Bio-Inspired Lattice Exhibiting Strain-Rate Insensitive Energy Absorption under Multi-Angle Dynamic Impact

Lattice structures are promising for lightweight impact protection, yet conventional body-centered cubic (BCC) and face-centered cubic (FCC) designs remain prone to vertex stress concentration, localized collapse, and unstable performance across strain rates and impact angles. Drawing inspiration from deep-sea glass sponges, this study introduces a vertex-modified body-centered cubic (VMBCC) lattice that shifts corner connections and integrates a triaxial cross-support to reconfigure load-transfer paths. 316L VMBCC, BCC, and FCC lattices of comparable relative density were fabricated via selective laser melting (SLM) and evaluated through drop-weight axial impact tests. Multi-angle responses were obtained through validated finite element models. The VMBCC lattice forms a global diagonal deformation band rather than localized shear or layer-wise collapse, yielding markedly enhanced performance. Under axial impact, its specific plateau stress increases by 51.04% and 80.65%, and its specific energy absorption (SEA) by 50.00% and 76.84%, compared with BCC and FCC lattices. Across strain rates from [Formula: see text] to [Formula: see text], the VMBCC maintains its deformation mode and achieves SEA up to 16.11[Formula: see text]J/g, demonstrating clear strain-rate-insensitive energy absorption. Finite element analysis further confirms its superior performance under oblique loading. These findings establish a robust bio-inspired lattice architecture delivering stable, high-efficiency energy absorption under diverse dynamic impact conditions.