  We investigate numerically the dynamics of crack propagation along a weak
plane using a model consisting of fibers connecting a soft and a hard clamp.
This bottom-up model has previously been shown to contain the competition of
two crack propagation mechanisms: coalescence of damage with the front on small
scales and pinned elastic line motion on large scales. We investigate the
dynamical scaling properties of the model, both on small and large scale. The
model results compare favorable with experimental results.
