Multiple impacts behavior of Nomex honeycomb sandwich structures with elastomer-enhanced CFRP skins

Elastomers demonstrate significant potential for enhancing the impact resistance of lightweight structures. CFRP/Nomex honeycomb sandwich structures, widely applied in aerospace engineering, require particular focus on improving their impact resistance. The study introduces elastomeric interlayers into the skin of CFRP/Nomex honeycomb sandwich structures for the first time, employing a combined experimental- numerical approach to investigate the multiple impact behavior of this novel configuration. Firstly, multiple low-velocity impacts tests were conducted on both the novel and conventional sandwich structures. Secondly, finite element models were built for simulating multiple impacts on the novel sandwich structure. Thirdly, the damage mechanisms and energy dissipation of the novel sandwich structure under multiple impacts were thoroughly investigated. Finally, the validated numerical models were further used to explore other multiple impacts conditions. Results demonstrate that the elastomers significantly enhance the multiple impact resistance of CFRP/Nomex honeycomb sandwich structures. The key contributions of this study include the experimental characterization of multiple low-velocity impact behaviors in novel sandwich structures and the numerical assessment of their damage mechanisms.