Elastic–Plastic Homogenization of Additively Manufactured F2CCZ Cells

In recent years the demand of components with low weight and high mechanical properties in terms of strength and stiffness has rapidly increased. In this scenario, lattice structures can provide a compelling alternative with respect to the classical bulk components. In this study, the elastic–plastic behaviour of face centred cubic unit cell with vertical strut (F2CCZ) manufactured through laser powder bed fusion (LPBF) and made of AlSi10Mg, was explored. Standard bulk unnotched specimens were initially produced and tensile tests were performed to investigate the elastic–plastic behaviour of the material. The obtained results were used to perform, through finite element (FE), elastic–plastic homogenization of the representative volume elements (RVEs) with nominal geometry and by using periodic boundary conditions (PBCs). A novel simplified approach combining Hill yielding criterion, Levy-Mises plastic flow rule and a reference plastic curve was proposed to describe the different hardening of RVEs in the various directions. Simplified mathematical expressions were proposed and validated to characterize, for the first time, the dependence of elastic–plastic homogenized properties on the aspect ratio (AR). After that, novel graded lattice specimens, with the aim of localizing the failure in the centre of the specimen, were designed and tensile tests were performed with digital image correlation (DIC) for strain measurements. The scanning electron microscope (SEM) was used to investigate the differences between as-built and as-designed strut diameters, and the obtained results were employed to perform FE simulations. Finally, the proposed framework was validated both numerically and experimentally, and a discussion is provided.