A novel stress profile-driven hybrid mechanical metamaterial designed for additive manufacturing with improved mechanical performance and energy absorption properties

Additive manufacturing (AM) has transformed the production of intricate lattice structures, allowing for precise control over unit cell topology and spatial configuration because of its unmatched design flexibility. Optimizing mechanical performance via hybrid lattice topologies that incorporate several unit cell types is an unaddressed research topic, necessitating further investigation for tailored mechanical properties. A novel hybrid lattice cell (IFCC) has been proposed, integrating bending-dominated FCC with stretch-dominated Iso-Truss lattice structure for achieving the characteristics of both unit cells. Furthermore, layered hybrid lattice configurations were designed, comprising FCC, Iso Truss, and interconnected face-centered cubic (IFCC), and fabricated using the fused deposition modeling (FDM) additive manufacturing process with polylactic acid (PLA) material. A quasi-static compression experiment and finite element simulations were conducted to evaluate the mechanical properties of the novel hybrid lattice structures. The IFCC hybrid lattice achieved SEA of 3.93 kJ/kg. Among the layered hybrid configurations, HS4 had the highest SEA of 5.96 kJ/kg, exhibiting a 332% and 555% enhancement compared to homogeneous FCC and ISO truss structures, respectively. These findings underscore the potential of hybrid lattice structures for customized mechanical properties in energy-absorbing applications, thereby paving the way for future advancements in lightweight, high-performance materials.