Additively manufactured lattice and sandwich structure consists of hybrid GFRP–PLA PU–graphite-foam for lightweight structure applications

Enhancing structural strength through hybrid laminates in the manufacturing process is a feasible approach. Striking a balance between superior material strength and reduced weight is pivotal. This study delves into advancing the mechanical capabilities of a sandwich composite consisting of PU foam with a graphite filler adhered in an additively lattice structure manufactured and reinforced with GFRP skin. Leveraging the low density of PU foam, utilizing additive manufacturing for lattice structure creation, and integrating GFRP skin result in a composite material with robust mechanical properties. The research underscores the influence of material type and thickness on mechanical characteristics. The optimal reinforcement was achieved at a 2% concentration of graphite powder in PU foam. The infusion of polyurethane foam into the composite enhances stiffness and compressive strength, evidenced by bending test values of 0.37 kN for the Lidinoid lattice, and 0.22 kN for the Weairephelan lattice. This improvement contrasts with the PU foam-free counterpart, which records 0.36, and 0.15 kN for the Lidinoid and Wearierphelan lattice, respectively. In summary, adding PU foam to the sandwich composite yields enhanced rigidity and compressive strength.