2026-10-14T13:13:39Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33940582 2026-09-18T18:14:09Z category_1 category_146 category_21 category_734 portal_87 item_type_3 month_year_09_2026

Tailoring stiffness and energy absorption in hybrid re-entrant and S-shaped lattice structures Ali Nabizadeh (25073665) Kaan Yildiz (25073668) Biophysics Space Science Biotechnology Biological Sciences not elsewhere classified Auxetic lattice structures hybrid lattice structures re-entrant unit cells S-shaped unit cells specific energy absorption <p>Auxetic metamaterials are engineered architectures characterized by a negative Poisson’s ratio (NPR), exhibiting the unconventional property of lateral expansion under tension and contraction under compression. While configurations such as re-entrant, chiral, and star-shaped unit cells offer advantages like increased shear modulus and enhanced fracture toughness, the widely utilized re-entrant unit cell faces critical limitations, including severe localized stress concentrations that can lead to premature structural failure. To address these challenges, this study investigates a novel class of hybrid auxetic metamaterials that integrate high-stiffness re-entrant unit cells with curvature-based S-shaped cells designed to redistribute localized loads. Utilizing fused filament fabrication, fourteen distinct lattice configurations were fabricated to examine the influence of unit-cell proportions, cross-linking topologies (Type 1 and Type 2), and spatial column distributions (centralized vs. distributed). Experimental compression tests, validated by finite element analysis, demonstrate that hybridization effectively overcomes the individual limitations of the parent geometries. The results reveal that balanced hybrid architectures provide a synergistic mechanical response, with the R3S2T2C configuration achieving a peak specific energy absorption of 3.59 J/g, which is 66% higher than that of the monolithic re-entrant lattice. Furthermore, the study identifies that Type 2 cross-linking and centralized re-entrant core arrangements stabilize the plateau regime while delaying the onset of densification. By quantifying the tradeoffs between initial stiffness, mean crushing stress, and NPR stability, this research provides a comprehensive design framework for the development of tunable, high-performance auxetic lattices for aerospace structures, impact protection systems, and adaptive medical devices.</p> 2026-09-18T18:14:09Z Dataset Dataset 10.6084/m9.figshare.33940582.v1 https://figshare.com/articles/dataset/Tailoring_stiffness_and_energy_absorption_in_hybrid_re-entrant_and_S-shaped_lattice_structures/33940582 CC BY 4.0