Failure progressions in sandwich composites for crashworthiness applications

Sandwich composites are being considered for several automotive applications due to their high strength-to-weight and stiffness-to-weight ratios. Since crashworthiness is an important consideration for automotive applications, energy absorption under impact loading is also a key property. This investigation focused on the effects of material and geometric variables of automotive sandwich composites on failure progressions and energy absorption during edgewise impact loading. The baseline sandwich configurations consisted of woven carbon-epoxy or P4 carbon-epoxy facesheets and either end-grain balsa or polyurethane foam cores. In an effort to explore the feasibility of designing a sandwich composite configuration for energy absorption, variations on facesheet thickness, core thickness, and core density were investigated. By varying each of these parameters, the effects on failure mode and energy absorption could be determined. Results suggest that sandwich composites may be designed for enhanced energy absorption through the proper selection of facesheet and core materials and geometries such that high energy absorbing failure progressions are produced.