A method and apparatus are presented. The apparatus comprises a first unitary structure, a second unitary structure, and a number of joints between the first unitary structure and the second unitary structure. The first unitary structure has a plurality of T-shaped cross-sections. The second unitary structure has a plurality of T-shaped cross-sections.

Systems and methods are provided for placing preforms onto a mandrel. One illustrative method includes moving a mandrel in a process direction relative to a station(s) that comprises multiple pick-and-place machine(s), identifying a tray that stores a preform comprising an unhardened fiber-reinforced material, placing the strong back at the preform via at least one of the pick-and-place machine(s), applying a vacuum to hold the preform in contact with the strong back, transporting the preform to a mandrel via the pick-and-place machine(s), and placing the preform onto the mandrel.

A method and apparatus for compacting composite stringers. In one illustrative embodiment, an apparatus comprises a compacting structure, a compactor vacuum system, and a carrier vacuum system. The compacting structure has a shape configured to contact layers of uncured composite material for a composite stringer. The compactor vacuum system is associated with the compacting structure. The compactor vacuum system is configured to cause the compacting structure to apply a pressure to the layers of uncured composite material when a compactor vacuum is applied to the compactor vacuum system. The carrier vacuum system is associated with the compacting structure. The carrier vacuum system is configured to hold the layers of uncured composite material against the compacting structure when a carrier vacuum is applied to the carrier vacuum system.

A securement assembly for securing a vertical tail fin assembly to an aircraft includes a first lug member secured to the vertical tail fin assembly. The securement assembly further includes a first clevis member. The first clevis member includes a first end portion of the first clevis member is engaged to the first lug member. A second end portion of the first clevis member is secured to a first fuselage frame constructed of a composite material with a first fastener which extends through the second end portion and the first fuselage frame in a first direction transverse to the first fuselage frame.

A pressure bulkhead for a pressurized vehicle such as an aircraft employs a plurality of layers of composite fiber material having uni-directional fibers arranged in a single direction within the composite fiber material. The pressure bulkhead incorporates non-traditional radial and circumferential stiffening members into a composite laminate and aligns the radial stiffening members with the direction of dominant load paths. The radial and circumferential stiffening members are interlaid between full layers of the composite fiber material. Related methods of manufacturing the pressure bulkhead include using automated fiber placement equipment to form each layer of the pressure bulkhead and discretely orient the integral stiffeners and the uni-directional fibers in each layer.

A method for assembling a stiffened composite structure includes a step of positioning a plurality of dry fibers along a first side of a pre-preg composite laminate skin element wherein the pre-preg composite laminate skin element is dimensionally changeable. The method further includes a step of positioning an interlayer between the plurality of dry fibers and the first side of the pre-preg composite laminate skin element and a step of infusing the plurality of dry fibers with a resin forming a plurality of infused fibers. The method also includes a step of co-curing the pre-preg composite laminate skin element and the plurality of infused fibers.

An elastic structure anti-impact frame body for use in ships, automobiles, aircraft, trains, railcars and other moving vehicles, said frame body being a wholly or partially elastic frame, the bearing components constituting the frame body forming an arc-shape or a wave-shaped curve, and the frame body being made of an elastic material. The whole or part of the structure of the elastic structure anti-impact frame body has an elastic deformation function; on the premise that the elastic structure does not affect normal driving or bearing capacity, under the force of an impact on said frame, the frame body will elastically deform within a corresponding safe range, and can cushion and absorb the energy of the impact; the frame body, when releasing the energy of the impact, returns to the original shape, greatly improving the anti-impact security factor.

A configuration and manufacturing method for a trailing edge of an aircraft airfoil, such as a control surface or a lifting surface is described. The trailing edge is formed and configured by upper and lower composite covers, which are stitched to each other with a metallic wire, such as the metallic wire is electrically in contact with upper and lower metallic meshes to provide electrical continuity between meshes. According to a method, upper and lower covers configuring the trailing edge, are stitched with the metallic wire before curing the covers, so that the metallic wire gets embedded within the composite material. A trailing edge for an aircraft airfoil, which is easy to manufacture and that at the same time fulfills aerodynamic, mechanical and electrical conductivity requirements is described.

In an example, a composite stringer is described. The composite stringer includes a composite stringer and a base flange. The composite stringer includes a top flange, a first skin flange and a second skin flange configured to be coupled to a support structure, a first web extending between the first skin flange and a first side of the top flange, and a second web extending between the second skin flange and a second side of the top flange. The support structure includes at least one of a skin of a vehicle or a base charge. The base flange includes a bottom surface extending between the first skin flange and the second skin flange. The bottom surface of the base flange is configured to be coupled to the support structure. The base flange also includes a top surface extending between the first web and the second web.

A composite structure including a composite body having an outer surface, wherein the composite body is elongated along a span axis, and a detection layer connected to the outer surface of the composite body, the detection layer including a plurality of strips, wherein each strip comprises a plurality of glass fibers embedded in a matrix material, is elongated along a detection axis, the detection axis being substantially aligned with the span axis, and is spaced a non-zero distance apart from adjacent strips such that a discontinuity is defined between adjacent strips.