Predicting Fracture Energies and Crack-Tip Fields of Soft Tough Materials

TL;DR

This paper introduces a scaling theory and a coupled model to predict fracture energies and crack-tip fields in soft tough materials, validated by experiments and guiding material design.

Contribution

It presents a new combined theoretical and computational approach to predict fracture behavior in soft materials, integrating dissipation effects.

Findings

The model accurately predicts fracture energies under large deformation.

Experimental validation confirms the model's quantitative predictions.

A general toughening diagram aids in designing new soft tough materials.

Abstract

Soft materials including elastomers and gels are pervasive in biological systems and technological applications. Whereas it is known that intrinsic fracture energies of soft materials are relatively low, how the intrinsic fracture energy cooperates with mechanical dissipation in process zone to give high fracture toughness of soft materials is not well understood. In addition, it is still challenging to predict fracture energies and crack-tip strain fields of soft tough materials. Here, we report a scaling theory that accounts for synergistic effects of intrinsic fracture energies and dissipation on the toughening of soft materials. We then develop a coupled cohesive-zone and Mullins-effect model capable of quantitatively predicting fracture energies of soft tough materials and strain fields around crack tips in soft materials under large deformation. The theory and model are quantitatively validated by experiments on fracture of soft tough materials under large deformations. We further provide a general toughening diagram that can guide the design of new soft tough materials.