Bio-inspired alternating collinear tubular lattice metamaterial for enhanced energy absorption and compressive stability

Tubular lattice metamaterials are prized for their lightweight nature and exceptional mechanical properties, particularly resistance to bending and buckling. However, their performance is inherently limited by hollow nodal connections, which act as stress-concentrating geometric imperfections that compromise stiffness, strength, and stability. Inspired by the reinforced skeletal architecture of the seahorse tail, we introduce a novel alternating collinear plate-reinforced tubular (ACPT) lattice metamaterial. Through integrated simulation and experimental analysis, we demonstrate that our bioinspired design eliminates these detrimental hollow nodes. The ACPT lattice achieves remarkable enhancements over conventional simple cubic tubular (SCT) lattices, including a 219% increase in Young’s modulus and a 120% increase in yield strength. The hybrid plate reinforcement simultaneously boosts buckling resistance, resulting in a 59% improvement in specific energy absorption and superior compressive stability. Furthermore, we show that the elastoplastic properties and large deformation behavior can be effectively tuned via the plate-to-tube thickness ratio. These demonstrable advantages underscore the ACPT lattice’s high potential for advanced lightweight applications requiring exceptional load-bearing capacity and energy absorption, showcasing a successful bioinspired strategy to overcome the inherent limitations of conventional lattice metamaterials.