Design and impact resistance analysis of sandwich structures with auxetic honeycomb core

Sandwich structures are widely used in the design of impact-resistant structures and their core layers play a crucial role in enhancing the impact-resistance of the structures. To enhance the energy absorption performance of sandwich structures, new cores consisting of multilayer honeycombs with auxetic cells are proposed. The deformation and failure behavior are investigated by numerical and experimental approaches. In the process of experiment, the deformation processes of sandwich structures under drop weight impact are captured by high-speed photography. The effects of auxetic cell geometry and multilayer core configuration on energy absorption are systematically investigated. The results demonstrate that the impact resistance of the sandwich structures with auxetic honeycomb core is significantly influenced by the geometric dimensions of the honeycomb cells and the core configuration. In the parallel arrangement, the maximum energy absorption of the sandwich structure can be increased by 67.01% (4.99 kJ) through modifying the geometry and configuration of the honeycomb core. In the orthogonal arrangement, the contact force transmitted to the bottom concrete slab can be reduced by up to 87.27% (1090.86 kN) through adjusting the geometric dimensions of auxetic cells within the sandwich structure. The deformation and failure process of sandwich structures in numerical simulation are in good agreement with the experimental deformation and failure process under high-speed photography. This work provides a reliable basis for designing composite sandwich structures under impact loads.