Innovative fuselage design for safe and green aircraft Environmental and economic concerns are forcing aircraft designers to come up with new ways of reducing aircraft weight and costs to keep air transport competitive. Carbon fibre reinforced composite materials combined with a lattice structural design have the potential to make a significant contribution. Industrial Technologies © Thinkstock Aeronautics is a key asset for the future of Europe, but the industry is currently facing the challenge of making aircraft more affordable, safer, cleaner and quieter. Simultaneously, it must account for the demand that is likely to triple over the next 20 years. The WASIS (Composite fuselage section wafer design approach for safety increasing in worst case situations and joints minimizing) project rose to this challenge by designing a new fuselage structure that incorporated many cost-saving features. Researchers' broad goal was to develop a stiffer fuselage by replacing conventional aluminium structures with an all-composite lattice design. Team members worked on a composite fuselage structure based on the lattice (wafer) stiffening concept, which optimises geometrical and mass properties of transition zones of fuselage structural joints. Specially designed joining elements (semi-loops and micro-pins) allow for openings in the structure. As a result, only the fuselage skin fibres are cut, while the lattice ribs remain continuous. Except for making more reliable joints and preventing wastage of expensive composite material, these micro-pins also improve the load transfer from metals to composites. The design of the innovative fuselage section was merged with the highly efficient filament winding technology to reduce manufacturing costs and time. Virtual testing reduced the number of prototypes required, thereby saving additional material. Special tooling was designed to fully automate a complex manufacturing process. The skin, the ribs and the embedded joining elements were manufactured in a single process, forming a one-piece fuselage. Researchers also assessed the safety of carbon fibre-reinforced polymer through simulations and testing from the very first design stages to ensure the structure can better withstand accidental loads. Furthermore, the viboracoustical behaviour was also investigated. WASIS offers a unique opportunity to combine modern composite materials with automated manufacturing, together leading to stronger and lighter aircraft frames. This will reduce fuel consumption and manufacturing wastage. Meanwhile, new designs will make repairs easier. These innovations will foster European industry. Keywords Fuselage, aircraft, composite materials, lattice structures, wafer design, filament winding; grid stiffened structures
