LIGHTNING-RESISTANT AERONAUTICAL STRUCTURE

Abstract

Aeronautical structure (20) capable of receiving a lightning strike, this structure (20) comprising a body (22) of composite material formed by the stacking of several layers of fibers embedded in a polymer matrix, a first (26) of these layers defining an external surface (30) of the body (22) and comprising, in a plane (P26) of the first layer (26), series of unidirectional fibers (34) arranged side by side and along one another, or unidirectional strips of fibers (36) arranged side by side and along one another, characterized in that said first layer (26) comprises, in the plane (P26) of the first layer (26), electro-conductive cords (40) which extend parallel to the series or strips of fibers (24, 26), at a distance from one another, and which are intercalated between series or strips of fibers (24, 26) without being woven into the fibers. Figure for the summary: Figure 4

Description

Title of the invention: Lightning-proof aeronautical structure Technical field of the invention

[0001] The present invention relates in particular to an aeronautical structure capable of receiving a lightning strike, as well as a method for manufacturing such a structure. This structure is, for example, selected from a nacelle or part of a nacelle, a wing or part of a wing, a fuselage or part of a fuselage, a cowling, a flap, a turbomachine blade (in particular an unfaired blade), a turbomachine casing, etc. Technical downstream

[0002] Due to their privileged exposure to storm clouds, aeronautical structures must be designed to withstand a direct lightning strike.

[0003] However, more and more composite materials are being used in the design of aeronautical structures; these composite materials consist of fibers embedded in a polymer matrix. These materials do not exhibit sufficient electrical conductivity. It is therefore most often necessary to add a metallic material to their surface to aid in energy dissipation, and in particular in current conduction.

[0004] Indeed, the best way to improve the dissipation of electrical energy in a fiber-based composite material is to add a metallic material to its surface.

[0005] These metallic materials must be lightweight in order to limit mass gain and highly deformable in order to allow the manufacture of parts according to complex geometries.

[0006] Existing solutions today are therefore mainly oriented towards metallic reinforcements, such as fabrics or metal mesh, which are used in folds or surface layers to protect the layers of fibers which have a structural function.

[0007] These metallic reinforcements, whether woven or not, can be pre-impregnated (with a resin compatible with the resin used to form the aforementioned matrix) or dry.

[0008] Solutions also exist where metallic threads are woven with the fibers to form a functionalized fiber fabric that therefore has a dual function: structural and lightning-resistant. However, this type of fabric is only used on the external surface of composite materials.

[0009] However, the current lightning protection solutions mentioned above have drawbacks: • Dry metal reinforcements are generally used in the direct manufacturing process of a composite structure. This involves creating a fibrous preform made of dry fibers, into which resin is then infused or injected. In this type of process, the dry lightning reinforcement must be positioned alone, often facing the mold used to manufacture the structure, so that it is on the aerodynamic or external side of the structure. However, this reinforcement is complex to position and hold in place, especially on a mold with a complex and non-developable geometry. • Pre-impregnated metal reinforcements are used in indirect manufacturing processes for composite structures, meaning when a semi-finished product is used where the reinforcement and resin have already been mixed. These pre-impregnated solutions have the advantage of being easier to position in the mold due to their "sticky" nature. However, these semi-finished products are suitable for manufacturing composite parts by manually draping pre-impregnated plies or layers (large pieces of prepreg) and are therefore not automated. • Fiber and wire co-weaving solutions (e.g., IWWF, an acronym for InterWoven Wire Fabric) are used in direct or indirect manufacturing processes depending on whether the reinforcement is dry or impregnated. However, using this material requires either qualifying it to utilize its mechanical strength potential or disregarding it from a strength perspective (which still generates unnecessary weight). Furthermore, like the previous solutions, this type of solution is currently dedicated to the manufacture of manually draped composite parts.

[0010] The invention proposes a solution to at least some of the problems of the prior art, this solution being simple, effective and economical. Summary of the invention

[0011] The invention relates to an aeronautical structure capable of receiving a lightning strike, this structure comprising a body made of composite material formed by stacking several layers of fibers embedded in a polymer matrix, a first of these layers defining an external surface of the body capable of receiving a lightning strike and comprising, in a plane of the first layer, series of unidirectional fibers arranged side by side and along one another, or unidirectional strips of fibers arranged side by side and along one another, characterized in that said first layer comprises, in the plane of the first layer, electro-conductive cords which extend parallel to the series or strips of fibers, at a distance from each other, and which are interleaved between series or strips of fibers without being woven into the fibers.

[0012] The invention thus proposes to functionalize at least one of the body layers by adding electro-conductive cords to that layer. Unlike the prior art, these cords are not woven into the fibers. The fibers, and the series or strips, have unidirectional orientations, that is, they all extend in the same direction and are therefore parallel to each other and arranged side by side in the plane of the layer concerned. Like the fibers and the series or strips, the electro-conductive cords have a unidirectional orientation, that is, they have an elongated shape and extend in the same direction as the fibers and series or strips. The fibers and series or strips, on the one hand, and the electro-conductive cords, on the other hand, therefore extend parallel to each other within the same layer and in the plane of that layer.This means that they are generally arranged edge to edge within the same layer.

[0013] A single functionalized layer is sufficient to give the body the property of electrically conducting current in the event of a lightning strike, and therefore a lightning protection function. In the presence of a single functionalized layer, current dissipation occurs along the electro-conductive cords.

[0014] The structure according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0015] - a second layer, disposed directly on the first layer, comprises, in a plane of this second layer:

[0016] - series of unidirectional fibers arranged side by side and along one another, or unidirectional fiber strips arranged side by side and along each other, and

[0017] - electro-conductive cords that extend parallel to the series or strips of fibers, spaced apart from each other, and which are interleaved between series or strips of fibers without being woven into those fibers,

[0018] - at least some of the electro-conductive cords of the first layer being in contact with at least some of the electro-conductive cords of the second layer; the superposition of two functionalized layers allows the cords of the first layer to be in contact with at least some cords of the second layer in order to strengthen the property of the body of electrical current conduction;

[0019] - the series or strips of fibers of the first layer, as well as the electro-cords The conductors of this first layer are inclined relative to the series or strips of fibers of the second layer, as well as to the electro-conductive cords of this second layer. layer; it is therefore understood that the fibers or strips of the first layer cross those of the second layer, and that the electro-conductive cords of the first layer cross those of the second layer; this allows each cord of one layer to be in contact with several cords of the other layer, which improves the electrical conductivity of the body and therefore its energy dissipation;

[0020] - each of the electro-conductive cords is a metallic wire, or a strand of wires metallic; the strands can be straight or braided;

[0021] - the electro-conductive cords have a thickness or a cross-sectional diameter which presents 80% to 120%, and preferably 90% to 110%, of a thickness of the series or bands of fibers of the layer containing these cords; this is particularly advantageous to ensure that the electro-conductive cords of the layers can be in contact from one layer to another, without however risking excessively thickening the layer, which could generate marks or bumps on the layer covering these cords and degrade the mechanical performance of the body; the thickness in question of the layer is preferably the final thickness of the layer after manufacture of the body and in particular polymerization of the matrix of the body;

[0022] - the electro-conductive cords of a layer are each located between two strips of unidirectional fibers of this layer, and the unidirectional fiber strips of the layer are each arranged between two electro-conductive cords of this layer, the fiber strips having the same width;

[0023] - the electro-conductive cords of the layer are each located between two sets of unidirectional fibers of this layer, and the series of unidirectional fibers of the layer are each arranged between two electro-conducting cords of this layer, the series of unidirectional fibers having the same number of fibers or the same width;

[0024] — the fibers are made of carbon;

[0025] — each of the electro-conductive cords is intercalated between the edges of two series or fiber strips;

[0026] — the electro-conductive cords are made of a metal or alloy chosen from bronze, aluminum, copper, etc.

[0027] — the electro-conductive cords of the first and second layers form a mesh of electro-conductive cords;

[0028] - the structure is chosen from a nacelle or part of a nacelle, a wing or part wing, fuselage or part of fuselage, cowling, flap, turbomachine blade (including an unfaired blade), and turbomachine casing.

[0029] The present invention also relates to a method for manufacturing an aeronautical structure as described above, comprising the following steps:

[0030] a) for the first layer, preferably depositing simultaneously on a support, in a plane of this first layer, series of unidirectional fibers side by side and along each other, or unidirectional strips of fibers side by side and along each other, as well as electro-conductive cords extending parallel to the series or strips of fibers, spaced apart from each other, and which are intercalated between series or strips of fibers without being woven into these fibers, and optionally:

[0031] b) for the second layer, preferably depositing simultaneously on the first layer, in a plane of this second layer, series of unidirectional fibers side by side and along each other, or unidirectional strips of fibers side by side and along each other, as well as electro-conductive cords which extend parallel to the series or strips of fibers, at a distance from each other, and which are intercalated between series or strips of fibers without being woven into these fibers, so that at least some of the electro-conductive cords of this second layer are in contact with at least some of the electro-conductive cords of the first layer.

[0032] The method according to the invention may comprise one or more of the following features or steps, taken individually or in combination with each other: • steps a) and b) are carried out by an ATL or AFP type process; an ATL process, which is the acronym for Automated Tape Layup, is a process which consists of depositing unidirectional fiber strips in an automated manner (i.e. by a robotic machine); an AFP process, which is the acronym for Automated Fiber Placement, is a process which consists of depositing several fibers or series of unidirectional fibers in an automated manner;

[0033] — the strips or series of fibers have constant widths;

[0034] — the fibre strips have a width between 20mm and 50cm;

[0035] — the series of fibers have a width between 5 and 40mm;

[0036] - the support is a mold for manufacturing the body;

[0037] - the series or strips of fibers of the first layer, as well as the electro-cords conductors of this first layer are inclined relative to the series or strips of fibers of the second layer, as well as to the electro-conductive cords of this second layer;

[0038] - the fiber series or strips, as well as the electro-conductive cords, are dry during step a) and / or step b);

[0039] - the series or strips of fibers, as well as the electro-conductive cords, are pre impregnated with a resin, and preferably with the same resin, before step a) and / or step b);

[0040] - during step a) and / or step b), each of the electro-conductive cords of the or Each layer is attached to a longitudinal edge of a series of fibers or to a unidirectional band of that layer. Brief description of the figures

[0041] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0042] [Fig-1] [Fig.1] is a schematic axial cross-sectional view of a turbomachine aircraft;

[0043] [Fig.2] [Fig.2] is a very schematic cross-sectional view of an aeronautical structure according to the invention;

[0044] [Fig.3a] [Fig.3a] is a schematic perspective view of a strip or series of fibers associated with an electro-conductive cord formed by a metallic wire;

[0045] [Fig.3b] [Fig.3b] is a schematic perspective view of a strip or series of fibers associated with an electro-conductive cord formed by a strand of metallic wires;

[0046] [Fig.4] [Fig.4] is a schematic cross-sectional view of a multilayer aeronautical structure;

[0047] [Fig.5] [Fig.5] is a schematic cross-sectional view of another multilayer aeronautical structure;

[0048] [Fig. 6] [Fig. 6] is a schematic view of tooling for the automated dispensing of fiber strips or series, and simultaneously of electro-conductive cords, and illustrates a manufacturing process according to the invention; and

[0049] [Fig.7] [Fig.7] is a schematic view of another automated tooling for depositing strips or series of fibers, and simultaneously of electro-conductive cords, and illustrates a manufacturing process according to the invention. Detailed description of the invention

[0050] Fig. 1 illustrates an aircraft turbomachine 10.

[0051] The turbomachine 10 is susceptible to receiving a lightning strike and includes at least one structure which must withstand this strike and which must in particular be able to dissipate the energy of the lightning by conducting the current it generates.

[0052] In the case of a turbomachine, it is the nacelle 12 surrounding the engine 14 that is most likely to receive a lightning strike. This nacelle thus forms an aeronautical structure that must have a lightning protection function.

[0053] An aircraft includes other aeronautical structures that must have an anti-lightning function. This is the case, for example, of the aircraft fuselage, the aircraft wings or sails, etc.

[0054] In this application, the term aeronautical structure means any structure of an aircraft capable of receiving a lightning strike.

[0055] An aeronautical structure 20 is schematically represented in cross-section in [Fig.2].

[0056] The aeronautical structure 20 comprises a body 22 made of composite material formed by stacking several layers 24, 26, 28 of fibers embedded in a polymer matrix.

[0057] Reference E designates the exterior of the structure 20. The surface 30 of the body 22 facing outwards E is an exterior surface which is susceptible to receiving a lightning strike.

[0058] The reference I designates the interior of the structure 20. The surface 32 of the body 22 oriented towards the interior I is an interior surface.

[0059] Although the structure 20 shown has only three layers 24, 26, 28, the number of layers of the structure 20 is not limiting.

[0060] Among these layers 24, 26, 28, at least one layer 26, called the first layer, comprises, in a plane P26 of this layer 26, series of unidirectional fibers 34 arranged side by side and along one another, or unidirectional strips 36 of fibers arranged side by side and along one another.

[0061] According to the invention, this layer 26 comprises, in the plane P26 of this layer, electro-conductive cords 40 which extend parallel to the series 34 or the unidirectional strips 36, at a distance from each other, and which are intercalated between series 34 or the strips 36 without being woven into the fibers.

[0062] Depending on the number of layers, layer 26 can be the outermost layer of the body 22, namely the one located on the outer side and which defines the external surface 30. The external surface 30 of the body 22 is thus functionalized.

[0063] Preferably, at least one other of the layers, adjacent to the first layer, is also functionalized as in the example shown.

[0064] The layer 24, called the second layer, arranged directly on the first layer 26, comprises, in a plane P24 of this layer 24, series of unidirectional fibers 34 arranged side by side and along one another, or unidirectional strips 36 of fibers arranged side by side and along one another.

[0065] The layer 24 further comprises, in the plane P24 of this layer, electro-conductive cords 40 which extend parallel to the series 34 or the unidirectional strips 36, at a distance from each other, and which are intercalated between series 34 or the strips 36 without being woven into the fibers.

[0066] At least some of the electro-conductive cords 40 of the first layer 26 are preferably in contact with at least some of the electro-conductive cords 40 of the other of these layers 24 in order to enhance the electrical current conductivity capacity of the body 22.

[0067] It is therefore understood that, in the plane P24, P26 of each layer 24, 26, the cords 40 are arranged next to the series of fibers 34 or the strips 36 and advantageously edge to edge with these series of fibers 34 or strips 36, as can be seen in figures 3a and 3b.

[0068] It is clear from these drawings that the cords 40 are parallel to the fiber series 34 or the strips 36. In [Fig. 3a], each cord 40 is formed by a metal wire. In [Fig. 3b], each cord 40 is formed by a strand of metal wires.

[0069] The electro-conductive cords 40 are made of a metal or alloy chosen from bronze, aluminum, copper, etc.

[0070] The fibers are, for example, made of carbon.

[0071] In the embodiment of [Fig.4], the electro-conductive cords 40 each have a thickness or diameter D in section which represents 80% to 120%, and preferably 90% to 110%, of a thickness X of the series of fibers 34 or of the strips 36 of the layer 24, 26 comprising these cords 40.

[0072] This is particularly advantageous for ensuring that the electroconductive cords of the layers can be in contact from one layer to another, without risking excessively thickening the layer, which could generate marks or bumps on the layer covering these cords and degrade the mechanical performance of the body.

[0073] The thickness X in question of the layer is preferably the final thickness of the layer after fabrication of the body 22 and in particular polymerization of the matrix of the body.

[0074] The cords 40 of the two layers 24, 26 can form a mesh of the type illustrated in [Fig.5].

[0075] In this figure, the series of fibers 34 or the strips 36 of the first layer 26, as well as the electro-conductive cords 40 of this layer 26, are inclined with respect to the series of fibers 34 or the strips 36 of the second layer 24, as well as the electro-conductive cords 40 of this second layer 24.

[0076] It is therefore understood that the series of fibers 34 or the bands 36 of the first layer 26 cross those of the second layer 24, and that the electro-conductive cords 40 of the first layer 26 cross those of the second layer 24. This allows each of the cords 40 of one layer to be in contact with several cords 40 of the other layer, which improves the electrical conductivity capacity of the body.

[0077] In the case of the use of strips 36, the electro-conductive cords 40 of each of the layers 24, 26 are preferably each located between two strips 36 of this layer, and the unidirectional strips 36 of each of the layers 24, 26 are each arranged between two electro-conductive cords 40 of this layer.

[0078] The 36 fiber strips preferably have the same width L. The 36 fiber strips have, for example, a width L between 20mm and 50cm.

[0079] In the case of using series of fibers 34, the electro-conductive cords 40 of each of the layers 24, 26 are preferably each located between two series of fibers 34 of this layer, and the series of fibers 34 of each of the layers are each arranged between two electro-conductive cords 40 of this layer.

[0080] The series of fibers 34 preferably have the same number of fibers or the same width L. The series of fibers 34 have for example a width L between 5 and 40mm.

[0081] The present invention also relates to a method for manufacturing the aeronautical structure 20 comprising the following steps:

[0082] a) for the first layer 26, preferably depositing simultaneously on a support 45 ([Fig.7]), in the plane P26 of this first layer 26, series of unidirectional fibers 34 next to and along each other, or unidirectional strips of fibers 36 next to and along each other, as well as electroconductive cords 40 which extend parallel to the series or strips of fibers 34, 36, at a distance from each other, and which are intercalated between series or strips of fibers 34, 36 without being woven into these fibers,

[0083] and possibly (in the case of using a second functionalized layer)

[0084] b) for the second layer 24, preferably deposit simultaneously on the first layer 26, in a plane P24 of this second layer 24, series of unidirectional fibers 34 side by side and along each other, or unidirectional strips of fibers 36 side by side and along each other, and electro-conductive cords 40 extending parallel to the series or strips of fibers 34, 36, at a distance from each other, and interleaved between series or strips of fibers 34, 36 without being woven into these fibers, so that at least some of the electro-conductive cords 40 of this second layer 24 are in contact with at least some of the electro-conductive cords 40 of the first layer 26.

[0085] The support 45 on which the layers are deposited and formed is preferably a mold for manufacturing the body 22.

[0086] The fibre series 34 or the strips 36, as well as the electro-conductive cords 40, can be dry during steps a) and / or b). Alternatively, they are pre-impregnated with a resin before steps a) and / or b).

[0087] In a particular embodiment of the process, each electroconductive cord 40 is pre-assembled to the fiber series 34 or the strip 36 during steps a) and / or b), or before these steps. Each cord 40 can then be held to the side of a series or strip 34, 36 by means of a fastening device which may be the resin used to impregnate the fibers or an assembly element such as a thread surrounding the series of fibers 34 or strips 36 (such as wrapping), or a discontinuous plastic veil that binds the cord 40 to the series or strip of fibers.

[0088] Steps a) and / or b) can be carried out by an ATL or AFP type process.

[0089] The cords 40 are for example deposited parallel to the series of fibers 34 or to the strips 36 by a specific AFP / ATL automatic draping head 50 during the draping of the layers on the support 45 or the mold ([Fig.6]).

[0090] In a preferred solution illustrated in [Fig. 7], the laying of the cords 40 can be carried out simultaneously with the laying of the series of fibers and strips 34, 36. The draping head 50 must then be equipped with an additional module comprising:

[0091] - 60 spools of 40 cords, and

[0092] - a device 70 for cutting cords 40.

[0093] The series of fibers or strips 34, 36 are supplied by reels 80 also associated with a cutting device 90 for the series or strips 34, 36.

[0094] The series or strips 34, 36 as well as the cords 40 can be applied to the support 45 by the same roller 100.

[0095] The unwinding positions of the cords 40 are such that these cords 40 are deposited between two series of fibers or strips 34, 36.

[0096] In another variant, the cords 40 can be deposited by a second head independent of the first depositing head of the series or strips 34, 36, this second head depositing the cords 40 on the support 45, between the series or strips 34, 36 deposited by the first head.

[0097] Preferably, the cords 40 are laid after the laying of the series or strips 34, 36 with which they are associated, which allows the binder of the fibers to be used to fix the cords 40 with the draping.

[0098] In yet another embodiment, the cords 40 are deposited before the series or strips 34, 36 and are then provided with their own binder to attach to the fibers or strips as soon as they are deposited. The binder being either a thermoplastic or a raw thermosetting resin.

[0099] The preferred solution is for these cords to be slightly impregnated with the same resin as the fibers.

[0100] Naturally, the aeronautical structure according to the invention could comprise more than two adjacent functionalized layers and, for example, three layers comprising electro-conductive cords. The electro-conductive cords of the intermediate functionalized layer would then be in contact with at least some of the electro-conductive cords of the two adjacent functionalized layers located respectively above and below the intermediate layer.

Claims

Claims

1. Aeronautical structure (20) capable of receiving a lightning strike, this structure (20) comprising a body (22) made of composite material formed by stacking several layers of fibers embedded in a polymer matrix, a first (26) of these layers defining an external surface (30) of the body (22) capable of receiving a lightning strike and comprising, in a plane (P26) of the first layer (26), series of unidirectional fibers (34) arranged next to and along each other, or unidirectional strips of fibers (36) arranged next to and along each other, characterized in that said first layer (26) comprises, in the plane (P26) of the first layer (26), electrically conductive cords (40) which extend parallel to the series or strips of fibers (34, 36), at a distance from each other, and which are interposed between series or strips of fibers (34, 36) without being woven into the fibers.

2. An aeronautical structure (20) according to claim 1, wherein a second (24) of the layers, arranged directly on the first layer (26), comprises, in a plane (P24) of this second layer (24): - series of unidirectional fibers (34) arranged next to and along each other, or unidirectional strips of fibers (36) arranged next to and along each other, and - electrically conductive cords (40) which extend parallel to the series or strips of fibers (34, 36), at a distance from each other, and which are interposed between series or strips of fibers (34, 36) without being woven into these fibers, at least some of the electrically conductive cords (40) of the first layer (26) being in contact with at least some of the electrically conductive cords (40) of the second layer (24).

3. Aeronautical structure (20) according to claim 2, in which the series or strips of fibers (34, 36) of the first layer (26), as well as the electrically conductive cords (40) of this first layer (26), are inclined relative to the series or strips of fibers (34, 36) of the second layer (24), as well as to the electrically conductive cords (40) of this second layer (24).

4. Aeronautical structure (20) according to one of the preceding claims, in which each of the electrically conductive cords (40) is a metal wire, or a strand of metal wires.

5. Aeronautical structure (20) according to one of the preceding claims, in which the electrically conductive cords (40) have a thickness or diameter (D) in section which represents 80% to 120%, and preferably 90% to 110%, of a thickness (X) of the series or strips of fibers (34, 36) of the layer (24, 26) comprising these cords (40).

6. Aeronautical structure (20) according to one of the preceding claims, in which the electrically conductive cords (40) of a layer (24, 26) are each located between two unidirectional fiber strips (36) of this layer (24, 26), and the unidirectional fiber strips (36) of the layer (24, 26) are each arranged between two electrically conductive cords (40) of this layer (24, 26), the fiber strips (36) having the same width (L).

7. Aeronautical structure (20) according to one of claims 1 to 5, in which the electrically conductive cords (40) of the layers (24, 26) are each located between two series of unidirectional fibers (34) of this layer (24, 26), and the series of unidirectional fibers (34) of the layer (24, 26) are each arranged between two electrically conductive cords (40) of this layer (24, 26), the series of unidirectional fibers (34) having the same number of fibers or the same width (L).

8. Aeronautical structure (20) according to one of the preceding claims, in which the structure (20) is chosen from a nacelle (12) or part of a nacelle, a wing or part of a wing, a fuselage or part of a fuselage, a cowl, a flap, a turbomachine blade, and a turbomachine casing.

9. A method of manufacturing an aeronautical structure (20) according to one of the preceding claims, wherein it comprises the following steps: a) for the first layer (26), preferably simultaneously depositing on a support (45), in a plane (P26) of this first layer (26), series of unidirectional fibers (34) next to and along each other, or unidirectional strips of fibers (36) next to and along each other, as well as electrically conductive cords (40) which extend parallel to the series or strips of fibers (34, 36), at a distance from each other, and which are interposed between series or strips of fibers (34, 36) without being woven into these fibers, and optionally: b) for the second layer (24), preferably simultaneously depositing on the first layer (26), in a plane (P24) of this second layer (24), series of unidirectional fibers (34) next to and along each other, or unidirectional strips of fibers (36) next to and along each other, as well as electrically conductive cords (40) which extend parallel to the series or strips of fibers (34, 36), at a distance from each other, and which are interposed between series or strips of fibers (34, 36) without being woven to these fibers, so that at least some of the electrically conductive cords (40) of this second layer (24) are in contact with at least some of the electrically conductive cords (40) of the first layer (26).

10. Method according to claim 9, wherein step a) and / or step b) is / are carried out by a method of the ATL or AFP type.

11. A method according to claim 9 or 10, wherein the support (45) is a mold for manufacturing the body.

12. Method according to one of claims 9 to 11, in which the series or strips of fibers (34, 36) of the first layer (26), as well as the electrically conductive cords (40) of this first layer (26), are inclined relative to the series or strips of fibers (34, 36) of the second layer (24), as well as to the electrically conductive cords (40) of this second layer (24).

13. Method according to one of claims 9 to 12, in which the series or strips of fibers (34, 36), as well as the electrically conductive cords (40), are dry during step a) and / or step b).

14. Method according to one of claims 9 to 13, in which the series or strips of fibers (34, 36), as well as the electrically conductive cords (40), are pre-impregnated with a resin, and preferably with the same resin, before step a) and / or step b).

15. Method according to one of claims 9 to 14, in which, during step a) and / or step b), each of the electrically conductive cords (40) of the or each layer (24, 26) is secured to a longitudinal edge of a series of fibers or a unidirectional strip (34, 36) of this layer.

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