Nonmonotonic Aging and Memory in a Frictional Interface

TL;DR

This paper demonstrates that a frictional interface exhibits glassy dynamics, including nonmonotonic aging and memory effects, influenced by microcontact geometry, supported by experimental measurements and a theoretical model.

Contribution

It introduces a theoretical model incorporating interface geometry to explain glassy behavior in frictional systems, supported by experimental evidence.

Findings

Frictional interfaces show nonmonotonic aging after load changes.

Memory effects are observed in the frictional resistance.

Theoretical model aligns with experimental results.

Abstract

We measure the static frictional resistance and the real area of contact between two solid blocks subjected to a normal load. We show that following a two-step change in the normal load the system exhibits nonmonotonic aging and memory effects, two hallmarks of glassy dynamics. These dynamics are strongly influenced by the discrete geometry of the frictional interface, characterized by the attachment and detachment of unique microcontacts. The results are in good agreement with a theoretical model we propose that incorporates this geometry into the framework recently used to describe Kovacs-like relaxation in glasses as well as thermal disordered systems. These results indicate that a frictional interface is a glassy system and strengthen the notion that nonmonotonic relaxation behavior is generic in such systems.