A comparative study of impulse-resistant metal sandwich plates

Abstract

The performance of metal sandwich plates under impulsive blast loads is compared to that of solid plates made of the same material and having the same weight. Three core geometries are considered: pyramidal truss, square honeycomb and folded plate. Plates of infinite length and clamped along their sides are subject to uniform impulsive load. The momentum impulse is applied to the face sheet towards the blast in the case of the sandwich plate, while it is distributed uniformly through the thickness of the solid plate. Large impulses are considered that are sufficient to produce lateral plate deflections more than 10% of the plate width. Fracture is not considered; the plates are assumed to have sufficient ductility to be able to sustain the deformations. A limited study of weight optimization is carried out for each of the core types with respect to the respective geometric parameters, including core and face sheet thickness, core member aspect ratios and relative density. A well-designed sandwich plate can sustain significantly larger blast impulses than a solid plate of the same weight. If the blast medium is water, fluid-structure interaction can reduce the momentum imparted to a sandwich plate by almost a factor of two relative to that imparted to a solid plate of the same weight, and, consequently, the relative benefit of the sandwich plate is significantly enhanced over its solid counterpart. r

Response of metallic pyramidal lattice core sandwich panels to high intensity impulsive loading in air

“…Recent experiments have shown that the back face deflections of centrally loaded edge clamped sandwich panels can be significantly less than equivalent areal density solid plates subjected to the same loading [3][4][5][6][7][8]. Theoretical assessments indicate this beneficial effect arises from two phenomena: a reduction in the impulse acquired by the sandwich panel front face as a result of a fluid-structure interaction (FSI) effect [3,4,[8][9][10] and the higher flexural stiffness and strength of the sandwich.…”

“…After the beneficial FSI effect had been confirmed in water [2][3][4][5][6][7][8], numerous sandwich panel concepts for impulse and pressure mitigation have been explored [7][8][9][10][11][12][13][14][15][16][17].…”

Underwater blast response of free-standing sandwich plates with metallic lattice cores

“…Recently, attention has been paid to the potential use of sandwich plates in this protective role. Fleck and Deshpande [1] and Xue and Hutchinson [2] have argued that an underwater blast imparts a lower momentum to sandwich plates than monolithic plates of equal mass. The reduced momentum is associated with the earlier onset of cavitation in the water for sandwich plates with a light front face sheet and a deformable core.…”

Impact response of ductile self-reinforced composite corrugated sandwich beams

“…A fundamental issue with the inherent brittleness of these systems is that although they perform well when the structures deform in their elastic regime, they tend to fail catastrophically when a specific level of impact momentum is reached [9]. In contrast, metals show a more benign transition at increased levels of impact momentum due their ability to deform plastically [11]. The chief disadvantage with metal alloys is their high density; this necessitates that the structures become very thin walled and buckling dominated structures at low areal densities.…”