Criticality and mechanical enhancement in composite fibre networks

TL;DR

This study uses lattice simulations to explore how the interplay of fibre mechanics and matrix elasticity in biological-like composite networks leads to critical phase transitions and enhanced mechanical properties.

Contribution

It uncovers the microscopic mechanisms and phase transitions responsible for mechanical synergy in composite fibre networks, highlighting the roles of fibre deformation modes and matrix interactions.

Findings

Identification of distinct mechanical regimes and phase transitions.

Critical behaviour characterized by diverging strain fluctuations.

Mechanisms of mechanical enhancement linked to fibre and matrix interactions.

Abstract

Many biological materials consist of sparse networks of disordered fibres, embedded in a soft elastic matrix. The interplay between rigid and soft elements in such composite networks leads to mechanical properties that can go far beyond the sum of those of the constituents. Here we present lattice-based simulations to unravel the microscopic origins of this mechanical synergy. We show that the competition between fibre stretching and bending and elastic deformations of the matrix gives rise to distinct mechanical regimes, with phase transitions between them that are characterized by critical behaviour and diverging strain fluctuations and with different mechanisms leading to mechanical enhancement.