Tailoring stiffness and energy absorption in hybrid re-entrant and S-shaped lattice structures

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>