Blast resistance of sandwich structures consisting of re-entrant honeycombs reinforced by catenary

In order to further improve the blast resistance of re-entrant honeycomb (RH) cored sandwich panels while ensuring manufacturability, a sandwich panel consisting of RH reinforced by catenary is proposed, and its blast resistance is evaluated through the finite element method validated by the explosion experiments of reinforced RH (RRH) cored sandwich panels. The numerical results show that the RRH core can achieve an 18.7% decline in the maximum deflection of back facesheets, and a 25.7% increase in energy absorption, compared to the classic RH core with the same relative density. When RRH and RH cores share the same thickness, the former can achieve a 76.1% decrease in the maximum deflection of back facesheets and a 10.4% improvement in energy absorption. Furthermore, the deformation behavior of sandwich panels and core units is analyzed to determine that both the formation of more plastic hinges and a larger deformation region than those observed in classic RH cores promote the better blast resistance of RRH cored sandwich panels. Additionally, a parametric analysis is carried out to suggest that increasing the core thickness and catenary height of RRH units can further improve the anti-blast performance.