Manufacturing process of a fibrous casing preform with integrated stiffener

Abstract

Method for manufacturing a fibrous casing preform with integrated stiffener The invention relates to a method for manufacturing a fibrous preform (200) for an aeronautical casing comprising winding a main fibrous texture (100) onto an external surface of a mandrel (50) having a profile corresponding to the internal profile of the casing to be manufactured, the method being characterized in that it further comprises winding at least two secondary fibrous textures (210, 220) onto the wound main fibrous texture (100), each wound secondary fibrous texture (210, 220) comprising a body portion (211, 221) extending axially and at least one first stiffener portion (213, 223) extending radially from a first end (211a, 221a) of the body portion (211, 221) of said secondary fibrous textures (210, 220) wound, the first two stiffener portions (213, 223) of at least two of the secondary fibrous textures (210,220) wound being arranged in contact with each other. Figure for the abstract: Fig. 4,

Description

Title of the invention: Method for manufacturing a fibrous casing preform with integrated stiffener Technical field

[0001] The present invention relates to the manufacture of aeronautical casings, and in particular the manufacture of aircraft engine fan casings. Prior art

[0002] An aircraft engine conventionally comprises a fan, comprising a plurality of fan blades and a low-pressure compressor surrounded by a fan casing, also called a "FAN casing" or "retention casing". The fan makes it possible to compress all of the air entering the engine, the air then being separated between a primary flow, which passes through the low-pressure compressor, and a secondary flow.

[0003] In order to improve the performance of the aircraft engine, it is necessary to increase the bypass ratio, that is to say to increase the ratio between the mass flow rate of the primary flow and the mass flow rate of the secondary flow. This increase in the bypass ratio involves in particular an increase in the diameter of the fan, and thus an increase in the diameter of the fan casing. However, such an increase in size promotes the excitation of natural vibration modes of the casing.

[0004] To avoid these natural modes of vibration, it is possible to add stiffeners to the fan casing. These stiffeners are conventionally added by gluing stiffener sectors made of composite material around the casing.

[0005] However, such a method adds numerous manufacturing steps. Indeed, it requires the manufacturing of stiffener sectors in composite material, then the bonding of the stiffener sectors together to obtain an annular stiffener and the bonding of the sectors to the casing, requiring an autoclave. Description of the invention

[0006] In order to overcome the aforementioned drawbacks, the invention proposes a method for manufacturing a fibrous preform for an aeronautical casing comprising the winding of a main fibrous texture on an external surface of a mandrel having a profile corresponding to the internal profile of the casing to be manufactured, the mandrel extending circumferentially around an axial direction, the method being characterized in that it further comprises the winding of at least two secondary fibrous textures on the wound main fibrous texture, each wound secondary fibrous texture comprising a body portion extending in the axial direction in contact with the external surface of the mandrel and at least a first stiffener portion extending along a radial direction perpendicular to the axial direction from a first end of the body portion of said wound secondary fibrous textures, the first two stiffener portions of at least two of the wound secondary fibrous textures being arranged in contact with each other so as to form a stiffener preform part.

[0007] Thus, the stiffener is integrated from the manufacture of the fiber casing preform, and can be densified by the matrix at the same time as the rest of the fiber casing preform. Thus, additional manufacturing steps are limited, in particular gluing and autoclaving. In addition, since the fiber reinforcement of the stiffener is continuous with the fiber reinforcement of the casing, the stiffener is more robustly bonded to the rest of the casing.

[0008] According to a particular embodiment of the invention, the wound main fibrous texture comprises a body portion extending in the axial direction and two flange portions extending in the radial direction on either side of the body portion of said wound main fibrous texture.

[0009] According to another particular embodiment of the invention, at least one of the wound secondary fibrous textures comprises a flange portion extending from a second end of the body portion of said at least one wound secondary fibrous texture in the radial direction, said second end being opposite the first end of said body portion, the flange portion of the at least one wound secondary fibrous texture being arranged in contact with one of the flange portions of the wound main fibrous texture.

[0010] According to another particular embodiment of the invention, the two wound secondary fiber textures further comprise a second stiffener portion extending from the end of the first stiffener portion in the axial direction, the two first stiffener portions and the two second stiffener portions of the two wound secondary fiber textures forming a stiffener preform part.

[0011] It is thus possible to obtain a “T” shaped stiffener. Such a stiffener makes it possible to obtain a stiffening greater than the stiffening obtained with an “I” shaped stiffener of the same height in the radial direction. Such a “T” shaped stiffener shape thus makes it possible to obtain the desired stiffening while limiting the size of the final casing obtained, that is to say by limiting the maximum external diameter of the final casing obtained.

[0012] According to another particular embodiment of the invention, the two second stiffener portions of the two wound secondary fibrous textures extend in opposite directions.

[0013] According to another particular embodiment of the invention, the fibrous textures secondary coiled fibers completely cover the main coiled fiber texture.

[0014] According to another particular embodiment of the invention, the wound secondary fibrous textures only partially cover the wound main fibrous texture.

[0015] Thus, the mass of the final aircraft casing is reduced, allowing fuel savings in operation.

[0016] According to another particular embodiment of the invention, the secondary fibrous textures are wound so as to make more than one complete turn of the mandrel.

[0017] According to another particular embodiment of the invention, the main fibrous texture is produced in a single piece by three-dimensional weaving.

[0018] The mechanical properties of the casing obtained are thus improved.

[0019] The invention also relates to a method for manufacturing an aeronautical casing made of composite material comprising the manufacture of a fibrous aeronautical casing preform as described previously and the densification by at least one matrix of said fibrous preform.

[0020] The invention further relates to an aeronautical casing made of composite material obtained by the method of manufacturing an aeronautical casing as described above. Brief description of the drawings

[0021] [Fig-1] [Fig.l] is a schematic perspective view of a mandrel having the shape of the casing to be made, around which a main fibrous texture is wrapped.

[0022] [Fig.2] [Fig.2] is a schematic sectional view of the main fiber texture of [Fig.l] wrapped around the mandrel.

[0023] [Fig.3] [Fig.3] is a schematic perspective view of the mandrel and texture main fibrous texture of figures 1 and 2 around which two secondary fibrous textures are wound according to a first embodiment of the invention.

[0024] [Fig.4] [Fig.4] is a schematic sectional view of the main fiber texture and secondary fibrous textures of Figures 1 to 3 wound around the mandrel so as to form a fibrous casing preform according to a first embodiment of the invention.

[0025] [Fig.5] [Fig.5] is a schematic sectional view of the main fiber texture and secondary fibrous textures wound around the mandrel so as to form a fibrous casing preform according to a second embodiment of the invention.

[0026] [Fig.6] [Fig.6] is a schematic sectional view of the main fiber texture and secondary fibrous textures wound around the mandrel so as to form a fibrous casing preform according to a third embodiment of the invention.

[0027] [Fig.7] [Fig.7] is a schematic sectional view of the main fiber texture and secondary fibrous textures wrapped around the mandrel so as to form a fibrous casing preform according to a fourth embodiment of the invention.

[0028] [Fig-8] [Fig.8] is a schematic sectional view of the fibrous casing preform according to [Fig.4] arranged in a mold for the densification of the preform by a matrix. Description of the embodiments

[0029] The method of the invention makes it possible to produce an aeronautical casing, in particular an aircraft engine fan casing. The casing to be produced has an annular shape. The casing to be produced extends circumferentially around a reference axis. Preferably, the casing to be produced comprises an annular flange at each of its ends along the reference axis.

[0030] In order to produce such a casing, a mandrel is used whose external surface corresponds to the internal profile of the casing to be manufactured. An example of such a mandrel is illustrated in [Fig.l]. The mandrel 50 is defined by an axial direction DA, extending along the reference axis of the mandrel 50, and by a radial direction DR, extending perpendicular to the axial direction DA.

[0031] The mandrel 50 comprises a body 51 having an annular geometry. Preferably, the mandrel 50 comprises a first flange 52 arranged at one end of the body 51 in the axial direction DA, and a second flange 53 arranged at the other end of the body 51 in the axial direction DA. The flanges 52 and 53 make it possible to form the fibrous reinforcement of the upstream and downstream external flanges of the casing to be produced.

[0032] Figures 1 and 2 illustrate the winding of a main fibrous texture 100 around the mandrel 50.

[0033] The main fibrous texture 100 is produced in a well-known manner by weaving, for example by means of a jacquard type loom on which a bundle of warp threads has been arranged in a plurality of layers, the warp threads being linked by weft threads.

[0034] In order to obtain interesting mechanical characteristics for the fan casing, the main fibrous texture 100 is preferably produced by three-dimensional weaving. By “three-dimensional weaving” or “3D weaving” is meant here a weaving method by which at least some of the warp threads bind weft threads on several layers of weft threads or vice versa. The fibrous texture may have an interlock weave pattern. By “interlock” weave is meant here a weave pattern in which each layer of warp threads binds several layers of weft threads, with all the threads of the same warp column having the same movement in the plane of the weave. Other weave patterns are conceivable.

[0035] The fibers of the main fibrous texture 100 may be carbon, ceramic, glass or aramid fibers, or a mixture of such fibers. In particular In particular, the main fibrous texture 100 may be made from fibers made of the following materials: silicon carbide, alumina, mullite, silica, an aluminosilicate, a borosilicate, or a mixture of several of these materials. According to a preferred embodiment of the invention, the fibers of the main fibrous texture 100 are made of carbon or glass.

[0036] The main fibrous texture 100 has a strip shape which extends in length along a longitudinal direction Dx and in width along a transverse direction DY. The longitudinal direction Dx may correspond to the direction along which the warp threads extend, and the transverse direction DY may correspond to the direction along which the weft threads extend.

[0037] The width of the main fibrous texture 100 along the transverse direction DY must be adapted to the casing to be produced.

[0038] As illustrated in Figures 1 and 2, the main fibrous texture 100 is wound around the mandrel 50. The winding of the main fibrous texture 100 can be carried out so that the main fibrous texture 100 extends in width in the axial direction DA. Thus, the transverse direction DY and the axial direction DA coincide for the wound main fibrous texture 100. The main fibrous texture 100 makes at least one complete revolution of the mandrel 50. The main fibrous texture 100 can make only one complete revolution of the mandrel 50. The main fibrous texture 100 can make more than one complete revolution of the mandrel 50. In particular, the main fibrous texture 100 can make at least several complete revolutions of the mandrel 50. Thus, the main fibrous texture 100 can be wound around the mandrel 50 so as to make several layers 101, 102, 103 around the mandrel 50, as illustrated in [Fig.2].In this configuration, the layers thus formed are in contact with each other.

[0039] The main fibrous texture 100 preferably extends over the entire width of the mandrel 50 in the axial direction DA. In particular, the main fibrous texture 100 can cover the flanges 52 and 53. This results in a main fibrous texture 100 wound around a reference axis.

[0040] Thus, the wound main fibrous texture 100 comprises a body portion 110 and possibly one or two flange portions 120 and 130. The body portion 110 of the wound main fibrous texture 100 is superimposed on the body 51 of the mandrel 50. The body portion 110 of the wound main fibrous texture 100 may be formed by several superimposed layers. Thus, the body portion 110 of the wound main fibrous texture 100 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 110 of the wound main fibrous texture 100 extends mainly in the axial direction DA. The body portion 110 of the wound main fibrous texture 100 extends in thickness along the radial direction DR.

[0041] In the case where the wound main fibrous texture 100 comprises one or two flange portions 120 and 130, the flange portion(s) 120 and 130 are each adjacent to one of the flanges 52, 53 of the mandrel 50. In other words, the flange portion(s) 120 and 130 each cover one of the flanges 52, 53 of the mandrel 50. The flange portion(s) 120 and 130 of the wound main fibrous texture 100 may each be formed by several superimposed layers. Thus, the flange portion(s) 120 and 130 of the wound main fibrous texture 100 extend in the radial direction DR. In other words, in a section plane comprising the reference axis, the flange portion(s) 120 and 130 of the wound main fibrous texture 100 extend mainly in the radial direction DR. The flange portion(s) 120 and 130 of the wound main fibrous texture 100 extend in thickness in the axial direction DA.

[0042] Thus, the flange portion(s) 120 and 130 of the wound main fibrous texture 100 extend in the radial direction DR each from one of the ends in the axial direction DA of the body portion 110 of the wound main fibrous texture 100. The flange portion(s) 120 and 130 of the wound main fibrous texture 100 are directly adjacent to the body portion 110 of the wound main fibrous texture 100.

[0043] When the main fibrous texture 100 is wound around the mandrel 50, the secondary fibrous textures are wound. The secondary fibrous textures are wound around the wound main fibrous texture 100. The secondary fibrous textures are wound in contact with the wound main fibrous texture 100.

[0044] The secondary fibrous textures are produced in a well-known manner by weaving, for example by means of a jacquard-type loom on which a bundle of warp threads has been arranged in a plurality of layers, the warp threads being linked by weft threads.

[0045] In order to obtain interesting mechanical characteristics for the fan casing, the secondary fibrous textures are preferably produced by three-dimensional weaving. The secondary fibrous textures may have an interlock weave pattern. Other weave patterns are possible.

[0046] The fibers of the secondary fibrous textures may be carbon, ceramic, glass or aramid fibers, or a mixture of such fibers. In particular, the secondary fibrous textures may be made from fibers made of the following materials: silicon carbide, alumina, mullite, silica, an aluminosilicate, a borosilicate, or a mixture of several of these materials. According to a preferred embodiment of the invention, the fibers of the Main fiber texture 100 are carbon or glass.

[0047] The secondary fibrous textures have a strip shape which extends in length in a longitudinal direction and in width in a transverse direction. The longitudinal direction may correspond to the direction in which the warp threads extend, and the transverse direction may correspond to the direction in which the weft threads extend.

[0048] The winding of the secondary fibrous textures can be carried out so that the secondary fibrous textures extend in width along the axial direction DA. Thus, the transverse direction of the secondary fibrous textures and the axial direction Da coincide for the wound secondary fibrous textures. The wound secondary fibrous textures can make less than one complete revolution of the mandrel 50. The wound secondary fibrous textures can make at least one complete revolution of the mandrel 50. The secondary fibrous textures can make only one complete revolution of the mandrel 50. The secondary fibrous textures can make more than one complete revolution of the mandrel 50. In particular, the secondary fibrous textures can make several complete revolutions of the mandrel 50. Thus, the secondary fibrous textures can be wound around the mandrel 50 so as to make several layers around the mandrel 50.In this configuration, the layers thus formed are in contact with each other. Preferably, the secondary fibrous textures do not overlap each other in the radial direction DR.

[0049] According to a first embodiment of the invention illustrated in Figures 3 and 4, the secondary fiber textures are wound so as to form a stiffener preform portion in the shape of an “I” and so as to cover the entire wound main fiber texture 100.

[0050] [Fig.3] illustrates the winding of a first secondary fibrous texture 210 and a second secondary fibrous texture 220 around the wound main fibrous texture 100.

[0051] In the example illustrated in Figures 3 and 4, the secondary fiber textures 210 and 220 are each wound over two complete turns, so as to form two layers. As indicated previously, it is of course not outside the scope of the invention if the secondary fiber textures make less than one complete turn of the mandrel 50, only one complete turn of the mandrel 50, or more than one complete turn of the mandrel 50.

[0052] The winding of the main fibrous texture 100 and the secondary fibrous textures 210 and 220 makes it possible to obtain a fibrous casing preform 200 as illustrated in section in [Fig.4].

[0053] The first wound secondary fibrous texture 210 comprises a body portion 211, a stiffener portion 213 and optionally a flange portion 212.

[0054] The body portion 211 of the first wound secondary fibrous texture 210 is superimposes on the body 51 of the mandrel 50. The body portion 211 of the first wound secondary fibrous texture 210 superimposes on the body portion 110 of the main fibrous texture 100 wound in the radial direction DR. The body portion 211 of the first wound secondary fibrous texture 210 may be formed by several superimposed layers. Thus, the body portion 211 of the first wound secondary fibrous texture 210 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 211 of the first wound secondary fibrous texture 210 extends mainly in the axial direction DA. The body portion 211 of the first wound secondary fibrous texture 210 extends in thickness in the radial direction DR.

[0055] The body portion 211 of the first wound secondary fibrous texture 210 extends along the axial direction DA between a first end 211a and a second end 211b. In this first embodiment, the second end 211b of the first wound secondary fibrous texture 210 is adjacent to the end of the body portion 110 of the wound main fibrous texture 100. The wound main fibrous texture 100 comprising flange portions 120 and 130, the second end 211b of the first wound secondary fibrous texture 210 is adjacent to one of the flange portions 130 of the wound main fibrous texture 100.

[0056] The stiffener portion 213 of the first wound secondary fiber texture 210 extends in the radial direction DR from one of the ends of the body portion 211 of the first wound secondary fiber texture 210. The stiffener portion 213 of the first wound secondary fiber texture 210 extends in the radial direction DR from the first end 211a of the body portion 211 of the first wound secondary fiber texture 210. The stiffener portion 213 of the first wound secondary fiber texture 210 extends in thickness in the axial direction DA.

[0057] The stiffener portion 213 of the first wound secondary fiber texture 210 may be formed by several layers superimposed along the axial direction DA, as illustrated in [Fig. 4]. However, it does not go beyond the scope of the invention if the stiffener portion 213 of the first wound secondary fiber texture 210 is formed by a single layer.

[0058] In the case where the first wound secondary fibrous texture 210 comprises a flange portion 212, the flange portion 212 of the first wound secondary fibrous texture 210 is adjacent to the flange portion 130 of the wound main fibrous texture 100. In other words, the flange portion 212 of the first wound secondary fibrous texture 210 covers the flange portion 130 of the wound main fibrous texture 100.

[0059] The flange portion 212 of the first wound secondary fiber texture 210 extends in the radial direction DR from one of the ends of the body portion 211 of the first wound secondary fiber texture 210. The flange portion 212 of the first wound secondary fiber texture 210 extends in the radial direction DR from the end of the body portion 211 of the first wound secondary fiber texture 210 opposite the stiffener portion 213. The flange portion 212 of the first wound secondary fiber texture 210 extends in the radial direction DR from the second end 211b of the body portion 211 of the first wound secondary fiber texture 210. The flange portion 212 of the first wound secondary fiber texture 210 extends in thickness in the axial direction DA.

[0060] The flange portion 212 of the first wound secondary fibrous texture 210 may be formed by several layers superimposed along the axial direction DA, as illustrated in [Fig. 4]. However, it does not go beyond the scope of the invention if the flange portion 212 of the first wound secondary fibrous texture 210 is formed by a single layer.

[0061] The second wound secondary fibrous texture 220 comprises a body portion 221, a stiffener portion 223 and optionally a flange portion 222.

[0062] The body portion 221 of the second wound secondary fiber texture 220 is superimposed on the body 51 of the mandrel 50. The body portion 221 of the second wound secondary fiber texture 220 is superimposed on the body portion 110 of the main fiber texture 100 wound in the radial direction DR. The body portion 221 of the second wound secondary fiber texture 220 may be formed by several superimposed layers. Thus, the body portion 221 of the second wound secondary fiber texture 220 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 221 of the second wound secondary fiber texture 220 extends mainly in the axial direction DA. The body portion 221 of the second wound secondary fibrous texture 220 extends in thickness along the radial direction DR.

[0063] The body portion 221 of the second wound secondary fiber texture 220 extends in the axial direction DA between a first end 221a and a second end 221b. In this first embodiment, the second end 221b of the second wound secondary fiber texture 220 is adjacent to the end of the body portion 110 of the wound main fiber texture 100. The wound main fiber texture 100 comprising flange portions 120 and 130, the second end 221b of the second wound secondary fiber texture 210 is adjacent to one of the flange portions 120 of the wound main fiber texture 100. The first end 221a of the second secondary fiber texture 220 wound is adjacent to the first end 211a of the first wound secondary fibrous texture 210.

[0064] The stiffener portion 223 of the second wound secondary fiber texture 220 extends in the radial direction DR from one of the ends of the body portion 221 of the second wound secondary fiber texture 220. The stiffener portion 223 of the second wound secondary fiber texture 220 extends in the radial direction DR from the first end 221a of the body portion 221 of the second wound secondary fiber texture 220. The stiffener portion 223 of the second wound secondary fiber texture 220 extends in thickness in the axial direction DA.

[0065] The stiffener portion 223 of the second wound secondary fiber texture 220 may be formed by several layers superimposed along the axial direction DA, as illustrated in [Fig. 4]. However, it does not go beyond the scope of the invention if the stiffener portion 223 of the second wound secondary fiber texture 220 is formed by a single layer.

[0066] The stiffener portion 223 of the second wound secondary fiber texture 220 is adjacent to the stiffener portion 213 of the first wound secondary fiber texture 210. The stiffener portion 223 of the second wound secondary fiber texture 220 is in contact with the stiffener portion 213 of the first wound secondary fiber texture 210. The contact surface between the stiffener portion 223 of the second wound secondary fiber texture 220 and the stiffener portion 213 of the first wound secondary fiber texture 210 extends in the radial direction DR. Preferably, the contact surface between the stiffener portion 223 of the second wound secondary fiber texture 220 and the stiffener portion 213 of the first wound secondary fiber texture 210 extends over the entire circumference of the secondary fiber textures 210 and 220.Preferably, the free end of the stiffener portion 223 of the second wound secondary fiber texture 220 and the free end of the stiffener portion 213 of the first wound secondary fiber texture 210 are in contact.

[0067] In the case where the second wound secondary fibrous texture 220 comprises a flange portion 222, the flange portion 222 of the second wound secondary fibrous texture 220 is adjacent to the flange portion 120 of the wound main fibrous texture 100. In other words, the flange portion 222 of the second wound secondary fibrous texture 220 covers the flange portion 120 of the wound main fibrous texture 100.

[0068] The flange portion 222 of the second wound secondary fibrous texture 220 extends in the radial direction DR from one of the ends of the body portion 221 of the second wound secondary fibrous texture 220. The flange portion 222 of the second wound secondary fiber texture 220 extends in the radial direction DR from the end of the body portion 221 of the second wound secondary fiber texture 220 opposite the stiffener portion 223. The flange portion 222 of the second wound secondary fiber texture 220 extends in the radial direction DR from the second end 221b of the body portion 221 of the second wound secondary fiber texture 220. The flange portion 222 of the second wound secondary fiber texture 220 extends in thickness in the axial direction DA.

[0069] The flange portion 222 of the second wound secondary fibrous texture 220 may be formed by several layers superimposed along the axial direction DA, as illustrated in [Fig. 4]. However, it does not go beyond the scope of the invention if the flange portion 222 of the second wound secondary fibrous texture 220 is formed by a single layer.

[0070] The fibrous casing preform 200 thus obtained comprises a body preform portion, a stiffener preform portion and possibly two flange preform portions. The body preform portion is formed by the body portion 110 of the wound main fibrous texture 100, by the body portion 211 of the wound first secondary fibrous texture 210 and by the body portion 221 of the wound second secondary fibrous texture 220. The stiffener preform portion is formed by the stiffener portion 213 of the wound first secondary fibrous texture 210 and by the stiffener portion 223 of the wound second secondary fibrous texture 220.One of the flange preform parts is formed by one of the flange portions 120 of the wound main fiber texture 100 and the flange portion 222 of the wound second secondary fiber texture 220, while the other flange preform part is formed by the other flange portion 130 of the wound main fiber texture 100 and the flange portion 212 of the wound first secondary fiber texture 210.

[0071] According to a second embodiment of the invention illustrated in [Fig.5], the secondary fiber textures are wound so as to form a “T”-shaped stiffener preform portion and so as to cover the entire wound main fiber texture 100.

[0072] In the example illustrated in [Fig. 5], the secondary fibrous textures 310 and 320 are each wound over a complete turn, so as to form a single layer. As indicated previously, it is of course not outside the scope of the invention if the secondary fibrous textures make less than one complete turn of the mandrel 50, or more than one complete turn of the mandrel 50.

[0073] The winding of the main fibrous texture 100 and the secondary fibrous textures 310 and 320 makes it possible to obtain a fibrous casing preform 300 such as as illustrated in section in [Fig.5].

[0074] The first wound secondary fibrous texture 310 comprises a body portion 311, a first stiffener portion 313, a second stiffener portion 314 and optionally a flange portion 312.

[0075] The body portion 311 of the first wound secondary fiber texture 310 is superimposed on the body 51 of the mandrel 50. The body portion 311 of the first wound secondary fiber texture 310 is superimposed on the body portion 110 of the main fiber texture 100 wound in the radial direction DR. The body portion 311 of the first wound secondary fiber texture 310 may be formed by several superimposed layers. Thus, the body portion 311 of the first wound secondary fiber texture 310 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 311 of the first wound secondary fiber texture 310 extends mainly in the axial direction DA. The body portion 311 of the first wound secondary fibrous texture 310 extends in thickness along the radial direction DR.

[0076] The body portion 311 of the first wound secondary fibrous texture 310 extends in the axial direction DA between a first end 311a and a second end 311b. In this second embodiment, the second end 311b of the first wound secondary fibrous texture 310 is adjacent to the end of the body portion 110 of the wound main fibrous texture 100. The wound main fibrous texture 100 comprising flange portions 120 and 130, the second end 311b of the first wound secondary fibrous texture 310 is adjacent to one of the flange portions 130 of the wound main fibrous texture 100.

[0077] The first stiffener portion 313 of the first wound secondary fiber texture 310 extends in the radial direction DR from one of the ends of the body portion 311 of the first wound secondary fiber texture 310. The first stiffener portion 313 of the first wound secondary fiber texture 310 extends in the radial direction DR from the first end 311a of the body portion 311 of the first wound secondary fiber texture 310. The first stiffener portion 313 of the first wound secondary fiber texture 310 extends in thickness in the axial direction DA.

[0078] The second stiffener portion 314 of the first wound secondary fiber texture 310 extends the first stiffener portion 313. Thus, the second stiffener portion 314 of the first wound secondary fiber texture 310 extends from the end of the first stiffener portion 313 of the first wound secondary fiber texture 310. In particular, the second stiffener portion 314 of the first wound secondary fiber texture 310 extends from the end of the first stiffener portion 313 opposite the body portion 311 of the first wound secondary fibrous texture 310.

[0079] The second stiffener portion 314 of the first wound secondary fiber texture 310 extends in the axial direction DA from the end of the first stiffener portion 313 of the first wound secondary fiber texture 310. The second stiffener portion 314 of the first wound secondary fiber texture 310 extends in thickness in the radial direction DR.

[0080] The first and second stiffener portions 313 and 314 of the first wound secondary fiber texture 310 may be formed by a single layer, as illustrated in [Fig. 5]. However, it does not go beyond the scope of the invention if the first and second stiffener portions 313 and 314 of the first wound secondary fiber texture 310 are formed by several layers superimposed along the axial direction DA.

[0081] In the case where the first wound secondary fibrous texture 310 comprises a flange portion 312, the flange portion 312 of the first wound secondary fibrous texture 310 is adjacent to the flange portion 130 of the wound main fibrous texture 100. In other words, the flange portion 312 of the first wound secondary fibrous texture 310 covers the flange portion 130 of the wound main fibrous texture 100.

[0082] The flange portion 312 of the first wound secondary fiber texture 310 extends in the radial direction DR from one of the ends of the body portion 311 of the first wound secondary fiber texture 310. The flange portion 312 of the first wound secondary fiber texture 310 extends in the radial direction DR from the end of the body portion 311 of the first wound secondary fiber texture 310 opposite the stiffener portion 313. The flange portion 312 of the first wound secondary fiber texture 310 extends in the radial direction DR from the second end 311b of the body portion 311 of the first wound secondary fiber texture 310. The flange portion 312 of the first wound secondary fiber texture 310 extends in thickness in the axial direction DA.

[0083] The flange portion 312 of the first wound secondary fibrous texture 310 may be formed as a single layer, as illustrated in [Fig. 5]. However, it does not go beyond the scope of the invention if the flange portion 312 of the first wound secondary fibrous texture 310 is formed by several layers superimposed along the axial direction DA.

[0084] The second wound secondary fibrous texture 320 comprises a body portion 321, a first stiffener portion 323, a second stiffener portion 324 and optionally a flange portion 322.

[0085] The body portion 321 of the second wound secondary fiber texture 320 is superimposed on the body 51 of the mandrel 50. The body portion 321 of the second wound secondary fiber texture 320 is superimposed on the body portion 110 of the main fiber texture 100 wound in the radial direction DR. The body portion 321 of the second wound secondary fiber texture 320 may be formed by several superimposed layers. Thus, the body portion 321 of the second wound secondary fiber texture 320 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 321 of the second wound secondary fiber texture 320 extends mainly in the axial direction DA. The body portion 321 of the second wound secondary fibrous texture 320 extends in thickness along the radial direction DR.

[0086] The body portion 321 of the second wound secondary fibrous texture 320 extends along the axial direction DA between a first end 321a and a second end 321b. In this second embodiment, the second end 321b of the second wound secondary fibrous texture 320 is adjacent to the end of the body portion 110 of the wound main fibrous texture 100. The wound main fibrous texture 100 comprising flange portions 120 and 130, the second end 321b of the second wound secondary fibrous texture 310 is adjacent to one of the flange portions 120 of the wound main fibrous texture 100. The first end 321a of the second wound secondary fibrous texture 320 is adjacent to the first end 311a of the first wound secondary fibrous texture 310.

[0087] The first stiffener portion 323 of the second wound secondary fiber texture 320 extends in the radial direction DR from one of the ends of the body portion 321 of the second wound secondary fiber texture 320. The first stiffener portion 323 of the second wound secondary fiber texture 320 extends in the radial direction DR from the first end 321a of the body portion 321 of the second wound secondary fiber texture 320. The first stiffener portion 323 of the second wound secondary fiber texture 320 extends in thickness in the axial direction DA.

[0088] The stiffener portion 323 of the second wound secondary fiber texture 320 is adjacent to the stiffener portion 313 of the first wound secondary fiber texture 310. The stiffener portion 323 of the second wound secondary fiber texture 320 is in contact with the stiffener portion 313 of the first wound secondary fiber texture 310. The contact surface between the stiffener portion 323 of the second wound secondary fiber texture 320 and the stiffener portion 313 of the first wound secondary fiber texture 310 extends in the radial direction DR. Preferably, the contact surface between the stiffener portion 323 of the second wound secondary fibrous texture 320 and the stiffener portion 313 of the first wound secondary fibrous texture 310 extends over the entire circumference of the secondary fibrous textures 310 and 320. Preferably, the free end of the stiffener portion 323 of the second wound secondary fibrous texture 320 and the free end of the stiffener portion 313 of the first wound secondary fibrous texture 310 are in contact.

[0089] The second stiffener portion 324 of the second wound secondary fiber texture 320 extends the first stiffener portion 323. Thus, the second stiffener portion 324 of the second wound secondary fiber texture 320 extends from the end of the first stiffener portion 323 of the second wound secondary fiber texture 320. In particular, the second stiffener portion 324 of the second wound secondary fiber texture 320 extends from the end of the first stiffener portion 323 opposite the body portion 321 of the second wound secondary fiber texture 320.

[0090] The second stiffener portion 324 of the second wound secondary fiber texture 320 extends in the axial direction DA from the end of the first stiffener portion 323 of the second wound secondary fiber texture 320. The second stiffener portion 324 of the second wound secondary fiber texture 320 extends in thickness in the radial direction DR.

[0091] The second stiffener portion 324 of the second wound secondary fiber texture 320 extends in a direction opposite to the direction in which the second stiffener portion 314 of the first wound secondary fiber texture 310 extends.

[0092] The first and second stiffener portions 323 and 324 of the second wound secondary fiber texture 320 may be formed by a single layer, as illustrated in [Fig. 5]. However, it does not go beyond the scope of the invention if the first and second stiffener portions 323 and 324 of the second wound secondary fiber texture 320 are formed by several layers superimposed along the axial direction DA.

[0093] In the case where the second wound secondary fibrous texture 320 comprises a flange portion 322, the flange portion 322 of the second wound secondary fibrous texture 320 is adjacent to the flange portion 120 of the wound main fibrous texture 100. In other words, the flange portion 322 of the second wound secondary fibrous texture 320 covers the flange portion 120 of the wound main fibrous texture 100.

[0094] The flange portion 322 of the second wound secondary fibrous texture 320 extends in the radial direction DR from one of the ends of the body portion 321 of the second wound secondary fibrous texture 320. The flange portion 322 of the second wound secondary fibrous texture 320 extends in the direction radial DR from the end of the body portion 321 of the second wound secondary fiber texture 320 opposite the stiffener portion 323. The flange portion 322 of the second wound secondary fiber texture 320 extends in the radial direction DR from the second end 321b of the body portion 321 of the second wound secondary fiber texture 320. The flange portion 322 of the second wound secondary fiber texture 320 extends in thickness in the axial direction DA.

[0095] The flange portion 322 of the second wound secondary fibrous texture 320 may be formed by a single layer, as illustrated in [Fig. 5]. However, it does not go beyond the scope of the invention if the flange portion 322 of the second wound secondary fibrous texture 320 is formed by several layers superimposed along the axial direction DA.

[0096] The thus obtained casing fiber preform 300 comprises a body preform portion, a stiffener preform portion and possibly two flange preform portions. The body preform portion is formed by the body portion 110 of the wound main fiber texture 100, by the body portion 311 of the wound first secondary fiber texture 310 and by the body portion 321 of the wound second secondary fiber texture 320. The stiffener preform portion is formed by the first stiffener portion 313 and the second stiffener portion 314 of the wound first secondary fiber texture 310 and by the first stiffener portion 323 and the second stiffener portion 324 of the wound second secondary fiber texture 320.One of the flange preform parts is formed by one of the flange portions 120 of the wound main fiber texture 100 and the flange portion 322 of the wound second secondary fiber texture 320, while the other flange preform part is formed by the other flange portion 130 of the wound main fiber texture 100 and the flange portion 312 of the wound first secondary fiber texture 310.

[0097] According to a third embodiment of the invention illustrated in [Fig.6], two secondary fibrous textures are wound so as not to cover the entire wound main fibrous texture 100. Such an embodiment makes it possible to limit the mass of the obtained fibrous casing preform, and thus to reduce the mass of the final casing made of composite material.

[0098] In the example illustrated in [Fig.6], the secondary fiber textures 410 and 420 are each wound over a complete turn, so as to form a single layer. As indicated previously, it is of course not outside the scope of the invention if the secondary fiber textures make less than one complete turn of the mandrel 50, or more than one complete turn of the mandrel 50.

[0099] The winding of the main fiber texture 100 and the fiber textures condaries 410 and 420 makes it possible to obtain a fibrous casing preform 400 as illustrated in section in [Fig.6].

[0100] The first wound secondary fiber texture 410 comprises a body portion 411 and a stiffener portion 413. In the example illustrated in [Fig. 6], the first secondary fiber texture 410 does not comprise a second stiffener portion as described in the second embodiment of the invention. However, it does not depart from the scope of this third embodiment if the first fiber texture 410 comprises a first stiffener portion and a second stiffener portion as described in the second embodiment, so as to obtain a stiffener preform portion in the shape of a “T” instead of an “I”.

[0101] The body portion 411 of the first wound secondary fiber texture 410 is superimposed on the body 51 of the mandrel 50. The body portion 411 of the first wound secondary fiber texture 410 is superimposed on the body portion 110 of the main fiber texture 100 wound in the radial direction DR. The body portion 411 of the first wound secondary fiber texture 410 may be formed by several superimposed layers. Thus, the body portion 411 of the first wound secondary fiber texture 410 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 411 of the first wound secondary fiber texture 410 extends mainly in the axial direction DA. The body portion 411 of the first wound secondary fibrous texture 410 extends in thickness along the radial direction DR.

[0102] The body portion 411 of the first wound secondary fiber texture 410 extends in the axial direction DA between a first end 411a and a second end 411b. In this third embodiment, the second end 411b of the first wound secondary fiber texture 410 is spaced a non-zero distance in the axial direction DA from the ends of the body portion 110 of the wound main fiber texture 110. Thus, the body portion 411 of the first wound secondary fiber texture 410 extends from the second secondary fiber texture 420 in the axial direction DA without reaching the end of the body portion 110 of the wound main fiber texture 100.

[0103] The wound main fibrous texture 100 comprising flange portions 120 and 130, the second end 411b of the first wound secondary fibrous texture 410 is spaced a non-zero distance from the flange portions 120, 130 of the wound main fibrous texture 100.

[0104] The stiffener portion 413 of the first wound secondary fiber texture 410 extends in the radial direction DR from one of the ends of the body portion 411 of the first wound secondary fiber texture 410. The stiffener portion 413 of the first wound secondary fiber texture 410 extends in the direction radial DR from the first end 411a of the body portion 411 of the first wound secondary fibrous texture 410. The stiffener portion 413 of the first wound secondary fibrous texture 410 extends in thickness along the axial direction DA.

[0105] The stiffener portion 413 of the first wound secondary fiber texture 410 may be formed by a single layer, as illustrated in [Fig. 6]. However, it does not go beyond the scope of the invention if the stiffener portion 413 of the first wound secondary fiber texture 410 is formed by several layers superimposed along the axial direction DA.

[0106] The wound second secondary fiber texture 420 comprises a body portion 421 and a stiffener portion 243. In the example illustrated in [Fig. 6], the second secondary fiber texture 420 does not comprise a second stiffener portion as described in the second embodiment of the invention. However, it does not depart from the scope of this third embodiment if the second fiber texture 420 comprises a first stiffener portion and a second stiffener portion as described in the second embodiment, so as to obtain a stiffener preform portion in the shape of a “T” instead of an “I”.

[0107] The body portion 421 of the second wound secondary fiber texture 420 is superimposed on the body 51 of the mandrel 50. The body portion 421 of the second wound secondary fiber texture 420 is superimposed on the body portion 110 of the main fiber texture 100 wound in the radial direction DR. The body portion 421 of the second wound secondary fiber texture 420 may be formed by several superimposed layers. Thus, the body portion 421 of the second wound secondary fiber texture 420 extends in the axial direction DA. In other words, in a section plane comprising the reference axis, the body portion 421 of the second wound secondary fiber texture 420 extends mainly in the axial direction DA. The body portion 421 of the second wound secondary fibrous texture 420 extends in thickness along the radial direction DR.

[0108] The body portion 421 of the second wound secondary fiber texture 420 extends in the axial direction DA between a first end 421a and a second end 421b. In this third embodiment, the second end 411b of the first wound secondary fiber texture 410 is spaced a non-zero distance in the axial direction DA from the ends of the body portion 110 of the wound main fiber texture 110. Thus, the body portion 421 of the second wound secondary fiber texture 420 extends from the first secondary fiber texture 410 in the axial direction DA without reaching the end of the body portion 110 of the wound main fiber texture 100.

[0109] The wound main fibrous texture 100 comprising flange portions 120 and 130, the second end 411b of the first wound secondary fibrous texture 410 is distant by a non-zero distance from the flange portions 120, 130 of the wound main fibrous texture 100.

[0110] The first end 421a of the second wound secondary fibrous texture 420 is adjacent to the first end 411a of the first wound secondary fibrous texture 410.

[0111] The stiffener portion 423 of the second wound secondary fiber texture 420 extends in the radial direction DR from one of the ends of the body portion 421 of the second wound secondary fiber texture 420. The stiffener portion 423 of the second wound secondary fiber texture 420 extends in the radial direction DR from the first end 421a of the body portion 421 of the second wound secondary fiber texture 420. The stiffener portion 423 of the second wound secondary fiber texture 420 extends in thickness in the axial direction DA.

[0112] The stiffener portion 423 of the second wound secondary fiber texture 420 may be formed by a single layer, as illustrated in [Fig. 6]. However, it does not go beyond the scope of the invention if the stiffener portion 423 of the second wound secondary fiber texture 420 is formed by several layers superimposed along the axial direction DA.

[0113] The stiffener portion 423 of the second wound secondary fiber texture 420 is adjacent to the stiffener portion 413 of the first wound secondary fiber texture 410. The stiffener portion 423 of the second wound secondary fiber texture 420 is in contact with the stiffener portion 413 of the first wound secondary fiber texture 410. The contact surface between the stiffener portion 423 of the second wound secondary fiber texture 420 and the stiffener portion 413 of the first wound secondary fiber texture 410 extends in the radial direction DR. Preferably, the contact surface between the stiffener portion 423 of the second wound secondary fiber texture 420 and the stiffener portion 413 of the first wound secondary fiber texture 410 extends over the entire circumference of the secondary fiber textures 410 and 420.Preferably, the free end of the stiffener portion 423 of the second wound secondary fiber texture 420 and the free end of the stiffener portion 413 of the first wound secondary fiber texture 410 are in contact.

[0114] The thus obtained casing fiber preform 400 comprises a body preform portion and a stiffener preform portion. The body preform portion is formed by the body portion 110 of the wound main fiber texture 100, by the body portion 411 of the wound first secondary fiber texture 410 and by the body portion 421 of the wound second secondary fiber texture 420. The stiffener preform portion is formed by the stiffener portion 413 of the first wound secondary fiber texture 410 and by the stiffener portion 423 of the second wound secondary fiber texture 420. As indicated previously, it is not outside the scope of the third embodiment if the stiffener preform portion is formed by first and second stiffener portions as described in the second embodiment, making it possible to obtain a “T”-shaped stiffener preform portion.

[0115] According to a fourth embodiment of the invention illustrated in [Fig.7], at least three secondary fibrous textures are wound around the wound main fibrous texture 100. Such an embodiment makes it possible to produce a casing with several stiffeners. The secondary fibrous textures can cover the entire wound main fibrous texture. The secondary fibrous textures can cover only a portion of the wound main fibrous texture, as is the case in the example of [Fig.7].

[0116] In the example illustrated in [Fig.7], four wound secondary fiber textures 510, 520, 610, 620 make it possible to obtain a fiber casing preform 500. However, it does not go beyond the scope of the fourth embodiment if the fiber casing preform is formed by three secondary fiber textures, or by at least five secondary fiber textures. The number of secondary fiber textures used to form the fiber casing preform may be even. The number of secondary fiber textures used to form the fiber casing preform may be odd. The same secondary fiber texture may belong simultaneously to two stiffener preform parts, the secondary fiber texture comprising at least one stiffener portion at each of the ends of its body portion. Such stiffener portions may have the same characteristics as the stiffener portions described in the previous embodiments.In particular, such stiffener portions can make it possible to produce “T” or “I” shaped stiffener preform parts, the same secondary fiber texture could make it possible to produce on the one hand a “T” shaped stiffener preform part and on the other hand an “I” shaped stiffener preform part.

[0117] In the example illustrated in [Fig.7], the secondary fibrous textures 510, 520, 610, 620 are each wound over a complete turn, so as to form a single layer. As indicated previously, it is of course not outside the scope of the invention if the secondary fibrous textures make less than one complete turn of the mandrel 50, or more than one complete turn of the mandrel 50.

[0118] The winding of the main fibrous texture 100 and the secondary fibrous textures 510, 520, 610, 620 makes it possible to obtain the fibrous casing preform 500 as illustrated in section in [Fig.7].

[0119] The first wound secondary fibrous texture 510 comprises a body portion 511, a stiffener portion 513 and possibly a flange portion 512. The body portion 511 of the first wound secondary fibrous texture 510 extends in the axial direction DA between a first end 511a and a second end 511b. The first wound secondary fibrous texture 510 may have the same characteristics as the first wound secondary fibrous texture 210 as described in the first embodiment.

[0120] The second wound secondary fiber texture 520 comprises a body portion 521 and a stiffener portion 523. The body portion 521 of the second wound secondary fiber texture 520 extends in the axial direction DA between a first end 521a and a second end 521b. The second wound secondary fiber texture 520 may have the same characteristics as the second wound secondary fiber texture 420 as described in the third embodiment.

[0121] The third wound secondary fiber texture 610 comprises a body portion 611, a first stiffener portion 613 and a second stiffener portion 614. The body portion 611 of the third wound secondary fiber texture 610 extends in the axial direction DA between a first end 611a and a second end 611b. The third wound secondary fiber texture 610 may have the same characteristics as the first wound secondary fiber texture 410 as described in the third embodiment, when the stiffener preform portion has a “T” shape.

[0122] In the example illustrated in [Fig.5], a non-zero distance extends along the axial direction DA between the second end 521b of the body portion 521 of the second wound secondary fiber texture 520 and the second end 611b of the body portion 610 of the third wound secondary fiber texture 610.

[0123] The fourth wound secondary fiber texture 620 comprises a body portion 621, a first stiffener portion 623, a second stiffener portion 624 and possibly a flange portion 622. The body portion 621 of the second wound secondary fiber texture 620 extends in the axial direction Da between a first end 621a and a second end 621b. The second wound secondary fiber texture 620 may have the same characteristics as the second wound secondary fiber texture 320 as described in the second embodiment.

[0124] The fibrous casing preform 500 thus obtained comprises a body preform portion, two stiffener preform portions and optionally two flange preform portions. The body preform portion is formed by the body portion 110 of the wound main fibrous texture 100 and by the body portions 511, 521, 611, 621 of the wound secondary fiber textures 510, 520, 610, 620. The first stiffener preform portion is formed by the stiffener portion 513 of the first wound fiber texture 510 and by the stiffener portion 523 of the second wound fiber texture 520. The second stiffener preform portion is formed by the first stiffener portion 613 and the second stiffener portion 614 of the third wound secondary fiber texture 610 and by the first stiffener portion 623 and the second stiffener portion 624 of the fourth wound secondary fiber texture 620.One of the flange preform parts is formed by one of the flange portions 120 of the wound main fiber texture 100 and the flange portion 622 of the wound fourth secondary fiber texture 620, while the other flange preform part is formed by the other flange portion 130 of the wound main fiber texture 100 and the flange portion 512 of the wound first secondary fiber texture 510.

[0125] It is of course not outside the scope of the fourth embodiment of the invention if other combinations are made for the secondary fibrous textures.

[0126] The fibrous casing preform 200, 300, 400 or 500 according to one of the preceding embodiments is intended to form the fibrous reinforcement of the aeronautical casing.

[0127] The fibrous casing preform is then densified using at least one matrix. The densification of the fibrous casing preform consists of filling the porosity of said preform, in all or part of the volume thereof, with the material(s) constituting said at least one matrix. The mandrel 50 can be used as part of a mold to carry out the densification or at least one step of the densification.

[0128] The matrix can be obtained in a manner known per se using the liquid process. The liquid process consists of impregnating the 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, optionally diluted in a solvent. The fibrous casing preform is placed in a mold that can be closed in a sealed manner with a housing having the shape of the final molded casing.

[0129] [Fig. 8] illustrates an example of a mold enabling the wet process for the first example of a fiber casing preform 200. The wet process can of course be carried out for other fiber casing preforms in accordance with the invention. The mold illustrated in [Fig. 8] for the wet process comprises the mandrel 50 used for winding. The mold for the wet process can also comprise two counter-molds 61 and 62 for closing the mold. If the fiber casing preform comprises a “T”-shaped stiffener preform portion as described in some of the previous embodiments, the counter- molds have a suitable shape. For example, counter-mold parts can be arranged between the second stiffener portions and the body portions.

[0130] Next, the liquid matrix precursor, for example a resin, is injected throughout the housing to impregnate the preform.

[0131] The transformation of the precursor into an organic matrix, namely its polymerization, is carried out by heat treatment, generally by heating the mold, after removal of any solvent and crosslinking of the polymer, the preform 200, 300, 400 or 500 being always maintained in the mold having a shape corresponding to that of the part to be produced. The organic matrix can in particular be obtained from epoxy resins, such as, for example, high-tenacity epoxy resin.

[0132] Preferably, the casing produced is made of organic matrix composite material, in order to obtain a better compromise between mass and mechanical characteristics.

[0133] In the case of the formation of a carbon or ceramic matrix, the heat treatment consists of pyrolyzing the organic precursor to transform the organic matrix into a carbon or ceramic matrix depending on the precursor used and the pyrolysis conditions. For example, liquid carbon precursors may be resins with a relatively high coke content, such as phenolic resins, while liquid ceramic precursors, in particular SiC, may be resins of the polycarbosilane (PCS) or polytitanocarbosilane (PTCS) or poly-silazane (PSZ) type. Several consecutive cycles, from impregnation to heat treatment, may be carried out to achieve the desired degree of densification.

[0134] The densification of the fibrous casing preform can also be carried out by the well-known transfer molding process known as “RTM” for “Resin Transfer Molding” in English. In accordance with the RTM process, the fibrous casing preform is placed in a mold having the shape of the casing to be produced.

[0135] A thermosetting resin is injected into the internal space delimited by the mold which includes the fibrous casing preform. A pressure gradient is generally established in this internal space between the place where the resin is injected and the orifices for discharging the latter in order to control and optimize the impregnation of the preform by the resin.

[0136] The resin used may be, for example, an epoxy resin. Resins suitable for RTM processes are well known. They preferably have a low viscosity to facilitate their injection into the fibers. The choice of temperature class and / or the chemical nature of the resin is determined according to the thermomechanical stresses to which the part must be subjected. Once the resin has been injected throughout the reinforcement, it is polymerized by heat treatment in accordance with the RTM process.

[0137] After injection and polymerization, the composite material casing is demolded, then trimmed to remove excess resin. The casing thus obtained may be raw, and require machining operations to obtain the final functional casing.

[0138] The aeronautical casing thus obtained comprises a body, at least one stiffener and possibly one or two flanges. The body has an annular shape. The flange(s) are arranged at the end of the body.

[0139] The body preform portion forms the fiber reinforcement of the housing body. The stiffener preform portion(s) form the fiber reinforcement of the stiffener(s) of the housing. The flange preform portion(s) form the fiber reinforcement of the flange(s).

[0140] The fibrous casing preform preferably extends over the entire width of the casing along its axis.

Claims

Claims

1. A method of manufacturing a fibrous preform (200; 300; 400; 500) for an aeronautical casing comprising: - winding a main fibrous texture (100) onto an external surface of a mandrel (50) having a profile corresponding to the internal profile of the casing to be manufactured, the mandrel (50) extending circumferentially around an axial direction (DA), the method being characterized in that it further comprises: - winding at least two secondary fibrous textures (210, 220) onto the wound main fibrous texture (100), each wound secondary fibrous texture (210, 220) comprising a body portion (211, 221) extending in the axial direction (DA) in contact with the external surface of the mandrel (51) and at least one first stiffener portion (213, 223) extending in a radial direction (DR) perpendicular to the axial direction (DA) from a first end (211a, 221a) of the body portion (211,221) of said wound secondary fibrous textures (210, 220), the two first stiffener portions (213, 223) of at least two of the wound secondary fibrous textures (210, 220) being arranged in contact with each other so as to form a stiffener preform portion.,

2. Manufacturing method according to claim 1, wherein the wound main fibrous texture (100) comprises a body portion (110) extending in the axial direction (DA) and two flange portions (120, 130) extending in the radial direction (DR) on either side of the body portion (110) of said wound main fibrous texture (100).

3. A manufacturing method according to claim 2, wherein at least one of the wound secondary fiber textures (210, 220) comprises a flange portion (212, 222) extending from a second end (211b, 221b) of the body portion (211, 221) of said at least one wound secondary fiber texture (210, 220) in the radial direction (DR), said second end (211b, 221b) being opposite the first end (211a, 221a) of said body portion (211, 221), the flange portion (212, 222) of the at least one wound secondary fiber texture (210, 220) being arranged in contact with one of the flange portions (120, 130) of the wound main fiber texture (100).

4. A manufacturing method according to any one of claims 1 to 3, wherein the two wound secondary fiber textures (310, 320) further comprise a second stiffener portion (314, 324) extending from the end of the first stiffener portion (313, 323) in the axial direction (DA), the two first stiffener portions (313, 323) and the two second stiffener portions (314, 324) of the two wound secondary fiber textures (310, 320) forming a stiffener preform part.

5. A manufacturing method according to claim 4, wherein the two second stiffener portions (314, 324) of the two wound secondary fiber textures (310, 320) extend in opposite directions.

6. A manufacturing method according to any one of claims 1 to 5, wherein the wound secondary fibrous textures (210, 220; 310, 320) completely cover the wound main fibrous texture (100).

7. A manufacturing method according to any one of claims 1 to 5, wherein the wound secondary fibrous textures (410, 420; 510, 520, 610, 620) only partially cover the wound main fibrous texture (100).

8. A manufacturing method according to any one of claims 1 to 7, wherein the secondary fibrous textures (210, 220) are wound so as to make more than one complete revolution of the mandrel.

9. A manufacturing method according to any one of claims 1 to 8, wherein the main fibrous texture (100) is made in a single piece by three-dimensional weaving.

10. Method for manufacturing an aeronautical casing made of composite material comprising the manufacture of a fibrous preform (200; 300; 400; 500) of an aeronautical casing according to any one of claims 1 to 9 and the densification by at least one matrix of said fibrous preform.

11. Aircraft casing made of composite material obtained by the manufacturing method according to claim 10.

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