  A simplified polycrystalline model (the so-called RL model) is proposed to
simulate the anisotropic viscoplastic behavior of metallic materials. A generic
method is presented that makes it possible to build a simplified anisotropic
material texture, based on the principal features of the pole figures. The
method is applied to a recrystallized zirconium alloy, used as clad material in
the fuel rods of nuclear power plants. An important database consisting in
mechanical tests performed on Zircaloy tubes is collected. Only a small number
of tests (pure tension, pure shear) are used to identify the material
parameters, and the texture parameters. It is shown that six crystallographic
orientations (6 "grains") are sufficient to describe the large anisotropy of
such hcp alloy. The identified crystallographic orientations match the
experimental pole figures of the material, not used in the identification
procedure. Special attention is paid to the predictive ability of the model,
i.e., its ability to simulate correctly experimental tests not belonging to the
identification database. These predictive results are good, thanks to an
identification procedure that enables to consider the contribution of each slip
system in each crystallographic orientation.
