Numerical study on structured sandwich panels exposed to spherical air explosions

There is a need to develop innovative protective shield structures to withstand extreme loads, such as impact and blast loading. Sandwich structures that absorb significant kinetic energy as strain energy through plastic deformation offer superior protection. This study conducts a numerical analysis of structured sandwich protective structures subjected to airblast loads using finite element modeling. First, an experimental result from the literature was used to validate and verify finite element models of an architected sandwich structure modeled in Abaqus/Explicit software. Second, parametric studies were conducted on sandwich structures with additional layers of insert plates and newly proposed core topologies for viable shield protection against airblast loading. The finite element analysis results indicated that, under the same impulsive load, the control sandwich panel exhibited higher kinetic energy, demanding a proportionally larger internal energy. Conversely, sandwich structures with additional inner core insert plates dissipated the imposed kinetic energy more efficiently, due to the inelastic plastic deformation of the proposed core configurations. Moreover, the energy absorption capacity and back sheet displacement time-history were significantly improved by dense-hierarchical inner core configurations. Additionally, the parametric study analysis showed that increasing the number of insert plates and designing the core topology of cellular walls to be redundant, dense-hierarchical, and braced against buckling significantly reduced core collapse mechanisms such as folding, buckling, and crushing. However, despite these benefits, a reversed effect on the areal specific energy absorption index was observed.