A composite hat stringer for stiffening a panel includes a plurality of composite fabric plies arranged to form a cap, a pair of flanges and a pair of webs respectively connecting the cap with the pair of flanges. The cap includes at least one 0° composite tape ply interleafed in the composite fabric plies within the cap.

A system includes a U-shaped chute, one or more feeder mechanisms, a sock application assembly, and a film application assembly. The chute has a chute inlet and a chute outlet and is configured to receive a mandrel having a mandrel length. The one or more feeder mechanisms are configured to move the mandrel into the chute inlet and through the chute. The sock application assembly has a sock material spool containing a breather sock in tubular form. The sock application assembly is configured to progressively apply the breather sock over the mandrel length as the mandrel exits the chute outlet. The film application assembly has a film material spool containing a film in tubular form. The film application assembly is configured to progressively apply the film over the breather sock covering the mandrel exiting the sock application assembly to thereby form a film-sock-mandrel assembly.

An improved composite stiffener and methods and tooling used to form the same. The stiffener includes one or more base flanges, a composite rod extending in an axial direction, a bulb cap surrounding the composite rod, and an upright web extending from the one or more base flanges to the base cap. The upright web includes a non-linear profile in the axial direction providing the improved lateral stiffness. The method includes providing tooling including a first compression tool extending in the axial direction and including a first web portion having a non-linear profile, and a second compression tool extending in the axial direction and including a second web portion having a non-linear profile. Plies are placed within the tooling and compressed such that at least a portion of plurality of plies are compressed in the web forming portion thereby forming a web of the bulb stiffener having a non-linear profile.

Aircraft stringers having carbon fiber reinforced plastic (CFRP) material reinforced flanges are disclosed. An example stringer to be coupled to a skin of an aircraft comprises a flange. The flange includes a first portion of a first stiffening segment. The flange further includes a first portion of a second stiffening segment coupled to the first portion of the first stiffening segment. The flange further includes a CFRP reinforcement segment coupled to the first portion of the first stiffening segment and to the first portion of the second stiffening segment. The CFRP reinforcement segment strengthens the first portion of the first stiffening segment and the first portion of the second stiffening segment.

A hat-stringer assembly (100) for an aircraft (500) comprises a hat stringer (110) with a first hat-stringer leg (140), a second hat-stringer leg (150), a first hat-stringer sidewall (114), a connecting wall (112), a second hat-stringer sidewall (116), and a ventilation opening (128), extending through the connecting wall (112). The hat stringer assembly (100) also comprises a fitting (200), comprising a first channel member (210) in contact with the first hat-stringer sidewall (114) and the first hat-stringer leg (140). The fitting (200) also comprises a second channel member (240) in contact with the second hat-stringer sidewall (116) and the second hat-stringer leg (150). The fitting (200) further comprises a web cap (260), in contact with the first channel member (210) and the second channel member (240). The web cap (260) comprises a web-cap opening (262), which is in fluidic communication with the ventilation opening (128).

A wing assembly includes a center wing structure and a pair of outer wing structures. The center wing structure includes a center wing front spar, a center wing rear spar, and an engine mounting location on each side of a wing centerline. Each outer wing structure includes an outer wing front and rear spar configured to be coupled respectively to the center wing front and rear spar to define a wing joint coupling the outer wing structure to the center wing structure. The center wing structure is configured such that the spar terminal ends of the center wing front and rear spars at each wing joint are located no further inboard than an engine centerline associated with the engine mounting location, and no further outboard of the engine centerline than ten percent of a distance between the engine centerline and the wing centerline.

A vented hat stringer for an aircraft comprises a first hat-stringer leg with a first-hat-stringer-leg surface, a second hat-stringer leg with a second-hat-stringer-leg surface, a first hat-stringer sidewall, a second hat-stringer sidewall, and a hat-stringer connecting wall, comprising a hat-stringer-connecting-wall surface and a virtual hat-stringer-connecting-wall symmetry plane, passing through hat-stringer connecting wall. The vented hat stringer further comprises a ventilation opening, extending through at least one of the first hat-stringer sidewall or the hat-stringer connecting wall, or extending through at least one of the second hat-stringer sidewall (116) or the hat-stringer connecting wall. The ventilation opening defines a ventilation-opening centerline, wherein the ventilation-opening centerline does not coincide with the virtual hat-stringer-connecting-wall symmetry plane.

A method for fabricating a composite wing structural component for an aircraft is described. The method comprises extruding a filler material into each mold channel of a plurality of mold channels of a die to form a plurality of filler segments, removing the plurality of filler segments from the plurality of mold channels of the die, and arranging the plurality of filler segments in a space in the composite structural component, the space being defined by a radius of the composite structural component, such that the filler segments are in end-to-end contact. The method further comprises curing the plurality of filler segments in the space to fuse the plurality of filler segments.

A process for producing a polymeric stiffened sheet-like component, for example a panel, for aircraft construction. Production includes integration of hollow stiffening profiles, for example closed omega stringers, onto a sheet-like component, for example an external skin, where the stringers and external skin are produced from thermoplastic composite material. The stringers are integrated onto the external skin by establishing contact between the stringers and the external skin and melting thermoplastic composite material with exposure to heat and pressure at the areas of contact between external skin and stringers. Melting of the other sections of the stringers is avoided with a pressurized cooling fluid with a temperature significantly below the melting point of thermoplastic composite material, the fluid flowing through the airtight enclosed space in the stringers. Use of closed airtight thermoplastic omega stringers allows integration of the stringers onto the external skin in absence of any flexible tube within the stringers.

This composite material structure is provided with: a first composite material that is obtained by stacking a plurality of first composite material sheets, each of which is obtained by impregnating electroconductive first reinforcing fibers with a first resin; a second composite material which is obtained by impregnating electroconductive second reinforcing fibers with a second resin; an insulating bonding layer that is arranged between the first composite material and the second composite material, thereby bonding the first composite material and the second composite material to each other; and an electroconductive member that connects the plurality of first composite material sheets.