Viscoelastic Fracture of Biological Composites

TL;DR

This paper investigates the viscoelastic fracture properties of biological composites like bone and nacre, analyzing their energy release and fracture energy scaling through theoretical models considering anisotropic structures.

Contribution

It introduces a comprehensive analysis of viscoelastic fracture in biological composites using both perturbative and non-perturbative methods for various anisotropic structures.

Findings

Identifies dominant lengthscales in viscoelastic fracture

Derives scaling laws for energy release rate

Discusses implications of anisotropy on fracture criteria

Abstract

Soft constituent materials endow biological composites, such as bone, dentin and nacre, with viscoelastic properties that may play an important role in their remarkable fracture resistance. In this paper we calculate the scaling properties of the quasi-static energy release rate and the viscoelastic contribution to the fracture energy of various biological composites, using both perturbative and non-perturbative approaches. We consider coarse-grained descriptions of three types of anisotropic structures: (i) Liquid-crystal-like composites (ii) Stratified composites (iii) Staggered composites, for different crack orientations. In addition, we briefly discuss the implications of anisotropy for fracture criteria. Our analysis highlights the dominant lengthscales and scaling properties of viscoelastic fracture of biological composites. It may be useful for evaluating crack velocity toughening effects and structure-dissipation relations in these materials.