Design and additive manufacturing of novel hybrid lattice metamaterial for enhanced energy absorption and structural stability

• A novel hybrid lattice metamaterial was designed by combining surface-lattice with modified reentrant trusses. • Hybridization of metamaterials significantly influenced mechanical properties and energy absorption. • HLM with thicker reentrant trusses and varied shell thickness demonstrated superior mechanical properties and dynamic performance. • Novel hybrid lattice metamaterial’s behavior proven by FEA and experimental tests. • The synergistic design enhances stability and performance by effectively resisting and dissipating compressive stresses. In this work, a novel dual-phase metamaterial, named as “hybrid lattice metamaterial (HLM),” are designed and fabricated by combining reentrant and sea-urchin (SU) based surface-lattice (SL) structure with polyamide12 (PA12) material via material extrusion (MEX) process. Four different designs with varying reentrant truss thicknesses of 0.8 mm (H1), 1.0 mm (H2), 1.2 mm (H3), and 1.5 mm (H4) have been modified to assemble seamlessly with the empty spaces within the SL structure. Quasistatic compression tests were conducted to evaluate the deformation modes and compression characteristics. The findings from quasistatic experiments were subsequently validated using numerical simulations. The H4 metamaterial exhibited superior structural properties, with 42 % increase in stiffness and 35 % enhancement in specific energy absorption compared to only SL structure. Additionally, dynamic sinusoidal compression tests were conducted to evaluate the dynamic elastic ratio (DER), hysteresis work and viscoelastic properties using the tan δ. The H4 metamaterial outperformed the SL in all dynamic properties, with a 50 % increase in elastic modulus and 36 % increase in hysteresis work. This study shows metamaterial properties can be tailored for specific requirements. SL structure facilitate elastic recovery, while H4 metamaterials offer superior energy absorption and stability, making it well-suited for protective equipment and impact-resistant components.