Nucleation and development of multiple cracks in thin composite fibers

TL;DR

This paper presents a simple one-dimensional model to predict the simultaneous nucleation and development of multiple cracks in thin composite fibers with an elastic core and brittle outer layer under tension.

Contribution

It introduces a coupled axial rod model with an interfacial condition to analyze crack patterns in composite fibers, providing a new predictive framework.

Findings

The model successfully predicts multiple crack nucleation.

It captures the influence of interfacial adhesion on crack development.

The approach offers insights into crack pattern formation in composites.

Abstract

We study the nucleation and development of crack patterns in thin composite fibers under tension in this work. A fiber comprises an elastic core and an outer layer of a weaker brittle material. In recent tensile experiments on such composites, multiple cracks were observed to develop simultaneously on the outer layer. We propose here a simple one-dimensional model to predict such phenomenon. We idealize the problem as two axially loaded rods coupled by a linear interfacial condition. The latter can be regarded as an adhesive that resists slip between the two materials. One rod is modeled as a brittle material, and the other a linearly elastic material, both undergoing finite deformations.