The Influence of Surface Finishing of Core on the Impact Behaviour of Polymer Foam-cored Sandwich Structures

Abstract

The interest on sandwich composite structures is increasing due to their good mechanical properties, the ability to tailor the sandwich structure to each component, and good formability. These materials are used in aerospace, wind energy and automotive industries, where minimising the weight of vehicle or components is very important. The increasing use of polymer foams in composite structures has encouraged the polymer industry to improve the mechanical properties of the core materials, by redesigning the materials and applying different types of surface finishing. In this research, the effect of surface finishing options on the impact behaviour of sandwich composite structures was investigated by performing low velocity drop weight impact tests, because impact is often critical in this kind of components. The sandwich composites used had a PVC polymer foam core with various surface finishing options (plain, flexi cut, knife cut, saw cut and mini cut), and were manufactured with Glass Fibre Reinforced Polymer (GFRP) skins through Resin Infusion under Flexible Tooling (RIFT). After the impact test, the delaminated areas at the back face of the samples with different finishes were measured and compared against each other. The surface finishing options affected the impact behaviour of the sandwich composite structure, and increased the ductility and energy-absorption capacity of the structure.