Manufacturing High-Performance and Complex Geometry Sandwich Structures by Additive Manufacturing Methods

This case study demonstrates a cost-effective method to manufacture geometrically complex, high-performance sandwich structures with integrated fastening points. The aim of the work is to address some of the key challenges related to the implementation of conventional sandwich structures which limit their industrial exploitation. Such challenges include: geometrical complexity, (specifically double curvature, thickness changes or ramps), attachment points and embedded fasteners. A technical demonstrator has been designed and manufactured. This includes a tailored core manufactured by additive layer manufacturing (ALM), with integrated structural attachment points and complex geometries. Bi-directional carbon fibre skins were deposited by Automated Fibre Placement and subsequently impregnated by vacuum assisted infusion. Density and mechanical properties of the ALM core are comparable to commercially available foam core materials, while demonstrating an overall production cost benefit by reducing the secondary manufacturing steps required. Integrated inserts eliminate the need for the implementation of resin reinforcement around fasteners, reducing the overall weight of the high performance structures. The demonstrator showcases a manufacturing process that is relevant to any industry that requires geometrically complex, light and stiff composite components, thus promoting cross-sector innovation.