Experimental characterization of a novel balsa cored sandwich structure with fiber metal laminate skins

Abstract

Balsa cored sandwich structures with fiber-reinforced polymer (FRP) skins are widely used to produce lightweight, high-stiffness and cost-effective structural components used in marine applications. However, balsa is a hydrophilic material, which is severely susceptible to moisture attacks. Unintended water penetration from the damaged FRP skins into the balsa cored sandwich structures can lead to the core decay and delamination of the core near the free edges. Thus, in this work, a concept for improving the damage tolerance of balsa cored sandwich structures by replacing the FRP skins with fiber metal laminates (FMLs) is proposed. To characterize the mechanical properties of these novel sandwich structures, a wide range of mechanical tests including three-point bending, edgewise compression with buckling as well as Charpy and high-velocity impact test were carried out on balsa cored sandwich specimens made of FMLs. A traditional sandwich structure made of woven E-glass fiber/epoxy skins was also prepared and tested for exploring the effect of skin material on the mechanical response of the studied sandwich structures. The experimental results showed that balsa cored sandwich structures composed of FML skins have an outstanding mechanical performance compared with those having the E-glass fiber/epoxy skins.