Abstract: A method for fabricating a central caisson of an aircraft wing including a frame formed from U-section crossmembers. Formation of at least one crossmember includes forming a stack comprising at least one layer of resin film applied to a layer of dry fibers, pressing this stack to confer on it a U-section form and such as to compress the layers thereof, and pre-polymerization and/or polymerization of the resin of the stack. The manipulated fiber layers are layers of dry fibers, such that manipulation thereof by an automated machine may be effected for a reasonable cost and at a high throughput. Deposition of resin films carried by removable leaves, i.e., of which one of the faces is not adhesive, likewise facilitates manipulation by an automated installation.

Abstract: A method is disclosed for manufacturing connecting members for connecting an aircraft wing to a center wing box, using preforms. The method involves a step of manufacturing at least one preform made of composite material forming the connecting member, and a step of assembling the preform or preforms by heat treatment to form the connecting member. The manufacturing method makes it possible, simply and quickly, to manufacture a connecting member that contributes to the connection between a center wing box of an aircraft and a wing of the aircraft.

Abstract: A method for manufacturing at least a portion of a box structure obtained from an outer skin and a plurality of sections each having a joining face in contact with the outer skin. The method comprises a step of positioning the sections on a mold, a step of obtaining a flat fiber preform having a thickness substantially equal to the outer skin, a step of placing a central portion of the fiber preform on the sections positioned on a first face of the mold and a step of forming a lateral extension of the fiber preform to press the fiber preform against a forming surface. A central wingbox obtained by the method is provided and a forming tool for carrying out the method.

Abstract: A device for manufacturing a stiffened panel with reinforcements which each have a final thickness and a final height. The manufacturing device includes tools configured to each support a preform of fibers having a U-shaped or C-shaped cross section with a base and two wings. Each tool comprises, at at least one of its first and second lateral faces, a set-back portion which, when two tools are juxtaposed, delimits a recess configured to form a reinforcement during a consolidation or polymerization step. The tools are dimensioned such that each recess has a width, at the consolidation or polymerization temperature, that is substantially equal to the thickness of the reinforcements. This solution makes it possible to more effectively control the geometry of the stiffened panel by avoiding the formation of beads. A method for manufacturing a stiffened panel using the device is also disclosed.

Abstract: A method for manufacturing a centre wing box which includes inner stiffeners, at least one of which has at least one through-hole is described. For each stiffener having at least one through-hole and having a first leg of a first U-shaped and C-shaped profile and a second leg of a second U-shaped and C-shaped profile, the method includes, for each through-hole, the steps of producing a first section of the through-hole in the first U-shaped or C-shaped profile and of producing a second section of the through-hole in the second U-shaped or C-shaped profile before the first and second U-shaped or C-shaped profiles are positioned on the mould.

Abstract: A method for fabricating a central caisson of an aircraft wing including a frame formed from U-section crossmembers. Formation of at least one crossmember includes forming a stack comprising at least one layer of resin film applied to a layer of dry fibers, pressing this stack to confer on it a U-section form and such as to compress the layers thereof, and pre-polymerization and/or polymerization of the resin of the stack. The manipulated fiber layers are layers of dry fibers, such that manipulation thereof by an automated machine may be effected for a reasonable cost and at a high throughput. Deposition of resin films carried by removable leaves, i.e., of which one of the faces is not adhesive, likewise facilitates manipulation by an automated installation.

Abstract: A method for manufacturing a part made of composite material comprising a reinforcement made up of fibers impregnated with a resin matrix, comprising the steps of laying dry fibers flat and covering the dry fibers on a flat surface of a laying tool, infusing flat dry fibers with the resin; forming the dry fibers on a counter-mold, a first polymerization at a first polymerization temperature, the first polymerization being undertaken to obtain 20% to 30% hardening of the resin to obtain an intermediate reinforcement, the first polymerization being subsequent to the steps of infusing and of forming, demolding and machining the intermediate reinforcement, a second polymerization of the machined intermediate reinforcement at a second polymerization temperature, the value of the second temperature being greater than the value of the first temperature.

Abstract: A method is disclosed for manufacturing connecting members for connecting an aircraft wing to a center wing box, using preforms. The method involves a step of manufacturing at least one preform made of composite material forming the connecting member, and a step of assembling the preform or preforms by heat treatment to form the connecting member. The manufacturing method makes it possible, simply and quickly, to manufacture a connecting member that contributes to the connection between a center wing box of an aircraft and a wing of the aircraft.

Abstract: A method for manufacturing a centre wing box which includes inner stiffeners, at least one of which has at least one through-hole is described. For each stiffener having at least one through-hole and having a first leg of a first U-shaped and C-shaped profile and a second leg of a second U-shaped and C-shaped profile, the method includes, for each through-hole, the steps of producing a first section of the through-hole in the first U-shaped or C-shaped profile and of producing a second section of the through-hole in the second U-shaped or C-shaped profile before the first and second U-shaped or C-shaped profiles are positioned on the mould.

Abstract: A method for manufacturing an aircraft central wing box from a plurality of U-shaped and C-shaped profile sections made of composite material and from an outer skin of fibrous reinforcements formed on the U-shaped and C-shaped profile sections. The C-shaped and U-shaped profile sections are obtained by a method involving a step of compressing resin-impregnated fibrous reinforcements at a pressure greater than or equal to 7 bar and at a temperature less than or equal to 90° C. This solution makes it possible to optimize the dimensional and geometric accuracy of the profile sections and the surface finish thereof.

Abstract: A method of molding a charge (12) during the manufacture of a composite part. The method comprises: placing the charge and a diaphragm (4) on a male tool, the charge having a first part (12a) which is positioned above a top of the male tool (2) and a second part (12b, 12c) which projects to one side of the maletool; and progressively deforming the second part of the charge against a side of the male tool by applying a pressure difference across the diaphragm and stretching the diaphragm over the male tool as the pressure difference is applied. The diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 5 MPa. Optionally a support membrane may be positioned on a opposite sides of the charge. In the case where a support membrane is used, then the diaphragm has a stiffness in the planeof the diaphragm which is higher than the stiffness of the support membrane in the plane of the support membrane.

Abstract: A method for manufacturing a composite component from a plurality of plies of fibres embedded in a resin includes the following steps: forming a preliminary composite component by draping the plurality of fibre plies in a mould; laying up the preliminary composite component by stacking layers comprising at least one airtight film, a drainage fabric and a cover sheet; polymerizing the preliminary composite component arranged on a table of an enclosure of an apparatus of the autoclave type, equipped with a device for measuring the temperature T inside the enclosure, by applying a temperature cycle and a pressure cycle; demoulding a raw composite component; testing the dimensions and defect rate of the raw component, wherein the polymerization step includes the application of a pressure P in the enclosure as soon as the temperature T in the enclosure is greater than or equal to a threshold temperature Ts.

Abstract: The present application is concerned with methods of determining optimised fibre paths for complex composite components manufactured from multiple layers of composite material, particularly such components manufactured using an automated fibre placement (AFP) process. One aspect provides a method of determining an optimised fibre path for a geometrical feature of a composite component comprising a plurality of layers of composite material, each layer of composite material comprising a plurality of unidirectional fibres embedded in a matrix. The method includes manufacturing a test piece by: laying up a plurality of composite plies to form a planar charge, each composite ply comprising a plurality of unidirectional fibres embedded within a matrix; and shaping the planar charge by forming it over a mandrel using a hot drape forming process, the shaped charge having a shape corresponding to the geometrical feature of the composite component.

Abstract: A method of manufacturing two or more composite parts, the method comprising: assembling the composite parts on a mandrel by laying a series of layers of bands of composite material onto the mandrel with a placement machine,—rotating the mandrel as the bands are laid onto the mandrel; attaching two or more debulk frames (10, 11) to the mandrel between opposed edges of the composite parts after the composite parts have been assembled; wrapping the mandrel, debulk frames (10, 11) and composite parts in a debulk bag; heating the composite parts,—forming a vacuum between the mandrel and the debulk bag so that the debulk bag is sucked into voids between the debulk frames and the heated composite parts and progressively presses against the heated composite parts whereby excess material is squeezed by the debulk bag towards their opposed edges; and removing the debulk bag and the composite parts from the mandrel.

Abstract: A method of manufacturing two or more composite parts, the method comprising: assembling the composite parts on a mandrel by laying a series of layers of bands of composite material onto the mandrel with a placement machine,—rotating the mandrel as the bands are laid onto the mandrel; attaching two or more debulk frames (10, 11) to the mandrel between opposed edges of the composite parts after the composite parts have been assembled; wrapping the mandrel, debulk frames (10, 11) and composite parts in a debulk bag; heating the composite parts,—forming a vacuum between the mandrel and the debulk bag so that the debulk bag is sucked into voids between the debulk frames and the heated composite parts and progressively presses against the heated composite parts whereby excess material is squeezed by the debulk bag towards their opposed edges; and removing the debulk bag and the composite parts from the mandrel.

Abstract: The surface of a moulding tool, for receiving a first aircraft component, for example a spar, is shaped to correspond to the surface of a second aircraft component, for example a wing skin. A gap is defined between the tool and the first component. Resin is drawn into the gap by a suction pump. The resin fills the gap and cures to forma shim. The first and second components, which are in the form of composite material structures, are then joined together without any significant voids being formed therebetween.

Abstract: A method of moulding a charge (12) during the manufacture of a composite part. The method comprises: placing the charge and a diaphragm (4) on a male tool, the charge having a first part (12a) which is positioned above a top of the male tool (2) and a second part (12b, 12c) which projects to one side of the maletool; and progressively deforming the second part of the charge against a side of the male tool by applying a pressure difference across the diaphragm and stretching the diaphragm over the male tool as the pressure difference is applied. The diaphragm has a tensile modulus in the plane of the diaphragm which is greater than 5 MPa. Optionally a support membrane may be positioned on a opposite sides of the charge. In the case where a support membrane is used, then the diaphragm has a stiffness in the planeof the diaphragm which is higher than the stiffness of the support membrane in the plane of the support membrane.

Abstract: A method of manufacturing a composite part, the method comprising: placing a charge on a male tool having a convex surface region; debulking the charge on the male tool by applying pressure to the charge, the applied pressure varying over the surface of the charge so as to be intensified where the charge engages the convex surface region of the male tool; and curing the charge on a female tool having a concave surface region. The charge is formed and debulked in a series of stages to form a laminate. The charge is formed at a first temperature T1; debulked at a second temperature T2; and cured at a third temperature T3, wherein T1<T2<T3.

Abstract: A method of monitoring the performance of a pressure intensifier for use in the manufacture of a composite part. The method comprises: placing an array of pressure sensors adjacent a curved region of a mould tool; compressing the pressure sensors between a pressure intensifier and the mould tool; and monitoring the distribution of pressure across the curved region of the mould tool with the array of pressure sensors.

Abstract: The surface of a moulding tool, for receiving a first aircraft component, for example a spar, is shaped to correspond to the surface of a second aircraft component, for example a wing skin. A gap is defined between the tool and the first component. Resin is drawn into the gap by a suction pump. The resin fills the gap and cures to forma shim. The first and second components, which are in the form of composite material structures, are then joined together without any significant voids being formed therebetween.