Prediction of the friction coefficient of filled rubber sliding on dry and wet surfaces with self-affine large roughness

Abstract

The friction of filled rubber on a rough surface is mainly determined by the rubber viscoelasticity and the surface property of multiple-scale asperities that can be represented by the power spectral density of the surface profile (i.e., power spectrum of surface roughness). This paper investigates a prediction model of rubber friction on dry and wet surfaces with large roughness under lightly squeezing, and finds a high stationary friction coefficient that depends on sliding speed. To this end, we demonstrated friction testing at low velocities with carbon-black-filled rubber and a hard substrate having self-affine surface roughness. From the experiment results, we estimated the hysteresis friction coefficient related to energy dissipation resulting from cyclic deformations of the viscoelastic rubber by applying the theory developed by Persson [(J. Chem. Phys. 115, 3840 (2001)]. We discussed the additional factor, an adhesion force, which also increases the friction coefficient. We concluded that the hysteresis loss of rubber viscoelastic deformation contributes most of the friction force, accounting for the nonlinear viscoelastic behavior of filled rubber, and that the operative surface wavelength extends to the order of micrometers.

Orthotropic Laminated Open-cell Frameworks Retaining Strong Auxeticity under Large Uniaxial Loading

“…For example, some structural units can be transformed into structures having surface asperities and asymmetric structures such as airfoil-like geometries, including the structural union of these geometries of different sizes. Such deformability gives the structural materials unique functionality across multiple length-scales, such as enhanced frictional resistance due to an increase in real contact area5556 and improved lifting performance with reduced drag effects575859.…”

Evaluation of Vehicle Braking Performance on Wet Pavement Surface using an Integrated Tire-Vehicle Modeling Approach

“…The friction coefficients of a wet pavement usually decline 20–30% compared with the coefficients of a dry pavement at a very low speed. From Persson’s theory, this is mainly proposed to be owed to the “the sealing effect” of water film which inhibits the contact between the tire rubber and the concave asperities of the pavement surface (Figure 2) ( 28 ), which was corroborated in later tests ( 29 ).…”

“…All asphalt mixture specimens were fabricated into slabs with a size of 450 × 400 × 50 mm using a wheel-roller compaction machine. To generate a wet pavement surface, water was sprayed onto the dry surface uniformly until the concave asperities were sealed with water ( 29 ). Digital stereo-photographic systems cannot easily capture the saturated surface because water is translucent.…”

Scaling theory of rubber sliding friction

“…About 20 years ago a number of groups began to develop rather sophisticated models for rubber friction 11 – 14 . A particular element of these theories is the description of surface roughness using the concept of self-similarity and scale invariance, which subsequently has also been pursued by others 15 – 17 . Especially the theory of Persson 13 , 14 et al underwent substantial extensions over the past 20 years.…”