Abstract: A panel including an outer face sheet; an inner face sheet; a foam disposed between the outer face sheet and the inner face sheet; and a core structure (e.g., a stringer comprising a hat structure) between the foam and the inner face sheet; and between the foam and the outer face sheet. The core structure is protected from impact damage and increases flexural stiffness of the panel on an aircraft wing.

Abstract: A structure has a net-area-tension fastener pattern formed in the skin panel for receiving fasteners defining a net-area-tension joint for coupling a component attach fitting of a component to the skin panel. The net-area-tension fastener pattern includes two or more rows of fastener holes, including a first row and a last row. Each row is oriented generally perpendicular to a primary load direction of a load that the component is capable of exerting on the skin panel. The first row is located upstream of the last row relative to the primary load direction. The fastener holes in the first row and the last row are respectively the smallest and the largest in the net-area-tension fastener pattern. The rows are spaced apart at a spacing ratio of hole spacing to hole diameter. The spacing ratio of the first row is greater than the spacing ratio of the last row.

Abstract: Described herein are stringer assemblies, such as blade stringers, and methods of forming thereof. A stringer assembly comprises a first fabric composite stiffener, a second fabric composite stiffener, and an intermediate tape composite stiffener, disposed between and connected to each of the first and second stiffeners. Using three separate components allows forming sharp bends, eliminating voids and gap fillers, and adding new features, such as edge reinforcements. Each of the first and second fabric composite stiffeners comprises a web portion, a flange portion, and a curved portion, positioned between the web and flange portions. The web portions surround and are attached to the intermediate tape composite stiffener and, in some examples, include tapered-out edges for additional rigidity. The flange portions are attached to the composite base. The curved portions conform to the flared-out edges of the intermediate tape composite stiffener, which extends and connects to the composite base.

Abstract: A wing assembly include at least one fuel tank having a tank outboard end. In addition, the wing assembly includes a stout wing rib located proximate the tank outboard end and extending between a front spar and a rear spar. The wing assembly also includes at least one outboard wing rib located outboard of the stout wing rib and defining an outboard wing bay. The wing assembly also includes an upper skin panel and a lower skin panel each coupled to the front spar, the rear spar, the stout wing rib, and the outboard wing rib. A plurality of bead stiffeners are coupled to the upper skin panel and/or the lower skin panel and are spaced apart from each other within the outboard wing bay.

Abstract: A movable surface of an aircraft has a front spar extending along a spanwise direction between opposing movable surface ends. The movable surface also includes a plurality of ribs defining a plurality of bays between adjacent pairs of the ribs. Each rib extends between the front spar and a trailing edge portion of the movable surface. The movable surface further includes an upper and a lower skin panels coupled to the ribs and the front spar. In addition, the bull surface includes a plurality of bead stiffeners coupled to an inner surface of at least one of the upper skin panel and the lower skin panel. The bead stiffeners within the bays are spaced apart from each other and are oriented non-parallel to the front spar and have a bead stiffener cap having opposing cap ends respectively locate proximate the front spar and the trailing edge portion.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a stringer having a first stiffener extending along a path and having a first flange portion and a first web portion, wherein the first stiffener is formed from a composite including a fabric reinforcement; a second stiffener extending along the path and having a second flange portion and a second web portion, the first web portion being opposed and spaced from the second web portion, wherein the second stiffener is formed from a composite including a fabric reinforcement; and an intermediate stiffener extending along the path, the intermediate stiffener being positioned between the first web portion and the second web portion, the intermediate stiffener having a first side and a second side, the first side being connected to the first web portion and the second side being connected to the second web portion, wherein the intermediate stiffener is formed from a composite including unidirectional reinforcement fibers.

Abstract: A method, apparatus, and system for managing a composite part. An acceptable level of a warpage is identified for the composite part. The warpage for the composite part is a change in the composite part as manufactured that deviates from design specifications for the composite part. Orientations in a stacking sequence for plies in the composite part are selected that result in the composite part having the acceptable level of the warpage and a desired strength to form selected orientations. The composite part is manufactured using the selected orientations.

Abstract: An apparatus including one or more panels including an outer face sheet comprising a plurality of first composite materials; an inner face sheet comprising a plurality of second composite materials; and a plurality of foam pieces disposed between the outer face sheet and the inner face sheet, wherein the foam pieces reduce warping of the panels.

Abstract: A panel including an outer face sheet; an inner face sheet; a foam disposed between the outer face sheet and the inner face sheet; and a core structure (e.g., a stringer comprising a hat structure) between the foam and the inner face sheet; and between the foam and the outer face sheet. The core structure is protected from impact damage and increases flexural stiffness of the panel on an aircraft wing.

Abstract: A movable surface of an aircraft has a front spar extending along a spanwise direction between opposing movable surface ends. The movable surface also includes a plurality of ribs defining a plurality of bays between adjacent pairs of the ribs. Each rib extends between the front spar and a trailing edge portion of the movable surface. The movable surface further includes an upper and a lower skin panels coupled to the ribs and the front spar. In addition, the bull surface includes a plurality of bead stiffeners coupled to an inner surface of at least one of the upper skin panel and the lower skin panel. The bead stiffeners within the bays are spaced apart from each other and are oriented non-parallel to the front spar and have a bead stiffener cap having opposing cap ends respectively locate proximate the front spar and the trailing edge portion.

Abstract: 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.

Abstract: A wing assembly include at least one fuel tank having a tank outboard end. In addition, the wing assembly includes a stout wing rib located proximate the tank outboard end and extending between a front spar and a rear spar. The wing assembly also includes at least one outboard wing rib located outboard of the stout wing rib and defining an outboard wing bay. The wing assembly also includes an upper skin panel and a lower skin panel each coupled to the front spar, the rear spar, the stout wing rib, and the outboard wing rib. A plurality of bead stiffeners are coupled to the upper skin panel and/or the lower skin panel and are spaced apart from each other within the outboard wing bay.

Abstract: 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.

Abstract: A structure has a net-area-tension fastener pattern formed in the skin panel for receiving fasteners defining a net-area-tension joint for coupling a component attach fitting of a component to the skin panel. The net-area-tension fastener pattern includes two or more rows of fastener holes, including a first row and a last row. Each row is oriented generally perpendicular to a primary load direction of a load that the component is capable of exerting on the skin panel. The first row is located upstream of the last row relative to the primary load direction. The fastener holes in the first row and the last row are respectively the smallest and the largest in the net-area-tension fastener pattern. The rows are spaced apart at a spacing ratio of hole spacing to hole diameter. The spacing ratio of the first row is greater than the spacing ratio of the last row.

Abstract: Stringers and aircraft skin structures and related methods are disclosed. An example apparatus includes a skin structure and a support. The support includes a first surface, a second surface opposite the first surface, and a tapered edge extending from the first surface. The example apparatus includes a first material disposed between a first portion of the support and a first portion of the skin structure to couple the second surface of the support to the skin structure and a second material disposed between a second portion of the support and a second portion of the skin structure. The second material is different than the first material. The second portion of the support includes at least a portion of the tapered edge.

Abstract: Described herein are stringer assemblies, such as blade stringers, and methods of forming thereof. A stringer assembly comprises a first fabric composite stiffener, a second fabric composite stiffener, and an intermediate tape composite stiffener, disposed between and connected to each of the first and second stiffeners. Using three separate components allows forming sharp bends, eliminating voids and gap fillers, and adding new features, such as edge reinforcements. Each of the first and second fabric composite stiffeners comprises a web portion, a flange portion, and a curved portion, positioned between the web and flange portions. The web portions surround and are attached to the intermediate tape composite stiffener and, in some examples, include tapered-out edges for additional rigidity. The flange portions are attached to the composite base. The curved portions conform to the flared-out edges of the intermediate tape composite stiffener, which extends and connects to the composite base.

Abstract: Provided is a stringer having a first stiffener extending along a path and having a first flange portion and a first web portion, wherein the first stiffener is formed from a composite including a fabric reinforcement; a second stiffener extending along the path and having a second flange portion and a second web portion, the first web portion being opposed and spaced from the second web portion, wherein the second stiffener is formed from a composite including a fabric reinforcement; and an intermediate stiffener extending along the path, the intermediate stiffener being positioned between the first web portion and the second web portion, the intermediate stiffener having a first side and a second side, the first side being connected to the first web portion and the second side being connected to the second web portion, wherein the intermediate stiffener is formed from a composite including unidirectional reinforcement fibers.

Abstract: An interleaved layer construction of a composite panel and a composite plank constructed of three sub-planks that are adhered together and secured to the panel stiffen and strengthen the panel.