PSI - Issue 79

Petru Mihai Margitas et al. / Procedia Structural Integrity 79 (2026) 348–353

353

Another measure of the energy efficiency is the cushion factor C defined as the ratio of the stress at a given compression to the absorbed energy. Considering the absorbed energy at maximum load, the variation of cushion factor versus compression strength is plotted in Fig. 5.b. The cushion factor serves as an indicator of energy absorption efficiency; lower values correspond to more efficient lattice structures capable of absorbing higher amounts of energy at a given stress level. The sponge-like lattice structure exhibited the lowest cushion factor among the analyzed

configurations. 4. Conclusions

The paper presents the mechanical response under static compression testing of three lattice structures: with unit cells representing a square, triangle, and sponge-like structures. The specimens were manufactured using DLP photopolymerization technique. The experimental results, consisting in fracture load, specific strength, and energy absorption, were evaluated as functions of the relative density of the lattice structures. It was observed that all investigated parameters exhibited higher values for the sponge-like structure, indicating superior compression behavior and enhanced energy absorption capability. Acknowledgements This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS - UEFISCDI, project number PN-IV-P1-PCE-2023-1446, within PNCDI IV. References Brighenti, R., Cosma, M.P., Marsavina, L., Spagnoli, A., Terzano, M. 2021. Multiphysics modelling of the mechanical properties in polymers obtained via photo-induced polymerization. Advanced Manufacturing Technology, 117, 481-499. Brighenti, R., Marsavina, L., Marghitas, M.P., Montanari, M., Spagnoli A., Tatar, F. 2023. The effect of process parameters on fracture toughness of specimens obtained via DLP additive manufacturing technology. Materials Today: Proceedings, 78(2), 331-336. Cui, C.Y., Chen, L., Feng, S., Cui, X.G., Lu, J.Z., 2023. Novel cuttlebone-inspired hierarchical bionic structure enabled high energy absorption, Thin Walled Structures, 186, 110693. Du, G., Qian, Y., 2024. Bio-inspired innovations in 3D concrete printing: structures, materials and applications. Applied Materials Today, 41, 102459. Fernandes, M.C., Aizenberg, J., Weaver, J.C., Bertoldi, K., 2020. Mechanically robust lattices inspired by deep-sea glass sponges, Natural Materials, 20(2), 237–241. Fu, J., Liu, Q., Liufu, K.M., Deng, Y.C., Fang, J.G., Li, Q., 2019. Design of bionic-bamboo thin-walled structures for energy absorption, Thin Walled Structures, 135, 400-413. Khan, N., Riccio, A., 2024. A systematic review of design for additive manufacturing of aerospace lattice structures: Current trends and future directions, Progress in Aerospace Sciences, 149, 101021. Maconachie, T., Leary, M., Lozanovski, B., Zhang, X., Qian, M., Faruque, O., Brandt, M., 2019. SLM lattice structures: Properties, performance, applications and challenges, Materials and Design, 183, 108137. Marghitas, M., Popa C.-F., Marsavina, L. 2025. On the Size and Notch Effect in AM Photo-Polymerized Components, Fatigue and Fracture of Engineering Materials and Structures, 48(9), 3790-3804. Marsavina, L, Linul, E., 2020. Fracture toughness of rigid polymeric foams: A review. Fatigue & Fracture of Engineering Materials & Structures, 43, 2483-2514. Przeslawski, R., 2012. Deep sea glass sponge. Cosmos, https://cosmosmagazine.com/science/biology/deep-sea-glass-sponge/. Ufodike, C. O., Ahmed M.F., Dolzyk, G., 2021. Additively manufactured biomorphic cellular structures inspired by wood microstructure, Journal of the Mechanical Behavior of Biomedical Materials, 123, 104729. Wang, P., Yang, F., Lu, G.X., Bian, Y.J., Zhang, S.Y., Zheng, B.L., et al., 2022. Anisotropic compression behaviors of bio-inspired modified body centered cubic lattices validated by additive manufacturing, Composites Part B: Engineering, 234, 109724. Xia, P., Liu, Q.C., Fu, H., Yu, Y.P., Wang, L.J., Wang, Q.Y., Xue, Y., Yu X., Zhao, F., 2023. Mechanical properties and energy absorption of 3D printed double-layered helix honeycomb under in-plane compression, Composite Structures, 315, 116982. Zhang, F., Yang, Z., Li, X., Guo, K., Lu, L., Dong, Z. 2025. Facile fabrication of robust cork-inspired superhydrophobic aerogel for continuous oil spill and emulsion absorption, Separation and Purification Technology, 356, Part A, 129888. Zhang, H., Hu, D., Peng, H., Yuan, W., Zhang, Z., Yang, Z., Zhang Z., 2024. In-plane crashworthiness study of bio-inspired metallic lattice structure based on deep sea glass sponge. Thin-Walled Structures, 205, 112505.