Research Papers: Elastohydrodynamic Lubrication

Algebraic Equations for the Pile-Up Geometry in Debris Particle Indentation of Rolling Elastohydrodynamic Contacts

[+] Author and Article Information
George K. Nikas

Kadmos Engineering Ltd.,
3 Princes Mews,
Hounslow TW3 3RF, UK
e-mail: gnikas@teemail.gr

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received June 9, 2015; final manuscript received August 21, 2015; published online October 27, 2015. Assoc. Editor: Sinan Muftu.

J. Tribol 138(2), 021503 (Oct 27, 2015) (14 pages) Paper No: TRIB-15-1191; doi: 10.1115/1.4031516 History: Received June 09, 2015; Revised August 21, 2015

Metallic microparticles of 5–100 μm in size often contaminate elastohydrodynamic (EHD) contacts and indent surfaces. The geometrical characteristics of dents by such solid particles are linked to the way surface damage may evolve and how it may affect the life of the damaged contacts. In many cases, debris dents appear with shoulders raised above the original surface. Material piling-up this way causes high-pressure spikes when dents are over-rolled by an element such as a ball in a rolling bearing. This study introduces an approximate analytical method based on the so-called expanding cavity model (ECM) to calculate pile-up geometry with simple algebraic equations in thermoviscoplastic indentation of rolling EHD contacts by ductile spherical microparticles. Based on an experimentally validated debris indentation model published by the author, the pile-up model is shown to give realistic predictions in a wide range of operating parameters. Upon experimental validation, the new model is used to study the effects of particle size and hardness, Coulomb friction coefficient (CFC), strain hardening, and rolling velocity of EHD contacts on pile-up geometrical parameters including length, height, volume, and curvature.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

Pile-up geometry (not to scale) and notation

Grahic Jump Location
Fig. 2

Experimental validation. Input data in column “validation” of Table 1.

Grahic Jump Location
Fig. 3

Effect of particle size

Grahic Jump Location
Fig. 4

Effect of particle hardness

Grahic Jump Location
Fig. 5

Effect of friction coefficient

Grahic Jump Location
Fig. 6

Effect of rolling velocity

Grahic Jump Location
Fig. 7

Effect of strain-hardening exponent




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.

Related Journal Articles
Related eBook Content
Topic Collections

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