Energy absorption characteristics and negative Poisson's ratio effect of TPMS-based hybrid lattice metamaterials

Lightweight lattice metamaterials with improved mechanical properties and high energy absorption capacity have garnered significant attention due to their extensive engineering applications in medical devices, transportation, and aerospace engineering. Balancing the mechanical performance of lattice structures remains a primary focus and challenge in innovative material design. Compared to conventional truss-based lattices such as body-center cubic (BCC) lattices, the shell-based lattices with triply periodic minimal surfaces (TPMS) demonstrate superior stiffness, energy absorption efficiency, and thermal dissipation owing to the unique topological configurations. This paper proposed a TPMS-BCC-based hybrid (TBH) lattice structure by integrating the Primitive-type TPMS and traditional truss-based lattice. The TBH lattices exhibit a body-centered-cubic configuration at the macro scale while possessing minimal surface characteristics along the strut direction. Various TBH lattice samples were fabricated from polymer materials by using selective laser sintering (SLS), and the quasi-static crushing experiments of the TBH lattices were conducted to investigate deformation modes and energy absorption performance. The TBH lattice demonstrates dual plateau stress stages, distinct negative Poisson's ratio effects, and stable plastic deformation. Based on the experimentally validated finite element model, performance comparisons with conventional lattices were conducted numerically. At identical relative densities, specific energy absorption of TBH exceeds that of conventional BCC lattices by 80.47%. Compared with the Primitive-type TPMS lattice, it further demonstrates a 12.97% increment in specific energy absorption and a 47.68% reduction in the peak crush force, exhibiting a more stable plastic deformation stage. A parametric analysis was conducted to investigate the mechanical properties of TBH lattices with different geometric parameters. By integrating the advantages of traditional BCC lattices and Primitive-type TPMS structures, TBH lattices provide a feasible strategy for the optimized design of energy-absorbing lattice structures.