Optimum design of composite honeycomb sandwich panels subjected to uniaxial compression

Abstract

Sandwich construction provides a very lightweight structural configuration for many load conditions. The use of composite materials with their high stiffness, high strength, and anisotropy makes sandwich construction even more competitive for many applications. It is very desirable to design these structures for minimum weight to insure their most effective use. Closed-form analytical solutions are presented herein for the analysis and design of minimum weight, composite material hex-cell and square cell honeycomb core sandwich and panels subjected to in-plane uniaxial compressive loads. These methods account for overstressing, overall buckling, core shear instability, face wrinkling, and monocell buckling. The optimum face thickness, core depth, cell wall thickness, and cell size are analytically determined. The methods insure minimum weight, as well as provide methods to compare various material systems, compare honeycomb sandwich construction with other panel architectures, and assess the weight penalties associated with using nonoptimum honeycomb sandwich constructions. A comparison of various polymer, metal, and ceramic matrix composite materials is made by way of example.