IM7/8552 Carbon/Epoxy Sine Wave Beam Pultrusion-Based Process Automation

Graphite/epoxy sine wave beams are used in several production aircraft, including wings of the F-22 Raptor. These lightweight structures replace traditional flat web I-beams with an undulating web surface that greatly increases buckling resistance, resulting in thinner, lighter, more durable structures. Because of their non-planar layout, traditional hand layup / autoclave cured fabrication of sine wave beams is extremely expensive. Approaches such as automated tape layup and resin transfer molding have reduced cost somewhat, but finished sine wave beams can still easily exceed $500 to $1,000 per pound. In the current era of cost-driven performance, disruptive manufacturing technology that significantly reduces cost is required. KaZaK proposes to develop and demonstrate a pultrusion-based technology for completely automating the production of sine wave beams using IM7/8552 prepreg. Previous work at KaZaK has suggested application of similar pultrusion technology to flat web I-beams reduces cost by a minimum of 50% compared to other fabrication approaches. KaZaK will interact with Sikorsky Aircraft to select an appropriate helicopter structure, ensuring that our evolving design and manufacturing methods, in combination with use of qualified prepreg, will speed the acceptance of this paradigm-breaking manufacturing technology by the aerospace industry.