title: Static and dynamic friction of hierarchical surfaces.
abstract: Hierarchical structures are very common in nature, but only recently have they been systematically studied in materials science, 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 true also 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 one-dimensional 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.
authors.affiliation: Department of Physics and Nanostructured Interfaces and Surfaces inter-departmental Center, University of Torino, Via Pietro Giuria 1, 10125, Torino, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Costagliola
authors.affiliation: Department of Physics and Nanostructured Interfaces and Surfaces inter-departmental Center, University of Torino, Via Pietro Giuria 1, 10125, Torino, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Bosia
authors.affiliation: Laboratory of Bio-Inspired & Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.|Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Povo, Trento, Italy.|School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
authors.forename: Nicola M
authors.initials: NM
authors.lastname: Pugno