Dynamics and structure of interfacial crack fronts

TL;DR

This study experimentally investigates the dynamics and structure of interfacial crack fronts in Plexiglas, revealing power law velocity distributions and anisotropic burst scaling, advancing understanding of fracture front behavior.

Contribution

It provides new experimental insights into the velocity fluctuations and burst activity of interfacial crack fronts, highlighting anisotropic scaling behaviors.

Findings

Velocity distribution follows a power law for high velocities.

Burst activity exhibits a power law size distribution.

Local burst sizes scale differently parallel and perpendicular to the crack front.

Abstract

The propagation of an interfacial crack front through a weak plane of a transparent Plexiglas block has been studied experimentally. A stable crack in mode I was generated by loading the system by an imposed displacement. The local velocities of the fracture front line have been measured by using an high speed CCD camera. The distribution of the velocities exhibits a power law behavior for velocities larger than the average front velocity <v> with a crossover to a slowly increasing function for velocities lower than <v>. The fluctuations in the velocities reflect an underlying irregular bursts activity with a power law distribution of the bursts. We further found that the size of the local bursts scales differently in the direction parallel to and perpendicular to the fracture front.