Abstract: Aircraft that incorporates a rounded-hat composite stringer connected to an inner side of the skin of the aircraft to form an elongate conduit that defines a conduit axis, where the conduit axis includes at least one curving portion. The rounded-hat composite stringer can be manufactured by constructing a lower forming die and an upper forming die, each forming die having a length and defining a curve along at least a portion of the length of the die, cutting a pre-cured flat composite charge dimensioned to form the rounded-hat composite stringer, pressing the flat composite charge between the lower and upper forming dies to shape the composite charge into a pre-formed stringer having an inner side between curved fillet portions, contacting a forming member against the inner side of the pre-formed stringer, applying radius fillers to the curved fillet portions of the pre-formed stringer, curing the pre-formed stringer, and removing the forming member from the cured stringer.

Abstract: Methods and devices of fabricating a stringer for a vehicle. The stringer can be constructed from two charges that are formed together into the stringer. During fabrication, the charges are placed over support members with the ends of each charge extending over a die cavity. The charges are secured and a punch die forces the first ends into the die cavity forming blades of the stringer. The charges are secured thus tensioning the charges during the punch process.

Abstract: A composite structure is fabricated using a preform comprising a stack of unidirectional prepreg plies that are stitched together. During curing of the prepreg, the stitches melt and dissolve.

Abstract: A composite structure is fabricated using a preform comprising a stack of unidirectional prepreg plies that are stitched together. During curing of the prepreg, the stitches melt and dissolve.

Abstract: The present disclosure is directed to a method of making a composite part. The method comprises covering a mold tool for a composite part with a parting film. The method further comprises laying up at least one layer of pre-preg on the parting film covering the mold tool to form a laid-up composite part and removing the laid-up composite part from the parting film. The parting film comprises a polymer sheet having a first major surface and a second major surface; and a first adhesive disposed on the first major surface of the polymer sheet, the first adhesive adhering the polymer sheet to the mold tool.

Abstract: Aircraft that incorporates a rounded-hat composite stringer connected to an inner side of the skin of the aircraft to form an elongate conduit that defines a conduit axis, where the conduit axis includes at least one curving portion. The rounded-hat composite stringer can be manufactured by constructing a lower forming die and an upper forming die, each forming die having a length and defining a curve along at least a portion of the length of the die, cutting a pre-cured flat composite charge dimensioned to form the rounded-hat composite stringer, pressing the flat composite charge between the lower and upper forming dies to shape the composite charge into a pre-formed stringer having an inner side between curved fillet portions, contacting a forming member against the inner side of the pre-formed stringer, applying radius fillers to the curved fillet portions of the pre-formed stringer, curing the pre-formed stringer, and removing the forming member from the cured stringer.

Abstract: A composite part, such as a stiffener is formed in place. A composite charge is placed on a tool spanning a mold cavity, with the centerline of the charge offset from the centerline of the mold cavity. Opposite sides of the charge are held against the tool as the charge is formed into the mold cavity. One side of the charge is held against movement on the tool while the other side of the charge is allowed to slip over the tool toward the mold cavity.

Abstract: Methods and devices of fabricating a stringer for a vehicle. The stringer can be constructed from two charges that are formed together into the stringer. During fabrication, the charges are placed over support members with the ends of each charge extending over a die cavity. The charges are secured and a punch die forces the first ends into the die cavity forming blades of the stringer. The charges are secured thus tensioning the charges during the punch process.

Abstract: The present disclosure is directed to a method of making a composite part. The method comprises covering a mold tool for a composite part with a parting film. The method further comprises laying up at least one layer of pre-preg on the parting film covering the mold tool to form a layed-up composite part and removing the layed-up composite part from the parting film. The parting film comprises a polymer sheet having a first major surface and a second major surface; and a first adhesive disposed on the first major surface of the polymer sheet, the first adhesive adhering the polymer sheet to the mold tool.

Abstract: A method of making a composite part comprises covering a mold tool for a composite part with a parting film, the parting film comprising a polymer sheet and a pressure sensitive adhesive. The parting film is positioned so that the polymer sheet is between the mold tool and the pressure sensitive adhesive. At least one layer of pre-preg is layed up on the parting film covering the mold tool to form a layed-up composite part. The pre-preg comprises an adhesive. The layed-up composite part is removed from the parting film.

Abstract: Systems and methods for defining a surface contour of a layered charge of material are disclosed herein. The systems include a forming die, which includes a forming surface shaped to define a desired surface contour of the layered charge, and a fluidly actuated support, which includes a support surface that is adjacent to the forming surface and located to support the layered charge. The systems further include a vacuum bag that at least partially defines an enclosed volume and a vacuum source configured to selectively apply a vacuum to the enclosed volume. The methods include locating the layered charge on the forming surface and on the support surface, covering the layered charge with the vacuum bag to define the enclosed volume, applying the vacuum to the enclosed volume, compressing the fluidly actuated support, translating the support surface, and deforming the layered charge to define the desired surface contour.

Abstract: A method of making a composite part comprises covering a mold tool for a composite part with a parting film, the parting film comprising a polymer sheet and a pressure sensitive adhesive. The parting film is positioned so that the polymer sheet is between the mold tool and the pressure sensitive adhesive. At least one layer of pre-preg is layed up on the parting film covering the mold tool to form a layed-up composite part. The pre-preg comprises an adhesive. The layed-up composite part is removed from the parting film.

Abstract: A composite structure is fabricated using a preform comprising a stack of unidirectional prepreg plies that are stitched together. During curing of the prepreg, the stitches melt and dissolve.

Abstract: Apparatuses and methods for forming a joggle and a longitudinal ridge in a multi-ply composite charge are disclosed. Charges may be formed in a forming press that comprises a joggled die, with a longitudinal ridge and a joggle that crosses the longitudinal ridge, and a conforming die, with a series of longitudinally-spaced die fingers. The die fingers include pairs of die members configured to move laterally between a closed position and an open position, with each die member configured to tilt longitudinally.

Abstract: Systems and methods for assembling a skin of a composite structure are disclosed herein. The methods include operatively attaching a charge of composite material to a flexible substrate to define an initial conformation for a composite-substrate assembly and locating the composite-substrate assembly and a layup mandrel proximal to one another. The methods further include pressing the composite-substrate assembly against an outer surface of the layup mandrel to deform the composite-substrate assembly to a final conformation. The methods also include affixing the charge of composite material to the outer surface of the layup mandrel and releasing the charge of composite material from the flexible substrate while retaining the charge of composite material on the outer surface of the layup mandrel. The systems include the flexible substrate, the layup mandrel, and an assembly deformation structure that is configured to press the composite-substrate assembly against the outer surface of the layup mandrel.

Abstract: Methods and tools for forming composite structures with predetermined, non-planar patterns of contours, as well as apparatuses including such composite structures, are disclosed herein. Example methods include defining a pattern of contours in a flexible sheet of composite material, conforming the flexible sheet of composite material to a layup mandrel, and curing the flexible sheet of composite material. Example tools include a body with an engagement surface for engaging a flexible sheet of composite material, the body having regions of relative stiffness and regions of relative compliance, and a vacuum distribution manifold configured to selectively apply a vacuum to the regions of relative compliance to deform the engagement surface to define a predetermined, non-planar pattern of contours.

Abstract: A composite part, such as a stiffener is formed in place. A composite charge is placed on a tool spanning a mold cavity, with the centerline of the charge offset from the centerline of the mold cavity. Opposite sides of the charge are held against the tool as the charge is formed into the mold cavity. One side of the charge is held against movement on the tool while the other side of the charge is allowed to slip over the tool toward the mold cavity.

Abstract: Apparatuses and methods for forming a joggle and a longitudinal ridge in a multi-ply composite charge are disclosed. Charges may be formed in a forming press that comprises a joggled die, with a longitudinal ridge and a joggle that crosses the longitudinal ridge, and a conforming die, with a series of longitudinally-spaced die fingers. The die fingers include pairs of die members configured to move laterally between a closed position and an open position, with each die member configured to tilt longitudinally.

Abstract: Methods of and systems for assembling stiffened composite structures are disclosed. Some methods include loading a stiffener onto an inner mold line layup mandrel and then loading a filler structure within the stiffener cavity of the stiffener. Some methods include loading, with a loading tool, a stiffener charge and a filler structure onto an inner mold line layup mandrel so the respective stiffener charge conforms to a stiffener form of the inner mold line layup mandrel to form a stiffener. Some methods include loading, with a loading tool, a stiffener and a filler structure onto an inner mold line layup mandrel.

Abstract: Systems and methods for defining a surface contour of a layered charge of material are disclosed herein. The systems include a forming die, which includes a forming surface shaped to define a desired surface contour of the layered charge, and a fluidly actuated support, which includes a support surface that is adjacent to the forming surface and located to support the layered charge. The systems further include a vacuum bag that at least partially defines an enclosed volume and a vacuum source configured to selectively apply a vacuum to the enclosed volume. The methods include locating the layered charge on the forming surface and on the support surface, covering the layered charge with the vacuum bag to define the enclosed volume, applying the vacuum to the enclosed volume, compressing the fluidly actuated support, translating the support surface, and deforming the layered charge to define the desired surface contour.