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A numerical study on roughness-induced adhesion enhancement in a sphere with an axisymmetric sinusoidal waviness using Lennard-Jones interaction law
Citation Link: https://doi.org/10.15480/882.2951
Publikationstyp
Journal Article
Date Issued
2020-09-04
Sprache
English
Author(s)
Papangelo, Antonio
Institut
TORE-DOI
TORE-URI
Journal
Volume
8
Issue
9
Article Number
90
Citation
Lubricants 8 (9): 90 (2020)
Publisher DOI
Scopus ID
Publisher
Multidisciplinary Digital Publishing Institute
Usually, roughness destroys adhesion and this is one of the reasons why the “adhesion paradox”, i.e., a “sticky Universe”, is not real. However, at least with some special type of roughness, there is even the case of adhesion enhancement, as it was shown clearly by Guduru, who considered the contact between a sphere and a wavy axisymmetric single scale roughness, in the limit of short-range adhesion (JKR limit). Here, the Guduru’s problem is numerically solved by using the Boundary Element Method (BEM) with Lennard-Jones interaction law, which allowed us to explore the contact solution from the rigid to the JKR limit. It is shown that adhesion enhancement stops either for low Tabor parameter, or by large waviness amplitudes, due to the appearance of internal cracks within the contact patch. We do not seem to find a clear threshold for “stickiness” (complete elimination of adhesion), contrary to other recent theories on random roughness. The enhancement effect is well captured by an equation in terms of the Johnson parameter derived by Ciavarella-Kesari-Lew, and is much larger than the Persson-Tosatti enhancement in terms of increase of real contact area due to roughness. The Persson-Tosatti energetic argument for adhesion reduction seems to give a lower bound to the effective work of adhesion.
Subjects
adhesion
roughness
adhesion enhancement
JKR model
Lennard-Jones
DDC Class
600: Technik
620: Ingenieurwissenschaften
More Funding Information
Deutsche Forschungsgemeinschaft (DFG)
Italian Ministry of Education, University and Research under the Programme Department of Excellence
Publication version
publishedVersion
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