Rubber friction: role of the flash temperature

TL;DR

This paper investigates how local flash temperature increases during rubber sliding on rough surfaces affect friction, revealing that temperature rise reduces friction at higher velocities and influences stability in practical applications like tires.

Contribution

It introduces a model that incorporates local temperature effects into rubber friction analysis, highlighting the significance of flash temperature in dynamic friction behavior.

Findings

Local heating reduces rubber friction at velocities above 0.01 m/s.

Temperature increase can cause stick-slip instabilities.

Implications for tire-road friction and ABS braking systems.

Abstract

When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. Most surfaces of solids have roughness on many different length scales, and when calculating the friction force it is necessary to include the viscoelastic deformations on all length scales. The energy dissipation will result in local heating of the rubber. Since the viscoelastic properties of rubber-like materials are extremely strongly temperature dependent, it is necessary to include the local temperature increase in the analysis. At very low sliding velocity the temperature increase is negligible because of heat diffusion, but already for velocities of order 0.01 m/s the local heating may be very important. Here I study the influence of the local heating on the rubber friction, and I show that in a typical case the temperature increase results in a decrease in rubber friction with increasing sliding velocity for v > 0.01 m/s. This may result in stick-slip instabilities, and is of crucial importance in many practical applications, e.g., for the tire-road friction, and in particular for ABS-breaking systems.