calculation of Stribeck Curves for Line Contacts,” Tribol. Int., 33(3–4), pp. 175–181. [CrossRef]
Faraon, I. C. , and Schipper, D. J. , 2007, “ Stribeck Curves for Starved Line Contacts,” ASME J. Tribol., 129(1), pp. 181–187. [CrossRef]
Redlich, A. C. , Bartel, B. , and Deters, L. , 2003, “ Calculation of EHL Contacts in Mixed Lubrication Regime,” Tribol. Ser., 41, pp. 537–547.
Greenwood, J. A. , and Williamson, J. B. P. , 1966, “ Contact of Nominally Flat Surfaces,” Philos. Trans. R. Soc. London, Ser. A, 295(1442), pp. 300–319. [CrossRef]
Moes, H. , 1992, “ Optimum Similarity Analysis With Applications to Elastohydrodynamic Lubrication,” Wear, 159(1), pp. 57–66. [CrossRef]
Masjedi, M. , and Khonsari, M. M. , 2014, “ Theoretical and Experimental Investigation of Traction Coefficient in Line-Contact EHL of Rough Surfaces,” Tribol. Int., 70, pp. 179–189. [CrossRef]
Chang, L. M. , and Jeng, Y. R. , 2014, “ A Mathematical Model for the Mixed Lubrication of Non-Conformable Contacts With Asperity Friction, Plastic Deformation, Flash Temperature, and Tribo-Chemistry,” ASME J. Tribol., 136(2), p. 022301. [CrossRef]
Björling, M. , Habchi, W. , Bair, S. , Larsson, R. , and Marklund, P. , 2013, “ Towards the True Prediction of EHL Friction,” Tribol. Int., 66, pp. 19–26. [CrossRef]
Wang, Q. , Zhu, D. , Yu, T. , Cheng, H. S. , Jiang, J. , and Liu, S. , 2004, “ Mixed Lubrication Analyses by a Micro-Macro Approach and a Full-Scale Micro EHL Model,” ASME J. Tribol., 126(1), pp. 81–91. [CrossRef]
Zhu, D. , and Hu, Y. Z. , 1999, “ The Study of Transition From Full Film Elastohydrodynamic to Mixed and Boundary Lubrication,” The Advanced Frontier of Engineering Tribology, Proceedings of the 199 STLE/ASME H.S. Cheng Tribology Surveillance, pp. 150–156.
Hu, Y. Z. , and Zhu, D. , 2000, “ A Full Numerical Solution to the Mixed Lubrication in Point Contacts,” ASME J. Tribol., 122(1), pp. 1–9. [CrossRef]
Ai, X. , 1993, “ Numerical Analyses of Elastohydrodynamically Lubricated Line and Point Contacts With Rough Surfaces by Using Semi-System and Multigrid Methods,” Ph.D. dissertation, Northwestern University, Evanston, IL.
Wang, W. Z. , Wang, H. , Liu, Y. C. , Hu, Y. Z. , and Zhu, D. , 2003, “ A Comparative Study of the Methods for Calculation of Surface Elastic Deformation,” Proc. Inst. Mech. Eng., Part J, 217(2), pp. 145–153. [CrossRef]
Liu, Y. C. , Wang, Q. , Wang, W. , Hu, Y. , and Zhu, D. , 2006, “ Effects of Differential Scheme and Mesh Density on EHL Film Thickness in Point Contacts,” ASME J. Tribol., 128(3), pp. 641–653. [CrossRef]
Zhu, D. , 2007, “ On Some Aspects in Numerical Solution of Thin-Film and Mixed EHL,” Proc. Inst. Mech. Eng., Part J, 221(5), pp. 561–579. [CrossRef]
Wang, W. Z. , Wang, S. , Shi, F. H. , Wang, Y. C. , Chen, H. B. , Wang, H. , and Hu, Y. Z. , 2007, “ Simulations and Measurements of Sliding Friction Between Rough Surfaces in Point Contacts: From EHL to Boundary Lubrication,” ASME J. Tribol., 129(3), pp. 495–501. [CrossRef]
Liu, Y. C. , Wang, Q. , Zhu, D. , Wang, W. , and Hu, Y. , 2009, “ Effects of Differential Scheme and Viscosity Model on Rough-Surface Point-Contact Isothermal EHL,” ASME J. Tribol., 131(4), p. 044501. [CrossRef]
Wang, W. Z. , Hu, Y. Z. , Liu, Y. C. , and Zhu, D. , 2010, “ Solution Agreement Between Dry Contacts and Lubrication System at Ultra-Low Speed,” Proc. Inst. Mech. Eng., Part J, 224(10), pp. 1049–1060. [CrossRef]
Zhu, D. , and Wang, Q. , 2011, “ Elastohydrodynamic Lubrication (EHL): A Gateway to Interfacial Mechanics―Review and Prospect,” ASME J. Tribol., 133(4), p. 041001. [CrossRef]
Zhu, D. , and Wang, Q. , 2013, “ Effect of Roughness Orientation on the Elastohydrodynamic Lubrication Film Thickness,” ASME J. Tribol., 135(3), p. 031501. [CrossRef]
Zhu, D. , Wang, J. X. , and Wang, Q. , 2015, “ On the Stribeck Curves for Lubricated Counterformal Contacts of Rough Surfaces,” ASME J. Tribol., 137(2), p. 021501. [CrossRef]
Martini, A. , Zhu, D. , and Wang, Q. , 2007, “ Friction Reduction in Mixed Lubrication,” Tribol. Lett., 28(2), pp. 139–147. [CrossRef]
Zhu, D. , and Hu, Y. Z. , 2001, “ A Computer Program Package for the Prediction of EHL and Mixed Lubrication Characteristics, Friction, Subsurface Stresses and Flash Temperatures Based on Measured 3D Surface Roughness,” Tribol. Trans., 44(3), pp. 383–390. [CrossRef]
Zhu, D. , and Cheng, H. S. , 1989, “ An Analysis and Computational Procedure for EHL Film Thickness, Friction and Flash Temperature in Line and Point Contacts,” Tribol. Trans., 32(3), pp. 364–370. [CrossRef]
Dyson, A. , 1970, “ Frictional Traction and Lubricant Rheology in Elastohydrodynamic Lubrication,” Philos. Trans. R. Soc. London, A, 266(1170), pp. 1–33. [CrossRef]
Houpert, L. , Flamand, L. , and Berthe, D. , 1981, “ Rheological and Thermal Effects in Lubricated E.H.D. Contacts,” ASME J. Lubr. Technol., 103(4), pp. 526–532.
Hsiao, H.-S. S. , and Hamrock, B. J. , 1992, “ A Complete Solution for Thermal-Elastohydrodynamic Lubrication of Line Contacts Using Circular Non-Newtonian Fluid Model,” ASME J. Tribol., 114(3), pp. 540–551. [CrossRef]
Liu, Y. C. , Wang, H. , Wang, W. Z. , Hu, Y. Z. , and Zhu, D. , 2002, “ Method Comparison in Computation of Temperature Rise on Frictional Interface,” Tribol. Int., 35(8), pp. 549–560. [CrossRef]
Trachman, E. G. , and Cheng, H. S. , 1973, “ Rheological Effects on Friction in Elastohydrodynamic Lubrication,” NASA Technical Report No. CR-2206.
Liu, S. B. , Wang, Q. , and Liu, G. , 2000, “ A Versatile Method of Discrete Convolution and FFT (DC-FFT) for Contact Analyses,” Wear, 243(1–2), pp. 101–111. [CrossRef]
Pu, W. , Wang, J. X. , and Zhu, D. , 2016, “ Progressive Mesh Densification (PMD) Method for Numerical Solution of Mixed Elastohydrodynamic Lubrication,” ASME J. Tribol., 138(2), p. 021502. [CrossRef]
Zhu, D. , Liu, Y. , and Wang, Q. , 2014, “ On the Numerical Accuracy of Rough Surface EHL Solution,” Tribol. Trans., 57(4), pp. 570–580. [CrossRef]
Bair, S. , and Winer, W. O. , 1992, “ The High Pressure High Shear Stress Rheology of Liquid Lubricants,” ASME J. Tribol., 114(1), pp. 1–9. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Schematic of the Stribeck curve for journal bearings (from Ref. [6])

Grahic Jump Location
Fig. 2

Measured friction in a lubricated circular contact

Grahic Jump Location
Fig. 3

Rolling–sliding test apparatus constructed

Grahic Jump Location
Fig. 4

A sample of measured Stribeck curve: (a) friction versus rolling speed and (b) friction versus calculated λ ratio

Grahic Jump Location
Fig. 5

Comparison between measured and calculated Stribeck curves at different loads for 4503(32) base oil G* = 5031, W* = 0.1217 × 10−5–0.8521 × 10−5, U* = 0.6470 × 10−15–0.2265 × 10−9: (a) friction versus rolling speed and (b) friction versus calculated λ ratio

Grahic Jump Location
Fig. 6

Comparison between measured and calculated Stribeck curves at different loads for 75 W/90 base oil G*= 5009, W*= 0.1217 × 10−5–0.8521 × 10−5, and U*= 0.1436 × 10−14–0.5025 × 10−9

Grahic Jump Location
Fig. 7

Sample numerical solutions of film thickness, pressure, and flash temperature rise on surface 1 lubricant: base oil of MTF 75 W/90, load: 500 N

Grahic Jump Location
Fig. 8

Comparison between commodity 4503(32) and its base oil

Grahic Jump Location
Fig. 9

Comparison between commodity 75 W/90 and its base oil

Grahic Jump Location
Fig. 10

Stribeck curves for commodity gear oil Mobil 600 XP 68—kinematic viscosities: 67.9 cSt at 40 °C and 8.8 cS at 100 °C; density: 0.88 g/cm3 at 15.6 °C

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In