Aging of the frictional properties induced by temperature variations

TL;DR

This paper investigates how small temperature variations can cause significant aging effects in static friction, challenging traditional explanations based solely on material creep or water condensation.

Contribution

It introduces a toy-model demonstrating that temperature fluctuations alone can induce notable increases in static friction over time.

Findings

Temperature variations can significantly increase static friction.

Friction aging can occur without material creep or water bridges.

Toy-model effectively captures temperature-induced friction changes.

Abstract

The dry frictional contact between two solid surfaces is well-known to obey Coulomb friction laws. In particular, the static friction force resisting the relative lateral (tangential) motion of solid surfaces, initially at rest, is known to be proportional to the normal force and independent of the area of the macroscopic surfaces in contact. Experimentally, the static friction force has been observed to slightly depend on time. Such an aging phenomenon has been accounted for either by the creep of the material or by the condensation of water bridges at the microscopic contacts points. Studying a toy-model, we show that the small uncontrolled temperature changes of the system can also lead to a significant increase of the static friction force.