This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Modelling of the Asperity Contact Area on Actual 3D Surfaces
Technical Paper
2005-01-1864
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The Greenwood model has been extensively used for calculation of the asperity pressures under mixed lubrication conditions, but usually assuming that the surfaces are gaussian. In this work, the Greenwood parameters are calculated from actual, non-gaussian, engine surfaces measured by White Light Interferometer. Results from 2D profiles and 3D measurements are compared. An improved way to calculate the Greenwood parameters and to apply them for estimation of the contact area and pressure is described. To illustrate the methodology, some examples of topography characterization and modeling for engine liners are presented. The influence of the asperity summit height average on the predicted contact area calculation is discussed.
To explore and validate the proposed method, several WLI measurements from different engine HDD liners were analyzed using a proprietary code. For each surface, the bearing contact area against a flat plane was calculated for different surface separations, e.g. 0.5 to 3.0 micrometer. The values were then compared with those predicted by the Greenwood model using the calculated asperity summit distribution. With the corrections proposed the correlation was very good. The contact area, and the resultant asperity pressure, were significantly higher than the values usually predicted by commercial codes.
Recommended Content
Authors
Citation
Tomanik, E., "Modelling of the Asperity Contact Area on Actual 3D Surfaces," SAE Technical Paper 2005-01-1864, 2005, https://doi.org/10.4271/2005-01-1864.Also In
References
- McCool, J.I. “Comparison of models for the contact of rough surface” Wear 107 1986
- Zavarise, G. et al. “On the reliability of microscopical contact models” Wear 257 229 245 2004
- Greenwood, J.A. Williamson, J. “Contact of nominally flat surfaces” Proc. R. Soc. London, Series A 295 300 319 1966
- Greenwood, J.A. Tripp, J.H. “The Contact of Two Nominally Flat Rough Surfaces” Proc Inst Mech Engrs 1970-71 185 48 625 633 1970
- Thomas, T. Rosen, B-G “Determination of the Optimum Sampling Interval for Rough Contact Mechanics” Tribology International 33 2000 601 610 2000
- Robbe-Valloire, F. “Statistical analysis of asperities on a rough surface” Wear 249 2001 401 408 2001
- Tomanik, E. et al. “A simple numerical procedure to calculate the input data of Greenwood-Williamson model of asperity contact for actual engineering surfaces” Leeds-Lyon Symposium on Tribology: Tribological research and design for engineering systems TRIBOLOGY SERIES 41 205 216 2003
- Greenwood, J.A. “A Unified Theory of Surface Roughness” Proc. R. Soc. Lond. A 393 133 157 1984
- Tomanik, E. Ferrarese, A. “Use Of An Asperity-Contact Model To Simulate SI Engine's 3-Piece Oil Ring Profiles Regarding Wear And Lubrication” ASME Journal of Engineering for Gas Turbines and Power