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 of manufacturing stiffened structural panel for an aircraft including a main sheet made of composite material with unidirectional fibers, and a stiffening structure secured to the main sheet and made of a composite material comprising a resin and chopped fibers, the stiffening structure including on the one hand a base adhering to one of the two lateral faces of the main sheet, and a network of stiffeners in the form of a grid projecting from the base. The method includes a step of compression molding the stiffening structure from a block formed of a prepolymer reinforced with chopped fibers.

Abstract: In order to be able to reduce the time and cost required for final assembly of an aircraft, a junction rib designed for the wing-central wingbox junction comprises a central web and an upper flange and a lower flange which extend from the main web, on a first side, the main web having a junction surface arranged on a second side opposite the first side, the main web including rows of orifices opening on the second side in the junction surface and on the first side, comprising a first row of orifices and a third row of orifices formed in an upper part of the main web on either side of the upper flange, and a second row of orifices formed in a lower portion of the main web, each one of the rows of orifices comprising orifices in a free state.

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 of manufacturing stiffened structural panel for an aircraft including a main sheet made of composite material with unidirectional fibers, and a stiffening structure secured to the main sheet and made of a composite material comprising a resin and chopped fibers, the stiffening structure including on the one hand a base adhering to one of the two lateral faces of the main sheet, and a network of stiffeners in the form of a grid projecting from the base. The method includes a step of compression molding the stiffening structure from a block formed of a prepolymer reinforced with chopped fibers.

Abstract: A central wing box for an aircraft, including a top panel, a bottom panel, a front spar, a rear spar, and at least one secondary rib. A secondary rib includes two stiffeners, a first stiffener extending adjacent to the top panel and to one of the front spar and the rear spar, and a second stiffener extending adjacent to the bottom panel and to the other of the front spar and the rear spar. A reduced number of components can be employed, thereby simplifying the construction of the central wing box of an aircraft, particularly the installation of the secondary ribs.

Abstract: In order to be able to reduce the time and cost required for final assembly of an aircraft, a junction rib designed for the wing-central wingbox junction comprises a central web and an upper flange and a lower flange which extend from the main web, on a first side, the main web having a junction surface arranged on a second side opposite the first side, the main web including rows of orifices opening on the second side in the junction surface and on the first side, comprising a first row of orifices and a third row of orifices formed in an upper part of the main web on either side of the upper flange, and a second row of orifices formed in a lower portion of the main web, each one of the rows of orifices comprising orifices in a free state.

Abstract: The manufacture of structural elements for aircraft requires the use of complex and costly methods, particularly in the case of parts of elongate overall shape and variable thickness or cross section made of composite material. The disclosure herein proposes to overcome this problem by a method that allows the manufacture of a structural part from a preform made of composite material of simple shape obtained by pultrusion and of one or more reinforcing elements made of composite material and secured by cocuring with the preform to a region of this preform which region is to be reinforced.

Abstract: A central wing box for an aircraft, including a top panel, a bottom panel, a front spar, a rear spar, and at least one secondary rib. A secondary rib includes two stiffeners, a first stiffener extending adjacent to the top panel and to one of the front spar and the rear spar, and a second stiffener extending adjacent to the bottom panel and to the other of the front spar and the rear spar. A reduced number of components can be employed, thereby simplifying the construction of the central wing box of an aircraft, particularly the installation of the secondary ribs.

Abstract: A method for disassembling two ultrasonically welded elements, one of the elements comprising, at a surface opposite the other element, an energy director that concentrates the heating during ultrasonic welding and forms a material junction between the two assembled elements after the ultrasonic welding. The method includes the steps of positioning a wire between the two assembled elements, so as to be secant to the energy director, said wire having suitable mechanical characteristics allowing it to cut the junction formed by the energy director and moving the wire between the two assembled elements so as to cut said junction.

Abstract: A keel beam connected to a central wing box of an aircraft and ensuring the connection between a front structure and a rear structure of an aircraft is characterized in that it includes, on the one hand, a U-shaped body with a horizontal base and two solid lateral walls, and on the other hand, a cover which has a U shape oriented in the same manner as the body, with a base in the lower portion and curved edges, the ends of which are oriented upward so that each curved edge includes an outer surface flattened against and fixed to the inner surface of the lateral walls in order to define, with the body, a closed section, the cover including openings for accessing the inside of the keel beam.

Abstract: The manufacture of structural elements for aircraft requires the use of complex and costly methods, particularly in the case of parts of elongate overall shape and variable thickness or cross section made of composite material. The disclosure herein proposes to overcome this problem by a method that allows the manufacture of a structural part from a preform made of composite material of simple shape obtained by pultrusion and of one or more reinforcing elements made of composite material and secured by cocuring with the preform to a region of this preform which region is to be reinforced.

Abstract: A method for producing a central wing box having an upper panel, a lower panel, a front spar and a rear spar, the upper edges of said spars approximately parallel to an axis Y being connected by the upper panel, and the lower edges of said spars approximately parallel to the axis Y being connected by the lower panel. The method includes producing at least one panel and at least one spar from composite material in one piece.

Abstract: A method for producing a central wing box including an upper panel, a lower panel, a front longeron, a rear longeron and four corners, wherein at least one panel and one longeron are obtained from a single flat metal wall which is bent along a bending line at approximately 90° which corresponds to a corner connecting said panel to said longeron.

Abstract: A composite structural member with fiber reinforcement comprising a plurality of layers oriented relative to a longitudinal direction of said member in directions including 0°, 90° and +/??, the relative proportion of layers in one of these orientations being variable along a transverse direction of said member so as to spatially adjust the rigidity of the member according to a defined distribution of mechanical stresses along this transverse axis. The rigidity of the member is adapted locally to the stress system so as to dissipate the force flux over the entire volume of said member.

Abstract: The invention relates to a structural frame made from a composite material. The purpose of the invention is to obtain a structural frame with high mechanical performances while remaining simple in construction. This purpose is achieved in arranging sets of single-directional fibers in the main part of the structural frame at a predetermined angle. This system may be used as a structural frame particularly for an aircraft fuselage.

Abstract: A method for producing a central wing box having an upper panel, a lower panel, a front spar and a rear spar, the upper edges of said spars approximately parallel to an axis Y being connected by the upper panel, and the lower edges of said spars approximately parallel to the axis Y being connected by the lower panel. The method includes producing at least one panel and at least one spar from composite material in one piece.

Abstract: The invention relates to a composite structural member with fiber reinforcement and its application in the production of a wing box for aircraft. More specifically, it relates to a composite structural member (230) with fiber reinforcement comprising a plurality of layers oriented relative to a longitudinal direction (2) of said member in directions including 0°, 90° and +/??, the relative proportion of layers in one of these orientations being variable along a transverse direction (3) of said member so as to spatially adjust the rigidity of the member according to a defined distribution of mechanical stresses along this transverse axis (3). Thus the rigidity of the member is adapted locally to the stress system so as to dissipate the force flux over the entire volume of said member.

Abstract: An aircraft includes a structure with structural elements (16) that are assembled to form a three-dimensional framework to which an aerodynamic envelope (14) is attached. At least some structural elements (16) are at least partly metallic and—at the connection with the aerodynamic envelope (14)—including an interface that is made of material that has a conductivity that is below a threshold on the order of 10,000 S/m so as to form at least one electrical path that ensures the functions of electric return and metallization of the electrical systems, whereby connections that ensure the electrical conduction are provided between the structural elements (16).

Abstract: A method for manufacturing a thin structural component made of composite and intended to withstand, on the one hand, working loads and, on the other hand, accidental loadings. The method involves creating a dry fiber preform of the component that is to be manufactured, and impregnating the aforementioned perform with a matrix-forming resin by resin transfer. The perform is created by assembling at least one structural layer, a first surface reinforcing layer on a first face of the aforementioned structural layer, and a second surface reinforcing layer on a second face of the structural layer. A number of plies in the two surface reinforcing layers is first of all calculated so that the finished component will be able to withstand the accidental loadings, then a number of plies in the structural layer is calculated, with due consideration given to increases in structural strength contributed by the surface reinforcing layers so that the finished component will be able to withstand the working loads.