Lockheed Martin Corporation

Timothy Dennis Iwanczyk

Peter A Buck

William J Arbegast

Mark Harry Wexler

A method for fabrication or production of composite structures, which has particular advantages when fabricating large structures, includes the steps of procuring a composite panel, such as carbon-fiber-reinforced resin. The edge of the composite panel its adhesively fixed in the slot of a bifurcated metallic piece. After the composite panel is adhesively fixed to the metallic piece, the metallic piece is stir-friction welded to another metal piece. The stir-friction welding occurs at a lower temperature than fusion welding, and so the adhesive bond between the metallic element and the composite panel is less affected. When two composite panels are each adhesively fastened to a metallic element, the two metallic elements can, in turn, be stir-friction welded. Thus, large panels can be fabricated.

Method for making large composite structures without use of an autoclave

An improved fuel tank for a lifting body re-entry vehicle having a particular external shape comprising four elongated lobes each having an external surface, each of the external surfaces having selected cylindrical and conical shapes, the lobes being selectively mateable to form a combined external configuration having a multiplicity of cylindrical and conical shapes conformable to at least a portion of the external shape of the vehicle. The cylindrical and conical shapes have variable radii at selected cross-sections thereof, such radii being selected for forming the external configuration. In a particular embodiment, the fuel tank has an initial portion, a midsection portion and a final portion and the cross-sectional shape of the initial portion of the fuel tank is that of two overlapping circles whose centers are positioned above one another, each of the circles being formed by two of the four lobes. In the midportion of the fuel tank, the cross-sectional shape is that of four overlapping circles whose centers are positioned to form a four-lobed closed arcuate figure. In the final portion of the fuel tank, the cross-sectional shape of the fuel tank is that of two overlapping circles whose centers are positioned aside one another, each of the circles being formed by two of the four lobes. When two such fuel tanks are placed side-by-side, the combined external surfaces closely approximate a large portion of the shape of the re-entry vehicle.

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St. Tammany Parish, LA, United States of America

Timothy Dennis Iwanczyk