Subcritical crack growth in fibrous materials

TL;DR

This study investigates subcritical crack growth in fibrous paper materials, demonstrating a thermally activated rupture model that accurately predicts crack growth behavior based on microstructure and external conditions.

Contribution

The paper introduces a new model linking microstructure to crack growth in fibrous materials, validated by experiments on fax paper under various conditions.

Findings

Crack growth curves characterized by mean rupture time and growth length

Model reproduces shape and parameter dependence of growth curves

Rupture length scale aligns with cellulose microfibril diameter

Abstract

We present experiments on the slow growth of a single crack in a fax paper sheet submitted to a constant force $F$. We find that statistically averaged crack growth curves can be described by only two parameters : the mean rupture time $\tau$ and a characteristic growth length $\zeta$. We propose a model based on a thermally activated rupture process that takes into account the microstructure of cellulose fibers. The model is able to reproduce the shape of the growth curve, the dependence of $\zeta$ on $F$ as well as the effect of temperature on the rupture time $\tau$. We find that the length scale at which rupture occurs in this model is consistently close to the diameter of cellulose microfibrils.