Propagation Mechanism of Brittle Cracks

TL;DR

This paper uses a new model to study two-dimensional brittle crack propagation, revealing how voids influence crack roughening and branching instabilities, aligning with experimental observations.

Contribution

It introduces a model that simulates crack propagation with void formation and branching, providing insights into the underlying stress fields and crack dynamics.

Findings

Void formation causes crack path roughening.

Increased crack speed leads to branching instabilities.

Simulation results match experimental behaviors.

Abstract

We employ a recently developed model that allows the study of two-dimensional brittle crack propagation under fixed grip boundary conditions. The crack development highlights the importance of voids which appear ahead of the crack as observed in experiments on the nano-scale. The appearance of these voids is responsible for roughening the crack path on small scales, in agreement with theoretical expectations. With increasing speed of propagation one observes the branching instabilities that were reported in experiments. The simulations allow understanding the phenomena by analyzing the elastic stress field that accompanies the crack dynamics.