阅读说明：本技术 用于由复合材料制备的抗冲击性提高的壳体的纤维织构 (Fiber texture for impact-resistant enhanced housings made from composite materials ) 是由 弗朗索瓦·查理 多明尼克·玛丽·克里斯蒂安·库普 赫维·格雷林 于 2019-07-18 设计创作，主要内容包括：一种带状纤维织构(100)具有在多层经纱线或经向股线与沿横向延伸的多层纬纱线或纬向股线(30)之间的三维或多层编织结构。所述纤维织构包括第一部分(P1),所述第一部分沿纵向从织构的近端部分(110)起在确定长度(LP1)上延伸,并且在所述第一部分中,所述多层纬纱线或纬向股线中的一层或多层由多组纱线或股线组成,每组纱线或股线至少包括一根碳纤维纱线或碳纤维股线以及一根玻璃纤维纱线或玻璃纤维股线。每组纱线中的碳纤维纱线或碳纤维股线与玻璃纤维纱线或玻璃纤维股线按照相同的编织图案或编织方式编织在一起。所述纤维织构还包括第二部分(P2),所述第二部分存在于所述纤维织构的第一部分和远端部分(120)之间,在所述第二部分中,所述多层纬纱线或纬向股线的多层包括碳纤维纱线或碳纤维股线。(A ribbon-like fibrous texture (100) has a three-dimensional or multi-layer weave structure between multiple layers of warp or warp strands and multiple layers of weft or weft strands (30) extending in the cross direction. The fiber texture comprises a first portion (P1) extending in a longitudinal direction over a determined length (LP1) from a proximal portion (110) of the texture and in which one or more of the layers of weft or fill yarns are composed of groups of yarns or strands each comprising at least one carbon fiber yarn or carbon fiber strand and one glass fiber yarn or glass fiber strand. The carbon fiber yarns or carbon fiber strands in each set of yarns are woven with the glass fiber yarns or glass fiber strands in the same weave pattern or weave. The fibrous texture further comprises a second portion (P2) which is present between the first portion and the distal end portion (120) of the fibrous texture, in which second portion the plurality of layers of weft or fill yarns comprise carbon fiber yarns or carbon fiber strands.)

1. A ribbon-like fibrous texture (100) having a determined length (L) between a proximal portion (110) and a distal portion (120)₁₀₀) Extending in a longitudinal direction (X) and having a determined width (l) between a first side edge (101) and a second side edge (102)₁₀₀) Extending in a cross direction (Y), the fibrous texture having a three-dimensional or multi-layer weave between a plurality of layers of warp or warp strands (20) extending in a machine direction and a plurality of layers of weft or weft strands (30) extending in a cross direction,

characterized in that the fibrous texture comprises a first portion (P1) having a determined length (L) in the longitudinal direction from the proximal portion (110)_P1) And in which one or more of said plurality of weft or fill threads consists of a plurality of groups of yarns or threads, each group of yarns or threads comprising at least one carbon fiber yarn or strand (Tc1-Tc9) and one glass fiber yarn or strand (Tv1-Tv9), the carbon fiber yarn or strand and the glass fiber yarn or strand being woven together in the same weaving pattern or manner, said fiber texture further comprising a second portion (P2) which is present in the longitudinal direction of said fabricBetween the first and distal end portions of the fibrous texture, in the second portion, multiple layers of the plurality of layers of weft or fill yarns comprise carbon fiber yarns or carbon fiber strands (Tc1-Tc 9).

2. The fibrous texture according to claim 1, wherein the plurality of layers of weft or fill yarns of the first part present on the side of the inner surface (F1) of the fibrous texture (100) comprises a plurality of groups of yarns or strands, each group of yarns or strands comprising at least one carbon or carbon fiber strand and one glass or glass fiber strand, the other layers of weft or fill yarns present on the side of the outer surface (F2) of the fibrous texture comprising carbon or carbon fiber strands.

3. The fibrous texture according to claim 1 or 2, wherein the first part of the fibrous texture comprises a holding portion (130) extending inwardly from a side edge (101, 102) of the fibrous texture in a cross direction (Y), the holding portion comprising more glass fiber yarns or strands than parts (140, 150) adjacent to the holding portion in the cross direction.

4. A fiber preform (60) for an aircraft shell (810), comprising a winding of a plurality of turns of a fiber texture according to any one of claims 1 to 3, the first portion (P1) being located on the side of a radially inner surface of the preform and the second portion (P2) being located on the side of a radially outer surface of the preform.

5. A gas turbine casing (810) made of composite material comprising a fiber reinforcement constituted by a fiber preform according to claim 4 and a matrix densifying the fiber reinforcement.

6. The housing (810) of claim 5, wherein the housing is a gas turbine fan housing.

7. An aircraft gas turbine engine (80) having a casing (810) according to claim 5 or 6.

8. Method for producing a fibrous texture (100) by three-dimensional or multilayer weaving between layers of warp or warp threads (20) extending in a longitudinal direction (X) and layers of weft or weft threads (30) extending in a transverse direction (Y), said fibrous texture being in the form of tapes with a determined length (L) between a proximal end portion (110) and a distal end portion (120)₁₀₀) Upper edge extending in longitudinal direction and having a determined width (I) between a first side edge (101) and a second side edge (102)₁₀₀) The upper part extends along the transverse direction (Y),

characterized in that it comprises knitting a first portion (P1) of determined length (L) longitudinally from a proximal portion (110)_P1) And in which one or more of said plurality of layers of weft or fill yarns consists of a plurality of groups of yarns or yarns, each group of yarns or yarns comprising at least one carbon or carbon fiber yarn (Tc1-Tc9) and one glass or glass fiber yarn (Tv1-Tv9), the carbon or carbon fiber yarn and the glass or glass fiber yarn being woven together in the same weaving pattern or manner, said method further comprising weaving a second portion (P2) which is present longitudinally between a first portion and a distal portion of said fibrous texture, and in which second portion the plurality of layers of said plurality of layers of weft or fill yarns comprises carbon or carbon fiber yarns (Tc1-Tc 9).

9. The method according to claim 8, wherein the plurality of layers of weft or fill yarns present on the side of the inner surface (F1) of the fibrous texture (100) in the first portion comprises a plurality of groups of yarns or strands, each group of yarns or strands comprising at least one carbon or carbon fiber strand and one glass or glass fiber strand, the other layers of weft or fill yarns present on the side of the outer surface (F2) of the fibrous texture comprising carbon or carbon fiber strands.

10. The method of claim 8 or 9, wherein the first portion of the fibrous texture comprises: a retention portion extending laterally inward from a side edge of the fibrous texture; a yarn or strand inlet portion located between the first side edge of the fibrous texture and the retaining portion, wherein the glass fiber yarn or glass fiber strand is gradually inserted into multiple layers of the plurality of layers of weft or fill strands; and a yarn or strand outlet portion between a retaining portion and a second side edge of the fibrous texture, wherein fiberglass yarns or fiberglass strands are progressively withdrawn from the plurality of layers of weft or fill strands, the retaining portion comprising more fiberglass yarns or fiberglass strands than in the yarn or strand inlet and outlet portions.

Background

The present invention relates to a fibrous texture which may be used in particular, but not exclusively, for forming fibrous reinforcements for aircraft engine fan casings made of composite materials.

The manufacture of a shell made of composite material starts with the production of a fibrous texture in the form of a ribbon, which is produced by three-dimensional weaving between a plurality of layers of warp yarns and a plurality of layers of weft yarns. The fiber texture thus obtained is wound several turns on a mold or tool having the shape of the shell to be manufactured and held between the mold and the segments forming the countermold to obtain a fiber preform.

Once the fiber preform is produced, i.e. at the end of the winding of the fiber texture, the mold carrying the fiber preform is closed by a countermold and then conveyed to an oven or furnace where the preform is densified by a matrix, which may be obtained in particular by injecting and polymerizing a resin in the fiber preform.

The fan housing has three main functions, namely:

-ensuring the connection between the engine parts,

-defining an air intake in the engine;

ensuring entrapment by entrapping the debris ingested in the engine or the centrifugally expelled blades or blade debris, to prevent them from passing through the casing and reaching other parts of the aircraft

The first two functions have a low requirement on mechanical properties but are permanent. On the other hand, the third function, even if used very rarely, has high requirements on mechanical properties.

In a Fan Blade Out (FBO) event, the event can be divided into different phases for the housing:

stage 1: the contact between the blade and the casing is,

and (2) stage: the leading edge of the missing blade is sheared from the shell material,

and (3) stage: the shell is deformed under the action of high energy,

and (4) stage: recovering the energy stored in the casing associated with the lost blade fragments,

and (5) stage: establishing windmill rotation.

In phase 1, the casing is required to have a high stiffness in order to minimize deformation under the effect of contact with the blade. At this stage, energy is stored by the housing in the form of deformation.

In phase 2, the shell material should exhibit shear properties. The material is sheared and energy is dissipated by the shear.

At stage 3, the projectile has more difficulty penetrating the casing and the energy stored by the projectile is fully absorbed by the deformation of the casing. At this stage, a high rate of deformation of the housing material is required.

At stage 4, energy is recovered by deformation of the shell, restoring it to the original geometry.

In phase 5, the housing is subjected to fatigue stresses of high mechanical load.

The prior art housings generally satisfactorily ensure this function. However, it is still possible to further increase the mechanical strength of some housings to resist the impact of a projectile, particularly when the blades are disengaged and projected onto the housing.

An example of a fan casing made of composite material with a reinforced retaining area is described in particular in document WO 2017/109403.

Disclosure of Invention

According to a first aspect, the invention relates to a ribbon-like fibrous texture extending in a longitudinal direction over a determined length between a proximal end portion and a distal end portion and in a transverse direction over a determined width between a first side edge and a second side edge, the fibrous texture having a three-dimensional or multi-layer weave between a plurality of layers of warp threads or warp strands extending in the longitudinal direction and a plurality of layers of weft threads or weft strands extending in the transverse direction,

wherein the fibrous texture comprises a first portion extending over a determined length from a proximal portion in a longitudinal direction, and in the first part, one or more of the plurality of layers of weft yarns or weft strands is/are composed of a plurality of groups of yarns or strands, each group of yarns or strands comprises at least one carbon fiber yarn or carbon fiber strand and one glass fiber yarn or glass fiber strand, the carbon fiber yarn or carbon fiber strand and the glass fiber yarn or glass fiber strand in each group of yarns are woven together in the same weaving pattern or weaving manner, the fibrous texture further comprising a second portion, the second portion being present longitudinally between the first portion and the distal portion of the fibrous texture, in the second section, multiple layers of the plurality of layers of weft or fill yarns comprise carbon fiber yarns or carbon fiber strands.

The fiber texture is intended to be wound in several turns to form a fiber reinforcement for a composite shell. The first part is intended to form the radially inner part of the fibre reinforcement (first turn of winding). The second part is intended to form the radially outer part of the fibre reinforcement (the last turn of the winding).

The inventors have found that by judiciously placing glass fibre yarns or strands in carbon fibre yarns or strands in a fibre texture, the ability of the shell to resist impacts, such as the impact of a detached blade, can be improved. In fact, glass fiber yarns or strands have higher shear and tensile elongation strengths than carbon fiber yarns or strands. The fiber texture according to the invention therefore comprises in the first part a glass fiber weft or fill yarn intended to form the start of the winding and located on the side of impact with the blade, in order to give this first part greater shear strength. Furthermore, since the maximum dimension of the projectile is positioned perpendicular to the weft or fill yarn, the insertion of the fiberglass yarn or fiberglass strand in the direction of the weft yarn is particularly suited to the dynamics of the exfoliate event.

This therefore limits the penetration depth of the projectile (e.g. blade or blade portion) that strikes the inner surface of the casing. This thus leaves a large portion of the shell material, which allows to effectively ensure the management of the above-mentioned phases (in particular phases 3 to 5) during a blade shedding event or blade chipping.

By using multiple sets of yarns or strands in the first section, each set comprising at least one carbon fiber yarn or carbon fiber strand and one glass fiber yarn or glass fiber strand, two different functions can be performed. In fact, the carbon fiber yarns or strands give the shell the axial stiffness required for the required mechanical function, in particular in the phases 1 to 5 described above, while the glass fiber yarns or strands have a higher shear strength to satisfy the shear absorption function required for the shell in phase 2, as described above.

The invention therefore consists in using two different materials, namely carbon and glass, which are located in specific areas of the fibre reinforcement in order to react in an optimal way to the stresses of the shell during an impact event, such as loss of a blade or fracture of a blade, while limiting its mass.

In an exemplary embodiment, the plurality of layers of weft or fill yarns present on the side of the inner surface of the fiber texture in the first part comprises or consists of a plurality of groups of yarns or strands, each group of yarns or strands comprising at least one carbon fiber yarn or carbon fiber strand and one glass fiber yarn or glass fiber strand, and the other layers of weft or fill yarns present on the side of the outer surface of the fiber texture comprise or consist of carbon fiber yarns or carbon fiber strands. This allows to maintain a good stiffness in the first part and limits the influence of the use of glass fiber yarns or strands, which have a higher mass than carbon fiber yarns or strands.

In an exemplary embodiment, the first portion of the fiber texture comprises a holding portion extending laterally inward (set back) from a side edge of the fiber texture, the holding portion comprising more glass fiber yarns or strands than a portion laterally adjacent to the holding portion. The retaining portion is intended to be present opposite the blade and defines a retaining area of the casing to be obtained. This holding region of the casing has the function of holding debris, particles or objects ingested at the engine inlet, or blades or blade fragments radially separated and projected with respect to the casing by centrifugal force. Thus, glass fiber yarns or strands having a larger mass than carbon fiber yarns or strands are concentrated in areas that may be affected by the projectile (especially the blade or blade fragments). This therefore reduces the overall mass of the housing.

The invention also relates to a fiber preform for an aircraft shell, comprising a winding of a plurality of turns of a fiber texture as described above, a first portion being located on the side of the radially inner surface of the preform and a second portion being located on the side of the radially outer surface of the preform.

The invention also relates to a gas turbine casing made of composite material comprising a fiber reinforcement consisting of a fiber preform as described above and a matrix densifying the fiber reinforcement.

In an exemplary embodiment, the housing is a gas turbine fan housing.

The invention also relates to an aircraft gas turbine engine having a casing as described above.

Another object of the invention is a method for manufacturing a fibrous texture by three-dimensional or multilayer weaving between layers of warp or warp threads extending in a longitudinal direction and layers of weft or weft threads extending in a transverse direction, said fibrous texture being in the form of tapes extending in the longitudinal direction over a determined length between a proximal end portion and a distal end portion and extending in the transverse direction over a determined width between a first side edge and a second side edge, characterized in that said method comprises weaving a first portion extending in the longitudinal direction over a determined length from the proximal end portion and in which one or more of said layers of weft or weft threads are composed of groups of yarns or threads, each group of yarns or threads comprising at least one carbon fiber yarn or strand and one glass fiber yarn or strand, the carbon fiber yarn or carbon fiber strand and the glass fiber yarn or glass fiber strand in each group of yarns being according to the same weaving pattern And/or woven together, the method further comprising weaving a second portion longitudinally existing between the first portion and the distal end portion of the fibrous texture, in which second portion multiple layers of the plurality of layers of weft or fill yarns comprise carbon fiber yarns or carbon fiber strands.

In an exemplary embodiment, the plurality of layers of weft or fill yarns present on the side of the inner surface of the fiber texture in the first part comprises or consists of groups of yarns or strands, each group of yarns or strands comprising at least one carbon fiber yarn or carbon fiber strand and one glass fiber yarn or glass fiber strand, and the other layers of weft or fill yarns present on the side of the outer surface of the fiber texture comprise or consist of carbon fiber yarns or carbon fiber strands.

In one exemplary embodiment, the first portion of the fibrous texture comprises: a retention portion extending laterally inward from a side edge of the fibrous texture; a yarn or strand inlet portion located between the first side edge of the fibrous texture and the retaining portion, wherein the glass fiber yarn or glass fiber strand is gradually inserted into multiple layers of the plurality of layers of weft or fill strands; and a yarn or strand outlet portion between a retaining portion and a second side edge of the fibrous texture, wherein fiberglass yarns or fiberglass strands are progressively withdrawn from the plurality of layers of weft or fill strands, the retaining portion comprising more fiberglass yarns or fiberglass strands than in the yarn or strand inlet and outlet portions.

Drawings

Other features and advantages of the present invention will be shown, but not limited to, by the following description with reference to the accompanying drawings, in which:

fig. 1 is a schematic perspective view of a weaving machine, showing the three-dimensional weaving of a fiber texture;

FIG. 2 is a schematic perspective view of a fiber texture according to one embodiment of the present invention;

FIG. 3 is a cross-section taken at a first portion of the fibrous texture of FIG. 2 and showing a weave plane

FIG. 4 is a cross-section taken at a second portion of the fibrous texture of FIG. 2 and showing a weave plane;

FIG. 5 is a schematic perspective view showing the wrapping of the fibrous texture onto the forming tool;

FIG. 6 is an axial half-sectional view of a shell preform obtained by winding the fiber texture shown in FIG. 5;

FIG. 7 is a cross-sectional view illustrating the positioning of injection sectors on the casing preform of FIG. 6;

FIG. 8 is a perspective view of an aircraft engine according to one embodiment of the invention;

fig. 9A and 9B show cross-sections taken at a first portion of a fiber texture variation according to the present invention and show the weaving plane.

Detailed Description

The invention is generally applicable to fiber textures used to manufacture shells made of composite materials, including barrels or shells having ring clamps at their ends.

As shown in fig. 1, the fibrous texture 100 is produced in a known manner by weaving using a jacquard-type loom 5 on which a bundle of multi-layered warp or warp strands 20 is arranged, interconnected by weft or fill strands 30.

The fiber texture is formed by three-dimensional weaving. "three-dimensional weaving" or "3D weaving" as used herein refers to a weaving method in which at least some of the weft yarns are interconnected with warp yarns over several layers of warp yarns, and vice versa. The fiber texture may have an interlocking weave. As used herein, an "interlocked" weave is a weave in which each layer of weft yarns interconnects several layers of warp yarns, all of the yarns in the same weft yarn row moving in the same direction in the weave plane. Interlocking weaving that can be used is described in document WO 2006/136755. Other weaves may be envisaged, such as multi-canvas (multi-canvas) weaves, multi-satin (multi-satin) weaves and multi-twill (multi-twill) weaves. As used herein, a "multi-canvas weave or fabric" refers to a three-dimensional weave having several layers of weft yarns, each layer of the basic weave corresponding to a conventional canvas-type weave, but with points of the weave interconnecting multiple layers of weft yarns. As used herein, a "multiple satin weave or fabric" refers to a three-dimensional weave having several layers of weft yarns, each layer of the basic weave corresponding to a conventional satin type weave, but with some points of the weave interconnecting multiple and multiple layers of weft yarns. As used herein, a "multi-twill weave or fabric" refers to a three-dimensional weave having several layers of weft yarns, each layer of the basic weave corresponding to a conventional twill type weave, but with some points of the weave interconnecting multiple layers of weft yarns.

As shown in fig. 2, the fibrous texture 100 is in the form of a tape extending longitudinally in a longitudinal direction X corresponding to the direction of travel of the warp or warp strands 20 and transversely in a transverse direction Y corresponding to the direction of the weft or fill strands 30 between the first and second side edges 101, 102. The fiber texture has a determined length L between the proximal portion 110 and the distal portion 120₁₀₀Upper longitudinal extension, the proximal portion 110 being intended to form a winding start of the fiber preform on the forming tool and the distal portion 120 being intended to form a winding end of the fiber preform.

The fibrous texture also has a determined width l along the Y direction₁₃₀An upwardly extending central region 130, the central region 130 intended to form a housingThe barrel or shell of (a). The central zone 130 is intended to be present opposite the blade and defines the retaining zone of the casing to be obtained. The central area 130 is set back from the first side edge 101 and the second side edge 102 and is at a determined width l₁₃₀Upper extension of less than the width l of the texture 100₁₀₀. The central region 130 is located midway between the first side edge 101 and the second side edge 102. The central region 130 is delimited between two lateral regions 140 and 150, the two lateral regions 140 and 150 each having a defined width l in the Y direction₁₄₀And l₁₅₀Respectively extend above the base plate. The first lateral region 140 extends between the first lateral edge 101 and the central region 130. The second lateral region 150 extends between the second lateral edge 102 and the central region 130. Each of the lateral regions 140 and 150 is intended to form, at least in part, an annular clamp of the housing.

Length L of fibrous texture 100₁₀₀Determined according to the circumference of the tool or forming die, to allow a determined number of turns of the fiber texture, for example four turns, to be performed.

Fibrous texture 100 includes a first portion P1 extending from proximal portion 110 in direction X, first portion P1. The first portion P1 is intended to form a first part of a winding, thus forming the fibre-reinforcement of the shell (radially inside the winding, see fig. 7, which includes the radial direction R).

The fibrous texture 100 further comprises a second portion P2, the second portion P2 being different from the first portion P1, and the second portion P2 extending in the longitudinal direction X between the first portion P1 and the distal end portion 120. The second portion P2 is intended to form a second part of the winding and thus the fibre reinforcement of the shell (radially outside the winding).

In the example described herein, the fibrous texture 100 is at a length L₁₀₀Up to allow four turns to be wound on the tool or forming die. In the example still described here, the first portion P1 is at length L_P1And the length is defined to correspond to a first winding turn on a tool or forming die (fig. 7), and the second portion P2 corresponds to second, third and fourth winding turns on the tool or forming die (fig. 7).

Fig. 3 to 4 show the planes of the multi-canvas weaving of the fibrous texture 100 respectively in the first portion P1 and the second portion P2.

The examples of weaving planes shown in fig. 3 and 4 include a layer of 9 weft yarns and a layer of 8 warp yarns.

As shown in fig. 3, first portion P1 includes carbon fiber warp yarns or carbon fiber warp strands, denoted Cc. According to the invention, the layers of the multilayer weft or fill yarn are composed of groups of yarns or strands, each group of yarns or strands comprising at least one carbon fiber yarn or strand and one glass fiber yarn or strand, the carbon fiber yarn or carbon fiber strand and the glass fiber yarn or glass fiber strand in each group of yarns being woven together according to the same weaving pattern or weaving pattern. In the example described here, the 9 layers of weft yarns are all made up of groups of yarns or strands, each group comprising a carbon fiber yarn or strand, denoted Tc1 to Tc9, and a glass fiber yarn or strand, denoted Tv1 to Tv 9.

According to one variant, only some of the layers of weft or weft yarns present on the side of the inner surface of the fibrous texture consist of groups of yarns or strands comprising carbon fiber yarns or carbon fiber strands and glass fiber yarns or glass fiber strands, the other layers of the layers of weft or weft yarns consist of carbon fiber yarns or carbon fiber strands. For example, they may be the four first layers starting from the inner surface F1 of the fibrous texture 100, while the other weft or fill strands located on the side of the outer surface F2 of the fibrous texture consist only of carbon fiber yarns or carbon fiber strands.

As shown in fig. 4, the second portion P2 includes a carbon fiber warp yarn or carbon fiber warp strand, denoted Cc, and a carbon fiber weft yarn or carbon fiber weft strand, denoted Tc.

Thus, the properties of the weft or fill yarns change when moving along the longitudinal direction X of the fibrous texture 100.

An example has just been described in which the fiber texture has an interlocking weave of 9 weft layers and 8 warp layers. However, it is not beyond the scope of the invention when the number of weft and warp layers is different, or when the fiber texture has a weave different from a multi-canvas weave.

As shown in fig. 5, the fiber shell reinforcement is formed by winding onto the mandrel 50 of the aforementioned fiber texture 100, which constitutes the complete tubular fiber preform of the integrated shell. For this purpose, the mandrel 50 has an outer surface 51 whose contour corresponds to the inner surface of the shell to be produced. Mandrel 50 also has two flanges 52 and 53 to form fiber preform portions 62 and 63 (clamps 62 and 63 are visible in FIG. 6) corresponding to the clamps (clamps) of the shell. The turns positioned radially towards the inside of the preform correspond to a first portion P1 of the fibrous texture and the turns positioned radially towards the outside of the preform correspond to a second portion P2 of the fibrous texture.

Fig. 6 shows a cross-sectional view of a fiber preform 60 obtained after winding a fiber texture 100 on a mandrel 50 in multiple layers. The number of layers or turns is a function of the desired thickness and the thickness of the fiber texture. It is preferably at least equal to 2. In the example described herein, preform 60 contains 4 layers of fibrous texture 100.

The fiber preform 60 is then densified with the matrix.

Densification of a fibrous preform consists in filling all or part of the volume of the preform's pores with the material constituting the matrix.

The matrix can be obtained in a manner known per se after the liquid process. The liquid process includes impregnating the preform with a liquid composition comprising an organic precursor of the matrix material. The organic precursor is typically in the form of a polymer, such as a resin, optionally diluted in a solvent. The fiber preform is placed in a mold that can be sealed with a shell to the shape of the final shaped part. As shown in fig. 7, a fiber preform 60 is placed between the sections 54 forming the counter mold and the mandrel 50 forming the support, these elements having the external and internal shape, respectively, of the shell to be manufactured. A liquid matrix precursor, such as a resin, is then injected throughout the shell to impregnate the preform.

The conversion of the precursor into the organic matrix, i.e. the polymerization thereof, is carried out by thermal treatment (generally by heating the mould), in which the preform remains after removal of any solvent and crosslinking of the polymer, the shape of which corresponds to that of the part to be made. The organic matrix may in particular be obtained from an epoxy resin, for example a high performance epoxy resin sold, or from a liquid precursor of a carbon or ceramic matrix.

In the case of forming a carbon or ceramic substrate, the thermal treatment comprises pyrolysis of the organic precursor to convert the organic substrate to a carbon or ceramic substrate depending on the precursor used and the pyrolysis conditions. For example, the liquid carbon precursor may be a resin with a relatively high char yield, such as a phenolic resin, while the liquid ceramic precursor, particularly SiC, may be a Polycarbosilane (PCS), Polytitanocarbosilane (PTCS), or Polysilazane (PSZ) type resin. From impregnation to heat treatment, several successive cycles may be performed to obtain the desired degree of densification.

Densification of the fiber preform may be performed by the well-known Resin Transfer Molding (RTM) method. According to the RTM process, the fiber preform is placed in a mold having the shape of the shell to be produced. A thermosetting resin is injected into an interior space between the rigid material portion and the mold, the interior space containing the fiber preform. A pressure gradient is typically established in the interior space between the location of the resin injection and the resin discharge port to control and optimize the impregnation of the preform by the resin.

The resin used may be, for example, an epoxy resin. Resins suitable for use in RTM processes are well known. They preferably have a low viscosity to facilitate their infusion into the fibers. The selection of the temperature grade and/or chemical properties of the resin depends on the thermomechanical stresses that the component must withstand. After the resin is injected into the entire reinforcement, polymerization can be carried out by heat treatment according to the RTM process.

After injection and polymerization, the part is demolded. Finally the part is turned to remove excess resin and the chamfer is machined to obtain a shell 810 having a rotated shape, as shown in fig. 8.

The housing 810 shown in FIG. 8 is a housing for a gas turbine aircraft engine fan 80. As shown in fig. 8, this engine includes, in the airflow direction from upstream to downstream, a fan 81, a compressor 82, a combustor 83, a high-pressure turbine 84, and a low-pressure turbine 85, which are arranged at an engine inlet. The engine is housed in a casing comprising several parts corresponding to the different engine components. For example, the fan 81 is surrounded by the housing 810.

Fig. 9A and 9B show a variant of the fiber texture according to the invention, in which, in the first part, the glass fiber yarns or strands for pairing with the carbon fiber yarns or strands in the weft or fill ply layer are concentrated in the fiber texture area intended to form the shell holding area, i.e. the area facing the blade, which may be affected by a separate blade or blade fragment.

More specifically, as shown in fig. 9A, a first lateral region 240 of the fibrous texture 200 (similar to the lateral region 140 of the fibrous texture 100 of fig. 2) corresponds to an entry portion in which glass fiber yarns or strands Tv1 to Tv9 are progressively inserted into the multiple layers of the multilayer weft or fill yarn to be grouped with carbon fiber yarns or strands Tc1 to Tc9, respectively, according to the same weave pattern or weave.

In the central area 230 (similar to the central area 130 of the fiber texture 100 in fig. 2), all the glass fiber yarns or glass fiber strands Tv1 to Tv9 have been introduced into the fiber texture, so that the central area 230 concentrates most of the glass fiber yarns or glass fiber strands, the area 230 forming the holding part comprising more glass fiber yarns or glass fiber strands than in the inlet and outlet portions of the yarns or strands. The central region 230 is subjected to the greatest mechanical stresses during impact with a separate blade or blade fragment.

As shown in fig. 9B, a second lateral region 250 of the fiber texture 200 (similar to lateral region 150 of fiber texture 100 of fig. 2) corresponds to an exit portion in which the fiberglass yarns or strands Tv1-Tv9 are gradually withdrawn from the multiple layers of the multi-layer weft or fill yarn so as to be separated from the carbon fiber yarns or strands Tc1-Tc9, respectively.

Furthermore, according to a variant, the glass fiber yarns or strands present in the weft yarn layers of the lower face F1 and of the upper face F2 of the fibrous texture may remain, while the other glass fiber yarns or strands present below the lower face F1 and of the upper face F2 of the fibrous texture gradually exit outside the central zone of the fibrous texture. In other words, the glass fiber yarns or strands present in the sets of yarns or strands in the first layer of weft or fill strands as close as possible to the inner surface F1 and the outer surface F2 are continuous over the entire length of the texture, while the glass fiber yarns or strands present in the sets of yarns or strands in the weft or fill strands of the other layers below the surface layer are gradually drawn out of the texture outside the central region, as described above. Thus, a first partial fiber texture is obtained having continuous glass fiber yarns or glass fiber strands on both surfaces thereof. According to another variant, only one inner or outer surface of the fibrous texture may be provided with continuous glass fiber yarns or strands.