Composite materials for aircraft interiors
The use of composites for virtually every visible part means lighter commercial airplanes with significant fuel savings. The EU-funded project LIGHTBOX (Lightweight composite bus system housing for extreme environments) was initiated to promote the adoption of composite materials for housing avionic systems. Whether it is air-to-ground communications or in-flight entertainment equipment, these electronic systems are integrated into a rack usually located in the airplane cockpit. The individual compartments in the rack have dimensions that meet common specifications, like the Arinc 600 standard. This allows accommodating components with standardised dimensions and facilitates the addition of new devices in the case of subsequent retrofit of an airplane. The LIGHTBOX partners redesigned the current Arinc 600 housing using composite materials. The next step was to evaluate different manufacturing processes and materials before proposing the specific solutions. With the use of carbon fibre-reinforced plastic, the LIGHTBOX team achieved a 34% weight reduction with respect to a similar aluminium enclosure. The composite prototype built was lighter than machined aluminium enclosures and also exhibited equal or even better mechanical, electrical and thermal performance. A series of vibration, EMI-EMC and high-temperature tests were all passed successfully. More importantly, it can be manufactured at an affordable cost. For the prototype, affordable materials and out of autoclave processes have been used. Manufacturability aspects have also been considered from the early stage in order to achieve a production cost similar to the current aluminium design. As per the LIGHTBOX partners' estimations, just one carbon fibre-reinforced plastic enclosure can bring a fuel saving of about 1320 litres or a cost saving of about EUR 660 per year. The LIGHTBOX enclosure with connectors for avionic systems has reached a technology readiness level of 5.This level is a breaking point where the new technology is no longer a subject of research and experiment. Project partners are now at the stage where they may decide to commit to further investment for real-life implementation and commercialisation.
Keywords
Composite materials, commercial airplane, fuel saving, avionic system, carbon fibre-reinforced plastic, infusion, cost affordable, lightweight