EP4301917A1

EP4301917A1 - Fibrous texture for a thin-edged composite blade

Info

Publication number: EP4301917A1
Application number: EP22711271.1A
Authority: EP
Inventors: Dominique Marie Christian Coupe; Marc-Antoine COLOT
Original assignee: Safran SA
Current assignee: Safran SA
Priority date: 2021-03-03
Filing date: 2022-03-01
Publication date: 2024-01-10
Also published as: US20240133086A1; CN116940724A; FR3120325B1; US20240229308A9; WO2022185007A1; FR3120325A1

Abstract

A fibrous texture (200) for a blade has a three-dimensional weave between a first plurality of layers of filaments (201) and a second plurality of layers of filaments (202). The texture comprises a blade airfoil part (205) extending between a first edge (205a) and a second edge (205b) The texture comprises a first part (212) with at least three layers of filaments of the first plurality of filaments and at least three layers of filaments of the second plurality of filaments. Filaments of the two layers of filaments of the first plurality of filaments (201) bind filaments of the second plurality of filaments (202) to the two layers of filaments of the second plurality of filaments with a determined binding frequency.

Description

Title of the invention: FIBROUS TEXTURE FOR BLADE IN COMPOSITE MATERIAL WITH FINE EDGE

Technical area

The present invention relates to the general field of the manufacture of blades in composite material comprising a fibrous reinforcement densified by a matrix, the fibrous reinforcement being obtained by three-dimensional (3D) or multilayer weaving.

Prior technique

A targeted field is that of gas turbine blades for aeronautical engines or industrial turbines and, more particularly but not exclusively, fan blades for aeronautical engines.

The production of a blade in composite material obtained from a fibrous reinforcement produced by three-dimensional weaving and densified by a matrix is in particular described in document US 2005/0084377.

Three-dimensional (3D) or multi-layer weaving gives the resulting blade in composite material very good mechanical strength.

Optimizing the performance of aeronautical engines requires designing blades in composite material with increasingly thin edges to meet new aerodynamic requirements.

However, the 3D or multilayer weaving weaves used up to now to form blades in composite material do not make it possible to form very thin leading and/or trailing blade edges. In fact, in order to ensure good mechanical strength in the thin parts of the blade, 3D or multi-layer weaving weaves use a minimum number of three weft layers linked together by a minimum number of three warp layers.

However, there is a need for blades made of composite material having very thin leading and/or trailing edges, and this with good mechanical properties even at these edges. Disclosure of Invention

To this end, the invention proposes a fibrous texture intended to form the fibrous reinforcement of a turbomachine blade made of composite material comprising a fibrous reinforcement densified by a matrix, the texture being in a single piece and having a three-dimensional or multilayer weaving between a first plurality of layers of wires or strands extending in a longitudinal direction and a second plurality of layers of wires or strands extending in a transverse direction, the texture comprising a blade blade portion extending in the direction transverse between a first edge corresponding to a leading edge of the blade and a second edge corresponding to a trailing edge of the blade, said texture comprising a first part with at least three layers of threads of the first plurality of threads and at least three layers of yarns of the second plurality of yarns, characterized in that it further comprises at least a second part present at the level of the first o at the second edge of the blade blade portion of the fibrous texture, the second portion comprising only two layers of yarns from the first plurality of yarns and two layers of yarns from the second plurality of yarns, yarns from both layers of yarns of the first plurality of yarns binding yarns of the second plurality of yarns on the two layers of yarns of the second plurality of yarns according to a determined bonding frequency.

The fibrous texture of the invention makes it possible to achieve a minimum thickness in all or part of the edge(s) while retaining sufficient mechanical properties to ensure good mechanical strength of the leading and trailing edges of the final blade.

According to a particular characteristic of the fibrous texture of the invention, the latter comprises a second part present at the level of the first edge of the blade blade part of the fibrous texture, the second part comprising only two layers of threads of the first plurality of yarns and two layers of yarns of the second plurality of yarns, yarns of the two layers of yarns of the first plurality of yarns binding yarns of the second plurality of yarns on the two layers of threads of the second plurality of threads according to a first determined bonding frequency and a third part present at the level of the second edge of the blade blade part of the fibrous texture, the third part comprising only two layers of threads of the first plurality of yarns and two layers of yarns of the second plurality of yarns, yarns of the two layers of yarns of the first plurality of yarns binding yarns of the second plurality of yarns to the next two layers of yarns of the second plurality of yarns a second bonding frequency, the second part having a first yarn density of the second plurality of yarns and the third part having a second yarn density of the second plurality of yarns greater than the first density, the first bonding frequency in the second part being higher than the second bonding frequency in the second zone.

This makes it possible to adapt the weaving weave in the parts comprising only two layers of yarns according to the yarn density of the second plurality of yarns so as to avoid having a weave that is too loose or too tight in these parts. The fibrous texture has very thin parts which have a good ability to deform, that is to say that these parts are able to withstand significant deformations during the shaping of the texture while maintaining their integrity and, hence their reinforcing function.

In a particular embodiment of the fibrous texture, each thread of the first plurality of threads binds threads of the second plurality of threads following a multi-canvas type weave in the second part and following a multi-satin type weave in the third part. According to another particular characteristic of the fibrous texture of the invention, the second part comprises a first zone having a first density of yarns of the second plurality of yarns and a second zone having a second density of yarns of the second plurality greater than the first density, the bonding frequency in the first zone being greater than the bonding frequency in the second zone. This makes it possible to adapt the weaving weave in the same part of the texture comprising only two layers of weft yarns, that is to say in the same edge, when the yarn density of the second plurality of yarns varies in a significative way. In a particular embodiment of the fibrous texture, each thread of the first plurality of threads binds threads of the second plurality of threads according to a weave of the multi-canvas type in the first zone and according to a weave of the multi-satin type in the second area.

The invention also relates to a blade made of composite material comprising a fibrous reinforcement densified by a matrix, the blade extending in a longitudinal direction between a root portion or lower portion and a blade tip or an upper portion and , in a transverse direction, between a leading edge and a trailing edge, characterized in that the fibrous reinforcement of the blade body consists of a fibrous texture according to the invention.

Another subject of the invention is a process for weaving a fibrous structure intended to form the fibrous reinforcement of a blade made of composite material comprising a fibrous reinforcement densified by a matrix, the fibrous structure being woven in a single piece by three-dimensional weaving. or multilayer between a first plurality of layers of wires or strands extending in a longitudinal direction and a second plurality of layers of wires or strands extending in a transverse direction, the texture comprising a blade blade part extending along the transverse direction between a first edge corresponding to a leading edge of the blade and a second edge corresponding to a trailing edge of the blade, the method comprising the weaving of a first part with at least three layers of threads of the first plurality of threads and at least three layers of threads of the second plurality of threads, characterized in that it further comprises the weaving of at least a second part e has at the level of the first or second edge of the blade blade part of the fibrous texture, the second part comprising only two layers of threads from the first plurality of threads and two layers of threads from the second plurality of threads, yarns of the two layers of yarns of the first plurality of yarns binding yarns of the second plurality of yarns to the two layers of yarns of the second plurality of yarns according to a determined binding frequency.

According to a particular characteristic of the method of the invention, the latter comprises the weaving of a second part present at the level of the first edge of the blade blade part of the fibrous texture, the second part comprising only two layers of threads of the first plurality of yarns and two layers of threads of the second plurality of threads, threads of the two layers of threads of the first plurality of threads binding threads of the second plurality of threads on the two layers of threads of the second plurality of threads according to a first determined binding frequency and the weaving of a third part present at the level of the second edge of the blade blade part of the fibrous texture, the third part comprising only two layers of threads of the first plurality of threads and two layers of threads of the second plurality of threads, threads of the two layers of threads of the first plurality of threads binding threads of the second plurality of threads on the two layers of threads of the second plurality of threads according to a second bonding frequency, the second part having a first yarn density of the second plurality of yarns and the third part having a second yarn density of the second plurality of yarns greater than the first density, the first bonding frequency in the second part being higher than the second bonding frequency in the second zone. In a particular example of implementation of the method, each thread of the first plurality of threads binds threads of the second plurality of threads according to a weave of the multi-canvas type in the second part and according to a weave of the multi-satin type in the third part.

According to another particular characteristic of the method of the invention, the second part comprises a first zone having a first density of yarns of the second plurality of yarns and a second zone having a second density of yarns of the second plurality greater than the first density , the bonding frequency in the first zone being higher than the bonding frequency in the second zone. In a particular example of implementation of the method, each thread of the first plurality of threads binds threads of the second plurality of threads according to a weave of the multi-canvas type in the first zone and according to a weave of the multi-satin type in the second area.

The present invention also relates to a process for manufacturing a composite material blade comprising the following steps:

- production of a fibrous structure in accordance with the method of weaving a fibrous structure according to the invention, - shaping of the fibrous structure to form a fibrous preform of the blade to be manufactured,

- densification of the fibrous preform.

Brief description of the drawings

[Fig. 1] Figure 1 is a schematic view illustrating the three-dimensional weaving of a fibrous structure for the manufacture of an aeronautical engine blade in accordance with one embodiment of the invention,

[Fig. 2A-2D] FIGS. 2A to 2D show, along section II-II in FIG. 1, the various successive weaving weave planes of a portion of the fibrous structure of FIG. 1 intended to form part of the edge dawn attack,

[Fig. 3A-3D] FIGS. 3A to 3D show, along section III-III in FIG. 1, the various successive weaving weave planes of a portion of the fibrous structure of FIG. of dawn flight,

[Fig. 4] Figure 4 is a schematic perspective view of a fibrous blade preform from the fibrous structure of Figure 1,

[Fig. 5] Figure 5 is a schematic perspective view of a blade made of composite material obtained by densification by a matrix of the preform of Figure 4.

Description of embodiments

The invention generally applies to the production of blade bodies or blades in composite material made from a fibrous texture obtained by three-dimensional (3D) or multilayer weaving. Non-limiting examples of such blades are in particular fan blades, outlet guide vanes (called OGV for “Outlet Guide Vane”), inlet guide vanes (called IGV for “Inlet Guide Vane”), variable pitch angle (called V SV for "Variable Stator Vane"), etc.

A method of manufacturing a fibrous structure in accordance with the invention is described in relation to the manufacture of a turbine engine fan blade. The fibrous structure of the invention is obtained by three-dimensional weaving or by multi-layer weaving.

By "three-dimensional weaving" or "3D weaving" is meant here a mode of weaving by which at least some of the warp yarns bind weft yarns over several weft layers.

By "multi-layer weave" is meant here a 3D weave with several layers of weft whose basic weave of each layer is equivalent to a classic 2D fabric weave, such as a weave of the plain, satin or twill type, but with certain points of the weave that bind the weft layers together.

The production of the fibrous structure by 3D or multilayer weaving makes it possible to obtain a connection between the layers, therefore to have good mechanical strength of the fibrous structure and of the part made of composite material obtained, in a single textile operation.

An example of three-dimensional weaving is the interlock weave. By "interlock weave weave" is meant herein a 3D weave weave in which each warp layer binds several weft layers together with all the yarns of the same warp column having the same movement in the plane of the weave.

It may be desirable to use yarns of different chemical natures between different parts of the fibrous structure, in particular between core and skin, to confer particular properties on the part made of composite material obtained, in particular in terms of resistance to oxidation or wear.

Thus, in the case of a part made of thermostructural composite material reinforced with refractory fibers, it is possible to use a preform with carbon fibers in the core and ceramic fibers, for example silicon carbide (SiC), on the surface. in order to increase the wear and oxidation resistance of the composite part at this surface portion.

An exemplary embodiment of a fibrous structure in accordance with the invention is now described. In this example, the weaving is carried out on a Jacquard-type loom.

FIG. 1 very schematically shows a fibrous structure 200 intended to form the fibrous reinforcement of an aircraft engine blade. The fibrous structure 200 is obtained by three-dimensional weaving, or 3D weaving, or by multi-layer weaving carried out in a known way by means of a loom of the jacquard type on which a bundle of yarns or strands of warps 201 has been placed in a plurality of layers, the warp yarns linking weft yarns or strands 202 also arranged in a plurality of layers. A detailed embodiment of a fibrous preform intended to form the fibrous reinforcement of a blade for an aeroengine is in particular described in detail in documents US 7 101 154, US 7241 112 and WO 2010/061140.

The fibrous structure 200 is woven in the form of a strip extending generally in a direction D _c corresponding to the direction of the warp threads 201 and the longitudinal direction of the blade to be produced. The fibrous structure has a thickness along a direction D _e which is variable both in the direction D _c and in a direction D _T perpendicular to the direction D _c and corresponding to the direction of the weft yarns 202. The thickness variations are determined according to the longitudinal thickness and the profile of the blade of the dawn to be produced. In its part intended to form a root preform, the fibrous structure 200 has in the direction D _c a part of extra thickness 203 determined according to the thickness of the root of the blade to be produced. The fibrous structure 200 is extended by a part of decreasing thickness 204 intended to form the shank of the blade then by a part 205 intended to form the blade of the dawn. The fibrous structure 200 is woven in a single piece and must have, after cutting the nonwoven yarns, the shape and the almost final dimensions of the blade (“net shape”). To this end, in the parts of variations in thickness of the fibrous structure, as in the part of decreasing thickness 204, the reduction in thickness of the preform is obtained by gradually removing layers of warp and weft during the weaving.

The part 205 has in the direction D _T a profile of variable thickness between its edge 205a intended to form the leading edge of the blade and its edge 205b intended to form the trailing edge of the blade to be produced, a portion extra thickness (portion 212 in Figure 1) being present between the edges 205a and 205b.

Part 205 includes a first portion 212 constituting the majority of part 205. Portion 212 is located between a second portion 210 and a third portion 211 corresponding respectively to edges 205a and 205b of part 205. The first portion 212 not needing to be thin, it is produced by three-dimensional weaving, between at least three layers of warp threads and at least three layers of weft threads.

In accordance with the invention, the edges 205a and 205b of the part 205 each have a thickness along the direction D _e that is significantly less than that of the portion 212 in order to allow the formation of a blade with a leading edge and an edge very fine leaks. More specifically, the portions 210 and 211 are woven with only two layers of warp threads and two layers of weft threads, which makes it possible to achieve a minimum thickness while retaining sufficient mechanical properties to ensure mechanical strength of the edges of attack and flight of the final dawn.

Still in accordance with the invention, in the portions 210 and 211, the threads of the two layers of warp threads bind threads of the two layers of weft threads according to a determined binding frequency in order to adapt to the density of threads of frame in the part of the fibrous texture considered. More precisely, if the portion considered has a low density of weft threads which is measured by the number of weft threads per centimeter and which is materialized by more spaced columns of weft threads, a weave weave is used with a frequency bonding of the high warp threads in order to avoid too loose weaving which is detrimental to the mechanical strength of the final blade. Conversely, if the portion in question has a high density of weft yarns, a weaving weave is used with a lower warp yarn binding frequency to bind the weft yarns. By way of non-limiting example, the weft yarn density is considered low when the number of weft yarns in the direction D _c and per weft layer is less than or equal to 3.33 weft yarns per centimeter while the density of weft threads is considered high when the number of weft threads is greater than 3.33 threads per centimeter.

In the example described here, the fibrous texture 200 has a higher density of weft yarns in the second portion 210 corresponding to the edge 205a of the part 205 than in the third portion 211 corresponding to the edge 205b of the part 205. Consequently , the portion 211 is woven with a weaving weave having a bonding frequency of the warp threads greater than the bonding frequency of the weaving weave used to weave the portion 210. FIGS. 2A to 2D represent the various successive planes of a weaving weave used in the portion 210 which comprises two layers of weft yarns Ti and T ₂ . The warp yarns 2011 and 202 ₂ respectively belong to two layers of warp yarns. The weaving weave here corresponds to a multi-twill weave with a pitch of 4. The warp yarns 201 ₁ and 201 ₂ represented in FIGS. 2A to 2D have a low bonding frequency due to the density of yarns of high frame in portion 210.

FIGS. 3A to 3D represent the different successive planes of a weaving weave used in the portion 211 which comprises two layers of weft threads T ₃ and T ₄ . The warp threads 201 ₃ and 202 ₄ respectively belong to two layers of warp threads. The weaving weave here corresponds to an alternation, i.e. one weave plane out of two, between a multi-canvas weave and a multi-twill weave with a pitch of 4. Warp threads 201 ₃ and 201 ₄ shown in Figures 3A have 3D has a high bond frequency and higher than the bond frequency in portion 210 due to the lower weft density in portion 211.

The weaving weaves shown in Figures 2A-2D and 3A-3D are only examples of weaves having different warp yarn bonding frequencies matched to the weft yarn density. Other weaving weaves defined from a multi-twill weave, a multi-linen weave, or a mixture of these two types of weave can be used.

Furthermore, in the same portion of the fibrous texture, such as for example the portion 210 or the portion 211 , the weft yarn density can vary in particular along the direction D _c . In this case, a first zone of this portion having a low weft yarn density is woven with a weaving weave having a high warp yarn bonding frequency, while a second zone of the same portion having a weft greater than in the first zone is woven with a weaving weave having a bonding frequency of the warp yarns lower than the bonding frequency of the weave in the first zone.

In the example described here, the first portion 212 is woven with an interlock weave between at least three layers of warp yarns and three layers of warp yarns. frame. The reduction in thickness along the direction D _e of the second and third portions 210, 211 is obtained by gradually removing weft and warp threads in the first portion 212 near its junction with the second and third portions 210 , 211 .

Once the weaving of the fibrous structure 200 has been completed, the nonwoven yarns are cut at the edges of the structure. The fibrous preform 300 illustrated in FIG. 4 and woven in a single piece is then obtained. The preform 300 comprises a portion 303 of extra thickness, corresponding to the portion 203 of the fibrous structure 200, extended by a portion of decreasing thickness 304 corresponding to the portion 204 of the fibrous structure 200. The preform 300 also comprises a blade portion 305 corresponding to the part 205 of the fibrous structure 200 which extends in the direction D _T between a leading edge part 305a and a trailing edge part 205b corresponding respectively to the edges 205a and 205b of the fibrous structure 200. The blade part 305 further has in the direction D _T a portion of extra thickness 305e corresponding to the portion 212 of the fibrous structure 200. The leading edge part 305a and the trailing edge part 305b present in the direction D _e thicknesses e305a and e305b respectively which are much less than the thickness e305c of the extra thickness portion 305e.

The fibrous preform 300 is then densified in order to form a blade 10 of composite material illustrated in FIG. 5. The densification of the fibrous preform intended to form the fibrous reinforcement of the part to be manufactured consists in filling the porosity of the preform, in all or part of the volume thereof, by the material constituting the matrix. This densification can be carried out in a manner known per se according to the liquid process (CVL) or the gaseous process (CVI), or the ceramic filler injection process (Slurry Cast) or the impregnation process of a silicon alloy (Ml or RMI) or else following a sequence of one or more of these processes.

The liquid method consists of impregnating the preform with a liquid composition containing a precursor of the material of the matrix. The precursor usually comes in the form of a polymer, such as a high-performance epoxy resin, optionally diluted in a solvent. The preform is placed in a sealable mold with a housing having the shape of the final molded vane. Then, we close the mold and inject the liquid matrix precursor (for example a resin) throughout the housing to impregnate the entire fibrous part of the preform.

The transformation of the precursor into a matrix, namely its polymerization, is carried out by heat treatment, generally by heating the mould, after removal of any solvent and crosslinking of the polymer, the preform still being maintained in the mold having a shape corresponding to that of the part to be made.

In the case of the formation of a carbon or ceramic matrix, the heat treatment consists in pyrolyzing the precursor to transform the matrix into a carbon or ceramic matrix depending on the precursor used and the pyrolysis conditions. By way of example, liquid ceramic precursors, in particular of SiC or SiCN, can be resins of the polycarbosilane (PCS) or polytitanocarbosilane (PTCS) or polysilazane (PSZ) type, while liquid carbon precursors can be resins relatively high coke content, such as phenolic resins. Several consecutive cycles, from impregnation to heat treatment, can be carried out to achieve the desired degree of densification.

According to one aspect of the invention, in the case in particular of the formation of an organic matrix, the densification of the fibrous preform can be carried out by the well-known process of transfer molding called RTM ("Resin Transfer Moulding"). In accordance with the RTM process, the fiber preform is placed in a mold having the external shape of the part to be produced. A thermosetting resin is injected into the internal space of the mold which includes the fibrous preform. A pressure gradient is generally established in this internal space between the place where the resin is injected and the evacuation orifices of the latter in order to control and optimize the impregnation of the preform by the resin.

The densification of the preform can also be carried out by impregnation of polymer and pyrolysis (PI P), or by impregnation of a slurry ("slurry cast"), containing for example SiC and organic binders, followed by infiltration with liquid silicon (“Melt infiltration”).

The densification of the fibrous preform can also be carried out, in a known way, by gaseous route by chemical vapor infiltration of the matrix (CVI). The fibrous preform corresponding to the fibrous reinforcement of the blade to be produced is placed in a furnace in which a reaction gas phase is admitted. The pressure and the temperature prevailing in the oven and the composition of the gaseous phase are chosen so as to allow the diffusion of the gaseous phase within the porosity of the preform to form the matrix there by deposition, at the heart of the material in contact fibres, of a solid material resulting from the decomposition of a constituent of the gaseous phase or from a reaction between several constituents, contrary to the pressure and temperature conditions specific to CVD ("Chemical Vapor Deposition") processes which lead to exclusively to a deposit on the surface of the material.

The formation of a SiC matrix can be obtained with methyltrichlorosilane (MTS) giving SiC by decomposition of MTS while a carbon matrix can be obtained with hydrocarbon gases such as methane and/or propane giving carbon by cracking.

A densification combining the liquid route and the gas route can also be used to facilitate the implementation, limit the costs and the manufacturing cycles while obtaining satisfactory characteristics for the intended use.

The densification processes described above make it possible to produce, from the fibrous structure of the invention, mainly parts made of composite material with an organic matrix (CMO), a carbon matrix (C/C) and a ceramic matrix (CMC). ).

In the case of the production of a part in oxide/oxide composite material, the fibrous structure is impregnated with a slip loaded with refractory oxide particles. After elimination of the liquid phase of the slip, the preform thus obtained is subjected to a heat treatment in order to sinter the particles and obtain a refractory oxide matrix. The impregnation of the structure can be carried out with processes using a pressure gradient, such as injection molding type processes known as “RTM” or submicron powder suction known as “APS”.

After densification, a blade 10 of composite material is obtained which, as illustrated in FIG. 5, comprises in its lower part a foot 103 formed by the extra thickness part 303 of the fiber preform 300 which is extended by a stilt 104 formed by the part of decreasing thickness 304 of the preform 300 and a blade 105 formed by the blade part 305 of the fiber preform 300. The blade 105 comprises a leading edge 105a and a trailing edge 105b corresponding respectively to the leading edge 305a and trailing edge 305b portions of the fiber preform 300 and a portion of extra thickness 105e corresponding to the portion of extra thickness 305e of the fibrous preform 300. The leading edge 105a and the trailing edge 105b have a very small thickness because the fibrous reinforcement in these parts of the blade comprises only two layers of weft yarns bonded together by only two layers of weft threads as explained previously. In addition, the mechanical strength of these very thin parts is optimized by adapting the bonding frequency as a function of the weft yarn density. The fibrous structure and its method of manufacture according to the present invention can in particular be used to produce turbomachine blades having a more complex geometry than the blade represented in FIG. 5, such as blades comprising, in addition to that of FIG. , one or more platforms making it possible to perform functions such as those of vein sealing, anti-tipping, etc. The fibrous structure and its method of manufacture according to the present invention can for example be used for the manufacture of sectors of vane for gas turbine distributors or rectifiers.

Claims

[Claim 1] Fibrous texture (200) intended to form the fibrous reinforcement of a blade (10) of a turbomachine made of composite material comprising a fibrous reinforcement densified by a matrix, the texture being in a single piece and having a three-dimensional or multilayer weave between a first plurality of layers of wires (201) or strands extending in a longitudinal direction (D _c ) and a second plurality of layers of wires (202) or strands extending in a transverse direction (D _T ), the texture comprising a blade blade part (205) extending in the transverse direction between a first edge (205a) corresponding to a leading edge (105a) of the blade and a second edge (205b) corresponding to a trailing edge (105b) of the blade, said texture comprising a first part (212) with at least three layers of threads from the first plurality of threads and at least three layers of threads from the second plurality of threads, characterized in that which it also includes at least a second part (210, 211) present at the level of the first or second edge (205a, 205b) of the blade blade part (205) of the fibrous texture (200), the second part comprising only two layers of threads of the first plurality of threads (201) and two layers of threads of the second plurality of threads (202), threads (201i, 201 ₂ , 201 ₃ , 201 ₄ ) of the two layers of threads of the first plurality of threads ( 201) bonding yarns of the second plurality of yarns (202) on the two layers of yarns of the second plurality of yarns according to a determined bonding frequency.

[Claim 2] Fiber texture according to claim 1, comprising a second part (210) present at the first edge (205a) of the blade blade part (205) of the fiber texture, the second part comprising only two layers of threads of the first plurality of threads (201) and two layers of threads of the second plurality of threads (202), threads (201i, 201 ₂ ) of the two layers of threads of the first plurality of threads binding threads of the second plurality of threads on the two layers of threads of the second plurality of threads according to a first determined bonding frequency and a third part (211) present at the level of the second edge (205b) of the blade blade part (205) of the fibrous texture, the third part comprising only two layers of threads of the first plurality of threads

(201) and two layers of threads of the second plurality of threads (202), threads (201 ₃ , 201 ₄ ) of the two layers of threads of the first plurality of threads binding threads of the second plurality of threads on both layers of threads of the second plurality of threads according to a second bonding frequency, the second part (210) having a first density of threads of the second plurality of threads

(202) and the third portion having a second yarn density of the second plurality of yarns greater than the first density, the first bonding frequency being greater than the second bonding frequency.

[Claim 3] A fibrous fabric according to claim 2, wherein each thread of the first plurality of threads (201) binds threads of the second plurality of threads (202) in a multi-linen type weave in the second part and following a multi-satin type weave in the third part.

[Claim 4] Fibrous texture according to claim 1 or 2, in which the said at least a second part comprises a first zone having a first density in yarns of the second plurality of yarns and a second zone having a second density in yarns of the second plurality. plurality greater than the first density, the bonding frequency in the first area being greater than the bonding frequency in the second area.

[Claim 5] A fibrous texture according to claim 4, in which each yarn of the first plurality of yarns binds yarns of the second plurality of yarns in a multi-web type weave in the first zone and in a multi-web type weave. satin in the second area.

[Claim 6] Blade made of composite material (10) comprising a fibrous reinforcement densified by a matrix, the blade extending in a longitudinal direction (D _c ) between a root portion or lower portion (103) and a top of blade or an upper portion (105e) and, in a transverse direction (D _T ), between a leading edge (105a) and a trailing edge (105b), characterized in that the fibrous reinforcement of the blade body consists of a fibrous texture according to any one of claims 1 to 5.

[Claim 7] Method of weaving a fibrous structure (200) intended to form the fibrous reinforcement of a blade made of composite material comprising a fibrous reinforcement densified by a matrix, the fibrous structure being woven in a single piece by three-dimensional weaving or multilayer between a first plurality of layers of yarns or strands (201) extending in a longitudinal direction (D _c ) and a second plurality of layers of yarns or strands (202) extending in a transverse direction (D _T ), the texture comprising a blade blade portion (205) extending in the transverse direction between a first edge (205a) corresponding to a leading edge (105a) of the blade and a second edge (205b) corresponding to a trailing edge (105b) of the blade, the method comprising weaving a first portion (212) with at least three layers of yarns from the first plurality of yarns (201) and at least three layers of yarns from the second plurality of wires (202), characterized in that it further comprises the weaving of at least a second part (201, 211) present at the level of the first or second edge (205a, 205b) of the blade blade part of the fibrous texture, the second part comprising only two layers of threads of the first plurality of threads (201) and two layers of threads of the second plurality of threads (202), threads (201i, 201 ₂ , 201 ₃ , 201 ₄ ) of the two layers of threads of the first plurality of threads bonding threads of the second plurality of threads on the two layers of threads of the second plurality of threads according to a determined bonding frequency.

[Claim 8] A method according to claim 7, comprising weaving a second part (210) present at the first edge (205a) of the blade blade part (205) of the fibrous texture, the second part comprising only two layers of threads of the first plurality of threads (201) and two layers of threads of the second plurality of threads (202), threads (201i, 201 ₂ ) of the two layers of threads of the first plurality of threads binding threads of the second plurality of threads on the two layers of threads of the second plurality of threads according to a first determined bonding frequency and a third part (211) present at the level of the second edge (205b) of the blade blade part (205) of the fibrous texture, the third part comprising only two layers of threads of the first plurality of threads

[Claim 9] A method according to claim 8, wherein each yarn of the first plurality of yarns binds yarns of the second plurality of yarns in a multi-linen type weave in the second part and in a multi-satin type weave in the third part.

[Claim 10] A method according to claim 8 or 9, wherein said at least a second portion comprises a first area having a first density of yarns of the second plurality of yarns and a second area having a second density of yarns of the second plurality higher than the first density, the bonding frequency in the first zone being higher than the bonding frequency in the second zone.

[Claim 11] A method according to claim 10, wherein each yarn of the first plurality of yarns binds yarns of the second plurality of yarns in a multi-linen type weave in the first area and in a multi-satin type weave in the second area.

[Claim 12] A method of manufacturing a blade (10) of composite material comprising the following steps: producing a fibrous structure (200) in accordance with the method of weaving a fibrous structure according to any one of claims 7 to , shaping the fibrous structure to form a preform fibrous 300 of the blade to be manufactured, densification of the fibrous preform.