Computer simulations of damage formation and propagation in composites

The presence of complex microstructures in heterogeneous materials - matrix-inclusion composites - precludes any simple analytical solution of the effective transport/elastic properties and, therefore, of the damage patterns and propagation. Consequently, computer models provide the only theoretical method capable of grasping the spatio-temporal cooperative nature of the phenomena involved. In this paper we briefly discuss the `spring-network models,' which rely on high resolution finite difference grids below the crystal (or inclusion) scales; systems having several million degrees of freedom can presently be simulated.