Numerical modelling of the energetic behaviour of hybrid lattice structures

Study of the static and dynamic behavior of lattice structures made by additive manufacturing filled with polymers. The activity involves the creation of 3D CAD models of metallic cellular structures based on the characteristics of laboratory specimens. The metallic structures, made with AM, are filled with polymers with variable hardness (shoreA 30-60). Following, FEM numerical simulation are performed about the static compression behaviour of the samples and comparison with experimental results. When calibration of the static model is obtained, the analysis of the dynamic behavior of the sample itself is provided (modal and harmonic analysis). The same are repeated for a functional component. In this thesis finite element models have been developed to analyse the compression response of lattice structures based on two different architectures in metallic material, 316L. The first structure has a body-centered cubic lattice (BCC) while the second one has a similar lattice reinforced with vertical uprights on the Z axis (BCCZ). Three-dimensional models of polymeric material were also made and used to model structures under quasi-static compressive loads. The results of the finite element (FE) models of the lattice structures, as well as those of the polymeric models are compared with the experimental data and proved to be in good agreement. From the simulations carried out on the metal models it is demonstrated how the rigidity and the energy capacities could be improved by varying the geometry of the unit cell. Further tests were carried out on modified reticular structures to verify how the energetic behaviour varies as a function of combined elements. The modification consists in the infiltration of the lattice structure with a polymeric material. In this regard, this study focuses deeply on examining the experimental static behaviours of hybrid materials for both different cell topologies. In the last stages of this investigation, the hybrid structures were subjected to a dynamic stress test in order to estimate the energy absorbed by the compression structures.