The introduction of lattice structures, in order to reduce weight and increase structural performances, is becoming more and more requested in fields such as automotive, aerospace and biomedical. These challenges are satisfied by the advent of increasingly innovative additive manufacturing techniques, which have enabled not only the realization of complex structures, but also the implementation of alloys whose characteristics can be well suited to demanding fields of application. Within the scope of this thesis, the main characteristics of these structures are explored, outlining the differences according to the constituent topology, arrangement and density of unit cells. The main aim is the implementation of a structural optimization method by which, based on the above-mentioned properties, each different configuration shows significant improvements in energy absorption characteristics.