Reducing the quantity of raw material is a preferred method to reduce both the production cost and the energy footprint of structural materials. One method to create less massive materials, widely explored in research, consists in replacing them with 3D-printed truss-based structures. These structures are very porous and, by adjusting the spatial arrangement of beams — their architecture — it is possible to obtain spectacular stiffness values, much higher than those observed in materials of equivalent lightness (such as aerogels or solid foams, for example). The resulting mechanical metamaterials, however, remain very brittle, and different methods for including heterogeneities are being explored to make it resistant to fracture. The objective of this internship is to characterize the resistance to deformation and fracture, in tension and compression, of metacomposites, that is to say, a truss-based metamaterial with zones of different connectivities creating effective hard grains linked by soft joints. Numerical tests may also be carried out on a model of the material.