Rectification of stress by fiber networks: Manifestation of non-linear screening through self-organized buckling

TL;DR

This paper investigates how non-linear fiber networks transmit forces over large distances, revealing that organized buckling patterns lead to mechanical screening effects similar to electrostatic phenomena.

Contribution

It introduces a simple non-linear fiber network model demonstrating diverse mechanical phases and the emergence of organized buckling patterns that cause large-scale screening effects.

Findings

Network remodeling by buckling patterns alters mechanical response.

Large-scale behavior is explained by force dipole screening.

Poisson ratio is renormalized through buckling-induced patterns.

Abstract

Force transmission at large length scales is crucial for such biological functions as cell motility and morphogenesis. The networks that transmit these forces are malleable, patterned by active forces generated at the microscale by biological motors. In this paper we explore a simple model of a non-linear fiber network which has only two modes of deformation, but exhibits diverse mechanical phases with distinct large-scale response, tuned by the strength of a microscopic force dipole. We demonstrate, via numerical simulations, that the network is remodeled by organized patterns of buckling, which lead to a renormalization of the Poisson ratio. Finally, we show that the emergent behavior at large length scales can be ascribed to "mechanical screening" of the force dipole, analogous to dielectric screening of charges in electrostatics.