*2.1. Design of Experiment (DOE)*

The fatigue tests on trabecular lattices had the primary objective to experimentally characterize the fatigue life curve of different types of non-stochastic foams built with AlSi10Mg by AM. The data for this study were collected using a DOE approach [32] in order to provide novel information regarding the effects of design parameters (cell type, cell size and relative density) on lattice fatigue performance [33]. Although some research has been carried out on fatigue with this approach [33], none of the previous studies have reported such a wide investigation for AlSi10Mg.

Three different trusses layout have been selected: Body-Centered Cubic with vertical beams (Bccz), Octet and Rhombic Dodecahedron. For each cell type, two cells sizes, 5 mm and 7 mm, were adopted with two relative densities: 25% and 30%. In order to limit the number of specimens and the cost of the experimental campaign, the DOE with three factors and hybrid levels for each factor was executed in fractional factorial form. The details of the specimens produced for the fatigue test are reported in Table 1.


**Table 1.** Factors selected to design specimens for fatigue tests.

#### *2.2. Specimen Design*

The trabecular specimens presented a height/base side ratio of 2:1, similar to the one proposed previously [7]. Each specimen had a square bottom and a longer height to prevent the effect of borders and specimen shape. A picture of Bccz is shown in Figure 2 while detailed drawings with dimensions are reported in Appendix C. All specimens have two flat skins 1 mm thick at the square bases. This skin has been added in order to uniformly distribute the stress on first layer cells and to avoid peaks caused by manufacturing imperfections.

**Figure 2.** CAD Design of a Specimen.
