Phase-Field Modelling of Interface Failure in Brittle Materials

TL;DR

This paper introduces a phase-field model for interface failure in dissimilar brittle materials, addressing regularisation effects and proposing a correction to improve the reliability of crack propagation predictions.

Contribution

It develops a novel phase-field approach with a correction for interface failure, accounting for regularisation effects and interaction between crack and interface length scales.

Findings

The correction improves accuracy in 1D and multi-dimensional analyses.

Validated on three benchmark problems.

Enhances reliability of phase-field models for heterogeneous materials.

Abstract

A phase-field approach is proposed for interface failure between two possibly dissimilar materials. The discrete adhesive interface is regularised over a finite width. Due to the use of a regularised crack model for the bulk material, an interaction between the length scales of the crack and the interface can occur. An analytic one-dimensional analysis has been carried out to quantify this effect and a correction is proposed, which compensates influences due to the regularisation in the bulk material. For multi-dimensional analyses this approach cannot be used straightforwardly, as is shown, and a study has been undertaken to numerically quantify the compensation factor due to the interaction. The aim is to obtain reliable and universally applicable results for crack propagation along interfaces between dissimilar materials, such that they are independent from the regularisation width of the interface. The method has been tested and validated on three benchmark problems. The compensation is particularly relevant for phase-field analyses in heterogeneous materials, where cohesive failure in the constituent materials as well as adhesive failure at interfaces play a role.