Fiber fabric structure used for composite material casing and provided with reinforcing flanges

Abstract

The invention relates to a fibrous fabric structure (100) which is three-dimensionally woven between a plurality of layers of warp threads and a plurality of layers of weft threads. The fibrous fabric structure (100) comprises first to fifth portions (130, 140, 150, 160, 170). First and fifth portions (130, 170) extend in a transverse direction (Y) from the first and second side edges (101, 102), respectively. The first and fifth portions each include warp yarns comprised of a first type of fibers corresponding to carbon fibers having a Young's modulus greater than 290 GPa and an elongation at break of between 1.2% and 2%, and warp yarns comprised of a second type of fibers having a Young's modulus of between 150 GPa and 250 GPa and an elongation at break of between 4% and 6%.

Description

Technical Field

[0001] The present invention relates to a gas turbine casing, and more particularly but not limited to a gas turbine fan casing of an aircraft engine. Background Art

[0002] The manufacturing of a composite casing starts with the production of a fibrous fabric structure in strip form. The fibrous fabric structure is made by three-dimensional weaving between multiple layers of warp yarns and multiple layers of weft yarns. The fibrous fabric structure thus obtained is wound around a mold or tool having the shape of the casing to be produced several times and fixed between the mold and a component constituting a counter-mold, thereby obtaining a fiber preform.

[0003] After the fiber preform is made, that is, when the winding of the fibrous fabric structure is completed, the mold carrying the fiber preform is closed by the counter-mold and then transferred to an oven or furnace, where the preform is densified by a matrix. The matrix is obtained especially by injecting a resin into the fiber preform and polymerizing it.

[0004] Figure 8 Shows a composite fan casing 200 obtained by the above method. The fan casing 200 includes an upstream flange 230 and a downstream flange 270 for fixing to an intake duct and an intermediate casing housing ( Figure 8 not shown) respectively. The casing 200 also includes a blocking zone 250 located between an upstream structural zone 240 and a downstream structural zone 260.

[0005] The fan casing mainly has three functions:

[0006] Ensuring the connection of the engine components to each other;

[0007] Determining the intake cross-section of the engine;

[0008] Blocking by preventing debris entering the engine interior, or blades or blade fragments thrown out by centrifugal force, from completely penetrating the casing and releasing high-energy debris.

[0009] The first two functions do not require high mechanical properties but need to function continuously. On the contrary, although the third function is used very rarely, it requires high mechanical properties. For this reason, the quantity, nature, and arrangement of the fibers are optimized in the blocking zone of the casing so as to be able to withstand impacts and block high-energy blade fragments or objects. An example of a composite fan casing with a strengthened blocking zone is described in particular in document US2020 / 271015.

[0010] However, in a Fan Blade Out (FBO) event, a shock wave is generated and propagates from the impact zone (blocking zone) to all areas of the casing, especially the flange area. There is a deformation wave ahead of the shock wave. In some cases, this shock wave can cause excessive deformation of the casing flange, resulting in them being subjected to huge stresses during tension and compression, exceeding the limit of the material. These stresses, in turn, can generate cracks in these flanges, and then cause the crack front to expand to an unacceptable size, thus endangering the mechanical integrity of the fan casing.

[0011] Therefore, it is necessary to optimize the mechanical properties of the casing flange to withstand the shock wave after the impact caused by the blade out event. Summary of the Invention

[0012] To this end, the present invention provides a fibrous fabric structure in the form of a strip, extending a certain length in the longitudinal direction from a proximal part to a distal part, and extending a certain width in the transverse direction from a first side edge to a second side edge. The fibrous fabric structure is three-dimensionally woven between multiple layers of warp yarns extending in the longitudinal direction and multiple layers of weft yarns extending in the transverse direction. It is characterized in that the fibrous fabric structure includes a first to a fifth part, each part extending its determined length in the longitudinal direction of the fibrous fabric structure and a determined width in the transverse direction; the first part extends in the transverse direction from the first side edge, the second part extends in the transverse direction from the first part, the third part extends in the transverse direction from the second part, the fourth part extends in the transverse direction from the third part, and the fifth part extends in the transverse direction from the fourth part to the second side edge. The widths of the first and fifth parts in the transverse direction are greater than those of the second and fourth parts and less than that of the third part. The first and fifth parts each include warp yarns composed of a first type of fiber corresponding to carbon fibers with a Young's modulus greater than 290 GPa and a fracture elongation rate between 1.2% and 2%, and warp yarns composed of a second type of fiber with a Young's modulus between 150 GPa and 250 GPa and a fracture elongation rate between 4% and 6%. The second and fourth parts each include warp yarns composed of the first type of fiber, warp yarns composed of the second type of fiber, and warp yarns composed of a third type of fiber corresponding to carbon fibers with a Young's modulus greater than 250 GPa and a fracture elongation rate between 1.5% and 2.5%, and the third part includes warp yarns composed of the third type of fiber.

[0013] The fiber fabric structure according to the present invention can be used to manufacture a casing with flanges having improved mechanical properties. In fact, the warp yarns composed of the second type of fiber are mainly present in the first and fifth parts of the fiber fabric structure, and these two parts are used to form the upstream and downstream flanges of the casing. After molding, the fiber fabric structure of the present invention can form a fiber casing reinforcement, wherein the parts forming the upstream and downstream flanges contain fibers (the second type of fiber) with a lower stiffness (Young's modulus) than the other fibers (the first type and the second type of fiber) in the reinforcement, but a greater elongation at break. The flanges of the composite casing containing such a fiber reinforcement can thus better withstand the mechanical deformation imposed by the shock wave propagated after being impacted in the blocking area without being damaged. This solution aims to achieve the smoothest transition between the all-carbon fiber preform of the barrel section and the all-glass fiber area at the flange end by gradually introducing glass fiber bundles into the preform. Too drastic a change will lead to stress concentration, which will have a harmful effect.

[0014] The other parts of the fiber reinforcement used to form the upstream and downstream structural areas and the blocking area have a greater stiffness because the Young's modulus of the mainly present carbon fibers (the first type and the second type of fiber) is greater than that of the second type of fiber.

[0015] According to a special feature of the fiber fabric structure of the present invention, in the first and fifth parts of the fiber fabric structure, the warp yarns composed of the second type of fiber are present on the lower surface and the upper surface of the fabric structure and on the first and second side edges of the fabric structure, and the warp yarns composed of the first type of fiber are present inside the fabric structure. Therefore, the flanges of the casing have a certain flexibility on the surface and can adapt to the mechanical deformation propagated therein, while maintaining a certain internal stiffness due to the presence of the warp yarns composed of the first type of fiber to have sufficient structural properties.

[0016] According to another special feature of the fiber fabric structure of the present invention, the first and fifth parts contain 10% to 90% of the warp yarns composed of the second type of fiber, and the remaining warp yarns are composed of the first type of fiber.

[0017] According to another special feature of the fiber fabric structure of the present invention, in the second part of the fiber fabric structure, the number of warp yarns composed of the first type and the second type of fiber gradually decreases between the first part and the third part; in the fourth part, the number of warp yarns composed of the first type and the second type of fiber gradually decreases between the fifth part and the third part. This enables the stiffness of the fabric structure to gradually increase from the first and fifth parts to the third part of the fiber fabric structure, and thus enables the stiffness of the casing to gradually increase because the overall geometry of the third part is thicker and its composition only contains warp yarns composed of the third type of fiber, so it has the greatest stiffness.

[0018] The present invention also relates to an aircraft casing fiber preform, which includes winding the fiber fabric structure according to the present invention at least one turn. The fiber preform includes upstream and downstream flange preform parts respectively formed by the first and fifth parts of the fiber fabric structure, upstream and downstream structural area preform parts respectively formed by the second and fourth parts of the fiber fabric structure, and a barrier area preform part formed by the third part of the fiber fabric structure.

[0019] The present invention also relates to a gas turbine casing made of a composite material, which includes a fiber reinforcement composed of the fiber preform according to the present invention, and a matrix that densifies the fiber reinforcement. The casing can particularly be the casing of a gas turbine fan.

[0020] The present invention also relates to an aircraft gas turbine engine having a casing according to the present invention.

[0021] The present invention also relates to a method for manufacturing a fiber fabric structure by three-dimensional weaving between a plurality of layers of warp yarns extending in the longitudinal direction and a plurality of layers of weft yarns extending in the transverse direction. The fiber structure is in a strip shape, extending a predetermined length from a proximal part to a distal part in the longitudinal direction and a predetermined width from a first side edge to a second side edge in the transverse direction.

[0022] It is characterized in that the method includes weaving the first to fifth parts, each part extending its predetermined length in the longitudinal direction of the fiber fabric structure and a predetermined width in the transverse direction. The first part extends in the transverse direction from the first side edge, the second part extends in the transverse direction from the first part, the third part extends in the transverse direction from the second part, the fourth part extends in the transverse direction from the third part, and the fifth part extends in the transverse direction from the fourth part to the second side edge. The widths of the first and fifth parts in the transverse direction are greater than the widths of the second and fourth parts and less than the width of the third part.

[0023] It is further characterized in that each of the first and fifth parts includes warp yarns composed of a first type of fiber, which corresponds to carbon fibers having a Young's modulus greater than 290 GPa and a breaking elongation between 1.2% and 2%, and warp yarns composed of a second type of fiber, the Young's modulus of which is between 150 GPa and 250 GPa and the breaking elongation is between 4% and 6%.

[0024] It is further characterized in that each of the second and fourth parts includes warp yarns composed of a first type of fiber, warp yarns composed of a second type of fiber, and warp yarns composed of a third type of fiber, which corresponds to carbon fibers having a Young's modulus greater than 250 GPa and a breaking elongation between 1.5% and 2.5%, and the third part includes warp yarns composed of the third type of fiber.

[0025] Brief Description of the Drawings

[0026] Figure 1 is a schematic perspective view of a loom for three - dimensional weaving of a fibrous fabric structure;

[0027] Figure 2 is a schematic perspective view of a fibrous fabric structure according to an embodiment of the present invention;

[0028] Figure 3 is Figure 2 a side view of the fibrous fabric structure in , showing the plane of the weaving pattern;

[0029] Figure 4 is a schematic perspective view showing the fibrous fabric structure wound onto a forming tool;

[0030] Figure 5 is an axial half - sectional view of a casing preform obtained by winding the fibrous fabric structure as shown in Figure 4 ;

[0031] Figure 6 is a sectional view showing the positioning of the injection area on the casing preform of Figure 5 ;

[0032] Figure 7 is a perspective view of an aircraft engine according to an embodiment of the present invention;

[0033] Figure 8 is an axial half - sectional view of a fan casing of an aircraft engine in the prior art.

[0034] Detailed Description of the Embodiments

[0035] The present invention is generally applicable to fibrous fabric structures for manufacturing composite casings, which casings include a barrier zone or shield zone and have annular flanges at their ends.

[0036] As shown in Figure 1 , the fibrous fabric structure 100 is made by weaving in a known manner using a jacquard loom 5, on which multiple layers of warp yarn bundles or warp yarn strands 20 are placed, and the warp yarns are joined together by weft yarns or weft yarn strands 30.

[0037] The fibrous fabric structure is made by three - dimensional weaving. Here, "three - dimensional weaving" or "3D weaving" refers to a weaving method by which at least some weft yarns are joined to warp yarns on multiple layers of warp yarns and vice versa. The fibrous fabric structure can have an interlocking weave. Here, "interlocking" weave refers to a weaving pattern in which each layer of weft yarns joins multiple layers of warp yarns, and all the yarns in the same weft column have the same movement within the weaving plane. Other weaving patterns can also be used.

[0038] As shown in Figure 2As shown, the fiber fabric structure 100 is in the form of a strip, extending in a longitudinal direction X along a length direction, the longitudinal direction X corresponding to the running direction of the warp yarns or warp yarn strands 20; and extending in a width direction or a transverse direction between the first and second side edges 101 and 102 in a transverse direction Y, the transverse direction Y corresponding to the direction of the weft yarns or weft yarn strands 30. The fiber fabric structure extends in the longitudinal direction X from a proximal portion 110 for forming a winding start portion of a fiber preform on a forming tool to a distal portion 120 for forming a winding end portion of the fiber preform by a determined length L. 100 .

[0039] The length L of the fiber fabric structure 100 100 The circumference of the forming tool or the mold is determined so that a certain number of windings, for example four, can be performed on the fiber fabric structure to be produced.

[0040] From upstream to downstream (in Figure 2 The fiber fabric structure also has first to fifth parts 130, 140, 150, 160, 170, each of which is within the length L of the fiber fabric structure. 100 The first portion 130 extends from the first side edge 101 in the transverse direction Y to a certain width l 130 The first portion 130 is used to form an upstream annular flange of the casing. The second portion 140 extends from the first portion 130 in the transverse direction Y to a certain width l 140 The second portion 140 is used to form a portion of the upstream structural area of ​​the casing. The third portion 150 extends from the second portion 140 in the transverse direction Y to a certain width l 150 The third portion 150 is used to form the central structural area and the blocking area or shielding area of ​​the casing. The fourth portion 160 extends from the third portion 150 in the transverse direction Y to a certain width l 160 The fourth portion 160 is used to form a portion of the downstream structural area of ​​the casing. The fifth portion 170 extends from the fourth portion 160 in the transverse direction Y to a certain width l 170 , until the second side edge 102. The fifth portion 170 is used to form a downstream annular flange of the casing.

[0041] The first and fifth portions 130 and 170 have similar widths l 130 and l 170 , which are greater than the width l of the second and fourth portions 140 and 160 140 and l 160 , which is smaller than the width l of the third portion 150 150 .

[0042] Figure 3Shows the plane of the interlocking knitting pattern at the first, second, and third parts 130, 140, and 150 of the fibrous fabric structure 100.

[0043] According to the present invention, the first part 130 includes warp yarns made of different types of fibers. More specifically, the first part 130 includes warp yarns C made of a first type of fiber C2 , the first type of fiber corresponding to carbon fibers with a Young's modulus greater than 290 GPa and an elongation at break between 1.2% and 2%, and warp yarns C made of a second type of fiber V1 , the second type of fiber having a Young's modulus (E) between 150 GPa and 250 GPa and an elongation at break (A) between 4% and 6%. In the example described herein, the warp yarns C V1 are made of glass fibers, and the glass fibers can be, for example, replaced by AS and para-aramid (HM) fibers. For example, the first type of fiber can be Tenax TM type UMS40 carbon fiber (E = 390 GPa, A = 1.2%) sold by TEIJIN, and the second type of fiber can be E-GLASS type glass fiber (E = 165 GPa, A = 4.4%) sold by AGY HOLDING CORP.

[0044] As Figure 3 shown, the distribution of the warp yarns C made of the second type of fiber in the first part 130 is preferably such that these yarns C V1 are present on the lower and upper surfaces F1 and F2 of the fibrous fabric structure 100 and the first side edge 101 of the fabric structure 100, which are respectively used to form the radial inner and outer surfaces and the ends of the upstream flange preform part. The warp yarns C made of the first type of fiber V1 are preferably present inside the fabric structure. The first part 130 includes weft yarns T C2 all made of a third type of fiber, the third type of fiber corresponding to carbon fibers with a Young's modulus greater than 250 GPa and an elongation at break between 1.5% and 2.5%. For example, the third type of fiber can be C IM7 type carbon fiber (E = 276 GPa and A = 1.8%) sold by HEXCEL.

[0045] Similarly, the fifth part 170 ( Figure 3 not shown in the figure) includes warp yarns C made of the second type of fiber V1 and warp yarns C made of the first type of fiber C2 . The distribution of the warp yarns C made of the second type of fiber in the fifth part 170 is preferably such that these yarns C V1 are present V1Present on the lower surface F1 and the upper surface F2 of the fibrous fabric structure 100 and on the second side edge 102 of the fabric structure 100, which are respectively used to form the radially inner surface and the outer surface and the end of the downstream flange preform portion. The warp yarns C composed of the first type of fiber C2 are preferably present inside the fabric structure. The fifth part 170 includes the weft yarns T composed entirely of the third type of fiber C .

[0046] The first part 130 and the fifth part 170 contain 10% to 90% of the warp yarns C composed of the second type of fiber V1 , and the remaining warp yarns in these parts are composed of the first type of fiber, that is, 10% to 90% of the warp yarns C C2 .

[0047] The second part 140 also includes warp yarns composed of different types of fibers. More precisely, the second part 140 includes the above-mentioned warp yarns C composed of the first type of fiber C2 , the above-mentioned warp yarns C composed of the second type of fiber V1 , and the warp yarns C composed of the third type of fiber C1 , and the third type of fiber corresponds to carbon fiber with a Young's modulus greater than 250 GPa and a breaking elongation between 1.5% and 2.5%.

[0048] The warp yarns C composed of the second type of fiber in the second part 140 V1 are preferably distributed such that these yarns C V1 are present on the lower surface F1 and the upper surface F2 of the fibrous fabric structure 100.

[0049] Between the first part 130 and the third part 150, the warp yarns C V1 and C C2 composed of the first type and the second type of fiber respectively gradually decrease in number so as to be gradually replaced by the warp yarns C C1 composed of the third type of fiber. This enables the stiffness of the fabric structure to gradually increase from the first part 130 to the third part 150 of the fibrous fabric structure 100 and thus the stiffness of the casing to gradually increase, because the overall geometry of the third part is thicker and its composition only contains the warp yarns C C1 composed of the third type of fiber, so it has the greatest stiffness.

[0050] The second part 140 includes the weft yarns T composed entirely of the third type of fiber C .

[0051] Similarly, the fourth part 160 ( Figure 3 not shown in the figure) includes the warp yarns C composed of the first type of fiber C2 , the warp yarns C composed of the second type of fiber V1and the warp yarn C made of the third type of fiber C1 . The warp yarn C made of the second type of fiber in the fourth part 160 V1 is preferably distributed such that these yarns C V1 are present on the lower surface F1 and the upper surface F2 of the fibrous fabric structure 100. Between the fifth part 170 and the third part 150, the warp yarns C V1 and C C2 made of the first type and the second type of fiber respectively, gradually decrease in number so as to be gradually replaced by the warp yarn C C1 made of the third type of fiber. This enables the stiffness of the fabric structure to gradually increase from the fifth part 170 to the third part 150 of the fibrous fabric structure 100 and thus the stiffness of the casing to gradually increase, because the overall geometry of the third part is thicker and its composition only includes the warp yarn C C1 made of the third type of fiber, so it has the greatest stiffness. The fourth part 160 includes the weft yarn T C entirely made of the third type of fiber.

[0052] Therefore, when moving along the transverse direction Y of the fibrous fabric structure 100, the properties of the warp yarns change.

[0053] The warp yarn C made of the second type of fiber V1 is mainly present in the first part 130 and the fifth part 170 of the fibrous fabric structure 100, and these two parts are used to form the upstream and downstream flanges of the casing; while the warp yarn C C2 made of the first type of carbon fiber and the warp yarn made of the third type of carbon fiber are mainly distributed in the second part 140, the third part 150 and the fourth part 160 of the fibrous fabric structure 100, and these parts are used to form the structural area and the blocking area of the casing. After molding, the fibrous fabric structure 100 of the present invention can form a fibrous casing reinforcement, wherein the stiffness (Young's modulus) of the fibers (the second type of fiber) contained in the parts forming the upstream and downstream flanges is less than that of the other fibers (the first type and the second type of fiber) in the reinforcement, but the elongation at break is greater. The flanges of the composite casing containing such a fiber reinforcement can better withstand the mechanical deformation caused by the shock wave propagated after being impacted in the blocking area and will not be damaged. The other parts of the fiber reinforcement used to form the upstream and downstream structural areas and the blocking area have higher stiffness because the Young's modulus of the mainly contained carbon fibers (the first type and the third type of fiber) is greater than that of the second type of fiber.

[0054] According to a special feature of the fabric structure of the present invention, the warp yarn C V1 made of the second type of fiber is preferably distributed in the first part 130 and the fifth part 170 of the fabric structure 100 such that these yarns C V1It exists on the radial inner surface, outer surface, and ends of the upstream and downstream flange fiber reinforcements. Therefore, the flange has a certain flexibility on the surface and can adapt to the mechanical deformations propagating therein. At the same time, due to the presence of the warp yarn C composed of the first type of fibers C2 , it maintains a certain internal stiffness and thus has sufficient structural properties.

[0055] An example has just been described where the fibrous fabric structure is in an interlocking weave pattern of 8 layers of warp yarns and 7 layers of weft yarns. However, when the number of layers of weft yarns and warp yarns is different, or the fibrous fabric structure adopts a weaving pattern different from the interlocking weave, this is still within the scope of the present invention.

[0056] As Figure 4 shown, the fiber preform 60 for forming the casing fiber reinforcement is formed by winding the above-mentioned fibrous fabric structure 100 around the mandrel 50. This fiber reinforcement forms a complete one-piece casing tubular fiber preform. For this purpose, the mandrel 50 has an outer surface 51 whose contour corresponds to the inner surface of the casing to be manufactured. The mandrel 50 also includes two flanges 52 and 53 to form preform parts of the upstream 63 and downstream flanges 67 corresponding to the casing flanges, as Figure 5 shown. The upstream flange preform part 63 and the downstream flange preform part 67 are respectively formed by the first part 130 and the fifth part 170 of the fibrous fabric structure 100. The fiber preform 60 also includes an upstream structural region preform part 64 and a downstream structural region preform part 66 corresponding to the upstream and downstream structural regions of the casing( Figure 5 ). The upstream structural region preform part 64 and the downstream structural region preform part 66 are respectively formed by the second part 140 and the fourth part 160 of the fibrous fabric structure. The fiber preform 60 also includes a barrier region preform part 65 for forming the casing barrier region or shielding region. The barrier region preform part 65 is formed by the third part 150 of the fibrous fabric structure.

[0057] Figure 5 Shows a cross-sectional view of the fiber preform 60 obtained after winding the fibrous fabric structure 100 around the mandrel 50 at least one turn. In the example described here, the preform 60 contains 4 turns of winding of the fibrous fabric structure 100.

[0058] Then, the fiber preform 60 is densified using a matrix.

[0059] The densification of the fiber preform refers to filling the pores in all or part of the volume of the preform with the material constituting the matrix.

[0060] The matrix can be obtained by liquid-phase methods known per se. The liquid-phase method refers to impregnating a preform with a liquid composition containing an organic precursor of the matrix material. The organic precursor is usually in the form of a polymer, such as a resin, and may optionally be diluted with a solvent. The fiber preform is placed in a mold, which can be tightly sealed with a casing having the shape of the final molded part. As Figure 6 shown, here the fiber preform 60 is placed between a plurality of fan-shaped bodies 54 constituting the counter mold and a mandrel 50 constituting the support member. These components respectively have the external shape and the internal shape of the casing to be manufactured. Then, a liquid matrix precursor (such as resin) is injected into the entire casing to impregnate the preform.

[0061] The conversion of the precursor into an organic matrix, i.e., its polymerization process, is carried out by heat treatment. Usually, after removing any solvent and crosslinking the polymer, the mold is heated while the preform remains in the mold having a shape corresponding to that of the part to be produced. The organic matrix can be obtained especially from epoxy resins, such as commercially available high-performance epoxy resins, or from liquid precursors of carbon or ceramic matrices.

[0062] The fiber preform can be densified by a known resin transfer molding (RTM) method. According to the RTM method, the fiber preform is placed in a mold having the shape of the casing to be produced. A thermosetting resin is injected into the internal space defined between the rigid material part and the mold, and this space contains the fiber preform. Usually, a pressure gradient is established in the internal space between the resin injection position and the resin discharge port to control and optimize the impregnation of the resin into the preform.

[0063] The resin used can be, for example, an epoxy resin. Resins suitable for the RTM method are well known. They preferably have a low viscosity to facilitate injection into the fibers. The choice of the temperature grade and / or chemical properties of the resin is determined according to the thermomechanical stresses that the part must withstand. Once the resin is injected into the entire reinforcement, it is polymerized by heat treatment according to the RTM method.

[0064] After injection and polymerization, the part is demolded. Finally, the part is cut to remove the excess resin, and the chamfers are machined to obtain a casing 810 having the shape of a rotating body as Figure 7 shown.

[0065] Figure 7 The casing 810 shown is the fan casing of an aircraft gas turbine engine 80. As Figure 7 very schematically shown, such an engine includes, from upstream to downstream in the air flow direction: a fan 81 provided at the engine inlet, a compressor 82, a combustion chamber 83, a high-pressure turbine 84, and a low-pressure turbine 85. The engine is housed in a casing, and this casing has a plurality of parts corresponding to different components of the engine. Thus, the fan 81 is surrounded by the casing 810.

Claims

1. A fibrous fabric structure (100), in the form of a strip, extending in a longitudinal direction (X) from a proximal portion (110) to a distal portion (120) over a defined length (L 100 ) and in a transverse direction (Y) from a first side edge (101) to a second side edge (102) over a defined width (l 106 ), the fibrous fabric structure being three-dimensionally woven between multiple layers of warp yarns (20, 40) extending longitudinally and multiple layers of weft yarns (30) extending transversely, characterized in that The fibrous fabric structure (100) includes first to fifth portions (130, 140, 150, 160, 170), each portion extending a determined length in the longitudinal direction (X) of the fibrous fabric structure and a determined width in the transverse direction (Y). The first portion (130) extends from the first side edge (101) in the transverse direction, the second portion (140) extends from the first portion in the transverse direction, the third portion (150) extends from the second portion in the transverse direction, the fourth portion (160) extends from the third portion in the transverse direction, and the fifth portion (170) extends from the fourth portion in the transverse direction to the second side edge (102). The widths of the first and fifth portions (130, 170) in the transverse direction are greater than the widths of the second and fourth portions (140, 160) and less than the width of the third portion (150). The first and fifth portions (130, 170) each include warp yarns composed of a first type of fiber corresponding to carbon fibers having a Young's modulus greater than 290 GPa and an elongation at break between 1.2% and 2%, and warp yarns composed of a second type of fiber having a Young's modulus between 150 GPa and 250 GPa and an elongation at break between 4% and 6%. The second and fourth portions (140, 160) each include warp yarns composed of a first type of fiber, warp yarns composed of a second type of fiber, and warp yarns composed of a third type of fiber corresponding to carbon fibers having a Young's modulus greater than 250 GPa and an elongation at break between 1.5% and 2.5%. The third portion (150) includes warp yarns composed of the third type of fiber.

2. The fibrous fabric structure according to claim 1, wherein In the first and fifth portions, the warp yarns composed of the second type of fiber are present on the lower surface and the upper surface of the fabric structure and the first and second side edges of the fabric structure, and the warp yarns composed of the first type of fiber are present inside the fabric structure.

3. The fibrous fabric structure according to claim 1 or 2, wherein the first and fifth portions comprise 10% to 90% of the warp yarns made of a second type of fiber, and the remaining warp yarns are made of a first type of fiber.

4. The fabric structure according to any one of claims 1 to 3, wherein in the second portion of the fibrous fabric structure, the number of warp yarns made of the first and second types of fiber gradually decreases between the first and third portions, and in the fourth portion, the number of warp yarns made of the first and second types of fiber gradually decreases between the fifth and third portions.

5. A fiber preform (60) for an aircraft casing (810), comprising winding the fibrous fabric structure (100) according to any one of claims 1 to 4 at least one turn, the fiber preform comprising upstream and downstream flange preform portions (63, 67) formed by the first and fifth (130, 170) portions of the fibrous fabric structure (100) respectively, upstream and downstream structural zone preform portions (64, 66) formed by the second and fourth portions of the fibrous fabric structure respectively (140, 160), and a barrier zone preform portion (65) formed by the third portion of the fibrous fabric structure (150).

6. A gas turbine casing (810) made of a composite material, comprising a fiber reinforcement constituted by the fiber preform (60) according to claim 5, and a matrix for densifying the fiber reinforcement.

7. The casing (810) according to claim 6, wherein the casing is a gas turbine fan casing.

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

9. A method for manufacturing a fibrous fabric structure (100) by three-dimensionally weaving between multiple layers of warp yarns (20, 40) extending in a longitudinal direction (X) and multiple layers of weft yarns (30) extending in a transverse direction (Y), the fiber structure being in the form of a strip and extending in the longitudinal direction (X) from a proximal portion (110) to a distal portion (120) over a defined length (L100 ) that extends in the transverse direction (Y) from a first side edge (101) to a second side edge (102) to define a width (l 100 ), characterized in that The method includes weaving first to fifth parts (130, 140, 150, 160, 170), each part extending its determined length in the longitudinal direction (X) of the fibrous fabric structure and its determined width in the transverse direction (Y). The first part (130) extends from the first side edge (101) in the transverse direction, the second part (140) extends from the first part in the transverse direction, the third part (150) extends from the second part in the transverse direction, the fourth part (160) extends from the third part in the transverse direction, and the fifth part (170) extends from the fourth part in the transverse direction and up to the second side edge (102). The widths of the first and fifth parts (130, 170) in the transverse direction are greater than the widths of the second and fourth parts (140, 160) and less than the width of the third part (150). Among them, the first and fifth parts (130, 170) each include warp yarns composed of a first type of fiber, which corresponds to carbon fibers with a Young's modulus greater than 290 GPa and a breaking elongation rate between 1.2% and 2%, and warp yarns composed of a second type of fiber, whose Young's modulus is between 150 GPa and 250 GPa and the breaking elongation rate is between 4% and 6%. Among them, the second and fourth parts (140, 160) each include warp yarns composed of a first type of fiber, warp yarns composed of a second type of fiber, and warp yarns composed of a third type of fiber, which corresponds to carbon fibers with a Young's modulus greater than 250 GPa and a breaking elongation rate between 1.5% and 2.5%. The third part (150) includes warp yarns composed of the third type of fiber.

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