Design for Additive Manufacturing Driven Multi-Layered Hybrid Mechanical Metamaterials for Improved Mechanical Performance

In this study, hybrid lattice structures are created, combining truss-based and sheet-based triply periodic minimal surface (TPMS)-based structures. Body-centered cubic (BCC), octet, and diamond-TPMS lattice structures are hybridized utilizing multi-layer staking or longitudinal hybridization approach. Two types of hybrid lattice structures with varying strut thicknesses and unit-cell counts per layer are examined along with the homogenous lattice structures. The hybrid structures are additively manufactured using fused deposition modeling (FDM) process for conducting uniaxial compression tests to evaluate the mechanical properties of the hybrid structures in terms of load-bearing capacity, specific energy absorption (SEA), deformation, and collapse behavior. The investigation reveals that the homogenous lattice structures failed due to shear band formation, severely affecting their mechanical performance. Whereas the hybrid structures with one-unit cells per layer (HS7–HS12) deformed in a strictly layer-wise deformation pattern, corresponding to the stiffness of the unit cells. while those with one-unit cells per layer (HS1–HS6), display crushing behavior of each lattice structure simultaneously. HS7 demonstrats the highest SEA value of 12.7 kJ kg⁻¹, surpassing homogeneous diamond by 32% and homogenous BCC by 690%. The results establishes that the layer-staking pattern hybridization technique can effectively engineer progressive phase-wise mechanical response.