Coarsening of cracks in a uniaxially strained solid

We discuss the stress relaxation in a uniaxially strained solid due to the coarsening of a system of parallel cracks. We emphasize similarities and di fferences of this process to Ostwald ripening in a first order phase transi tion. A conventional mean-field approximation breaks down and several indep endent length scales have to be taken into account. Strong elastic interact ions between the cracks determine the growth behavior. We derive scaling la ws for the coarsening of the different length scales involved and the time evolution of stress relaxation, finally leading to the equilibrium state of a fractured body. The characteristic size of the cracks grows linearly in time which is much faster than in usual Ostwald ripening.