cyclic energy absorption and shape recovery of fiber-reinforced re-entrant lattice structures: experimental and numerical investigation

The development of lightweight architected lattices with superior energy absorption and recoverability is of great interest for protective systems and reusable structural components. this study investigates the mechanical performance of re-entrant auxetic lattices fabricated from pure pla (pp) and glass-fiber-reinforced pla composites (rp) produced via fused deposition modeling. quasi-static compression tests were conducted to evaluate stiffness, specific energy absorption (sea), mean crushing force, and crush force efficiency (cfe), while cyclic compression–recovery experiments assessed shape memory effects and reusability. the experimental findings were complemented by finite element simulations in abaqus/explicit. results indicate that rp structures exhibit higher stiffness, enhanced sea, and superior cfe compared with pp counterparts, owing to improved load transfer and suppression of local buckling by reinforcing fibers. although fiber–matrix debonding led to a temporary reduction in mean crushing force during the second cycle, rp specimens regained performance in subsequent cycles, highlighting their cyclic durability. shape recovery tests further confirmed that rp lattices maintained higher efficiency and stability across multiple deformation–heating cycles compared with pp. the combined experimental and numerical analysis demonstrates that fiber reinforcement significantly enhances the energy absorption capability and reusability of auxetic smp-based lattices, positioning them as promising candidates for next-generation crashworthy and impact-mitigation applications the development of lightweight architected lattices with superior energy absorption and recoverability is of great interest for protective systems and reusable structural components. this study investigates the mechanical performance of re-entrant auxetic lattices fabricated from pure pla (pp) and glass-fiber-reinforced pla composites (rp) produced via fused deposition modeling. quasi-static compression tests were conducted to evaluate stiffness, specific energy absorption (sea), mean crushing force, and crush force efficiency (cfe), while cyclic compression–recovery experiments assessed shape memory effects and reusability. the experimental findings were complemented by finite element simulations in abaqus/explicit. results indicate that rp structures exhibit higher stiffness, enhanced sea, and superior cfe compared with pp counterparts, owing to improved load transfer and suppression of local buckling by reinforcing fibers. although fiber–matrix debonding led to a temporary reduction in mean crushing force during the second cycle, rp specimens regained performance in subsequent cycles, highlighting their cyclic durability. shape recovery tests further confirmed that rp lattices maintained higher efficiency and stability across multiple deformation–heating cycles compared with pp. the combined experimental and numerical analysis demonstrates that fiber reinforcement significantly enhances the energy absorption capability and reusability of auxetic smp-based lattices, positioning them as promising candidates for next-generation crashworthy and impact-mitigation applications