SELF-AFFINE SCALING DURING INTERFACIAL CRACK FRONT PROPAGATION

Abstract

We have performed an experimental study of slow crack front propagation through a weak plane of a transparent Plexiglas block. Spatial random toughness fluctuations along the weak interface generate a rough crack line in pinning locally the cr ack front, and leads to an intermittent dynamics of the crack front line. Using a high speed and high resolution camera we are able to capture the features of this complex dynamics. A new analysis procedure is proposed in order to measure the waiting time fluctuations, and study the local burst dynamics and structure along the crack front during its propagation. First, we confirm previous results [1]: the fracture front dynamics is governed by local and irregular avalanches with very large size and velocity fluctuations, a nd can be described in terms of a FamilyVicsek scaling with a roughness exponent �≃ 0.6 and a dynamic exponent �≃ 1.2. Then, focusing in particular on the avalanches structure, we show that the system exhibits self-affi ne scaling with