Abstract: A device to assemble a skin and a frame of an aircraft fuselage. The device includes first and second brace members that extend along opposing sides of a gap. Arches are spaced apart and fixedly connected to the first and second brace members and that extend across the gap. A strongback is attached to and movable along the first and second brace members with the strongback having a curved shape that matches the plurality of arches. The strongback includes clamps configured to engage with the frame. First and second tension devices apply tension to the skin at the strongback.

Abstract: In an example, a system is disclosed. The system comprises a one-piece mandrel, a fuselage coupled to the one-piece mandrel, and a strongback apparatus positioned on the fuselage. The strongback apparatus comprises an arcuate central body comprising a front end, a rear end, and a plurality of elongated members that connect the front end to the rear end, and actuators mounted to the plurality of elongated members. The actuators are configured to move in a radially outward direction from extended positions to retracted positions and comprise (i) proximal ends mounted to the plurality of elongated members and (ii) distal ends having vacuum suction cups. In the extended positions, the vacuum suction cups engage the fuselage on which the strongback apparatus is positioned. As the actuators moves from the extended positions to the retracted positions, the vacuum suction cups pull the fuselage away from the one-piece mandrel.

Abstract: Systems and methods are provided for splicing airframe components. One embodiment is a method for assembling an airframe of an aircraft. The method includes forming a first skin of a first circumferential section of fuselage, the first skin including a distal portion comprising a lip and a shoulder, aligning a second skin of a second circumferential section of fuselage with the shoulder such that the lip overlaps the second skin, and affixing the first skin and the second skin together via a circumferential splice.

Abstract: Methods and apparatus involved in the process of hardening a composite part are disclosed herein. The methods include applying a preform to a mandrel, covering the preform with a caul plate, sealing the caul plate to the mandrel, pushing the caul plate toward the preform and the mandrel and hardening the preform into a composite part while the caul plate is held against the preform. The apparatus include a mandrel, a caul plate which defines a surface of a preform and where the caul plate may include a rigid material and seals disposed between the mandrel and the caul plate. In an additional aspect, the apparatus may include a sealed chamber with a mandrel and a caul plate and a circumferential seal between the mandrel and the caul plate.

Abstract: Systems (100) for assembling stiffened composite structures comprise a layup mandrel (102) and a network (104) of fluid lines (116) configured to be selectively and fluidically coupled to string bladders (118) positioned relative to the layup mandrel (102).

Abstract: A device to assemble a skin and a frame of an aircraft fuselage. The device includes first and second brace members that extend along opposing sides of a gap. Arches are spaced apart and fixedly connected to the first and second brace members and that extend across the gap. A strongback is attached to and movable along the first and second brace members with the strongback having a curved shape that matches the plurality of arches. The strongback includes clamps configured to engage with the frame. First and second tension devices apply tension to the skin at the strongback.

Abstract: A device to assemble a skin and a frame of an aircraft fuselage. The device includes first and second brace members that extend along opposing sides of a gap. Arches are spaced apart and fixedly connected to the first and second brace members and that extend across the gap. A strongback is attached to and movable along the first and second brace members with the strongback having a curved shape that matches the plurality of arches. The strongback includes clamps configured to engage with the frame. First and second tension devices apply tension to the skin at the strongback.

Abstract: Systems and methods are provided for demolding a composite part from a mandrel. The method includes mechanically coupling a first arm of an extraction tool to a first arcuate portion of a composite part that has been hardened onto a mandrel, mechanically coupling a second arm of an extraction tool to a second arcuate portion of the composite part, and separating the composite part from the mandrel by iteratively performing the following operations until the composite part no longer contacts the mandrel: elastically straining the first arcuate portion of the composite part via the first arm, and elastically straining the second arcuate portion of the composite part via the second arm.

Abstract: Described herein are methods and systems for forming composite stringer assemblies or, more specifically, for shaping composite charges while forming these stringer assemblies. A system comprises a bladder, having a bladder core, and a bladder skin. The bladder core is formed from foam. The bladder skin is formed from an elastic material and encloses the bladder core. When a composite stringer assembly is formed, the bladder is positioned over a charge base. The charge base later becomes a stringer base, such as a fuselage section or a wing skin. A charge hat is then positioned over the bladder and is conformed to the bladder. A combination of the bladder skin and the bladder core provides support during this forming operation and later while the stringer assembly is cured. In some examples, the bladder core is collapsible for the removal of the bladder from the cavity of the stringer assembly.

Abstract: An apparatus for processing a composite structure includes a mandrel that includes a tooling surface and vacuum bagging that includes an elastomeric membrane and a bagging surface. The apparatus also includes a surface interface formed between the mandrel and the elastomeric membrane. The surface interface includes a suction channel formed in at least one of the tooling surface of the mandrel and the bagging surface of the elastomeric membrane. The elastomeric membrane is configured to be sealed to the mandrel along the suction channel in response to a vacuum applied to the suction channel.

Abstract: Systems and methods are provided for splicing airframe components. One embodiment is a method for assembling an airframe of an aircraft. The method includes forming a first skin of a first circumferential section of fuselage, the first skin including a distal portion comprising a lip and a shoulder, aligning a second skin of a second circumferential section of fuselage with the shoulder such that the lip overlaps the second skin, and affixing the first skin and the second skin together via a circumferential splice.

Abstract: In an example, a system is disclosed. The system comprises a one-piece mandrel, a fuselage coupled to the one-piece mandrel, and a strongback apparatus positioned on the fuselage. The strongback apparatus comprises an arcuate central body comprising a front end, a rear end, and a plurality of elongated members that connect the front end to the rear end, and actuators mounted to the plurality of elongated members. The actuators are configured to move in a radially outward direction from extended positions to retracted positions and comprise (i) proximal ends mounted to the plurality of elongated members and (ii) distal ends having vacuum suction cups. In the extended positions, the vacuum suction cups engage the fuselage on which the strongback apparatus is positioned. As the actuators moves from the extended positions to the retracted positions, the vacuum suction cups pull the fuselage away from the one-piece mandrel.

Abstract: A mold insert and method of using a mold insert to make a composite part. The mold insert is configured to make a composite part from composite material. The mold insert is configured to be attached to a mandrel. Once attached, the composite material is applied to the mandrel over the mold insert, stringers, and bladders. The composite material is then cured on the mandrel. The mold insert can then be removed from the mandrel.

Abstract: Systems and methods are provided for demolding a composite part from a mandrel. The method includes mechanically coupling a first arm of an extraction tool to a first arcuate portion of a composite part that has been hardened onto a mandrel, mechanically coupling a second arm of an extraction tool to a second arcuate portion of the composite part, and separating the composite part from the mandrel by iteratively performing the following operations until the composite part no longer contacts the mandrel: elastically straining the first arcuate portion of the composite part via the first arm, and elastically straining the second arcuate portion of the composite part via the second arm.

Abstract: An apparatus for processing a composite structure includes a first processing-tool and a second processing-tool that are movable between an open position, in which the first processing-tool and the second processing-tool are separated from each other, and a closed position, in which the first processing-tool and the second processing-tool are configured to be sealed to each other. In the closed position, the first processing-tool and the second processing-tool are configured to be sealed to a mandrel-tool, located between the first processing-tool and the second processing-tool and supporting the composite structure. In the closed position, the first processing-tool, the second processing-tool, and the mandrel-tool form a vessel, configured to apply at least one of pressure and heat to the composite structure.

Abstract: Methods and apparatus involved in the process of hardening a composite part are disclosed herein. The methods include applying a preform to a mandrel, covering the preform with a caul plate, sealing the caul plate to the mandrel, pushing the caul plate toward the preform and the mandrel and hardening the preform into a composite part while the caul plate is held against the preform. The apparatus include a mandrel, a caul plate which defines a surface of a preform and where the caul plate may include a rigid material and seals disposed between the mandrel and the caul plate. In an additional aspect, the apparatus may include a sealed chamber with a mandrel and a caul plate and a circumferential seal between the mandrel and the caul plate.

Abstract: A method of processing a composite structure includes a step of positioning a first processing tool of a tooling assembly and a second processing-tool of the tooling assembly from an open position, in which the first processing-tool and the second processing-tool are spaced apart, to a closed position, in which the first processing-tool and the second processing-tool are sealed to each other and are sealed to a mandrel-tool, supporting the composite structure, to form a vessel that surrounds the composite structure. The method also includes a step of processing the composite structure.

Abstract: Described herein are methods and systems for forming composite stringer assemblies or, more specifically, for shaping composite charges while forming these stringer assemblies. A system comprises a bladder, having a bladder core, and a bladder skin. The bladder core is formed from foam. The bladder skin is formed from an elastic material and encloses the bladder core. When a composite stringer assembly is formed, the bladder is positioned over a charge base. The charge base later becomes a stringer base, such as a fuselage section or a wing skin. A charge hat is then positioned over the bladder and is conformed to the bladder. A combination of the bladder skin and the bladder core provides support during this forming operation and later while the stringer assembly is cured. In some examples, the bladder core is collapsible for the removal of the bladder from the cavity of the stringer assembly.

Abstract: A method of fabricating a composite structure is presented. The method comprises laying up a plurality of composite plies over a layup mandrel; positioning a first caul plate and a second caul plate over the plurality of composite plies, leaving composite material exposed; removing at least part of the composite material exposed between the first caul plate and the second caul plate to separate a first composite section from a second composite section; curing the first composite section and the second composite section to form a first composite part and a second composite part; and removing the first composite part and the second composite part from the layup mandrel immediately following curing.

Abstract: A method of fabricating a composite structure is presented. The method comprises laying up a plurality of composite plies over a layup mandrel; positioning a first caul plate and a second caul plate over the plurality of composite plies, leaving composite material exposed; removing at least part of the composite material exposed between the first caul plate and the second caul plate to separate a first composite section from a second composite section; curing the first composite section and the second composite section to form a first composite part and a second composite part; and removing the first composite part and the second composite part from the layup mandrel immediately following curing.