Numerical solution of the adhesive rubber-solid contact problem and friction coefficients using a scale-splitting approach.

We present a comprehensive investigation of the adhesive rubber-solid contact problem by analytical and numerical methods. Theories of rubber friction are reviewed and a new contact theory is developed. The adhesive contact problem is solved using the boundary element method. The introduction of adhesion leads to full coverage below a certain length scale. Friction coefficients are calculated from the spectral density of the rubber surface by splitting the numerical problem into two length scales. Adhesion is shown to increase friction at low velocities. The influence of filler is modeled by assuming that their size corresponds to a linear cross-over dimension separating the bulk elastomer from the composite. Finally, we discuss open problems and describe a simplified picture of rubber friction. • Adhesion increases low-velocity friction by increasing low-wavelength deformation amplitude. • Rubber has to be viewed as composite material at length scales relevant for friction. • Rubber's contour generally has a higher Hurst exponent than the substrate. • (Adhesion-induced) elastic instabilities probably determine friction at lowest velocities. [ABSTRACT FROM AUTHOR]