Enhancement of blast resistance of sandwich plates

This paper examines the effect of design modifications on response of sandwich plates to impulse pressure loads. The objective is to limit damage by delamination of the laminated facesheets and by crushing of the structural foam core. This has been achieved by introducing structural elements for energy storage, and by reducing the damage-related core crushing that dominates response of conventionally designed sandwich plates. In particular, ductile interlayers inserted between the outer facesheet and the foam core, can absorb a significant part of the incident energy, and protect the foam core from excessive deformation. One standard Design (1) and three modified sandwich plate Designs (2)-(4) have been analyzed and evaluated. The interlayers in modified designs were selected as a relatively stiff polyurethane rubber, and a fairly compliant elastomeric foam. Explicit dynamic finite element solutions were developed with the LS-Dyna software. The results show almost instant facesheet delamination and permanent crushing of the foam core in all designs. The pair of polyurethane and elastomeric foam interlayers reduced the peak kinetic energy and core compression by approximately 50%. The longitudinal strain in the outer facesheet was also reduced in the new sandwich designs to magnitudes which fall below the ultimate tensile limit. (C) 2007 Elsevier Ltd. All rights reserved.