Exploring multi-cell hybrid designs of multi-morphology lattices to enhance plastic energy absorption

This study explores the mechanical performance and energy absorption characteristics of stereolithography (SLA)-fabricated multi-morphology lattice structures, combining stretch-dominated FCC and bend-dominated BCC unit cells. The six lattice configurations—Control (FCC), Hourglass, Meso-I, Parallel, Peak, and Series—were designed and tested under uniaxial compression. The control FCC lattice demonstrated the highest specific energy absorption (SEA) of 2.3562 kJ/kg and crush force efficiency (CFE) of 0.565, showcasing superior energy absorption but exhibiting brittle failure behavior under compression. The Meso-I design achieved a balance between SEA (1.6335 kJ/kg) and CFE (0.4924), leveraging sequential collapse to distribute stress effectively and prevent catastrophic failure. The novel Hourglass topology displayed controlled deformation and high CFE (0.5469), emphasizing its suitability for load-bearing applications. The experimental results highlight the complementary benefits of integrating FCC and BCC unit cells, utilizing FCC's stiffness and BCC's flexibility to enhance energy absorption and structural stability. These findings underline the importance of lattice topology in optimizing mechanical performance for crash safety and impact resistance. The study also emphasizes the potential of SLA technology in fabricating complex lattice designs tailored for specific performance requirements. Future research should explore dynamic loading conditions, composite materials, and advanced design tools to further optimize lattice metamaterials.