A new model of damage accumulation is presented, which is based on the assumption that the damage build-up process is composed of several steps. Each stage is triggered by the destabilization of the current structural organization of the solid. All transformations are described by a single impact mechanism. The analysis of the damage accumulation may thus be regarded as an identification of: (i) the structural properties of a material at each stage of the damage accumulation and (ii) the mechanisms of structural transformations from stage i to stage i + 1. (c) 2008 Elsevier B.V. All rights reserved.