Energy Absorption and Deformation Behavior of 3D Printed Triply Periodic Minimal Surface Stainless Steel Cellular Structures under Compression

This article investigates the energy absorption performance and deformation mechanism of 316L stainless steel (SS316L) triply periodic minimal surface (TPMS) cellular structures fabricated by a selective laser melting (SLM) technique. The as-built specimens are subjected to abrasive blasting treatment to improve the surface quality of the printed parts, in order to reveal the true surface and mechanical characteristics of the TPMS structures. It is found that the P-type structure outperforms the G-type structure with a higher energy absorption capability at low relative densities (<0.35). The macroscopic examination of these micro-architectures reveals that the P-type structure develops a rapid local cell deformation following the diagonal shear geometry on the face sheet, whereas the G-type structure experiences continuous strain hardening along the stress plateau and deforms in a gradual manner during compression. The apparent strain hardening effect of the G-type structure is caused by the development of many macro-localities with extreme geometry distortion and cell wall self-contacting during compression. The findings in this study may provide valuable insight into design, fabrication, and post-fabrication treatment of metallic TPMS structures for the applications of high compression performance.