Design and experimental evaluation of a topology-optimized metamaterial cell fabricated via 3D printing for enhanced energy absorption

• Topology-optimized PLA metamaterials were fabricated via FDM. • Compression and impact tests revealed distinct responses. • Topology governs strength–energy absorption trade-off. • TV structure achieved high strength with 50% weight reduction. • TH structure showed superior impact energy absorption at 30% weight. In this study, three topology-optimized structures were constructed using polylactide (PLA) via material extrusion (MEX) to investigate their mechanical performance under compression and impact loading. The structures, named TV, TH, and TVH, underwent quasi-static compressive loading and dynamic impact testing to assess their load-bearing capacity and energy absorption characteristics. The results revealed significant differences in behavior across structural designs. While one structure exhibited the highest compressive strength, another demonstrated superior energy absorption under impact, highlighting the influence of topology on mechanical performance. For example, the weight of TV structure reduced to 50%, while these structures indicated highest compressive strength. Moreover, the weight of TH structures reduced to 30%, and these structures showed highest energy absorption. The findings indicate that topology optimization enables tailored structural responses, enabling the design of lightweight components with enhanced strength and energy dissipation.