METHOD FOR MANUFACTURING A COMPOSITE PANEL AND CORRESPONDING COMPOSITE PANEL

Abstract

The invention relates to a method for manufacturing a composite panel (13) for an aircraft turbomachine, the method comprising the following steps: - fabrication of a first skin (14) in a composite material comprising a fibrous reinforcement densified by a first polymer matrix, - fabrication of at least one ventilation element (18) from the first skin (14) by additive manufacturing, the ventilation element (18) being made of a thermoplastic material, - application of a core (16) with a honeycomb structure onto the first skin (14) and around the ventilation element (18), - fabrication of a second skin (15) in a composite material comprising a fibrous reinforcement densified by a second polymer matrix, onto the core (16) with a honeycomb structure. Figure for the abstract: Fig. 3

Description

Title of the invention: METHOD FOR MANUFACTURING A COMPOSITE PANEL AND CORRESPONDING COMPOSITE PANEL Technical field of the invention

[0001] The present invention relates to the aeronautical field. It relates in particular to a method for manufacturing a composite panel for the production of a turbomachine nacelle and the corresponding composite panel. Technological background

[0002] Aircraft turbomachinery generally comprises nacelles equipped with multifunctional panels. These nacelles may be, for example, an internal fixed structure enclosing a gas generator of a turbomachine and / or an external structure surrounding the internal structure. The internal fixed structure is subjected to high temperatures arising from hot gas flows passing through the gas generator. The internal fixed structure is equipped with composite material panels that protect it from these high temperatures.

[0003] Composite material panels may have a sandwich structure, which allows them to attenuate the noise emitted by the components of the gas generator. In this case, the core of the sandwich structure has a honeycomb-type structure and is sandwiched between an inner and an outer skin. Each inner and outer skin is made from a fibrous reinforcement densified with a sand-cured thermosetting resin.

[0004] When the internal fixed structure carries thrust reversers, the composite material panels with the sandwich structure provide mechanical and structural support for it. These types of composite material panels with a sandwich structure can then offer mechanical support, acoustic attenuation, and thermal protection.

[0005] Figure 1 shows a portion of an internal fixed structure 01 which can also provide ventilation by means of ventilation tubes 02 integrated through the sandwich structure. The ventilation tubes 02 are add-on components, each fitted into a hole 03 that passes through the internal fixed structure 01 on both sides. The holes 03 are drilled after the assembly of the inner skin 04, the outer skin 05, and the core 06. The ventilation tubes 02 are made of a metallic material and are then installed in a corresponding hole 03. The ventilation tubes 02 are made of rolled sheet metal that is machined and welded.

[0006] Each ventilation tube 02 is fixed to the internal fixed structure 01 by means of fastening elements 07 such as rivets which pass through the inner skin 04 on one side and are embedded, at least partially, in the web 06 of the internal fixed structure 010 on the other. In particular, each ventilation tube 02 comprises a body 08 which is arranged at the web 06 and a flange 09 extending projecting from one end of the body 08. The flange 09 includes openings 010 through which the fastening elements 07 pass and which allow the ventilation tube 02 to be fixed. Each ventilation tube 02 has a conduit 011 opening onto an internal surface 012 of the internal fixed structure 01 and an external surface 013 of the internal fixed structure 01.The body of the ventilation tubes 02 has diameters between 5 and 20 mm and the duct 011 also each has an axis which is inclined at approximately 45° relative to the external surface 013 of the internal fixed structure 01.

[0007] The inclination of the duct 011 increases the area or surface in which the hole will be made, which creates a loss of surface area for the acoustic function performed by the core 06. Furthermore, these ventilation tubes 02 are mounted manually and each ventilation tube 02 is fixed with at least three fixing devices which is tedious, lengthens the assembly time and is costly.

[0008] There is a need to resolve all or part of the aforementioned drawbacks. Summary of the invention

[0009] The objective of the present invention is to provide a simple and economical solution for easily integrating ventilation means into the composite panel while improving acoustic performance and reducing mass.

[0010] We achieve this objective in accordance with the invention by means of a method for manufacturing a composite panel for an aircraft turbomachine, the method comprising the following steps: - creation of a first skin in a composite material comprising a fibrous reinforcement densified by a first polymer matrix, - fabrication of at least one ventilation component from the first skin by additive manufacturing, the ventilation component being made of a thermoplastic material, - application of a core with an alveolar structure onto the first skin and around the ventilation organ, - creation of a second skin in a composite material comprising a fibrous reinforcement densified by a second polymer matrix, on the core with an alveolar structure.

[0011] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, this process makes it possible to obtain a panel with the ventilation component(s) already mounted within the composite panel without the need for additional fasteners. This eliminates numerous manufacturing steps, particularly manual ones, required to produce a complete composite panel. Additive manufacturing of the ventilation component(s) allows material to be added only to areas that strictly require specific equipment, such as the ventilation component itself, resulting in time and weight savings. The integration of the ventilation component is virtually automated during the manufacturing of the composite panel.In addition, the thermoplastic used as the material for the ventilation unit allows for automation of the manufacturing process, as thermoplastic is a material that facilitates assembly, particularly by welding / heat welding.

[0012] The process also includes one or more of the following steps and / or features, taken alone or in combination when technically feasible:

[0013] - the polymer matrix of the first skin and / or the second skin comprises a thermoplastic resin.

[0014] - the production of the first skin and / or the second skin includes an application of several fiber strips.

[0015] - the fibrous reinforcement of the first skin and / or the second skin comprises pre-impregnated fibers.

[0016] - the process includes a step of producing at least a portion of the core alveolar structure by additive manufacturing on the first skin around each ventilation organ.

[0017] - Additive manufacturing includes the technique of fused filament deposition.

[0018] - the production of the first skin includes a sub-step of making holes in the first skin.

[0019] - the process includes a step of applying a coating to the first skin and / or under the second skin.

[0020] - the core with an alveolar structure is shaped to perform a function acoustic and has an identical density across the entire surface of the composite panel.

[0021] - the alveolar structure has a density between 40kg / m3 and 150 kg / m3.

[0022] - the core with an alveolar structure is arranged in the form of several blocks.

[0023] - the manufacturing process includes a step of applying a coating to the alveolar-structured soul.

[0024] The invention also relates to a composite panel manufactured using a process as described above. The ventilation element is integrated into the core. alveolar structure, and is fixed to the first skin and second skin via the first and second polymeric matrix. Brief description of the figures

[0025] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent upon reading the following detailed explanatory description, of embodiments of the invention given by way of purely illustrative and non-limiting examples, with reference to the accompanying schematic drawings in which: - Fig. 1 illustrates a cross-section of an example of a portion of an internal fixed structure of a turbomachine according to the prior art; - Fig. 2 is an axial and partial cross-sectional view of an example of a turbomachine equipped with at least one internal fixed structure provided with ventilation means according to the invention; - Fig. 3 illustrates a portion of a composite panel for a turbomachine which is equipped with ventilation means according to the invention; - Figure 4 schematically and in detail represents an example of a ventilation means according to the invention; and, - Fig. 5 illustrates a flowchart of a manufacturing process for a composite panel according to the invention. Detailed description of the invention

[0026] The [Fig.1] has been described in the preceding.

[0027] In this description, identical or substantially identical elements and / or elements with the same functions are represented by the same numerical references.

[0028] Figure 2 represents a turbomachine 1 intended to be mounted on an aircraft (not shown). The aircraft comprises, for example, a fuselage and two wings extending on either side of the fuselage relative to the fuselage axis. Each wing can carry at least one turbomachine.

[0029] The turbomachine 1 can be a turbojet or a turboprop.

[0030] The turbomachine 1 may include at least one propeller 2 or a fan which is either shrouded or unshrouded.

[0031] The turbomachine 1 has a longitudinal axis X, which is here the axis of rotation of the rotors of the turbomachine.

[0032] In the present invention, and more generally, the terms "upstream," "downstream," "axial," and "axially" are defined with respect to the gas flow in the turbomachine and with respect to the longitudinal axis X of the turbomachine. Similarly, the terms "radial," "radially," "internal," and "external" are defined with respect to a radial axis Z perpendicular to the longitudinal axis X.

[0033] The turbomachine 1 generally comprises, from upstream to downstream, a compressor assembly, a combustion chamber and a turbine assembly which preferably forms a gas generator 3.

[0034] The turbomachine 1 is in particular a twin-spool, twin-flow turbomachine. The compressor assembly here comprises a low-pressure compressor and a high-pressure compressor. The turbine assembly here comprises a low-pressure turbine and a high-pressure turbine. The rotors of the low-pressure compressor and the low-pressure turbine are connected, for example, by a low-pressure shaft to form a low-pressure casing. The rotors of the high-pressure compressor and the high-pressure turbine are connected, for example, by a high-pressure shaft to form a high-pressure casing.

[0035] In this embodiment, the blower 2 or propeller is mounted upstream of the compressor assembly. Advantageously, but not exclusively, the blower 2 comprises blower blades 4 which are surrounded, for example, by a blower housing 5.

[0036] The turbomachine 1 also includes, advantageously but not limitingly, a nacelle 6, which encloses, in a non-limiting manner, certain components of the turbomachine.

[0037] Advantageously, but not exclusively, the nacelle 6 comprises an internal fixed structure 7 known by the English acronym "IFS" for "Inner Fixed Structure". The internal fixed structure 7 is advantageously arranged around at least a portion of the gas generator 3 with respect to the longitudinal axis X. The internal fixed structure 7 delimits, at least in part, with a central annular body 8, a primary flow channel 9 in which a primary flow circulates when the turbomachine 1 is in operation.

[0038] Advantageously, but not limitingly, the nacelle 6 comprises an external fixed structure 10, known by the English acronym "OFS" for "Outer Fixed Structure." The external fixed structure 10 is advantageously centered on the longitudinal axis X and surrounds the internal fixed structure 7. The internal fixed structure 7 and the external fixed structure 10 at least partially delimit a secondary flow channel 11 in the case of a turbofan engine. A secondary flow is intended to circulate in the secondary flow channel in the case of a turbofan engine and when the turbomachine 1 is operating. The secondary flow channel 11 is arranged radially outside the primary flow channel 9.

[0039] By way of non-limitation, the external fixed structure 10 is extended upstream along the longitudinal axis X by an annular air inlet sleeve 12 which surrounds the blower housing 5.

[0040] Figure 3 shows a portion of an example of a composite panel 13. Advantageously, the composite panel 13 has a sandwich-type structure. The composite panel 13 can be used to construct the internal fixed structure 7 or the external fixed structure 10 of the nacelle 6.

[0041] The composite panel 13 comprises a first skin 14, a second skin 15 and a core 16 arranged between the first skin 14 and the second skin 15. In installation situation and by way of example, the first skin 14 is swept by the primary flow and the second skin 15 is swept by the secondary flow.

[0042] The first skin 14 and the second skin 15 are preferably made of a composite material. Each first skin 14 and second skin 15 comprises a densified fibrous reinforcement in a polymer matrix.

[0043] Advantageously, the polymer matrix comprises a thermoplastic resin. The thermoplastic resin may be selected from the group comprising polyethylene, polypropylene, polyetheretherketone, polyetherketoneketone, or polyaryletherketones.

[0044] The fibrous reinforcement is achieved, for example, using several plies or layers of fibers superimposed one on top of the other. The fibers may include carbon, glass, or polyamide fibers. By way of example, the carbon fibers may be selected from polyetherketone, polyetheretherketone, polyetherketoneketone, and polyacrylonitrile fibers.

[0045] The core 16, for example, has at least a first portion made of a honeycomb-type alveolar structure. The alveolar structure helps to reduce the noise emitted, for example, by the gas generator. The alveolar structure comprises cells or alveoli whose partitions preferably have a hexagonal cross-section, known as a honeycomb. Of course, the alveolar wall can have another shape, such as rectangular, triangular, etc. Advantageously, the alveolar partition has a predetermined thickness.

[0046] The core 16 can be made of a metallic material such as aluminum, titanium, or steel. Aluminum is preferred because it is a lightweight material. Alternatively, the core 16 can be made of a composite material. As another alternative, the core 16 can be made of a polymer material such as polyetheretherketone (without fibers and / or particles).

[0047] Advantageously, the first skin 14 includes holes 17 which each communicate with the alveoli of the core 16. The noise emanating from the gas generator 3 rises into the alveoli of the core 16 in which it is trapped.

[0048] Still with reference to [Fig.3], the composite panel 13 includes ventilation means allowing air exchange between the inside of the internal fixed structure 7 and the outside of the internal fixed structure 7.

[0049] In particular, the composite panel 13 advantageously, but not limited to, includes at least one ventilation element 18 integrated or embedded within the composite panel 13. Advantageously, several ventilation elements 18 are embedded within the web 16 of the composite panel 13. By way of example, the ventilation elements 18 are located in the middle of the composite panel 13. Naturally, the arrangement of the ventilation elements 18 depends on the type of turbomachine and the air intake points.

[0050] The ventilation elements 18 are advantageously manufactured at the same time or almost at the same time as the composite panel 13. However, the ventilation elements 18, the first skin 14, the second skin 15, and the core 16 are not manufactured using the same technique. Indeed, the first and second skins 14, 15 can be manufactured by laminating layers of fibers or by automated fiber placement (known by the English acronym "AFP" for Automated Fiber Placement), and at least part of the core can be manufactured by pultrusion if it is plastic or by bonding and expanding strips if it is metallic.

[0051] With reference to [Fig. 4], each ventilation element 18 comprises a body 19 having a shape of revolution about an axis of revolution A. The body 19 has a circular cross-section. Of course, the body 19 can have any type of shape.

[0052] The ventilation member 18 comprises a duct 20 which extends between a first orifice 21 and a second orifice 22. According to one embodiment, the duct 20 extends on either side of the body 19 with respect to the axis of revolution A. The duct 20 optionally has a central axis B which is inclined with respect to the axis of revolution A of the body 19. By way of example, the angle of inclination of the central axis B is on the order of 45°.

[0053] The body 19 advantageously, but not exclusively, has a height equal to the height of the core 16 of the composite panel 13. The body 19 optionally has an internal surface 23 and an external surface 24 that are opposite along the axis of revolution A. Advantageously, the internal surface 23 is, for example, flush with an internal surface of the core 16. The external surface 24 is, for example, flush with an external surface of the core 16.

[0054] According to a non-limiting example embodiment, the conduit 20 passes for example through a first opening 25 made in the first skin 14 and extends preferably towards the inside of the first skin 14. The first orifice 21 opens for example inside the first skin 14.

[0055] According to another embodiment, the conduit 20 passes through a second opening 26 made in the second skin 15 and preferably extends towards the outside of the second skin 15. The second orifice 22 opens, for example, to the outside of the second skin 15.

[0056] Advantageously, the ventilation element(s) 18 are made of a thermoplastic material. This allows for better compatibility, particularly in terms of attachment, with at least the first matrix of the first skin 14. Advantageously, the thermoplastic material is also compatible with the second matrix of the second skin 15. The melting temperature ranges, for example, of the thermoplastic materials of the ventilation elements 18 and the first and second matrices must be similar or coincide.

[0057] The thermoplastic material of the ventilation element(s) 18 is advantageously selected from the group comprising polyethylene, polypropylene, polyetheretherketone, polyetherketoneketone, polyetherimide, or polyaryletherketones. The thermoplastic material of the ventilation element(s) 18 may be identical to that of at least the first polymer matrix. Alternatively, the thermoplastic material of the ventilation element(s) 18 is different from at least the first polymer matrix.

[0058] We will now describe a manufacturing process 100 of a composite panel 13 for an aircraft turbomachine with reference to [Fig.5].

[0059] The manufacturing process 100 includes a step 110 of producing a first skin 14 of composite material comprising a densified fibrous reinforcement in a first polymer matrix. The first skin 14 is produced, for example, by applying several plies or strips of fibers which are deposited onto a support (not shown). This support may be, for example, a mold having the shape of the final part to be obtained.

[0060] Preferably, the fibers in the first matrix are pre-impregnated fibers.

[0061] The first matrix preferably comprises a thermoplastic resin.

[0062] According to one embodiment, the fiber strips are deposited onto the substrate via an application element, such as at least one roller (not shown). Alternatively, the fibers can be deposited using the process known by the English acronym "FPP".

[0063] The fiber strips are then optionally compacted onto the substrate to promote, for example, their adhesion. The compaction element can be the same roller (not shown) that applies pressure to the fiber strips as they are laid down.

[0064] Advantageously, but not exclusively, the fiber strips undergo densification to further promote adhesion between the fibers. Densification can be achieved by means of a heating device that melts the first matrix. This device includes, for example, a furnace in which are The fiber strips are installed and then compressed. The temperature used by the heating device is between 200°C and 500°C depending on the thermoplastic material used and the desired final properties.

[0065] According to another preferred alternative, particularly for composite panels 13 with large dimensions, the heating device emits radiation or heat onto the fiber strips as they are deposited onto the substrate. The heating device can be an infrared lamp or a laser. Panels 13 intended for creating fixed internal structures, for example, have a length of approximately 2 m and a width of approximately 1.50 m.

[0066] Advantageously, but not limitingly, during densification, compression is carried out so as to achieve better adhesion of the fibers to each other.

[0067] The embodiment step 110 optionally includes a substep 111 for creating holes 17 in the first skin 14. The holes 17 are advantageously made by mechanical drilling. For example, the mechanical drilling is carried out using a drill bit. Alternatively, the drilling can be carried out using a laser.

[0068] Advantageously, but not exclusively, the holes 17 may be circular. Alternatively, the holes 17 may be any shape provided that it allows fluidic communication with the core's cavities and is simple to manufacture. When circular, the holes 17 may have a diameter between 0.5 mm and 2 mm.

[0069] According to one embodiment, at least one first opening 25 is made in the first skin 14 during the application of the fiber strips. This opening 25 is coaxial with the first orifice 21 of the conduit 20. Alternatively, the first opening 25 is made by mechanical drilling or, for example, by a laser. The first opening 25 can also be made by water jet drilling.

[0070] The manufacturing process 100 advantageously comprises a step 120 of producing at least one ventilation element 18 by additive manufacturing on the first skin 14. Preferably, several ventilation elements 18 are manufactured on the first skin 14 using additive manufacturing. In other words, the ventilation element or elements 18 are built directly from the first skin 14.

[0071] Additive manufacturing makes it possible to obtain parts of varied and complex shapes by fusing layers of material. Furthermore, additive manufacturing makes it possible to deposit the material and manufacture each ventilation component 18 only in the areas where their installation is required, resulting in material savings, weight reduction, cost savings, and time savings.

[0072] In particular, the material is arranged layer by layer on a manufacturing support, here the first skin 14, and each layer of material is melted or fused by an energy-generating element, solidified, and then covered by other layers of the material. The operation is repeated multiple times until the complete part is obtained. Regarding the first orifice 21 of the conduit that must pass through the first opening 25, during the manufacturing of the first skin 14, a hole can be created by draping the fibers over the tube, or a machining operation can be performed subsequently to provide access to the first orifice 21.

[0073] There are several additive manufacturing techniques such as selective laser melting known by the English acronym "SLM" for "Selective Laser Melting" allowing the melting of powder of the material intended to make the final part or selective laser sintering known by the English acronym "SLS" for "Selective Laser Sintering.

[0074] Another non-limiting, and preferred, additive manufacturing technique is the fused filament deposition technique known by the English acronym "FFF" for "Fused Filament Fabrication".

[0075] The molten material is a thermoplastic, as previously stated. The thermoplastic material is suitable for additive manufacturing and is compatible with the material of the first skin 14 onto which it is deposited.

[0076] During the application of the first layer of material, it is bonded to the first skin 14 by heat welding. The material deposited on the first skin 14 has a temperature (between 200°C and 500°C) that softens or melts the thermoplastic resin of the first skin 14, thus welding at least part of the ventilation element 18 to the first skin 14 after cooling. Furthermore, since the thermoplastic materials are compatible, the bond between the first skin 14 and the ventilation element is lighter.

[0077] The manufacturing process 100 advantageously includes a step 130 of producing at least a portion of the honeycomb-structured core 16 by additive manufacturing on the first skin 14 around each ventilation element 18. The manufacturing of this portion of the core is carried out simultaneously with the manufacturing step of each ventilation element 18. This will facilitate the subsequent arrangement of the rest of the core 16. Indeed, the portion of the core obtained by additive manufacturing advantageously has walls perpendicular to the first skin 14 and also to the second skin 15 so as to facilitate the joining of the honeycomb-structured core 16.

[0078] The manufacturing process 100 advantageously comprises a step 140 of applying the honeycomb-structured core 16 onto the first skin 14. The core 16 is advantageously arranged around the ventilation element 18 and preferably around of each ventilation element 18. Advantageously, the core 16 is arranged around the portion of the core produced by additive manufacturing and surrounding each ventilation element.

[0079] Advantageously, but not exclusively, the core 16 is shaped to perform the acoustic function and has the same honeycomb structure over the entire surface of the composite panel 13. Preferably, the honeycomb structure has the same density over the entire surface of the composite panel. For example, the density of the honeycomb structure is between 30 kg and 150 kg / m³. Preferably, the density of the honeycomb structure is around 67 kg / m³, which is sufficient to obtain very good acoustic performance while remaining lightweight. This makes it possible to cover a maximum surface area with a honeycomb structure for acoustic function and to further improve the acoustic function of the composite panel. With this solution, at least 80% of the surface area lost in the prior art for installing ventilation components is recovered for performing the acoustic function.

[0080] Preferably, the core 16 is arranged in the form of several honeycomb blocks. This facilitates the installation of the core 16.

[0081] The manufacturing process 100 advantageously, but not exclusively, comprises a step 150 of producing the second skin 15 from a composite material comprising a densified fibrous reinforcement in a second polymer matrix. As with the first skin 14, the second skin 15 is produced, for example, by applying several plies or strips of fibers deposited onto a substrate. In this embodiment, the substrate is at least partly the core 16. In particular, the fiber strips are applied directly to the outward-facing surface of the core 16 and to a portion of the body of each ventilation component 18.

[0082] Preferably, the fibers of the second matrix are pre-impregnated fibers. The second matrix preferably comprises a thermoplastic resin. Advantageously, the first matrix and the second matrix are identical. Alternatively, the first matrix and the second matrix are different.

[0083] The fiber strips advantageously, but not exclusively, undergo compression to compact the fibers, thereby promoting adhesion between them. The fibers can be compacted in the same way as the fibers of the first skin 14, for example by roller.

[0084] According to one embodiment, the ventilation element(s) 18, in particular, for example, the material layers closest to the external surface, have a predetermined temperature so as to allow bonding with the second skin 15. The temperature of each ventilation element 18 must be greater than or equal to the melting temperature (between 200°C and 500°C) of the second matrix of the second skin 15. Thus, during the application of the fiber strips of the fibrous reinforcement of the second skin 15, these are fixed by means of the thermoplastic resin which is at a suitable temperature to carry out a heat seal.

[0085] The manufacturing step 150 further includes, but is not limited to, a densification substep. During this densification substep, the second matrix of the second skin 15 is polymerized (between 200°C and 500°C), which densifies the thermoplastic resin of the second skin 15 and the fibers of the fibrous reinforcement. The composite panel thus undergoes a second curing, for example. Simultaneously, the second matrix is ​​fixed during this step with the ventilation element 18. Preferably, the densification is carried out using a heating device such as an oven. The temperature is between 300°C and 500°C.

[0086] Alternatively, the embodiment step 150 includes a substep of heating only the fibrous reinforcement comprising pre-impregnated fibers so as to soften the second matrix (without melting it) to polymerize it and allow attachment to the ventilation element(s) 18. The heating can be carried out using a nozzle projecting an air stream or a laser, or an infrared lamp emitting radiation or heat. The heating can be carried out at a temperature between 200°C and 500°C, preferably 400°C.

[0087] According to yet another alternative, the second skin 15 is heated locally, for example, at the location where the ventilation organs 18 are arranged. The heating can be carried out using a laser to soften the second matrix of the second skin 15. The temperature can also be between 200°C and 500°C.

[0088] According to an optional embodiment, the manufacturing process 100 includes a step of applying at least one coating to the honeycomb-structured core 16. This coating improves the insulation and high-temperature resistance of the first skin 14 and protects the core 16 against oxidation. The core can oxidize, particularly when it is made of aluminum and the fibrous reinforcement includes carbon fibers. Advantageously, the coating is applied before the second skin 15 is formed. The coating preferably comprises glass fibers. Advantageously, the coating is arranged between the first skin 14 and the core 16 (as well as the ventilation element 18). If this coating is added, it must generally be compatible with the material of the core 16.

[0089] Advantageously, but not limitingly, a similar coating made preferably of glass fibers is applied to the external surface of the core 16.

[0090] The manufacturing process 100 includes in addition an optional machining step 160 of the composite panel.

[0091] The composite panel obtained with such a manufacturing process comprises at least one ventilation element fixed to the first skin 14 and to the second skin 15 during The composite panel is manufactured without additional fasteners. The manufacturing of the composite panel 13 is therefore automated. The thermoplastic material of the ventilation element allows for heat-welding to the dies of the first and second skins 14, 15 during manufacturing.

Claims

Demands

1. A method for manufacturing (100) a composite panel (13) for an aircraft turbomachine (1), the method comprising the following steps: - fabrication (110) of a first skin (14) in a composite material comprising a fibrous reinforcement densified by a first polymeric matrix, - fabrication (120) of at least one ventilation element (18) from the first skin (14) by additive manufacturing, the ventilation element (18) being made of a thermoplastic material, - application (140) of a core (16) with a honeycomb structure on the first skin (14) and around the ventilation element (18), - fabrication (150) of a second skin (15) in a composite material comprising a fibrous reinforcement densified by a second polymeric matrix, on the core (16) with a honeycomb structure.

2. A manufacturing method (100) according to claim 1, characterized in that the polymer matrix of the first skin (14) and / or the second skin (15) comprises a thermoplastic resin.

3. Manufacturing method (100) according to any one of claims 1 and 2, characterized in that the realization (110, 140) of the first skin (14) and / or the second skin (15) comprises an application of several fiber strips.

4. A manufacturing method (100) according to any one of claims 1 to 3, characterized in that the fibrous reinforcement of the first skin (14) and / or the second skin (15) comprises pre-impregnated fibers.

5. Manufacturing method (100) according to any one of claims 1 to 4, characterized in that it comprises a step of producing (130) at least a portion of the core (16) with a honeycomb structure by additive manufacturing on the first skin (14) around each ventilation element (18).

6. Manufacturing method (100) according to any one of claims 1 to 5, characterized in that the additive manufacturing comprises the fused filament deposition technique.

7. Manufacturing method (100) according to any one of claims 1 to 6, characterized in that the making (110) of the first skin (14) includes a substep of making (111) holes (17) in the first skin (14).

8. A manufacturing method (100) according to any one of the preceding claims, characterized in that it includes a step of applying a coating to the first skin (14) and / or under the second skin (15).

9. Manufacturing method (100) according to any one of the preceding claims, characterized in that the core (16) with a honeycomb structure is shaped to perform an acoustic function and has an identical density over the entire surface of the composite panel (13).

10. A manufacturing process (100) according to any one of the preceding claims, characterized in that the alveolar structure has a density between 40 kg / m3 and 150 kg / m3.

11. A manufacturing method (100) according to any one of the preceding claims, characterized in that the core (16) with a honeycomb structure is arranged in the form of several blocks.

12. Composite panel (13) made according to a manufacturing process according to any one of the preceding claims, the ventilation element (18) being integrated into the core (16) with a honeycomb structure, and being fixed to the first skin (14) and to the second skin (15) via the first and second polymeric matrix.

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