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.