The relative importance of long continuous crack and the behavior of finely fractured material in the penetration resistance of ceramics is not fully understood. This competition of failure processes can be studied computationally. However, there are few approaches for consistently treating the transition from fragmented ceramic material to the propagation of discrete crack features in continuum simulations. One way to account for the effects of discrete crack propagation within a continuum simulation is to reduce the strength of the material when it is near material that has failed and could represent a cracked region. The rate of crack propagation is controlled by reducing the material strength when a crack can arrive in the material element from a neighboring element. The extent of the strength reduction is determined by requiring that the new yield surface contain the stress state associated with a crack terminating in the neighboring element. This condition results in a material model that naturally accounts for the mesh size in a consistent and reasonable way. The model also includes variability in the material strength to help reduce the tendency for failure zones to follow mesh lines. By comparing simulations that use the crack time of arrival information and simulations that do not use this extra information, the types on impact problems that are sensitive to large scale crack growth can be identified.