From nucleation to percolation: when disorder strength and stress localization compete

The spatial correlation during a failure event of a one-dimensional fiber bundle model is studied when three main parameters guiding the dynamics of the model is tuned: the fluctuation of local strength ($beta$), range of stress relaxation ($gamma$), and size of the bundle ($L$). Both increasing disorder strength and stress release range favor rupture events, random in space like percolation. An increase in system size on the other hand nucleating failure. At an intermediate disorder strength and stress release range, when these two parameters compete, the failure process shows avalanches and precursor activities. A complex phase diagram on the $beta-gamma-L$ plane is presented showing different failure modes - nucleation, avalanche, and percolation, depending on the spatial correlation observed during the failure process.