Edgewise Compression Behavior of Three-Dimensional Integrated Woven Sandwich Composite Panels

This paper is concerned with the study of edgewise compression properties of newly developed sandwich panels denoted as 3D integrated woven sandwich composites (IWSCs). IWSC panels consist of two fabric faces that are interwoven by pile yarns and therefore, a very high skin-core debonding resistance is obtained. To qualify the mechanical properties of this structure, in this study, 3D woven samples with different pile heights and pile distribution densities were fabricated and then after the impregnation by resin, the effect of panel thickness, pile density, sample size, and types of resin on the edgewise compression behavior of IWSC panels were experimentally investigated. The results showed that edgewise compression properties of IWSC panels are increased with the increase of core heights as well as core pile density. Compared with the core height of 20 mm (H1), the peak load values of 30 mm panel thickness (H2) increase between 18 and 36%. Also, as the pile density increases from 2.1 cm-2 (D1) to 4.3 cm-2 (D3), the peak load values of samples increases about 6% to 14%. Furthermore, the composite produced by epoxy resin showed about 300% better compression properties than the composite fabricated by polyester resin. Warp and weft direction properties as well as size dependency of IWSC panels in edgewise compression test were also studied. The difference between the maximum load values for the warp and weft directions in the samples varies from 10% to 40%.