Abstract: An acoustic panel comprising a cellular structure, such as a honeycomb structure, having cells that open at least onto a first frontal face of the structure. The panel comprises a capsular skin which is fastened to the first frontal face of the cellular structure next to a plurality of cells. The capsular skin including a continuous layer of material, in one piece, forming capsules that extend into the cellular structure. At least one channel is provided at the apex of each capsule for the passage of acoustic waves. Such a panel effectively attenuates the noise of aircraft engines, in particular, the low frequencies. It is extremely easy to manufacture industrially, the capsular skin being able to be obtained by molding with polymerization in situ, the polymerizable material then adhering to the cellular structure while it polymerizes.

Abstract: A method for producing an alveolar soundproofing structure in which a portion of a membrane of a diaphragm including an acoustic outlet is inserted into a hole of a perforated membrane which covers a cell of the alveolar structure, and the diaphragm is pressed into the cell with the perforated membrane becoming deformed and is fixed at that location. It also relates to the alveolar structure. Such a method enables different types of diaphragms to be inserted into different configurations of cells and enables the diaphragm to be fixed therein, in accordance with the sound frequencies to be processed.

Abstract: A method for manufacturing a soundproofing assembly involving providing a first panel of honeycomb structure, fastening an intermediate plate against a second face of the first panel, adhesive-coating a layer of adhesive on the intermediate plate, providing a second panel of honeycomb structure, bonding the first face of the second panel to the layer of adhesive, and perforating the intermediate plate and the layer of adhesive through the cells of the first panel or the cells of the second panel at the bonding zone of the second panel. Such a method makes it possible to save time by dispensing with additional preparation steps.

Abstract: An acoustic panel including first and second cellular structures, the first cellular structure including a set-back portion to form a recess dimensioned to accommodate the second cellular structure such that first faces of the first and second cellular structures, in contact with a first, acoustically resistive layer, are coplanar and that first edge faces of the first and second cellular structures are coplanar when the second edge face of the second cellular structure is in contact with the set-back portion. By virtue of the set-back portion, the first and second cellular structures are positioned correctly with respect to one another, thus contributing to an optimization of the acoustic treatment.

Abstract: A honeycomb structure has a core made up of a plurality of corrugated sheets which are superposed and fixed together. The corrugated sheets are made from a thermally insulating material. The corrugated sheets are impregnated with a resin filled with thermally conductive powder along their entire length. The honeycomb structure can be used when the ambient temperature exceeds, for example, 120° C.

Abstract: A honeycomb structure having a core made up of a plurality of corrugated sheets which are superposed and adhesively bonded together is described. The corrugated sheets are made from a thermally insulating material. Bear filaments are made up of thermally conductive filaments. The honeycomb structure can be used when the ambient temperature exceeds, for example, 120° C.

Abstract: A method of manufacturing an acoustic treatment panel including at least one cellular structure with at least one anchor layer at the level of at least one of its faces. The anchor layer includes at least one adhesive sheet chosen from an adhesive film or a ply of pre-impregnated adhesive fibers in contact with the cellular structure. The method of manufacture includes, before the integration of the cellular structure in an acoustic treatment panel, a step of placing the anchor layer on a support, the adhesive sheet being the last to be placed, a step of placing the cellular structure on the anchor layer in contact against the adhesive sheet, and then a step of polymerization of the anchor layer and of the cellular structure.

Abstract: A method for manufacturing a sound absorption structure comprising a cellular panel, a porous layer positioned on a cellular panel first face, a reflective layer positioned on a cellular panel second face and a plurality of acoustic elements positioned in the cellular panel. The method comprises the steps of producing, for each acoustic element, a recess in the cellular panel opening out onto the first and second faces of the cellular panel, inserting the acoustic elements into their recesses, laying an anchoring layer on the second cellular panel face, curing or polymerization at a first pressure to connect each acoustic element to the cellular panel and/or to the anchoring layer, putting in place the porous layer and the reflective layer, and curing or polymerization at a second pressure to connect the porous layer and the reflective layer to the cellular panel.

Abstract: An assembly jig for a cellular structure made from strips of material placed adjacent to each other and joined together so as to form first and second cells, opening on the first and second faces of the cellular structure, respectively. This assembly jig includes a housing delimited by a base and first and second side faces, configured for housing the strips of material of a cellular structure to be formed, superimposed on each other, a plurality of pins configured to be positioned between the superimposed strips of material in the first and/or second cells. An assembly device comprising the jig, and a method for manufacturing a cellular structure using the jig are also provided.

Abstract: A module ensuring an acoustic attenuation of a flow of a first fluid and a heat exchange between the first fluid and a second fluid. The module comprises a perforated first wall with a cutout, a second wall, a cellular structure extending from the second wall to the first wall, a recess provided in the cellular structure between a perforated bottom and a perforated top, and a heat exchanger which is fixed inside the recess between the bottom and the top and in which the second fluid circulates. Such a module ensures an attenuation of sound waves and a heat exchange without limiting the attenuation surface.

Abstract: A method for manufacturing a porous layer of an acoustic attenuation structure, porous layer of an acoustic attenuation structure thus obtained and acoustic attenuation structure comprising the porous layer. A method for manufacturing a porous layer of an acoustic attenuation structure includes a first step of production of a solid layer including at least one structural frame embedded in a resin matrix and having first and second reinforcing strips arranged so as to delimit zones without reinforcing strips and a second step of production of through-holes in the zones without reinforcing strips of the solid layer using a laser beam.

Abstract: A resistive skin element for an acoustic panel intended for an aircraft includes a first ply, a second ply with openings and a wire mesh which is sandwiched between the two plies. First ply includes at least one layer made of C/PEAK and a film made of PEI. Second ply includes at least one layer made of PEI First ply is crossed by perforations. Second ply has openings configured so that second ply does not obstruct the perforations of first ply. The wire mesh allows perforations with large sizes to be made while keeping good acoustic properties.

Abstract: A door for a thrust reversal system, an aircraft with such a door, and a method for manufacturing a door of a thrust reversal system. The door comprises a wall formed from long fibers embedded in a thermoplastic resin matrix and a network of ribs overmolded on one of the faces of the wall. A propulsion assembly of an aircraft comprises a thrust reversal system having a plurality of such doors.

Abstract: An acoustic treatment panel includes at least one acoustically resistive layer, a reflective layer and at least one cellular structure interposed between the acoustically resistive layer and the reflective layer. The cellular structure includes cylindrical and identical main tubes which are closed at one end by the acoustically resistive layer and at the other end by the reflective layer, spacer zones between the main tubes, the spacer zones being sealed relative to one another, cutouts made at an end of certain main tubes, in contact with the reflective layer, and/or secondary tubes positioned in the main tubes and/or in the spacer zones, the cutouts and/or the secondary tubes being configured to generate acoustic cells of different dimensions from identical main tubes.

Abstract: An acoustic absorption structure comprising a plurality of resonators. Each resonator comprises a first chamber which has a first mouthpiece delimited by an edge pressed against an inner surface of a porous zone of a skin so that the first chamber and the skin delimit a first cavity, a second chamber, in which is positioned the first chamber, which delimits, with the first chamber, a second cavity, at least one acoustic orifice passing through the first chamber, at least one drainage orifice passing through the first chamber and at least one drainage hole passing the second chamber, each drainage orifice and each drainage hole being configured to limit an accumulation of fluid in the resonator. Also, an aircraft propulsive assembly or an aircraft comprising the acoustic absorption structure are provided.

Abstract: A method for manufacturing a cellular structure having first and second faces, rows of cells each alternatingly having first cells, which are open in the direction of the first face, second cells, which are open in the direction of the second face, and also third cells formed between each row of cells, each row of cells comprising first and second strips of material placed against one another. The first and second strips of material are shaped by bending. By contrast to plastic deformation, shaping by bending makes it possible to expand the choice of materials and thicknesses for the first and second strips of material. An advantageous cellular structure is thus obtained as well as an acoustic absorption coating comprising such a cellular structure.

Abstract: A method for manufacturing an acoustic absorption structure comprising a plurality of acoustic elements, each of which is positioned in one of the cells of a cellular panel. The method includes a step of manufacturing acoustic elements provided with at least two radial tongues, a step of manufacturing a cellular panel provided with slots configured to accommodate the radial tongues of each acoustic element, a step of force-fitting each acoustic element in one of the cells of the cellular panel until the radial tongues are accommodated in the slots. An acoustic absorption structure obtained using this method is provided.

Abstract: An assembly constituting an acoustically absorbent material and including a first panel, a second panel pierced with holes, an intermediate panel pierced with through-holes and arranged between the first panel and the second panel, a first structure between the first panel and the intermediate panel and including first cages, a second structure between the second panel and the intermediate panel and including second cages, and for each through-hole of the intermediate panel, a tube opening out at the two ends thereof, where one of the ends of the tube is fixed to the intermediate panel at the through-hole, and where the other end of the tube is accommodated inside a first cage. Such an assembly makes it possible to obtain broad-band attenuation and is easy to manufacture.

Abstract: An assembly forming an acoustic insulator having a first sheet, a pierced second sheet, and a plurality of first and second structures. Each first structure comprises a first and a second strip, wherein each is shaped to form half of the wall of a cage and wherein, for two successive halves, each strip comprises a facet of a joining wall. Each second structure is made up of a first and a second strip, wherein each is shaped to form half of the wall of a cone, wherein. For each strip, at least one of the wall halves of each cone is pierced. For two successive halves, each strip comprises one facet of the connecting wall. Each cone is located in a cell and each connecting wall is located between the two facets of a joining wall, and, between two adjacent first structures, a second structure is likewise fitted.

Abstract: A method for producing an acoustically resistive structure includes the steps of creating, consolidating and cutting a first layer of reinforcing fibres embedded in a first thermoplastic resin having a first melting point so as to obtain an interlayer, a step of laying a second layer of reinforcing fibres against a first face of the interlayer, a second consolidation step of consolidating the second layer of reinforcing fibres embedded in a second thermoplastic resin having a second consolidation temperature lower than the first melting point of the first resin so as to obtain a non-perforated external layer bound to the interlayer, a step of perforating the external layer and a step of laying an internal layer on a second face of the interlayer. An acoustically resistive structure obtained from the method as well as a sound-absorption panel including such an acoustically resistive structure are also described.