Dynamical stability of the crack front line

TL;DR

This paper investigates the dynamical stability of crack front lines using a 2D mass-spring model, revealing speed-dependent stability and roughness transitions between smooth and rough crack fronts.

Contribution

It introduces a numerical study of crack front stability, highlighting the transition from unstable to stable fronts and characterizing roughness behavior in both uniform and inhomogeneous models.

Findings

Straight crack fronts are unstable at low speeds.

Front stability improves at high speeds.

Roughness exponent is around 0.4 at low speeds.

Abstract

Dynamical stability of the crack front line that propagates between two plates is studied numerically using the simple two-dimensional mass-spring model. It is demonstrated that the straight front line is unstable for low speed while it becomes stable for high speed. For the uniform model, the roughness exponent in the slower speed region is fairly constant around 0.4 and there seems to be a rough-smooth transition at a certain speed. For the inhomogeneous case with quenched randomness, the transition is gradual.