Effect of roughness on the adhesive tractions between contacting bodies. (September 2018)

• Record Type: Journal Article
• Authors: Joe, Junki; Thouless, M.D.; Barber, J.R.
• Is Part Of: Journal of the mechanics and physics of solids. Volume 118(2018)
• Page Start: 365
• Page End: 373
• Publication Date: 2018-09
• Subjects: Contact mechanics -- Surface roughness -- Adhesion; Mechanics, Applied -- Periodicals; Solids -- Periodicals; Mechanics -- Periodicals; Mécanique appliquée -- Périodiques; Solides -- Périodiques; Mechanics, Applied; Solids; Periodicals; 531.05
• DOI: 10.1016/j.jmps.2018.06.005
• Languages: English
• ISSNs: 0022-5096

Abstract

Highlights: The paper presents an efficient procedure for predicting the effect of broad spectrum surface roughness on the effective adhesive traction law. Results agree well with the averages of direct numerical simulations for the relatively narrower spectra over which such simulations are computationally practicable. Near the unstable range, a greater reduction in adhesive effects is predicted and this behaviour has been confirmed for relatively narrow spectra using numerical simulations. At large wavenumbers [short wavelengths], the effect of roughness on adhesion is well-characterized by the height variance m 0 but at lower wavenumbers elastic effects become more important and incremental contributions to m 0 have less effect, except near the unstable range. Abstract: A method is proposed for estimating the effect of broad spectrum surface roughness on the adhesion between elastic bodies. At each length scale, the effect of fine scale roughness is modelled by a modified traction law whilst an added coarse scale increment is described by a probability distribution of mean gap as modified by elastic deformation. Instabilities occur for relatively smooth surfaces whose linear dimensions are sufficiently large to support long wavelength perturbations. The method is validated by comparison with direct numerical calculations, in the range where this is practicable. It is then applied to power-law spectra with various values of height variance and lower wavenumber cutoff. The results show that the effect of roughness is dominated by the height variance m 0, but at lower wavenumber elastic deformation reduces the dependence on m 0, except near the unstable range.