Griffith cracks in the mesoscopic microcrack theory
  The mesoscopic concept is applied to the description of microcracked brittle materials. The mesoscopic equations are solved in a special case when the microcracks are developing according to the Rice-Griffith evolution law. The evolution of the crack distribution function is investigated in case of simple loading conditions and for two different initial crack distribution functions. The time dependence of the average crack length is calculated, too. 
P. Van, C. Papenfuss and W. Muschik