Development of textile composite preforms for aircraft primary structures

Abstract

As part of the NASA sponsored Advanced Composite Technology program, Lockheed is developing woven and braided carbon fiber preforms for primary structural applications in transport airplane fuselage structures. The objective of this program is to develop composite primary structures that show significant weight saving compared to current metal transports and with a 20 to 25 percent reduction in acquisition cost. Both 2-D and 3-D braided frame preforms have been designed and fabricated. These preforms were resin transfer molded (RTM) and tested. Preforms using epoxy powder coated tows have been designed, fabricated and tested for fuselage window belt and side panel applications. These structures were designed to the Boeing 767X loads and criteria. Textile window-belt preforms will be supplied to Boeing for inclusion in large test panels with tow placed skins. Low-Cost Comvosite Structures The application of advanced composites to commercial aircraft structures has been extremely limited in the United States. The primary reason is cost. The military has demonstrated the weight savings and mission improvements but in general has been unable to reduce the cost to be comparable to or less than that of conventional metal structures. Commercial transport airplanes have been successfully produced in the USA for many years and provide a large part of the exports. To change the thinking of the producers requires that composites technology be developed and proven to be a lower cost alternative while maintaining all the safety and maintainability standards that the airlines are used to. The NASA Advanced Composites technology program was initiated to determine which technologies had potential for meeting the cost and weight goals for commercial transports and to develop and validate the most promising technologies.