Three-dimensional weaving method for a fiber structure with weft orientation in an unfolded portion and the resulting fiber structure

Abstract

In a three-dimensional weaving method for a fiber structure (200) between a warp yarn layer (203) and a weft yarn layer (204), the weft yarn (204) is woven in a longitudinal direction (D L ) are spaced apart from each other. The method comprises: weaving the expanded portion (222) in a fiber structure interwoven with an adjacent portion, the weft yarns of the weft yarn columns of the adjacent portion (230) being spaced apart from each other in the longitudinal direction (D L ) are juxtaposed in a first vertical stacking direction. During the process of weaving the unfolded portion (222), each weft yarn column (C T222 ) of the weft yarn relative to the vertical surface (205) of the fiber structure along a stacking direction (D S222 )position.

Description

Technical Field

[0001] The present invention relates to the production of components made of composite materials and, more particularly, to the production of fiber-reinforced structures for such components by three-dimensional (3D) weaving. Background Art

[0002] One area of ​​application of the present invention is the production of structural components made of composite materials, that is, structural components with fiber reinforcement and densified by a matrix, such as organic matrix composite (OMC), carbon-based (C / C) and ceramic-based (CMC) material components. Organic matrix composite (OMC), carbon-based (C / C) and ceramic-based (CMC) materials have replaced metal components in certain parts of turbines. Their use helps to optimize aircraft performance, in particular by increasing turbine efficiency and reducing the overall mass of the turbine, significantly reducing emissions harmful to the environment (CO, CO2, NO x wait).

[0003] The invention more particularly relates to a reinforced fiber structure obtained by three-dimensional weaving and comprising one or more unfolding portions, that is to say one or more portions to be unfolded during the shaping of the fiber structure.

[0004] An example of such a fiber structure is the fiber structure used to form the fiber reinforcement of a turbine ring sector made of composite material, as disclosed in particular in document US2012027572.

[0005] Figure 1 A fiber structure 10 is illustrated for forming a fiber reinforcement for a turbine ring sector made of composite material. The structure 10 is obtained by three-dimensional weaving between a plurality of warp yarns in the longitudinal direction D and a plurality of weft yarns. L The weft yarn extends in the transverse direction D T Here, the weft yarn is woven on the T Indicates multiple columns. The weft column C T In the longitudinal direction D L The weft yarns of each weft yarn row are spaced apart from each other along the longitudinal direction D L Vertical stacking direction D S10 Juxtaposed across the thickness of the fiber structure.

[0006] The structure 10 comprises a lower portion 12 forming the base of an annular sector and an upper portion 14 connected to the lower portion 12 via a central portion 16. The upper portion 14 comprises two flared portions 141 and 142 present at opposite outer ends of the central portion 16 and not connected to the lower portion 12. In other words, the fiber structure 10 comprises two non-interconnected areas 18 located at two opposite edges in the transverse direction of the structure 10, leaving the two flared portions free.

[0007] Figure 2 The shaping of the fiber structure 10 is illustrated by folding the flared portions 141 and 142 at 90° towards the central portion 16 in order to form, after densification, a flange for attaching the annular sector to an annular support structure in a turbine. After folding, the stacking direction of the weft yarns of the weft yarn rows present in the flared portions 141 and 142 is changed. More precisely, the stacking direction DS of the weft yarns of the weft yarn rows of the flared portions 141 and 142 is changed. 141 and DS 142 Respectively relative to their initial stacking direction DS 10 This angular change is caused by the shear forces applied to the unfolding portions 141 and 142 during their unfolding. INT The path at the outer radius R EXT The path is short.

[0008] This angular displacement in the weft yarn array results in the loss of the fiber structure at the inner radius, which can damage the finished component by creating an area without fiber reinforcement. Furthermore, this angular displacement can cause the relevant parts to be misaligned, which can alter the originally defined mechanical properties. Summary of the Invention

[0009] It would therefore be desirable to have a solution for producing fiber structures that does not have the above-mentioned disadvantages.

[0010] To this end, the present invention proposes a method for three-dimensional weaving between multiple layers of warp yarns and multiple layers of weft yarns in a fiber structure, wherein the warp yarns extend along a longitudinal direction corresponding to the direction of travel of the warp yarns, and the weft yarns extend along a transverse direction. The weft yarns are woven into multiple columns spaced apart from each other along the longitudinal direction, each weft yarn column is positioned relative to the vertical surface of the fiber structure, and the weft yarns of each weft yarn column are juxtaposed on the thickness of the fiber structure along a determined stacking direction. The method comprises: weaving at least one expanded portion in the fiber structure, the at least one expanded portion being interwoven with one or more adjacent portions of the fiber structure, the weft yarns of the weft yarn columns of the adjacent portions being juxtaposed in a first stacking direction perpendicular to the longitudinal direction, and is characterized in that during the process of weaving the at least one expanded portion, the weft yarns of each weft yarn column are juxtaposed in a second stacking direction different from the first stacking direction.

[0011] Thus, a fiber structure is formed, comprising one or more unfolded sections, in which the weft yarns of the weft yarn arrays are juxtaposed in a stacking direction forming an angle different from 90° with the longitudinal direction, which angle is capable of compensating for the angular variations imposed during the folding of the unfolded sections. Consequently, after folding the unfolded sections, the angular variations caused by the shear forces applied therein during their unfolding result in the horizontal straightening of the weft yarn arrays in these sections and prevent the fiber structure from falling out at the inner diameter.

[0012] According to a particular feature of the method according to the invention, the second stacking direction forms an angle with the longitudinal direction comprised between 60° and 80°, more preferably of about 70°.

[0013] The invention also relates to a method for producing a component made of a composite material, the method comprising:

[0014] - weaving a fiber structure according to the weaving method according to the invention,

[0015] - shaping the fiber structure by folding the at least one unfolded portion, thereby obtaining a fiber preform,

[0016] - Densification of the fiber preform by means of a matrix.

[0017] The method according to the invention for producing a component made of composite material can be used for producing turbine ring sectors, stiffeners or stationary or moving turbine blades.

[0018] The present invention also relates to a fiber structure having a three-dimensional fabric between multiple layers of warp yarns and multiple layers of weft yarns, the warp yarns extending in a longitudinal direction and the weft yarns extending in a transverse direction, the structure comprising a plurality of weft yarn columns spaced apart from each other along the longitudinal direction, the weft yarns of each weft yarn column being juxtaposed in a determined stacking direction on the thickness of the fiber structure, the fiber structure comprising at least one expanded portion interwoven with one or more adjacent portions of the fiber structure, the weft yarns of the weft yarn columns of the adjacent portions being juxtaposed in a first stacking direction perpendicular to the longitudinal direction, and characterized in that the weft yarns of each weft yarn column of the at least one expanded portion are juxtaposed in a second stacking direction different from the first stacking direction.

[0019] According to a particular feature of the structure of the invention, the second stacking direction forms an angle with the longitudinal direction comprised between 60° and 80°, more preferably of about 70°.

[0020] The invention also relates to a component made of composite material, comprising a fiber reinforcement densified by a matrix, characterized in that the fiber reinforcement comprises a fiber structure according to the invention.

[0021] According to particular characteristics of the component according to the invention, it corresponds to a turbine ring sector, a rib or a stationary or mobile turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic three-dimensional diagram of a fiber structure according to the prior art,

[0023] Figure 2 It shows Figure 1 A schematic front view of the structure after forming,

[0024] Figure 3 is a schematic perspective view of a jacquard loom according to one embodiment of the present invention,

[0025] Figure 4 yes Figure 3 A side view of the loom showing Figure 7 The first part of the fiber structure is woven,

[0026] Figure 5 yes Figure 3 A side view of the loom showing Figure 7 The second part of the fiber structure is woven,

[0027] Figure 6 yes Figure 3 A side view of the loom showing Figure 7 The third part of the fiber structure is the weaving,

[0028] Figure 7 is a schematic front view of a fiber structure according to one embodiment of the present invention.

[0029] Figure 8 yes Figure 7 Schematic front view of the fiber structure after forming. DETAILED DESCRIPTION

[0030] The present invention is generally applicable to the production of a fiber structure or fabric by three-dimensional (3D) weaving between layers of warp yarns and weft yarns, the structure comprising at least one portion that is adapted to unfold during its formation. As used herein, "three-dimensional weaving" or "3D weaving" refers to a weaving method in which at least some of the weft yarns bind the warp yarns to several layers of warp yarns, and vice versa. An example of a three-dimensional weaving is a weaving pattern known as an "interlocking" weave. As used herein, an "interlocking" fabric refers to a weaving pattern in which each layer of warp yarns binds together several layers of weft yarns, with all yarns in the same warp column having the same movement within the plane of the pattern. In particular, the yarns used herein may be carbon fiber yarns, such as silicon carbide (SiC) fibers, or ceramic fiber yarns, without the present invention being limited to these types of yarns.

[0031] Figure 3 A loom 100 for producing a fiber structure according to an embodiment of the present invention is illustrated. The loom 100 is equipped with Figure 3 The loom 100 further comprises a jacquard mechanism 101 supported by a superstructure not shown in the drawing. The loom 100 also comprises a harness 110 consisting of a weaving plate 111 and control yarns or heddles 113, each heddles 113 being connected at one end to a control hook 102 of the jacquard mechanism 101 and at the other end to one of the return springs 105 fixed to the frame 103 of the loom 100. Each heddles 113 comprises an eyelet 114 through which the warp yarns 203 pass. The warp yarns 201 are organized at the harness 110 of the loom into a plurality of layers and columns, which, as will be described below, are processed by the loom so as to allow the weft yarns 204 to be inserted according to the weaving pattern programmed in the loom. The warp yarns 203 are arranged in a longitudinal direction D corresponding to the direction in which they travel during weaving. L The weft yarn 204 extends in the longitudinal direction D L Vertical lateral direction D T In order to allow the introduction of each weft thread column during the weaving of the fiber structure, the warp take-up system ( Figure 3 This system is placed downstream of the loom and has the function of keeping all the warp threads in the clamping device and allowing them to travel a determined distance after each weft row has been inserted.

[0032] The healds 113 and their associated eyelets 114 extend in a zone Z, wherein the healds 113 and the eyelets 114 are activated by a substantially vertical oscillating movement indicated by the double arrow F. When a shed is created, as shown in FIG. Figure 3 , a portion of the healds is subjected to a pulling force exerted by the control hook 102. In this configuration, the healds 113 allow to lift some of the warp yarns 203, thereby forming a shed 104, which allows the passage of a lance 120 for the introduction of a weft yarn 204.

[0033] The lance 120 present downstream of the heald 113 is constituted by a rod 121 , the first end of which is connected to the actuation system ( Figure 3 ), thereby allowing the rod 121 to move in both directions D 121 The other end of the rod 121 is provided with a clamp 122, which picks up the weft yarn 204 stored on the bobbin 130 during the forward path of the rod 121 to loosen it in the shed 104 after passing through the shed 104. The weft yarn 204 thus placed inside the shed 104 is cut by the knife 140 near the bobbin 130 and is released at the other end thereof by the clamp 122.

[0034] The comb 150, which is located upstream of the lance 120 and in its rest position, is then folded downwards in order to compact the weft yarn introduced into the shed 104 onto the face 205 of the fiber structure 200. The lance 120 is then ready to pick up a new weft yarn 204 from the bobbin 130 and place it again in the shed 104 or in a different shed, depending on the desired weave. Thus, a fiber structure 200 with a 3D fabric between the warp yarns 203 and the weft yarns 204 is gradually formed.

[0035] A method for weaving a fiber structure 200 according to one embodiment is now described. In the example described here, the fiber structure 200 is used to form a fiber reinforcement for a turbine ring sector made of composite material. Figure 7 As illustrated in FIG, once the fiber structure 200 is woven, it comprises a lower portion 210 for forming the base of the annular sector and an upper portion 220 connected to the lower portion 210 via a central portion 230. The upper portion 220 includes two flared portions 221 and 222, which are respectively present at opposite outer ends of the central portion 230 facing each other, wherein the two base portions 211 and 212 of the lower portion 210 are present at opposite outer ends of the central portion 230. The flared portions 221 and 222 are not connected to the base portions 211 and 212 of the lower portion 212, and during weaving of the fiber structure, two non-interconnected areas 240 are formed at two opposite edges in the transverse direction of the structure 200, thereby leaving the two flared portions free.

[0036] Figure 4 The beginning of the weaving of the fiber structure 200 is shown, namely the weaving of the base portion 212 and the expansion portion 222. Each of the portions 222 and 212 is formed by 3D weaving between multiple layers of warp yarns 203 and multiple layers of weft yarns 204. The weft yarns are woven in the portions 222 and 212 in the longitudinal direction D L Multiple columns C spaced apart from each other T222 and C T212 Each weft yarn row C of the lower portion 212 T212 The weft yarn is along the longitudinal direction D L Vertically defined stacking direction D S212 During the process of weaving the portions 212 and 222, the weft yarns present in the flared portion 222 do not extend into the base portion 212 and vice versa, thereby forming a non-interconnected area 240 between the two portions.

[0037] According to the present invention, each weft yarn column C of the unfolded portion 222 T222 The weft yarn 204 is arranged relative to the vertical surface 205 of the fiber structure 200 along the stacking direction D S212 Different second stacking direction D S222 Positioning. The stacking direction of the weft yarns in each weft yarn column can be adjusted using the comb 150. In fact, the angle at which the comb strikes the weft yarns relative to the facade 205 of the fiber structure 200 determines the stacking direction of the weft yarns in each weft yarn column. In the present invention, an orientable comb is used so that its striking angle on the facade of the woven fiber structure is adjusted according to the stacking direction obtained in each weft yarn column. The striking direction of the comb is parallel to the longitudinal direction D L .

[0038] In the example described here, the comb 150 comprises a first fixing portion 151, a second fixing portion 152 and a third fixing portion 153 forming an angle therebetween. The comb 150 is mounted on a rotation axis R present here at the lower end of the fixing portion 151. 150 The comb 150 is also mounted on: V The positioning mechanism 170 is used to adjust the position of the comb and allows the comb to be adjusted along the longitudinal direction D. L Parallel striking direction D F The striking mechanism for striking the facade 205 of the fiber structure ( Figure 3 、 Figure 4 、 Figure 5 and Figure 6 (not shown).

[0039] During the process of weaving the base portion 212 and the flared portion 222, the comb 150 rotates about its rotation axis R 150Oriented so that the second fixing portion 152 is perpendicular to the longitudinal direction D L , and the third fixing portion 153 is in the longitudinal direction D L Forming an angle β greater than 90° 222 The comb 150 is arranged along the vertical direction D V The first fixing portion 151 and the second fixing portion 152 are positioned so as to face the base portion 212 and the expansion portion 222, respectively. F When struck, the weft yarns of the base portion 212 are aligned in a stacking direction D perpendicular to the longitudinal direction. S212 The weft yarns of the expanded portion 222 are juxtaposed in each weft yarn column and are arranged in the longitudinal direction D L Stacking direction D forming angle β222 S222 juxtaposed in each weft column.

[0040] Determine angle β 222 of value in order to compensate, that is to say to counteract, the angular variation exerted on the unfolded portion 222 by the shear forces during its forming by folding.

[0041] Figure 5 The weaving of the central portion 230 of the fiber structure 200 is shown. The central portion 230 is formed by 3D weaving between multiple layers of warp yarns 203 and multiple layers of weft yarns 204 in the succession of the base portion 212 and the expansion portion 222. The weft yarns are woven in the portion 230 in the longitudinal direction D L Multiple columns C spaced apart from each other T230 Each weft yarn row C of the lower portion 212 T230 The weft yarn is along the longitudinal direction D L Vertically defined stacking direction D S230 Juxtaposed across the thickness of the fiber structure.

[0042] During the process of braiding the central portion 230, the comb 150 rotates about its axis of rotation R 150 The comb 150 is oriented such that the second fixing portion 152 is perpendicular to the longitudinal direction. V The second fixing portion 152 is positioned so as to be opposite to the central portion 230. Therefore, each time the comb 150 is struck in the striking direction D F When hitting the vertical surface 205 of the fiber structure 200, the weft yarns of the central portion 230 are moved in the longitudinal direction D L Vertical stacking direction D S230 juxtaposed in each weft column.

[0043] Figure 6The weaving of the base portion 211 and the expansion portion 221 is shown. The portions 221 and 211 are formed by 3D weaving between multiple layers of warp yarns 203 and multiple layers of weft yarns 204 in the continuation of the central portion 230. The weft yarns are woven in the portions 221 and 211 to form a 3D weaving pattern in the longitudinal direction D. L Multiple columns C spaced apart from each other T221 and C T211 Each weft yarn row C of the lower portion 211 T211 The weft yarn is along the longitudinal direction D L Vertically defined stacking direction D S211 During the process of weaving the portions 211 and 221 , the weft yarns present in the flared portion 221 do not extend into the base portion 211 and vice versa, thereby forming a non-interconnected zone 240 between the two portions.

[0044] According to the present invention, each weft yarn row C of the unfolded portion 221 T221 The weft yarn 204 is arranged relative to the vertical surface 205 of the fiber structure 200 along the stacking direction D S211 Different second stacking direction D S221 position.

[0045] During the process of weaving the base portion 211 and the unfolded portion 221, the comb 150 rotates about its rotation axis R 150 Oriented so that the first fixing portion 151 is perpendicular to the longitudinal direction and the second fixing portion 152 is perpendicular to the longitudinal direction D L Forming an angle β less than 90° 221 The comb 150 is arranged along the vertical direction D V The first fixing portion 151 and the second fixing portion 152 are positioned so as to face the base portion 211 and the expansion portion 221, respectively. F When struck, the weft yarns of the base portion 211 are aligned in a stacking direction D perpendicular to the longitudinal direction. S211 The weft yarns of the expanded portion 221 are juxtaposed in each weft yarn column and are arranged in the longitudinal direction D L Forming angle β 221 Stacking direction D S221 juxtaposed in each weft column.

[0046] Determine angle β 221 of value in order to compensate, that is to say to counteract, the angular variation exerted on the unfolded portion 221 by the shear forces during its forming by folding.

[0047] At the end of weaving, we have Figure 7 The fiber structure 200 with the expanded portions 221 and 222 is shown in FIG. 1 , wherein the weft yarn row C T221 and CT221 The weft yarns form an angle β different from 90° with the longitudinal direction 221 and β 222 Stacking direction D S221 and D S222 Juxtaposed, said angles are able to compensate for the angular changes imposed during the folding of the unfolded parts 221 , 222 . Stacking direction D S221 With D S222 With longitudinal direction D L The angle β between 221 and β 222 The value of is between 60° and 80°, more preferably an angle of about 70°.

[0048] This compensation is Figure 8 As shown in the example, the Figure 8 The preform 300 obtained by shaping the fiber structure 200 (that is, after folding the unfolded portions 221 and 222 at 90° relative to the base portions 211 and 212 and the central portion 230) is shown. The unfolded portions 221 and 222 ( Figure 7 ) is subjected to a shear force F during its expansion CIS221 and F CIS222 The resulting change in angle leads to a horizontal straightening of the weft yarn rows in these sections and prevents the fiber structure from falling out at the inner radius.

[0049] The example just described relates to a fiber structure having a plurality of flared sections and a base section, wherein the flared sections and the base section are not interconnected. The present invention is of course applicable to fiber structures having different configurations, in particular simpler structures. The weaving method of the present invention can be applied to the weaving of fiber structures comprising a base section longitudinally extended by flared sections, the flared sections being intended to be folded during the shaping of the fiber structure to form an L-shaped preform, for example in the manufacture of reinforcing bars made of composite materials.

[0050] In general, the comb can include one or more fixed parts that can be simultaneously oriented along the axis of rotation. In the case where the fiber structure includes a base portion extended in the longitudinal direction by an expanded portion (which is intended to be folded during the formation of the fiber structure as described above), the comb can include only one fixed part, which is oriented differently depending on whether the base portion or the expanded portion is being woven. Thus, during the weaving of the expanded portion, the comb is oriented about its axis of rotation so that the fixed part forms an angle other than 90° with the longitudinal direction of the structure or the direction of travel of the warp yarns, the angle being determined so as to compensate (that is, eliminate) the angular variations exerted on the expanded portion by shear forces during its formation by folding. During the weaving process of the base portion, the comb is oriented about its axis of rotation so that the fixed part is perpendicular to the longitudinal direction or the direction of travel of the warp yarns.

[0051] According to a particular feature of the invention, the relative vertical positioning of the comb relative to the shape of the fiber structure can also be achieved in whole or in part by means for holding the woven fiber structure 200 downstream of the heddle 113 and the spray gun 120. In the example described here, the holding means 160 comprises a lower jaw 161 and an upper jaw 162, each of which is connected to an actuating device ( Figures 3 to 6 (not shown), the actuating device can maintain the braided structure 200 on the one hand, and can make the claws 160 and 161 move in the vertical direction D on the other hand. V The holding device 160 allows the vertical surface 205 of the braided structure to be moved in the vertical direction D V Move upwards or downwards relative to the comb 150. In case the weaving machine comprises such a holding device, a relative vertical positioning of the comb relative to the facade of the fiber structure can be achieved by the holding device or by a combined movement of the comb and the holding device.

[0052] The fiber preform 300 is then densified to form a component made of composite material, in the example described here, a gas turbine ring sector. Densification of the fiber preform, which is intended to form the fiber reinforcement of the component to be manufactured, involves filling all or part of the pores in the preform volume with the material forming the matrix. This densification can be carried out in a manner known per se using a liquid method (CVL), a gas method (CVI), a ceramic charge injection method (slurry casting), a silicon alloy infusion method (MI or RMI), or a sequence of one or more of these methods.

[0053] The liquid method involves impregnating a preform with a liquid composition containing a matrix material precursor. This precursor typically takes 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 shell in the shape of the final molded blade. The mold is then closed, and a liquid matrix precursor (e.g., resin) is injected throughout the shell to impregnate the entire fiber portion of the preform.

[0054] The conversion of the precursor into the matrix, ie its polymerization, is carried out by thermal treatment, generally by heating the mould after removing any solvent and crosslinking the polymer, the preform always being maintained in a mould having a shape corresponding to the part to be produced.

[0055] In the case of forming a carbon or ceramic matrix, the thermal treatment consists of the following steps: pyrolysis of the precursor to transform the matrix into a carbon or ceramic matrix, depending on the precursor used and the pyrolysis conditions. For example, the liquid ceramic precursor (particularly SiC or SiCN) can be a resin of the polycarbosilane (PCS), polytitanium carbosilane (PTCS), or polysilazane (PSZ) type, while the liquid carbon precursor can be a resin with a relatively high char content, such as a phenolic resin. Several consecutive cycles from impregnation to thermal treatment can be performed to achieve the desired degree of densification.

[0056] In particular, when forming an organic matrix, the fiber preform can be densified using the well-known transfer molding method known as RTM ("resin transfer molding"). According to the RTM method, the fiber preform is placed in a mold having the external shape of the component to be produced. A thermosetting resin is injected into the mold's interior space, which includes the fiber preform. To control and optimize the impregnation of the preform with the resin, a pressure gradient is typically established in the interior space between the point where the resin is injected and the vent.

[0057] Densification of the preform can also be achieved by polymer infusion and pyrolysis (PIP) or by impregnation of a slurry casting containing SiC and an organic binder, followed by infiltration with liquid silicon (“melt infiltration”).

[0058] Densification of the fiber preform can also be carried out in a known manner by gaseous means (through chemical vapor infiltration (CVI) of the matrix). The fiber preform, corresponding to the fiber reinforcement of the blade to be produced, is placed in an oven that allows the ingress of a reactive gas phase. The pressure and temperature prevailing in the oven, as well as the composition of the gas phase, are selected to allow the gas phase to diffuse within the pores of the preform, thereby forming a matrix by depositing a solid material, resulting from the decomposition of gas phase components or reactions between several components, in the core of the material in contact with the fibers. This differs from the pressure and high temperature conditions characteristic of CVD ("chemical vapor deposition") methods, which only result in deposits on the surface of the material.

[0059] The SiC matrix can be formed by decomposing methyltrichlorosilane (MTS) to obtain SiC, while the carbon matrix can be formed by cracking hydrocarbon gases such as methane and / or propane to obtain carbon.

[0060] Densification combining liquid and gas routes can also be used to facilitate implementation and limit costs and manufacturing cycles while obtaining satisfactory properties for the intended use.

[0061] The densification method described above allows the production of components primarily made of organic-matrix (OMC), carbon-matrix (C / C), and ceramic-matrix (CMC) composite materials from the fiber structures of the present invention. OMC, carbon-matrix, and ceramic-matrix composite materials replace metal components in certain parts of turbines. Their use contributes to optimizing aircraft performance, particularly by increasing turbine efficiency and reducing their overall mass, thereby significantly reducing harmful emissions to the environment (CO, CO2, NOx, and CO2). x wait).

[0062] After densification, a component made of composite material is obtained.

[0063] In particular, the fiber structure according to the invention and the method for its production can be used for producing turbine ring sectors, stiffeners, stationary or moving turbine blades.

Claims

1. A method for three-dimensionally weaving in a fiber structure (200) between a plurality of warp yarns (203) and a plurality of weft yarns (204), said warp yarns being arranged in a longitudinal direction (D) corresponding to the direction of travel of said warp yarns. L ) extends, the weft yarns extend in the transverse direction (D T ), the weft yarns (204) being woven into a plurality of columns spaced apart from each other along the longitudinal direction, each weft yarn column being positioned relative to a facade of the fiber structure, the weft yarns of each weft yarn column being juxtaposed in the thickness of the fiber structure along a determined stacking direction, the method comprising: At least one expanded portion is woven into the fiber structure, the at least one expanded portion (221) being interwoven with one or more adjacent portions (230) of the fiber structure, the weft yarn rows (C T230 ) of the weft yarn in the longitudinal direction (D L ) perpendicular to the first stacking direction (D S230 ) are juxtaposed on Characterized in that during the process of weaving the at least one unfolded portion (221), each weft yarn row (C T221 ) of the weft yarns in the first stacking direction (D S230 ) Different second stacking directions (D S221 ) are juxtaposed on top.

2. The method according to claim 1, wherein The second stacking direction (D S221 ) forms an angle between 60° and 80° with the longitudinal direction.

3. A method for manufacturing a component made of a composite material, the method comprising: Weaving a fiber structure (200) according to the weaving method according to claim 1 or 2, shaping the fiber structure by folding the at least one unfolded portion (221) so as to obtain a fiber preform, The fiber preform is densified by the matrix.

4. Use of the method for producing a component made of composite material according to claim 3 for producing a turbine ring sector, a stiffener or a stationary or mobile turbine blade.

5. A fiber structure (200), the fiber structure being a three-dimensional fabric composed of multiple layers of warp yarns (203) and multiple layers of weft yarns (204), wherein the warp yarns are arranged in a longitudinal direction (D L ) extends, the weft yarns extend in the transverse direction (D T ) extends, the structure comprising: A plurality of weft yarn columns spaced apart from each other along the longitudinal direction, the weft yarns of each weft yarn column being juxtaposed in the thickness of the fiber structure along a determined stacking direction, the fiber structure comprising at least one unfolded portion (221), the at least one unfolded portion being interwoven with one or more adjacent portions (230) of the fiber structure (200), the weft yarn columns (C T230 ) of the weft yarns in a first stacking direction (D) perpendicular to the longitudinal direction S230 ) are juxtaposed on Characterized in that each weft yarn row (C T221 ) of the weft yarns in the first stacking direction (D S230 ) Different second stacking directions (D S221 ) are juxtaposed on top.

6. The fiber structure according to claim 5, wherein The second stacking direction forms an angle of between 60° and 80° with the longitudinal direction.

7. A component made of composite material, comprising a fiber reinforcement densified by a matrix, characterized in that The fiber reinforcement comprises: the fiber structure according to claim 5 or 6.

8. Component according to claim 7, corresponding to a turbine ring sector, a stiffener or a stationary or moving turbine blade.

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