Quantitative prediction of effective toughness at random heterogeneous interfaces

TL;DR

This paper investigates how the effective toughness of heterogeneous interfaces influences crack propagation, revealing a transition from weak to strong pinning and providing a self-consistent model for toughness prediction.

Contribution

It introduces a systematic approach to predict effective toughness at heterogeneous interfaces, capturing the transition between weak and strong pinning regimes without free parameters.

Findings

Weak pinning corresponds to mean local toughness.

Strong pinning enhances effective toughness.

Self-consistent approximation accurately predicts toughness evolution.

Abstract

The propagation of an adhesive crack through an anisotropic heterogeneous interface is considered. Tuning the local toughness distribution function and spatial correlation is numerically shown to induce a transition between weak to strong pinning conditions. While the macroscopic effective toughness is given by the mean local toughness in case of weak pinning, a systematic toughness enhancement is observed for strong pinning (the critical point of the depinning transition). A self-consistent approximation is shown to account very accurately for this evolution, without any free parameter.