Composite materials take off
Composite materials have been used for many years in civil and military aircraft structures, mostly in non-critical areas like floors and panels, but also in control surfaces, mainly in the form of honeycomb structures. The inherent disadvantage of property validation prohibited their widespread use which would offer significant weight savings, translated to range, payload and fuel. A major breakthrough is under way and it will not be long before complete fuselages will be made predominantly from composites, thanks to research conducted by European aerospace and materials research Institutes under the APRICOS Programme. The programme focused on the technologies necessary for the development of composite fuselage structures, aiming to demonstrate a 30% life cycle cost saving over conventional metal aircraft. Specifications were developed and a certification approach with design requirements have been identified together with methods for stress and impact behaviour. Innovative composite technologies were developed in the areas of liquid and film resin infusions and in resin transfer moulding, applied initially at subcomponent level and eventually demonstrated on a full scale structure assembly under real industrial conditions. Cost analysis has verified that a composite fuselages are feasible, offering significant life cycle cost savings as well as justifying further research aimed at a full scale barrel tests, in order to achieve the goal of a composite fuselage in service.