Investigation on the effect of waved struts on the energy absorption of BCC base mechanical metamaterials

Mechanical metamaterials have attracted considerable attention due to their lightweight architecture and high energy absorption capability. In this study, a topological optimization approach was applied to conventional body-centered cubic (BCC) lattice structures through the introduction of waved diagonal struts and modified nodal point configurations. Four novel waved-strut lattice structures were designed and additively manufactured using fused deposition modeling (FDM) with PLA+ material. The mechanical behavior of the structures was experimentally evaluated under uniaxial compression loading in terms of compressive strength, deformation mechanism, and energy absorption capability. The optimized waved-strut lattices exhibited significantly different deformation mechanisms compared with the conventional BCC structure, including progressive local collapse, controlled buckling, and delayed shear failure. Among all samples, the hybrid BCC-W-M structure demonstrated the best overall mechanical performance, achieving a first maximum compressive strength of 2.53 MPa, which is 1.3 times higher than that of the conventional BCC lattice (1.87 MPa). Furthermore, the energy absorption density increased from 0.94 to 1.33 J.mm −3 , corresponding to an improvement of 1.44 times. The results demonstrate that waved-strut topological optimization can significantly enhance the mechanical efficiency and energy absorption performance of BCC lattice metamaterials.