Fracture, mechanics and chemistry: Intermittency and avalanche statistics in thermally activated creeping crack fronts along disordered interfaces

We propose a subcritical fracture growth model, coupled with the elastic redistribution of the acting mechanical stress along rugous rupture fronts. We show the ability of this model to quantitatively reproduce the intermittent dynamics of cracks propagating along weak disordered interfaces [1]. We assume that the fracture energy of such interfaces (in the sense of a critical energy release rate) follows a spatially correlated normal distribution. We compare various statistical features from the obtained fracture dynamics to that from experimental cracks propagating in sintered polymethylmethacrylate (PMMA) interfaces. In previous works, it has been demonstrated that such approach could reproduce the mean advance of fractures and their local front velocity distribution. Here, we go further by showing that the proposed model also quantitatively accounts for the complex self-affine scaling morphology of crack fronts and their temporal evolution, for the spatial and temporal correlations of the local velocity fields and for the avalanches size distribution of the intermittent growth dynamics. We thus provide new evidence that Arrhenius-like subcritical growth laws are particularly suitable for the description of creeping cracks.

Reference:

[1] Vincent-Dospital, T., Cochard, A., Santucci, S., Måløy, K.J., Toussaint, R.,  Thermally activated intermittent dynamics of creeping crack fronts along disordered interfaces. Sci Rep 11, 20418 (2021). https://doi.org/10.1038/s41598-021-98556-x