Overall elastoplastic behavior of anisotropic metal-matrix composites reinforced by aligned inclusions. Application to hydrided and irradiated Zircaloy-4 cladding tubes

The present work aims at determining a micromechanical model for the elastoplastic behavior of anisotropic metal-matrix composites reinforced by aligned inclusions. The microstructure of the studied material – hydrided and irradiated Zircaloy-4 cladding tubes – is supposed to be made of an anisotropic and elastoplastic matrix (irradiated Zircaloy) containing aligned isotropic elastic inclusions (hydrides). The homogeneous behavior of this non-linear two-phase material is obtained by a linearization model based on the modified secant method (Ponte Castañeda and Willis, 1995). The behavior of the linear comparison composite is estimated by the model of Ponte Castañeda and Willis (1995). The anisotropy of the macroscopic behavior rises both from the shape of the inclusions and from the plastic anisotropy of the matrix. The model is compared to three-dimensional numerical simulations and experimental data.