Sandwich Composites

Abstract

A sandwich composite is a layered construction formed by bonding two thin facings to a relatively thick core. It is a “stressed skin” construction in which the facings resist nearly all of the applied in-plane, edgewise loads and flatwise bending moments. The thin, spaced facings provide nearly all of the bending rigidity to the construction. A thick core spaces the facings and transmits shear between them so they are effective about a common neutral axis. The core also provides most of the shear rigidity to the sandwich. The advantage of spaced facings to provide greater stiffness without much increase in amount of material needed was reported by Timoshenko(1953) to have been investigated by Duleau, circa 1820. This investigation led to the design of tubular bridges, I-beams and other stiff structural shapes