  Capturing the dynamics of granular flows at intermediate length scales can
often be difficult. We propose studying the dynamics of contact networks as a
new tool to study fracture at intermediate scales. Using experimental
three-dimensional flow fields with particle-scale resolution, we calculate the
time evolving broken-links network and find that a giant component of this
network is formed as shear is applied to this system. We implement a model of
link breakages where the probability of a link breaking is proportional to the
average rate of longitudinal strain (elongation) in the direction of the edge
and find that the model demonstrates qualitative agreement with the data when
studying the onset of the giant component. We note, however, that the
broken-links network formed in the model is less clustered than our
experimental observations, indicating that the model reflects less localized
breakage events and does not fully capture the dynamics of the granular flow.
