Abstract: A process for producing a fiber reinforced, staged resin composite or repair patch containing a staged and cobonded adhesive, comprises providing a composite or patch formed of one or more layers of a fiber reinforced thermosetting resin such as a graphite-epoxy material and applying a layer of a thermosetting resin adhesive, e.g. an epoxy adhesive, to a surface of the fiber reinforced resin material. The arrangement is then placed in a vacuum environment such as a nonautoclave tool, to draw off volatiles from the resin, and the temperature is raised under conditions to stage the thermosetting resin of the adhesive and of the composite or patch, and cobonding the staged adhesive to the staged composite or patch. The resulting cobonded and staged composite-adhesive can be stored until ready for use, e.g. in repairing a damaged substrate.

Abstract: A process for manufacturing stiffened composite skin panel structures possessing novel hollow crown-shaped stiffener elements, and further including any combination of forward spars, aft spars, and transversely extending shear ties. The novel process embraces fabrication and curing of these structures without the use of mandrels. In practicing the method, the crown-shaped stiffeners, spars and shear ties are integrally bonded to a planar or curved skin structure to provide axial stiffness in semimonocoque components such as aircraft wings, stabilizers, fuselages, etc. The method of fabrication yields highly producible, structurally efficient composite aircraft components.

Abstract: System and method for producing a composite, particularly applicable for repairing damage to a structural component, wherein an electrical resistance heating element basically in the form of a layer of conductive carbon or graphite, e.g., in fiber form, becomes bonded to and forms a part of the cured composite. In the repair of a parent structure, a patch comprising a heat curable resinous material is applied to the parent structure, and a heat bondable adhesive film is positioned between the parent structure and the patch. An electrical resistance heating element in the form of a layer of graphite fibers is provided in contact with, or forming a part of, the patch, the heating element being capable of bonding the patch to the parent structure upon heating the adhesive bond to a predetermined temperature, to form a unitary structure comprised of the damaged parent structure, the patch and the heating element.