Static and dynamic friction of hierarchical surfaces

TL;DR

This paper investigates how hierarchical surface patterns influence static and dynamic friction in elastic materials, using numerical simulations to reveal mechanisms for tuning frictional properties.

Contribution

It introduces a systematic study of hierarchical structures' effects on friction coefficients through a spring-block model, highlighting their potential for material property optimization.

Findings

Hierarchical structures can significantly alter static and dynamic friction coefficients.

Numerical simulations reveal mechanisms for friction tunability via hierarchy.

Results suggest potential for designing materials with tailored frictional properties.

Abstract

Hierarchical structures are very common in Nature, but only recently have they been systematically studied in materials physics, in order to understand the specific effects they can have on the mechanical properties of various systems. Structural hierarchy provides a way to tune and optimize macroscopic mechanical properties starting from simple base constituents, and new materials are nowadays designed exploiting this possibility. This can be also true in the field of tribology. In this paper, we study the effect of hierarchical patterned surfaces on the static and dynamic friction coefficients of an elastic material. Our results are obtained by means of numerical simulations using a 1-D spring-block model, which has previously been used to investigate various aspects of friction. Despite the simplicity of the model, we highlight some possible mechanisms that explain how hierarchical structures can significantly modify the friction coefficients of a material, providing a means to achieve tunability.