11 - Aerospace applications

Abstract

The drive within the aerospace composites field over the last decade has been to reduce cost, increase component performance, and reduce component weight. Composites have now gained an accepted position in aircraft design, while carbon fiber-reinforced materials have become the mainstay of secondary components, such as wing movables (flaps, spoilers, rudder, etc.), and have found their way into primary structural components, such as complete horizontal stabilizer and vertical stabilizer structures. This chapter focuses on the use of carbon fiber-reinforced textile materials, since the other widely used composite reinforcement fibers, glass, and aramid have gained relatively limited use in the aerospace sector, owing to weight and lack of stiffness with regard to glass and to the problem of moisture absorption with respect to aramid fiber. Similarly, applications concentrate on the use of epoxy resin systems, as these dominate the aerospace composites sector. At the present time, pre-impregnated materials are utilized for nearly all composite components for aerospace structures. The largest volume of materials uses carbon fiber fabric, though in comparison, carbon unidirectional prepreg is growing at a stronger pace. This trend is, however, beginning to change with the advent of reliable processing routes with Resin Transfer Molding (RTM) or Resin Film Infusion (RFI) and a variety of other processing routes connected to these basic methods. This trend has come about due to the textile processing improvements of using high tow count carbon fibers for the preparation of textile fabrics and preforms. Applications for textile composites are usual where part consolidation is possible and overall sub-assembly construction cost is lowered against metallic components.