Abstract: An example mandrel for processing a part is described including a plurality of elastomeric components aligned end to end and spaced apart linearly to form a segmented mandrel body, and compressible interconnections positioned within spacing between adjacent elastomeric components and abutting the adjacent elastomeric components. The compressible interconnections allow the plurality of elastomeric components to expand axially due to thermal expansion resulting in a distribution of pressure. An example method for fabricating a composite part is also described including placing a base composite layer into a cavity of a tooling surface, inserting a mandrel into the cavity of the tooling surface such that the base composite layer is between the mandrel and the tooling surface, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing, and removing the mandrel from the cavity of the tooling surface.

Abstract: A bladder mandrel package, used to manufacture a composite structure, includes a mandrel and a wrap ply, surrounding the mandrel to form a wrapped mandrel. The bladder mandrel package also includes a first radius filler, coupled to the wrap ply at a first radius of the wrapped mandrel, and a second radius filler coupled to the wrap ply at a second radius of the wrapped mandrel. The mandrel, the wrap ply, the first radius filler, and the second radius filler are consolidated to from the bladder mandrel package.

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 example method of forming a composite structure includes applying a laminated charge onto an expandable pallet, moving the expandable pallet in a linear motion relative to a plurality of rollers, and progressively urging the laminated charge into a continuously expanding recess defined by the expandable pallet using the plurality of rollers. The plurality of rollers are oriented in a serial configuration so as to shape the laminated charge into at least part of a shape of the composite structure.

Abstract: An example mandrel for processing a part is described including an inner core having a material with first thermal properties, and an outer layer surrounding the inner core. The outer layer includes a material with second thermal properties different than the first thermal properties to enable uniform pressure distribution within the mandrel. An example method for fabricating a composite part is described including placing a base composite layer into a cavity of a tooling surface, inserting a mandrel into the cavity, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing the base composite layer and the skin such that during curing a pressure due to thermal expansion of one of the inner core and the outer layer is distributed by the other, and removing the mandrel from the cavity of the tooling surface following the curing.

Abstract: An example mandrel for processing a part is described including a plurality of elastomeric components aligned end to end and spaced apart linearly to form a segmented mandrel body, and compressible interconnections positioned within spacing between adjacent elastomeric components and abutting the adjacent elastomeric components. The compressible interconnections allow the plurality of elastomeric components to expand axially due to thermal expansion resulting in a distribution of pressure. An example method for fabricating a composite part is also described including placing a base composite layer into a cavity of a tooling surface, inserting a mandrel into the cavity of the tooling surface such that the base composite layer is between the mandrel and the tooling surface, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing, and removing the mandrel from the cavity of the tooling surface.

Abstract: There is provided a forming apparatus for constraining a composite charge and forming the composite charge into a highly contoured composite structure. The forming apparatus includes a first die and a second die between which the composite charge is formed. The first die has pairs of first die portions spaced apart to define a die cavity into which the composite charge is formed into a contoured hat section having a cap. The forming apparatus includes a constraining assembly having a constraining device positioned in the die cavity. The constraining device is designed to constrain a cap portion, and to apply an upward resistive force against the cap portion, and against a downward compressive force applied by the second die, to provide wrinkle prevention in the cap as the contoured hat section is formed. The constraining assembly has a retaining element to retain the constraining device.

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 forming a composite part from a mufti-ply prepreg composite charge comprises reducing pressure inside a bladder, located in a chamber that is at atmospheric pressure, below the atmospheric pressure. The method also comprises placing the multi-ply prepreg composite charge, having a first shape, in the chamber and reducing pressure inside the chamber below the atmospheric pressure. The method additionally comprises, while maintaining pressure inside the chamber below the atmospheric pressure, expanding the bladder within the chamber by increasing pressure inside the bladder to the atmospheric pressure, so that the multi-ply prepreg composite charge is compressed between the bladder and a forming tool, which is located inside the chamber, and the multi-ply prepreg composite charge is configured by the forming tool to a second shape, different from the first shape. The method also comprises curing the multi-ply prepreg composite charge, having the second shape.

Abstract: An example mandrel for processing a part is described including a plurality of elastomeric components aligned end to end and spaced apart linearly to form a segmented mandrel body, and compressible interconnections positioned within spacing between adjacent elastomeric components and abutting the adjacent elastomeric components. The compressible interconnections allow the plurality of elastomeric components to expand axially due to thermal expansion resulting in a distribution of pressure. An example method for fabricating a composite part is also described including placing a base composite layer into a cavity of a tooling surface, inserting a mandrel into the cavity of the tooling surface such that the base composite layer is between the mandrel and the tooling surface, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing, and removing the mandrel from the cavity of the tooling surface.

Abstract: A bladder mandrel package, used to manufacture a composite structure, includes a mandrel and a wrap ply, surrounding the mandrel to form a wrapped mandrel. The bladder mandrel package also includes a first radius filler, coupled to the wrap ply at a first radius of the wrapped mandrel, and a second radius filler coupled to the wrap ply at a second radius of the wrapped mandrel. The mandrel, the wrap ply, the first radius filler, and the second radius filler are consolidated to from the bladder mandrel package.

Abstract: A mandrel for processing a part is described that includes a solid mandrel body with an elastomeric material, and hollow micro-particles embedded within the solid mandrel body in a uniform distribution. The hollow micro-particles deform in response to a change in a processing environment resulting in a distribution of voids in the solid mandrel body. A method for fabricating a composite part is also described that includes placing a base composite layer into a cavity of a tooling surface, inserting the mandrel into the cavity, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing the base composite layer and the skin such that during curing the hollow micro-particles deform resulting in the distribution of voids in the solid mandrel body, and removing the mandrel from the cavity of the tooling surface following the curing.

Abstract: A method for manufacturing a cured composite structure from first stringers, second stringers and a panel comprising a first side and a second side, the method includes, for each first stringer, supporting the first stringer on the first side of the panel using a substantially rigid mandrel positioned within a first cavity defined between the first stringer and the first side of the panel, for each second stringer, supporting the second stringer on the second side of the panel using a flexible mandrel positioned within a second cavity defined between the second stringer and the second side of the panel, and co-curing the first stringers, the panel, and the second stringers while each of the one or more first stringers are supported by the respective substantially rigid mandrel and each of the one or more second stringers are supported by the respective flexible mandrel.

Abstract: An example apparatus for fabrication of a co-cured composite assembly includes a layup tool body with a cavity, a thermal expansion insert inserted into the cavity of the layup tool body and a first uncured composite part of the composite assembly is positioned onto the thermal expansion insert, and a solid internal mandrel configured for insertion onto the first uncured composite part. During curing, the first uncured composite part compacts and reduces in thickness while the solid internal mandrel and the thermal expansion insert each increase in size to apply pressure to the first uncured composite part.

Abstract: A bladder mandrel package, used to manufacture a composite structure, includes a mandrel and a wrap ply, surrounding the mandrel to form a wrapped mandrel. The bladder mandrel package also includes a first radius filler, coupled to the wrap ply at a first radius of the wrapped mandrel, and a second radius filler coupled to the wrap ply at a second radius of the wrapped mandrel. The mandrel, the wrap ply, the first radius filler, and the second radius filler are consolidated to from the bladder mandrel package.

Abstract: A method for manufacturing a cured composite structure from first stringers, second stringers and a panel comprising a first side and a second side, the method includes, for each first stringer, supporting the first stringer on the first side of the panel using a substantially rigid mandrel positioned within a first cavity defined between the first stringer and the first side of the panel, for each second stringer, supporting the second stringer on the second side of the panel using a flexible mandrel positioned within a second cavity defined between the second stringer and the second side of the panel, and co-curing the first stringers, the panel, and the second stringers while each of the one or more first stringers are supported by the respective substantially rigid mandrel and each of the one or more second stringers are supported by the respective flexible mandrel.

Abstract: An illustrative embodiment of the present disclosure provides a method of manufacturing a composite structure. A composite material having a closed cross-section or a partially closed cross-section is cured to form the composite structure, wherein the composite material is in contact with a foam mandrel assembly when curing begins. A supportive foam mandrel in the foam mandrel assembly is collapsed during curing.

Abstract: A bladder mandrel package, used to manufacture a composite structure, includes a mandrel and a wrap ply, surrounding the mandrel to form a wrapped mandrel. The bladder mandrel package also includes a first radius filler, coupled to the wrap ply at a first radius of the wrapped mandrel, and a second radius filler coupled to the wrap ply at a second radius of the wrapped mandrel. The mandrel, the wrap ply, the first radius filler, and the second radius filler are consolidated to from the bladder mandrel package.

Abstract: An example apparatus for fabrication of a co-cured composite assembly includes a layup tool body with a cavity, a thermal expansion insert inserted into the cavity of the layup tool body and a first uncured composite part of the composite assembly is positioned onto the thermal expansion insert, and a solid internal mandrel configured for insertion onto the first uncured composite part. During curing, the first uncured composite part compacts and reduces in thickness while the solid internal mandrel and the thermal expansion insert each increase in size to apply pressure to the first uncured composite part.

Abstract: A mandrel for processing a part is described that includes a solid mandrel body with an elastomeric material, and hollow micro-particles embedded within the solid mandrel body in a uniform distribution. The hollow micro-particles deform in response to a change in a processing environment resulting in a distribution of voids in the solid mandrel body. A method for fabricating a composite part is also described that includes placing a base composite layer into a cavity of a tooling surface, inserting the mandrel into the cavity, applying a skin to the mandrel and the base composite layer forming a package, enclosing the package in a vacuum bag and curing the base composite layer and the skin such that during curing the hollow micro-particles deform resulting in the distribution of voids in the solid mandrel body, and removing the mandrel from the cavity of the tooling surface following the curing.