Lightweight Aluminium Sandwich Structures for Marine Vehicles

Abstract

One of the most important design strategies for increasing the speed and/or efficiency of marine vehicles is that of weight reduction. This can be achieved by optimising structural design via judicious distribution of the most apt materials and via the application of innovative lightweight structures. Sandwich structures are ideal candidates for structural lightening since they provide excellent mechanical properties at low densities, and a wide range of properties via intelligent selection of face-sheet and core materials, and configurations. Further, sandwich structures selection for marine vehicles needs to consider manufacturing feasibility for large structures, sustainability issues and materials compatibility with the aggressive marine environment. As a possible alternative to the ubiquitous glass reinforced plastic (GRP) fibre composite sandwich materials used for marine vehicles, all-aluminium sandwich structures have several attractive properties such as light weight, high mechanical properties, sustainability, and corrosion resistance. Common architectures for metallic cores include: honeycomb, foam, corrugated and lattice. This work aims to evaluate the effectiveness of aluminium honeycomb sandwich structures in marine applications by providing a comparison with other lightweight solutions. Bending stiffness was used as the criterion to select honeycomb sandwich panels allowing valid comparisons with typical marine GFRP sandwich panels. A case study based on a possible replacement of a GFRP ship balcony with an equivalent aluminium honeycomb sandwich structure was introduced. The proposed balcony was analysed with a simplified numerical model, which gives useful information for the design of the proposed structure and the experimental set up of full scale tests. The acquired information can be applied to support the design of lightweight honeycomb sandwich panels to be used for balconies, decks, floors, ceilings and other structural elements of marine vehicles.