Advisory Circular AC 20-107B, pertaining to composite aircraft structure, will provide updated acceptable means for showing compliance with FAR requirements governing the airworthiness type certification of composite aircraft structures using fiber-reinforced materials. It supersedes AC 20-107A, dated April 25, 1984.
Complex materials, made of carbon fiber composites and a metal, are tricky to characterize. “We already know that titanium is a better match than aluminum with carbon fiber,” research coordinator Benoît Sagot-Duvauroux said. But now researchers are endeavoring to put numbers on corrosion and dilatation issues, for example. Simulation of real-world operating conditions is the key to success in this work.
Ongoing research into new composite materials is expected to yield major enhancements in performance, weight and cost for the aerospace industry in the coming years. New ways of laying up carbon fiber, such as weaving, are already enabling more complex shapes. Thermoplastic resins are making manufacturing easier, and the practice of integrating several functions into one part is reducing part counts.
Toyota confirmed that the fuselage of its experimental four-seat piston aircraft is a one-piece co-cured (single-molded) unit of a carbon fiber and resin composite material. The aircraft flew for the first time at Mojave (Calif.) Airport on May 31.
Eurocopter recently completed the manufacturing of an EC 155 rear fuselage using a fiber-placement process. The company said the procedure consisted of placing “unidirectional composite material on the lay-up mold” automatically. The technical development feasibility project showed that some components could be fully integrated into the manufacturing process.
Manufacturers are relying more on composite materials for business aircraft construction thanks to a drop in manufacturing costs and better automation. Largely because of improved curing processes, OEMs are gradually eliminating expensive tooling and slashing the overall number of parts needed for a given aerostructure.
EADS Socata (Booth No. 3871) has started exploring a liquid-resin infusion (LRI) process for composite fuselage construction. The French company this month launched a $12.5 million, four-year research and development program, dubbed Fuscomp, which eventually is expected to yield a composite fuselage demonstrator. Its current business aircraft offering, the single-turboprop Socata TBM 850, uses mainly metal construction.
Park Electrochemical, a supplier of advanced composite materials for aerospace structures, is showcasing a newly introduced prepreg (pre-impregnated material) that the company said is tailor-made for aircraft interiors.
The future of composites may lie in carbon nanotubes. Nano composites have already found their way into cars and sports gear, and now specialists in this technology are looking for aerospace applications.
What are the advantages and disadvantages of carbon-fiber reinforced plastics?