Mechanical Characterization of PU Based Sandwich Composites with Variation in Core Density

Abstract

Sandwich composite finds its application in varied fields of engineering, mainly due to the fact that they are light weight, have a better strength to weight ratio and to an extent corrosion resistant. Each application might involve different fabrication technique and selection of appropriate foam core and facings. In this study, three different core densities of PU foam combined with glass fiber facings are fabricated using vacuum bagging technique. Because of their complex nature of fabrication by adding epoxy resin between facings and core makes the evaluation of their mechanical characteristics quite difficult to predict. Since core material being the weakest part of the sandwich composite, studies are carried out to determine the effect of change in mechanical properties by increasing the core thickness and density. Further, the mechanical response of these sandwich composites are studied by carrying out flatwise, edgewise compressive test and flexural strength on a Mecmesin MultiTest 10 –i testing equipment as per ASTM standards. It is found that with increase in core density the flatwise compressive modulus increases and facesheet wrinkling in low density foam and core debonding in higher density foam was noticed in edgewise compression. The flexural tests showed that with increase in core thickness marginally increased the face being stress as compared with increase in core density.