Flexural Characterization of Sandwich Composites; Effect of Varying PU Foam Density and E-Glass Fabric on Flexural Strength

Abstract

Abstract

This paper presents the results of an extensive investigation on flexural behavior and failure mechanisms of sandwich composites with polyurethane (PU) foam core and glass reinforced vinylester as facesheet. The sandwich structures with PU foam of varied density and glass fibres of different architecture are tested under three point bending. The experimental values of face bending strength (FBS) and core shear stress (CSS) are evaluated. Effect of core density and E-glass fabric architecture on the flexural strength is investigated. It has been observed that variation of core density and fabric architecture play a vital role in the failure modes of the sandwich composites. Under flexural loading, sandwich composites failed through debonding between the facesheet and the core followed by delamination. With increase in the density of the core, failure mode changed from debonding to core cracking followed by severe fibre rupture.

Keywords: Foam core, flexural, debonding, core shear strength, delamination