Experimental characterization and modelling of cyclic elastoplastic response of an AISI 316L steel lattice structure produced by laser-powder bed fusion

In the last few years, many studies have been devoted to elucidating the mechanical properties of lattice structures produced by additive manufacturing (AM) techniques. Nevertheless, virtually none of the works dealt with the cyclic elastoplastic response, which is instead the focus of the present study. An AISI 316L steel FBCCZ (face and body-centered cell with vertical struts along the z-axis) lattice structure, produced by the AM technique laser-powder bed fusion (L-PBF), was experimentally tested and modelled using the finite element method. The mechanical behavior of the L-PBF AISI 316L steel was described by a non-linear kinematic (Chaboche's model) and isotropic (Voce's model) hardening model. Numerical results and their comparison with experimental evidence suggested that the study of a single unit cell by exploiting the periodicity condition can be severely impaired by the numerousness of the cells involved. More faithful models, accounting for the sample's edges effects, and including the effective dimension of the fabricated features by AM, lead to a highly satisfactory match, thus confirming the applicability of the proposed approach.