a b s t r a c tA representative volume element (RVE) is related to the domain size of a microstructure providing a ''good" statistical representation of typical material properties. The size of an RVE for the class of quasi-brittle random heterogeneous materials under dynamic loading is one of the major questions to be answered in this paper. A new statistical strategy is thus proposed for the RVE size determination. The microstructure illustrating the methodology of the RVE size determination is a metal matrix composite with randomly distributed aligned brittle inclusions: the hydrided Zircaloy constituting nuclear claddings. For a given volume fraction of inclusions, the periodic RVE size is found in the case of overall elastic properties and of overall fracture energy. In the latter case, the term ''representative" is discussed since the fracture tends to localize. A correlation factor between the ''elastic" RVE and the ''fracture" RVE is discussed.

International audienceThis study deals with the damage modeling of quasi-brittle interfaces such as the mortar/brick interfaces present in masonry walls. For this purpose, a model is developed based on a bulk model presented by Gambarotta and Lagomarsino, which takes the damage to the mortar joint into account. A quasi-fragile damage interface model is introduced using an asymptotic technique. This model memorizes some of the geometrical and mechanical characteristics of the interface, such as the thickness, elastic coefficients, normal and tangential stress, and the damage variable. Numerical simulations are performed using the Gyptis finite element software: academic cases involving traction and shear loads are presented