Abstract: An aircraft stringer lay-up assembly is provided comprising a contoured curing block and a first mandrel element positioned thereon. The first mandrel assembly includes a first bar assembly having a plurality of rigidity reducing first slots formed along a first mandrel length. The plurality of rigidity reducing first slots protruding partially through a first mandrel depth of the first mandrel element to allow the first bar assembly to conform to the contoured curing block. A composite ply assembly is laid up onto the first mandrel element and cured while conformed to said contoured curing block such that a contoured composite stringer element is generated.

Abstract: An aircraft stringer lay-up assembly is provided comprising a contoured curing block and a first mandrel element positioned thereon. The first mandrel assembly includes a first bar assembly having a plurality of rigidity reducing first slots formed along a first mandrel length. The plurality of rigidity reducing first slots protruding partially through a first mandrel depth of the first mandrel element to allow the first bar assembly to conform to the contoured curing block. A composite ply assembly is laid up onto the first mandrel element and cured while conformed to said contoured curing block such that a contoured composite stringer element is generated.

Abstract: An aircraft stringer lay-up assembly is provided comprising a contoured curing block and a first mandrel element positioned thereon. The first mandrel assembly includes a first bar assembly having a plurality of rigidity reducing first slots formed along a first mandrel length. The plurality of rigidity reducing first slots protruding partially through a first mandrel depth of the first mandrel element to allow the first bar assembly to conform to the contoured curing block. A composite ply assembly is laid up onto the first mandrel element and cured while conformed to said contoured curing block such that a contoured composite stringer element is generated.

Abstract: A method of manufacturing a unitary seamless section of an aircraft fuselage comprises disposing a thin lay-up mandrel element onto the outer shell surface of a cylindrical inner mandrel shell, thereby forming a mandrel with a lay-up surface. A plurality of resin impregnated stiffener fibers may be layed-up within a plurality of stiffener channels in the lay-up surface to form a plurality of stiffeners or stringers. The method further includes laying up a plurality of resin impregnated skin fibers onto the lay-up surface while the mandrel rotates to form a unitary pre-cured section of an aircraft fuselage.

Abstract: An aircraft stringer lay-up assembly is provided comprising a contoured curing block and a first mandrel element positioned thereon. The first mandrel assembly includes a first bar assembly having a plurality of rigidity reducing first slots formed along a first mandrel length. The plurality of rigidity reducing first slots protruding partially through a first mandrel depth of the first mandrel element to allow the first bar assembly to conform to the contoured curing block. A composite ply assembly is laid up onto the first mandrel element and cured while conformed to said contoured curing block such that a contoured composite stringer element is generated.

Abstract: An aircraft stringer lay-up assembly is provided comprising a first mandrel element having a first mandrel material with a first mandrel coefficient of thermal expansion. A composite ply assembly is laid up onto the first mandrel element to generate a primary lay-up surface. The composite ply assembly comprises a first primary fold-over portion folded onto to the first mandrel right end surface. A second primary fold over portion folds over to the first mandrel left end surface. The first mandrel coefficient of thermal expansion is adapted such that the first mandrel is movable between a first mandrel normal condition and a first mandrel heated condition where the first mandrel right end surface and the first mandrel left end surface move away from each other. The first primary fold-over portion and the secondary primary fold over portion are thereby moved such that wrinkles are pulled out of said primary lay-up surface.