Systematic numerical design of a supported FCC plate lattice with structural reinforcement and gradation for energy absorption

In structural engineering and protective applications, efficient energy-absorbing materials are essential. Additively manufactured plate lattices are promising due to their high stiffness-to-density ratio. This study presents a numerical analysis of three basic plate lattices, simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC), under large-strain quasi-static compression. The effects of unit cell count, relative density, and axial grading on energy absorption and stability are investigated. Hybrid structures combining two or three lattice types are also studied across various component ratios. Based on the findings, a new design combining FCC with vertical supports is proposed. Numerical results are validated through experiments on FCC, BCC, and the binary-hybrid FCC + BCC lattices, showing good agreement in force response and deformation patterns. The SC structure achieves the highest specific energy absorption (SEA) but suffers from poor stability due to vertical walls, while the FCC offers the best stability. Integrating 70 % SC into FCC or BCC enhances SEA but reduces structural stability. The proposed hybrid structure outperforms all others, achieving 30 % higher SEA than FCC alone while maintaining stable deformation. Axial grading further boosts SEA by 11.6 %. This work demonstrates a pathway to optimizing both energy absorption and mechanical stability in lattice-based materials.