Design and application of hybrid lattice metamaterial structures with high energy absorption and compressive resistance

Additive manufacturing (AM) technology has facilitated the design and application of various lattice structures, leading to an increasing focus on optimization studies. However, there is limited research on the selection of basic unit cell structures and lattice hybridization methods in hybrid lattice design. To address this gap, this study, guided by bionic principles, designs seven types of unit cell structures and introduces four novel cross- scale hybrid forms: holistic interpenetration, voxel alternation, layered transition, and multiscale embedding. Twelve sets of hybrid lattice metamaterial 3D models were constructed using implicit body programming design. The basic unit cell structures and hybrid lattice metamaterial specimens were fabricated via selective laser sintering (SLS) using thermoplastic polyurethane (TPU) powder as the raw material. Quasi-static compression tests were conducted to comprehensively evaluate the mechanical properties, energy absorption, and printability of the lattice structures. The results indicate that unit cells a and b exhibit superior mechanical performance compared to other cell structures. Additionally, hybrid lattice metamaterial structures 4 and 7, formed by cells a and b using voxel alternation and layered transition hybridization methods, respectively, show enhanced mechanical properties compared to other hybrid lattice metamaterials. The findings suggest that AM technology can be used to fabricate any hybrid lattice metamaterial structure. By adjusting design parameters for both the basic unit cell and hybridization methods, it is possible to achieve hybrid lattice metamaterials with optimized performance tailored to specific application scenarios, meeting industrial requirements.