Clusters, plasticity and damage: a missing link?

The properties of polyphase materials cannot always be described by average values characterizing the distribution of the second phase in the matrix. The internal stresses, the recrystallization behaviour in composites and the fracture mechanisms all depend on the distribution of the particles in space. This contribution will focus on the effect of clusters on mechanical properties of two-phase materials. We will give some examples of situations in which the existence of clusters may influence the properties of the materials: the case of internal stresses in composites, the kinetics of recrystallization, and the damage propagation in a cellular solid such as the trabecular bone. Rather than making a detailed analysis of each case, they will be taken as examples of the possible modelling techniques to be applied to this effect of clusters.