Load-separation curves for the contact of self-affine rough surfaces

Abstract There are two main approximate theories in the contact of rough solids: Greenwood-Williamson asperity theories (GW) and Persson theories. Neither of them has been fully assessed so far with respect to load-separation curves. Focusing on the most important case of low fractal dimension (D f...

Full description

Saved in:
Bibliographic Details
Main Authors: Antonio Papangelo, Norbert Hoffmann, Michele Ciavarella
Format: article
Language:EN
Published: Nature Portfolio 2017
Subjects:
R
Q
Online Access:https://doaj.org/article/48e3a91f64a1484ba287109e1913421c
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract There are two main approximate theories in the contact of rough solids: Greenwood-Williamson asperity theories (GW) and Persson theories. Neither of them has been fully assessed so far with respect to load-separation curves. Focusing on the most important case of low fractal dimension (D f  = 2.2) with extensive numerical studies we find that: (i) Persson’s theory describes well the regime of intermediate pressures/contact area, but requires significant corrective factors: the latter depend also on upper wavevector cutoff of the roughness; hence, (ii) Persson’s theory does not predict the correct functional dependence on magnification; (iii) asperity theories in the discrete version even neglecting interaction effects are more appropriate in the range of relatively large separations, also to take into consideration of the large scatter in actual realization of the surface.