阅读说明：本技术 用于由复合材料制备的抗剪强度提高的壳体的纤维织构 (Fiber texture for shear strength enhanced shells made from composite materials ) 是由 赫维·格雷林 弗朗索瓦·查理克斯 多米尼克·玛丽·克里斯蒂安·库普 于 2019-07-18 设计创作，主要内容包括：一种纤维织构(100),其呈带状,包括在近端部分(110)和中间部分(PI)之间沿纵向(X)延伸的第一部分(P1)。存在于所述纤维织构(100)的内表面(F1)一侧的一层或多层经纱线或经向股线至少部分地包括玻璃纤维纱线或玻璃纤维股线,其他层经纱线或经向股线的纱线或股线包括碳纤维纱线或碳纤维股线。所述纤维织构(100)还包括在纵向上存在于所述纤维织构的中间部分(PI)和远端部分(120)之间的第二部分(P2)。存在于所述纤维织构(100)的外表面(F2)一侧的多层经纱线或经向股线中的一层或多层至少部分地包括玻璃纤维纱线或玻璃纤维股线,而所述多层经纱线或经向股线中其他层纱线或股线包括碳纤维纱线或碳纤维股线。所述经纱线或股线在所述纤维织构(100)的整个长度(L100)上是连续的。(A fibrous texture (100) in the form of a ribbon comprising a first portion (P1) extending in a longitudinal direction (X) between a proximal portion (110) and an intermediate Portion (PI). One or more layers of warp or warp yarns present on the side of the inner surface (F1) of the fibrous texture (100) comprise at least in part glass fiber yarns or glass fiber strands, the yarns or strands of the other layers of warp or warp yarns comprising carbon fiber yarns or carbon fiber strands. The fibrous texture (100) further comprises a second portion (P2) present longitudinally between the intermediate Portion (PI) and the distal portion (120) of the fibrous texture. One or more of the layers of warp or warp yarns present on the side of the outer surface (F2) of the fibrous texture (100) comprise at least in part glass fiber yarns or strands, while the other layers of yarns or strands of the layers of warp or warp yarns comprise carbon fiber yarns or strands. The warp threads or strands are continuous over the entire length (L100) of the fibrous texture (100).)

1. A fibrous texture (100) in the form of a ribbon having a defined 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 fiber texture comprises a first portion (P1) present longitudinally between the proximal portion (110) and the intermediate Portion (PI), the one or more layers of warp or warp threads present on the side of the inner surface (F1) of the fiber texture (100) comprising at least in part glass fiber yarns or glass fiber strands (Cv6-Cv8), the yarns or strands of the other layers of warp or warp threads comprising carbon fiber yarns or carbon fiber strands (Cc1-Cc5),

and further in that the fiber texture further comprises a second portion (P2) present in the longitudinal direction between the middle and distal portions (120) of the fiber texture, one or more of the layers of warp or warp threads present on the side of the outer surface (F2) of the fiber texture (100) comprising at least in part glass fiber yarns or glass fiber strands (Cv6-Cv8), the other layers of yarns or threads of the layers of warp or warp threads comprising carbon fiber yarns or carbon fiber strands (Cc1-Cc5), the warp or warp threads being present over the entire length (L) of the fiber texture (100)₁₀₀) The above is continuous.

2. The fabric according to claim 1, wherein the glass fibre warp threads or yarns (Cv6-Cv8) present in the first portion (P1) on the side of the inner surface (F1) of the fibrous fabric (100) gradually rise in the intermediate Portion (PI) towards the outer surface (F2) of the fibrous fabric, so as to be present on the side of the outer surface (F2) of the fabric in the second portion (P2).

3. The fabric of claim 1 or 2, wherein one or more of the layers of weft or fill yarns present on the side of the inner surface (F1) of the fibrous fabric (200) in the first portion are constituted by glass fibre yarns or glass fibre strands (Tv), the other layers of yarns or strands being constituted by carbon fibre yarns or carbon fibre strands (Tc).

4. The fibrous texture according to any one of claims 1 to 3, wherein one or more of the layers of weft or fill yarns present on the side of the outer surface (F2) of the fibrous texture (200) in the second portion are constituted by glass fibre yarns or glass fibre strands (Tv), the other layers of yarns or strands being constituted by carbon fibre yarns or carbon fibre strands (Tc).

5. 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 4, 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.

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

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

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

9. 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 (100)Is in the form of a band of a determined length (L) between a proximal portion (110) and a distal 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 weaving a first portion (P1) longitudinally existing between said proximal portion (110) and intermediate Portion (PI), the warp yarn or yarns of the one or more layers existing on the side of the inner surface (F1) of said fibrous texture (100) comprising at least in part glass fiber yarns or glass fiber strands (Cv6-Cv8), the yarns or strands of the other layers comprising carbon fiber yarns or carbon fiber strands (Cc1-Cc5),

and further in that the method further comprises weaving a second portion (P2) present in longitudinal direction between the intermediate and distal portions (120) of the fiber texture, one or more of the layers of warp or warp threads present on the side of the outer surface (F2) of the fiber texture (100) comprising at least in part glass fiber yarns or glass fiber strands (Cv6-Cv8), the other layers of yarns or threads of the layers of warp or warp threads comprising carbon fiber yarns or carbon fiber strands (Cc1-Cc5), the warp or warp threads being over the entire length (L) of the fiber texture (100)₁₀₀) The above is continuous.

10. Method according to claim 9, wherein the glass fibre warp threads or yarns (Cv6-Cv8) present in the first portion (P1) on the side of the inner surface (F1) of the fibrous texture (100) gradually rise in the intermediate Portion (PI) towards the outer surface (F2) of the fibrous texture in order to be present on the side of the outer surface (F2) of the texture in the second portion (P2).

11. Method according to claim 9 or 10, wherein one or more of the layers of weft or fill yarns present on the side of the inner surface (F1) of the fibrous texture (200) in the first portion (P1) are constituted by glass fibre yarns or glass fibre strands (Tv), the other layers of yarns or strands being constituted by carbon fibre yarns or carbon fibre strands (Tc).

12. The method according to any one of claims 9 to 11, wherein one or more of the layers of weft or fill yarns present on the side of the outer surface (F2) of the fibrous texture (200) in the second portion are constituted by glass fibre yarns or glass fibre strands (Tv), the other layers of yarns or strands being constituted by carbon fibre yarns or carbon fibre strands (Tc).

Background

The present invention relates to a fibrous fabric which may be used in particular, but not exclusively, for forming a fibrous reinforcement for aircraft engine blower housings 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 blower housing has three main functions, namely:

-providing a connection between engine parts,

-defining an intake duct into the engine,

providing a control function, providing protection by trapping sucked debris or centrifugally projected blades or blade debris within the engine, 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 contact with the blade. At this stage, energy is stored by the housing in the form of deformation.

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

In phase 3, it is more difficult for the projectile to penetrate 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 typically provide this function in a satisfactory manner. However, it is still possible to further increase the mechanical resistance of certain housings to resist the impact of a projectile, particularly when the blades are disengaged and projected onto the housing.

An example of a blower housing made of composite material with a reinforced retaining zone is described in particular in document WO 2017/109403.

Disclosure of Invention

According to a first aspect, the invention relates to a fiber texture in the form of a ribbon 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 fiber texture having a three-dimensional or multi-layer weave between a plurality of layers of warp or warp strands extending in the longitudinal direction and a plurality of layers of weft or weft strands extending in the transverse direction, characterized in that the fiber texture comprises a first portion present in the longitudinal direction between the proximal end portion and an intermediate portion, the warp or warp strand or strands present on the side of the inner surface of the fiber texture at least partially comprising glass fiber yarns or glass fiber strands, the yarns or strands of the other layers of warp or warp strands comprising carbon fiber yarns or carbon fiber strands, and in that, the fiber texture further comprises a second portion present in the longitudinal direction between the middle and distal portions of the fiber texture, one or more of the layers of warp yarns or strands present on the side of the outer surface of the fiber texture comprising at least partly glass fiber yarns or glass fiber strands, the other layers of warp yarns or strands of the layers of warp yarns or strands comprising carbon fiber yarns or strands, the warp yarns or strands being continuous over the entire length of the fiber texture.

The fiber fabric is intended to be wound in several turns to form a fiber reinforcement for the 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 observed that by judiciously placing glass fiber yarns or strands in carbon fiber yarns or strands in a fiber 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 much higher shear strength and elongation resistance than carbon fiber yarns or strands. The fiber texture according to the invention therefore comprises in a first portion glass fiber warp threads or glass fiber warp strands, which are intended to form the start of the winding and which are located on the side of impact with the blade (several layers of warp threads or warp strands are located on the side of the inner surface of the fiber texture), in order to give this first portion a greater shear strength. This limits the penetration depth of a projectile (e.g., a blade or blade portion) that strikes the inner surface of the casing. Thus, a larger portion of the shell material is retained, which enables the above-mentioned phases (in particular phase 2 to phase 5) to be managed effectively during a blade loss or blade chipping event.

The other layer warp yarns or yarns in the first section are made of carbon fiber yarns or strands in order to maintain good stiffness in this first section and to limit the effect of using glass fiber yarns or strands, which are of higher quality than carbon fiber yarns or strands.

Furthermore, the fiber texture according to the invention comprises in the second part glass fiber warp threads or glass fiber warp strands, which are intended to form the outer layer of the winding. In the second part, glass fiber warp threads or glass fiber warp strands are present on the outer surface side of the fiber texture. Since the glass fibres have a higher deformation rate than the carbon fibres, a significant elastic deformation capacity is imparted to the second portion, enabling the energy transmitted by the blade to be absorbed by deformation and then restored to the blade by returning to the original shape (stages 3 and 4).

The other layer warp yarns or strands in the second section are made of carbon fiber yarns or strands in order to maintain good stiffness in this second section and to limit the effects of using glass fiber yarns or strands, which are of higher quality than carbon fiber yarns or strands.

The present invention therefore uses 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 the mass of the shell.

According to a particular aspect of the invention, the glass fiber warp threads or glass fiber warp strands present on the side of the inner surface of the fibrous texture in the first portion gradually rise towards the outer surface of the fibrous texture in the intermediate portion so as to be present on the side of the outer surface of said texture in the second portion. Thus, the warp yarns or warp strands are continuous over the entire length of the fibrous texture, which makes it possible to maintain the mechanical properties (in particular resistance to delamination and stress transmission) imparted by the three-dimensional weave or multilayer weave throughout the fibrous reinforcement.

In an exemplary embodiment, one or more of the layers of weft or fill yarns present on the inner surface side of the fibrous texture in the first portion are comprised of glass fiber yarns or glass fiber strands, and the other of the layers of weft or fill yarns are comprised of carbon fiber yarns or carbon fiber strands. If desired, the shear strength of the first part of the fiber texture can be further increased by using glass fiber weft yarns or glass fiber warp strands at the level of the glass fiber warp yarns or glass fiber warp strands.

In an exemplary embodiment, one or more of the layers of weft or fill strands present on the outer surface of the fibrous texture in the second portion are comprised of glass fiber yarns or glass fiber strands, and the other of the layers of weft or fill strands are comprised of carbon fiber yarns or carbon fiber strands. If necessary, the deformability of the second part of the fiber texture can be further increased by using glass fiber weft yarns or glass fiber weft strands at the level of warp yarns or warp strands which are likewise composed of glass fibers.

The invention is also directed to a fiber preform for an aircraft shell comprising a winding of a plurality of turns of a fiber texture as described above, the first portion being located on the side of the radially inner surface of the preform and the 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 example embodiment, the housing is a gas turbine blower housing.

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

The invention also relates to a method for producing 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, the fibrous texture being ribbon-shaped, extending in the longitudinal direction over a defined length between a proximal end portion and a distal end portion, and extending in the transverse direction over a defined width between a first side edge and a second side edge, characterized in that the method comprises weaving a first part which is present in the longitudinal direction between the proximal end portion and an intermediate portion, the one or more layers of warp or warp threads present on the side of the inner surface of the fibrous texture comprising at least partly glass fiber yarns or glass fiber strands, the yarns or strands of the other layers of warp or warp threads comprising carbon fiber yarns or carbon fiber strands, and in that, the method further comprises weaving a second portion, which is present in the longitudinal direction between the middle and distal portions of the fiber texture, one or more of the layers of warp yarns or strands present on the outer surface side of the fiber texture comprising at least partially glass fiber yarns or strands, the other layers of yarns or strands of the layers of warp yarns or strands comprising carbon fiber yarns or strands, the warp yarns or strands being continuous over the entire length of the fiber texture.

According to a particular aspect of the invention, the glass fiber warp threads or glass fiber warp strands present on the side of the inner surface of the fibrous texture in the first portion gradually rise towards the outer surface of the fibrous texture in the intermediate portion so as to be present on the side of the outer surface of said texture in the second portion.

In an exemplary embodiment, one or more of the layers of weft or fill yarns present on the inner surface side of the fibrous texture in the first portion are comprised of glass fiber yarns or glass fiber strands, and the other of the layers of weft or fill yarns are comprised of carbon fiber yarns or carbon fiber strands.

In an exemplary embodiment, one or more of the layers of weft or fill strands present on the outer surface of the fibrous texture in the second portion are comprised of glass fiber yarns or glass fiber strands, and the other of the layers of weft or fill strands are comprised of carbon fiber yarns or carbon fiber strands.

Drawings

Further characteristics and advantages of the invention will emerge from the following description, without limiting, 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 an embodiment of the present invention;

FIG. 3 is a longitudinal cross-section taken through a portion of the first and intermediate portions of the fibrous texture of FIG. 2 and showing a plane of knitting;

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

FIG. 5 is a longitudinal cross-section taken through a portion and a second portion of the intermediate portion of the fibrous texture of FIG. 2 and showing a weave plane;

FIG. 6 is a schematic perspective view showing the wrapping of the fibrous texture onto the forming tool;

FIG. 7 is a half view of an axial cross-section of a shell preform obtained by winding the fiber texture shown in FIG. 6;

FIG.8 is a cross-sectional view illustrating the positioning of injection sectors on the casing preform of FIG. 7;

FIG. 9 is a perspective view of an aircraft engine according to an embodiment of the invention;

FIG. 10 is a longitudinal cross-section taken at a portion of the first and intermediate portions of a fiber texture variation according to the present invention and showing the weave planes;

FIG. 11 is a longitudinal cross-section taken at a middle portion of the fiber texture variation and showing the weave pattern;

fig. 12 is a longitudinal cross-section taken through a portion and a second portion of the intermediate portion of the fibrous texture and showing the plane of weaving.

Detailed Description

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

As shown in fig. 1, the fibrous texture 100 is produced in a known manner by weaving using a jacquard loom 5 on which a bundle of multi-layered warp or warp strands 20 is arranged, bound 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 by 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 is interconnected with several layers of warp yarns, all of the yarns in the same weft yarn row moving in the same direction in the plane of the weave. Other weaves are also contemplated.

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 and 102. The fiber texture extends longitudinally over a determined length L100 between a proximal portion 110 and a distal portion 120, 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 fiber texture also has a defined width l along the Y direction₁₃₀Upward extensionAn extended central region 130, the central region 130 being intended to form a barrel or shell of a housing. 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 region 130 is set back from the first side edge 101 and the second side edge 102 and has a defined 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 l150, respectively. 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 flange of the housing.

The length L100 of the fiber texture 100 is determined according to the circumference of the forming tool or die to allow a determined number of turns of the fiber texture, for example four turns, to be performed.

The fibrous texture 100 has a first portion P1 located between the proximal portion 110 and the intermediate portion PI of the fibrous texture. The first portion P1 is intended to form a first part of a winding forming the fibre reinforcement of the housing (radially inside the winding, see fig.8, which shows the radial direction R). For example, the intermediate portion PI may be located at half the length of the fibrous texture 100, or more generally, between one quarter and three quarters of the length of the fibrous texture 100.

Fibrous texture 100 further includes a second portion P2 distinct from first portion P1, the second portion P2 residing between intermediate portion P1 and distal portion 120. The second portion P2 is intended to form a second part of the winding which forms the fibre reinforcement of the housing (radially outside the winding).

In the example described herein, the fibrous texture 100 extends over a length L100, allowing four turns to be wound on the forming tool or die. In the example still described herein, the first portion P1 is at length L_P1Upper extension of length L_P1Corresponding to forming tools or diesWhile the second portion P2 is at length L (fig. 8)_P2Upper extension of length L_P2Corresponding to the last winding turn on the forming tool or die (fig. 8), portion PI extends between portions P1 and P2 for a length corresponding to the third and fourth winding turns on the forming tool or die (fig. 8).

Fig. 3 to 5 show the planes of the interlocking weave of the fabric 100 respectively in the first portion P1, the intermediate portion PI and the second portion P2.

The examples of weaving planes shown in fig. 3 to 5 comprise 9 layers of weft yarns Tc and 8 layers of warp yarns Ccl to Cc5 and Cv6 to Cv 8. In the interlocking weave shown, the weft layers are formed by two adjacent weft half-layers offset from each other in the weft direction. Thus, there are 18 weft yarn half-layers staggered. Each layer of warp yarns interconnects 3 layers of weft yarns. A non-staggered arrangement may also be used, with the warp yarns of two adjacent warp layers aligned in the same row. Interlocking weaving that can be used is described in document WO 2006/136755.

In the example shown, the fiber texture comprises glass fiber warp yarns or glass fiber warp yarns, denoted Cv6 to Cv8, and carbon fiber warp yarns or carbon fiber warp yarns, denoted Cc1 to Cc 5. The fiber texture also comprises carbon fiber weft yarns or carbon fiber weft strands, denoted Tc.

As shown in fig. 3, first portion P1 includes five layers of warp yarns or strands, including carbon fiber yarns or strands Cc1 through Cc5, present on the side of outer surface F2 of fibrous texture 100, and three layers of warp yarns or strands, including carbon fiber yarns or strands Cv6 through Cv8, present on the side of inner surface F1 of the fibrous texture.

Once in the intermediate portion PI, the weaving is guided so as to gradually raise the glass fiber warp yarns or glass fiber warp strands Cv6 to Cv8 towards the outer surface F2 of the fiber texture by crossing with the carbon fiber warp yarns or carbon fiber warp strands Cc1 to Cc 5. In fig. 3, glass fiber warp yarns or warp strands Cv6 rise from two layers of weft or fill yarns by crossing in sequence with carbon fiber warp yarns or warp strands Cc5 and Cc4, which in turn fall in the weft layers toward the inner surface F1 of the fiber texture.

In fig. 4, the glass fiber warp yarns or warp strands Cv6-Cv8 towards the outer surface F2 continue to gradually rise towards the outer surface F2 of the fibrous texture, while the carbon fiber warp yarns or warp strands Cc1-Cc5 continue to gradually fall towards the inner surface F1 of the fibrous texture 100.

Fig. 5 shows the ends of the intermediate part PI, wherein glass fibre warp threads or glass fibre warp strands Cv6 to Cv8 are now present on the outer surface F2 side of the fibre texture 100. Thus, second portion P2 includes five layers of warp yarns or warp strands present on the side of inner surface F1 of fibrous texture 100, including carbon fiber warp yarns or warp strands Cc1-Cc5, and three layers of warp yarns or warp strands present on the side of outer surface F2 of fibrous texture 100, including carbon fiber warp yarns or warp strands Cv6-Cv 8.

Thus, the properties of the warp or warp strands 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 an interlocking weave.

Furthermore, it is advantageous if the carbon fiber yarns or carbon fiber strands and the glass fiber yarns or glass fiber strands present in the fiber texture have a similar cross section or volume. For example, the ratio of | V2-V1|/V1 may be less than or equal to 10%, where V1 represents the volume of the carbon fiber yarn or carbon fiber strand, V2 represents the volume of the glass fiber yarn or glass fiber strand, and | represents the absolute value.

The fiber texture may comprise glass fiber warp threads or glass fiber warp strands only in the transverse direction Y over a determined width. In particular, glass fiber warp yarns or glass fiber warp strands may be used only in the central region 130 of the fiber texture or in a portion thereof corresponding to what is referred to as a "retention region" where impact of blades or blade fragments may occur.

As shown in fig. 6, 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. The mandrel 50 also has two flanges 52 and 53 to form portions of fiber preforms 62 and 63 (flanges 62 and 63 are visible in FIG. 7) that correspond to the flanges 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. 7 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.8, 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 means of a thermal treatment (generally by heating the mould) in which the preform is always held after the removal of any solvent and the cross-linking 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 coke content, 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 fibre preform may be performed by the well-known Resin Transfer Moulding (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 exhaust 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. 9.

The housing 810 shown in FIG. 9 is a housing for a gas turbine aircraft engine 80 blower. As shown in fig.8, this engine includes, in the airflow direction from upstream to downstream, a blower 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 blower 81 is surrounded by the housing 810.

Fig. 10 to 12 show a variant of the fiber texture 200 according to the invention in which some weft yarns or weft strands are made of glass fibers (weft yarns or weft strands Tv). In fig. 10, more precisely, first portion P1 includes five layers of warp yarns or warp strands present on the side of outer surface F2 of fibrous texture 200, including carbon fiber yarns or carbon fiber strands Cc1 to Cc5, and three layers of warp yarns or warp strands present on the side of inner surface F1 of the fibrous texture, including carbon fiber yarns or carbon fiber strands Cv6 to Cv 8. Furthermore, the first four layers of weft yarns or yarns present on the side of the inner surface F1 of the fiber texture comprise glass fiber weft yarns or yarns, denoted Tv, while the other layers of weft yarns or yarns present on the side of the outer surface F2 of the fiber texture 200 comprise carbon fiber yarns or yarns, denoted Tc.

Once in the intermediate portion PI, the weaving is guided so as to gradually raise the outer surface F2 of the glass fiber warp or warp strands Cv6 to Cv8 towards the fiber texture by crossing with the carbon fiber warp or warp strands Cc1 to Cc 5. In the middle part PI, all weft or fill strand layers comprise carbon fiber yarns or carbon fiber strands Tc (fig. 10 to 12).

In fig. 12, second portion P2 includes five layers of warp yarns or warp strands present on the side of inner surface F1 of fibrous texture 100, including carbon fiber warp yarns or warp strands Cc1 through Cc5, and three layers of warp yarns or warp strands present on the side of outer surface F2 of fibrous texture 100, including carbon fiber warp yarns or warp strands Cv6 through Cv 8. Furthermore, the first four layers of weft yarns or weft strands present on the side of the outer surface F2 of the fibrous texture comprise glass fiber weft yarns or glass fiber weft strands denoted Tv, while the other layers of weft yarns or weft strands present on the side of the inner surface F1 of the fibrous texture 200 comprise carbon fiber yarns or carbon fiber strands denoted Tc.