SBIR-STTR Award

A unique textile process has been developed by Techniweave that employs multi-directional weaving. The process has been adapted to the fabrication of complex configurations that are potentially applicable as composite fittings in several areas within future aircraft designs. Lockheed Aircraft Company is the developer and manufacturer of the Air Force's F-22 Fighter Aircraft. There is interest in the development of innovative concepts for application of techniweave's 3-D woven insert to bulkhead structures on the F-22. A moderately loaded bulkhead structure from the F-22 center fuselage has been suggested for use in t demonstration program. There are several advantages of an integrated structure utilizing an innovative 3-D fitting design. The development of an appropriate preform that can be produced through automation and can be Resin Transfer Molded with a 350 F epoxy resin system has the potential of an affordable high performance airframe concept. Various insert designs need to considered in terms of adaptability to the F-22 bulkhead and potential for meeting loading and fatigue requirements. It is proposed to fabricate two selected concepts in an insert design including a cruciform configuration.

Woven 3-dimensional preform inserts combined with conventional carbon/epoxy laminating materials can be used to produce affordable high performance airframe structures. The present state-of-the-art in the design of fighter aircraft structures limits the use of composites to about 25 to 30% of the structure due to the inability of laminated composites to effectively carry high out of plane loads. The technology being developed in this program will result in composite joints that have fiber dominated rather than matrix dominated properties. Woven 3D preforms of Hercules IM7 carbon will be pre-impregnated with Fiberite 977-3 epoxy to produce inserts that can be combined with the conventional laminating materials.