Recent advances in hybrid lattice-cored sandwiches for enhanced multifunctional performance

Ultralight sandwich structures with either two-dimensional (2D) prismatic or three-dimensional (3D) lattice truss cores, such as honeycombs, folded panels (corrugations) and pyramidal trusses, are known to possess attractive mechanical stiffness/strength and impact resistance. These properties can be significantly improved further by inserting different materials into the interstices of the lattices to construct hybrid lattice-cored sandwiches, as summarized in this mini-review. Three different types of hybrid lattice-core for sandwich constructions are discussed, including ceramic- or concrete-filled lattice cores for superior penetration resistance, metallic or polymeric foam-filled lattice cores for simultaneous enhancement in load-bearing and energy absorption, and metallic honeycomb-corrugation cores for simultaneous load-bearing, energy absorption and broadband low-frequency sound absorption. Corresponding enhancement mechanisms are explored.