  We introduce and study a general framework for modeling the evolution of
crack networks. The evolution steps are triggered by exponential clocks
corresponding to local micro-events, and thus reflect the state of the pattern.
In an appropriate simultaneous limit of pattern domain tending to infinity and
time step tending to zero, a continuous time model, specifically a system of
ODE is derived that describes the dynamics of averaged quantities. In
comparison with the previous, discrete time model, studied recently by two of
the present three authors, this approach has several advantages. In particular,
the emergence of non-physical solutions characteristic to the discrete time
model is ruled out in the relevant nonlinear version of the new model. We also
comment on the possibilities of studying further types of pattern formation
phenomena based on the introduced general framework.
