document: The primary benefit of using a 3D model is that it allows the application of anisotropic material properties. As a hexagonal close packed lattice structure, a single zirconium grain is plastically anisotropic due to the difficulty of activating slip with a 〈c〉 component [23–26]. Abaqus allows this to be represented by setting plasticity potential ratios. The anisotropic elastic and plastic constants are shown in Table 1. Zirconium alloys can often have a bimodal basal pole distribution, with a tilt on the basal normal or c direction of ±30° in the normal direction being quoted for recrystallized Zircaloy-4 [27,28]. However, for simplicity the basal normal or c direction has been taken as being parallel to the normal direction. As such the 1, 2 and 3 directions in Table 1 correlate with the X, Y and Z global coordinate system for the 3D simulations, with the 3 direction correlating to the c direction of a zirconium unit lattice. Table 1 also shows the elastic properties incorporated into the simulations. The oxide layer has been simulated as a purely elastic material. Although it is known that the oxide is strongly textured [29], it is still simulated as a homogenous solid therefore isotropic material properties have been used for the oxide in all simulations.
doc_bio_tags: O O O O O O B I O O O O O O O B I I O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O B I I O B I I I I O O O O O B O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B O O O O O O O O O O O O B O B O O O O O O B I I O O O O O O B O O O O O O O O O O O O O B I I O O O O O B O O B
extractive_keyphrases: 3d model 3d simulations abaqus anisotropic elastic and plastic constants anisotropic material properties bimodal basal pole distribution isotropic material properties oxide plasticity potential ratios purely elastic material simulations zirconium
abstractive_keyphrases: oxide layer recrystallized zircaloy-4 zirconium grain zirconium unit lattice