Ultrahigh Damping Efficiency in Laser Powder Bed Fusion Kelvin Metamaterials for Hysteretic Applications

The burgeoning field of additive manufacturing has enabled the creation of mechanical metamaterials with unprecedented design freedom. This work presents an integrated experimental–numerical framework for characterizing the hysteretic behavior of a Kelvin‐type (truncated octahedron) lattice fabricated via laser powder bed fusion (LPBF) using 316L stainless steel. The objective is to assess its potential as a highly efficient energy‐dissipating device for structural applications. The hysteretic response is determined through a proportional incremental cyclic‐loading protocol and compared with a finite element‐based computational model. The model accurately captured the progressive decrease in effective stiffness and the corresponding increase in effective damping observed experimentally. The Kelvin lattice achieves exceptional damping efficiency, with effective damping values exceeding unity at large deformations. Custom shear fixtures produced via fused filament fabrication using polylactic acid provided precise, low‐cost testing supports for the LPBF specimens. The model also correctly identifies the specimen's failure location, confirming its predictive capability for future design optimization. Overall, this study demonstrates the feasibility of LPBF‐manufactured Kelvin structures as metallic dampers and establishes a reproducible, cost‐effective approach for testing and optimizing architected metamaterials for advanced energy‐dissipation applications.