Enhanced Compressive Mechanical Properties of Bio-Inspired Lattice Metamaterials with Taper Struts.

The stress distribution within the struts of lattice metamaterials is non-uniform under compressive loads, with stress concentrations typically occurring at the node regions. Inspired by bamboo, this study proposes a type of body-centered cubic (BCC) lattice metamaterial with tapered prism struts (BCCT). The compressive behavior, deformation modes, mechanical properties, and failure mechanisms of BCCT lattice metamaterials are systematically analyzed using finite element methods and validated through compression tests. Parametric analysis is conducted to investigate the effects of key design parameters, including volume fraction, shape parameter, and material properties. The results reveal that BCCT lattice metamaterials effectively eliminate stress concentration at nodes by redistributing stress toward the center of the struts. This redistribution changes the failure mode from shear band failure to layer collapse, while the struts maintain a bending-dominated deformation mechanism under compression. The mechanical properties of BCCT lattice metamaterials are significantly influenced by the shape factor. Furthermore, the mechanical properties of BCCT lattice metamaterials with different volume fractions and materials are consistently superior to BCC ones, which verifies the effectiveness and adaptability of lattice metamaterials with taper prismatic struts for potential lightweight applications.