Manufacture of a part without destruction of the sleeve

Abstract

The invention relates to a method for manufacturing a part, comprising: - obtaining a preform comprising a root portion inserted into a metal sleeve (500), a release agent (6) being inserted between the inner surface (510) of the metal sleeve (500) and the outer surface of the root portion, the geometry of the outer surface of the root portion (201) and the geometry of the inner surface (510) of the sleeve (500) being configured so as to be able to slide relative to one another; - densifying the preform so as to obtain a propeller blade or vane (300) comprising a root portion (301) formed by the root portion of the preform densified by a matrix; then - removing the metal sleeve (500) by sliding along the root portion (301).

Description

Description Title of the invention: Manufacturing a part without destroying the sleeve Technical Field

[0001] The present invention relates to the manufacture of a test specimen for performing analyses. In particular, the present invention allows for conformity testing of manufactured propeller blades or turbine blades. For example, the present invention allows for material integrity testing of manufactured propeller blades or turbine blades. Previous technique

[0002] Propeller blades or vanes can be made of composite material. In particular, they can be formed from a fiber reinforcement densified by a matrix, for example, a fiber reinforcement produced by three-dimensional weaving, possibly with metal components. Such blades or vanes include a root that is integrated into a rotor disc.

[0003] In particular, the new generation of unfaired engines (known as "open fan" or "open rotor" engines) requires more compact blade roots. This need arises from the requirement to be able to rotate the blade around its vertical axis to adapt its angle of attack to the flight regime (variable pitch blade). This requirement, combined with the fact that the blade must be integrated as low as possible on the rotor disc, necessitates a significant reduction in the footprint. To this end, the roots of the new generation of blades have an axisymmetric or nearly axisymmetric shape and reduced dimensions, such as the blade disclosed in document WO 2023 / 209289.

[0004] Blade roots, particularly those of the new generation, can be integrated into the rotor disc using metal shells or a metal sleeve. This metal sleeve is interposed between the blade root and the rotor. The metal sleeve is typically made of Inconel or titanium.

[0005] It is necessary to perform material health checks on the blade or turbine blade, particularly on the material health of the composite root. Indeed, the fiber orientation and matrix quality must be verifiable. However, the presence of the metal sleeve around the composite root hinders these checks, as the sleeve obstructs or reduces the passage of the waves required for the inspection.

[0006] It is therefore necessary to cut the metal sleeve in order to remove it, to allow for inspection of the composite material of the foot. However, such a process is costly. Description of the invention

[0007] To limit costs, the invention proposes a method for manufacturing a test specimen that does not require the destruction of the metal sleeve, and even allows its reuse for a new part. Indeed, the sleeve is often made of an expensive metal, such as titanium or Inconel, and it is therefore preferable not to damage it in order to be able to reuse it.

[0008] To this end, the invention proposes a method for manufacturing a part, also called a test specimen, configured to be subjected to analysis, comprising:

[0009] - the assembly of one or more fibrous blanks with a metal sleeve so as to obtain a preform comprising, along a longitudinal direction, a foot portion, an aerodynamic profile portion and a transition portion connecting the foot portion to the aerodynamic profile portion, the foot portion of the preform being inserted into the metal sleeve, the metal sleeve comprising an internal surface covering the external surface of the foot portion of the preform, an anti-adherent agent being interposed between the internal surface of the metal sleeve and the external surface of the foot portion of the preform, the geometry of the external surface of the foot portion of the preform and the geometry of the internal surface of the sleeve being configured so as to be able to slide relative to each other in at least one direction along the longitudinal direction,

[0010] - the densification of the preform by a matrix so as to obtain a blade or propeller blade comprising an airfoil portion, a transition portion and a root portion formed respectively by the airfoil portion, the transition portion and the root portion of the preform densified by the matrix, then

[0011] - the removal of the metal sleeve by sliding it along the base part of the blade or propeller blade.

[0012] Thus, the combination of the specific geometry and the anti-adhesive agent allows the metal sleeve to be easily removed without damage. It can then be reused for a new blade or propeller blade. Once the sleeve is removed, it is easier to perform all the necessary checks and analyses on the composite part.

[0013] According to a particular embodiment of the invention, the method further comprises cutting at least a portion of the base part of the blade or propeller blade for analysis after the removal of the metal sleeve.

[0014] Indeed, the analyses to be carried out may require cutting off part of the foot.

[0015] According to another particular embodiment of the invention, the cross-section of the external surface of the root portion of the blade or propeller blade is larger at the free end of said root portion than at the junction between the root portion and the transition portion of the blade or propeller blade, the method further comprising a step of cutting the blade or propeller blade at the transition portion so as to separate the root portion from the airfoil portion of the blade or propeller blade before the sleeve is removed, the sleeve being removed by sliding said sleeve away from the free end of the root portion of the blade or propeller blade.

[0016] According to another particular embodiment of the invention, the anti-adherent agent is applied at least partially in the form of an aqueous or non-aqueous solution. The anti-adherent agent can then be applied by spraying, dipping, brushing, or using a cloth. The anti-adherent agent can be applied only in the form of an aqueous or non-aqueous solution.

[0017] According to another particular embodiment of the invention, the anti-adherent agent is applied at least partially in the form of a tape comprising an adhesive surface and an anti-adherent surface having the anti-adherent agent. The anti-adherent agent may then comprise polytetrafluoroethylene, polyethylene, or silicone rubber. The anti-adherent agent may also be applied solely in the form of a tape comprising an adhesive surface and an anti-adherent surface having the anti-adherent agent.

[0018] According to another particular embodiment of the invention, the foot portion of the preform has a three-dimensional weave.

[0019] The invention also relates to a method for analyzing a portion of the root of a blade or propeller blade, comprising:

[0020] - the manufacture of a part, also called a test specimen, according to the process described previously, then

[0021] - the analysis of said document.

[0022] According to a particular embodiment of the invention, the analysis is carried out by X-rays or by ultrasound. Brief description of the drawings

[0023] [Fig. 1] Figure 1 is a schematic perspective view of the assembly of several fibrous blanks to obtain a preform mounted with a metal sleeve.

[0024] [Fig. 2] Figure 2 is a schematic cross-sectional view of the preform of Figure 1 mounted with the metal sleeve.

[0025] [Fig. 3] Figure 3 is a schematic cross-sectional view of the blade or propeller blade made of composite material obtained by densification of the preform of Figure 2 and fitted with the metal sleeve.

[0026] [Fig. 4] Figure 4 is a schematic cross-sectional view illustrating the cut of the blade or propeller blade of Figure 3 at the transition part.

[0027] [Fig. 5] Figure 5 is a schematic cross-sectional view illustrating the removal of the metal sleeve by sliding. Description of the implementation methods

[0028] The invention is generally applicable to the manufacture of propeller blade or blade test specimens. The invention finds an advantageous, but not exclusive, application in the manufacture of blade root or propeller test specimens for unfaired rotating wheels, such as those found in so-called "open rotor" aircraft engines.

[0029] The manufacturing process according to the invention comprises the assembly of one or more fibrous blanks.

[0030] The fiber blank(s) can be produced by three-dimensional weaving. In particular, the fiber blank(s) can be produced by three-dimensional weaving using a Jacquard-type loom on which a bundle of warp yarns or strands is arranged in a plurality of layers of several hundred yarns each, the warp yarns being bound together by weft yarns. The fiber blank(s) can each be woven in a single piece.

[0031] The term "three-dimensional weave" refers to a weaving method in which at least some of the warp yarns interlace weft yarns across multiple weft layers. A three-dimensional weave may incorporate another type of weave on its surface, such as two-dimensional weaving, to enhance its surface finish. Reversal of the warp and weft yarns is also possible. Various three-dimensional weaving methods that can be used to create the woven texture are described in WO 2006 / 136755.

[0032] The fiber blanks are intended to be assembled together to obtain a preform. The preform can be formed solely from one or more fiber blanks, resulting in a fiber preform. Alternatively, the preform can be formed from one or more fiber blanks and one or more metal portions. For example, the preform may have a portion comprising alternating metal and fiber layers.

[0033] Figures 1 and 2 illustrate the assembly of at least one first fibrous rough 101 with a second fibrous rough 102 to obtain a preform 200.

[0034] In the example illustrated in figures 1 and 2, the preform 200 is obtained by assembling a first fibrous spar blank 101 and a second fibrous airfoil blank 102. The first fibrous spar blank 101 is then intended to form at least the fibrous reinforcement of the blade or vane root and at least part of a fibrous reinforcement extending inside the airfoil part of the vane or vane.

[0035] The invention remains within the scope of this invention if the preform is obtained from a single fibrous blank, for example, a fibrous blank produced in one piece by three-dimensional weaving. Such a single fibrous blank can, for example, be folded and / or wound in certain portions to form the preform.

[0036] Nor does it fall outside the scope of the invention if the preform is obtained from several fibrous blanks arranged differently from the arrangement shown in figures 1 and 2, and having different geometries.

[0037] As explained previously, we also do not depart from the scope of the invention if the preform includes one or more metal portions.

[0038] The preform 200 comprises a foot portion 201, a transition portion 202 and an aerodynamic profile portion 203 along a longitudinal direction D L The transition portion 202 of the preform 200 connects the foot portion 201 to the airfoil portion 203 along the longitudinal direction D L The foot portion 201 of the preform 200 extends along the longitudinal direction D Lbetween the junction between the foot portion 201 and the transition portion 202 of the preform 200 and a free end of said foot portion 201.

[0039] The aerodynamic profile portion 203 of the preform 200 is not necessarily complete. Indeed, if the analyses and checks to be carried out on the specimen only concern the root area, it is not necessary for the blade or propeller blade produced to be complete at the aerodynamic profile level.

[0040] The foot portion 201 of the preform 200 includes a fibrous reinforcement, preferably made by three-dimensional weaving. The foot portion 201 of the preform 200 includes an external surface 220. The external surface 220 may correspond to the external surface 121 of one of the fibrous blanks 101, possibly shaped.

[0041] The foot portion 201 of the preform 200 may include an internal cavity, as illustrated in the figures. This internal cavity may open onto the exterior of the preform 200.

[0042] The external surface 220 of the foot portion 201 of the preform 200 can be axisymmetric about an axis A. The axis A preferably extends along the longitudinal direction D LThe external surface 220 of the foot portion 201 of the preform 200 can be a cylinder. Here, "cylinder" refers to a cylinder in the mathematical sense of the term, that is, a ruled surface whose generatrices are parallel. In particular, the external surface 220 of the foot portion 201 of the preform 200 can be a right cylinder, for example, a cylinder of revolution. The external surface 220 of the foot portion 201 of the preform 200 can also be a portion of a cone. Here, "cone" refers to a cone in the mathematical sense of the term, that is, a ruled surface defined by a generatrix and a direction curve. In particular, the external surface 220 of the foot portion 201 of the preform 200 can be a portion of a cone of revolution.

[0043] The external surface 220 of the foot portion 201 can be formed by several sub-portions 221, 222, 223 along the longitudinal direction D LEach sub-portion 221, 222, 223 of the external surface 220 of the foot portion 201 can be a cylinder, for example a cylinder of revolution, or a portion of a cone, for example a portion of a cone of revolution. In the illustrated example, the first sub-portion 221 of the external surface 220 of the foot portion 201 is adjacent to the transition portion 202, the third sub-portion 223 of the external surface 220 of the foot portion 201 includes the free end of the external surface 220, and the second sub-portion 222 of the external surface 220 of the foot portion 201 connects the first sub-portion 221 to the third sub-portion 223. In the illustrated example, the first sub-portion 221 is a cylinder, in particular a cylinder of revolution. In the illustrated example, the second sub-portion 222 is a portion of a cone, in particular a portion of a cone of revolution.In the illustrated example, the third sub-portion 223 is a cylinder, in particular a cylinder of revolution.

[0044] The geometry of the external surface 220 of the foot portion 201 of the preform 200 must be able to slide relative to an internal surface 510 of a metal sleeve 500. Thus, the cross-section of the geometry of the external surface 220 of the foot portion 201 of the preform 200 has an area that remains constant or decreases in at least one direction along the longitudinal axis D L In other words, the cross-section of the geometry of the external surface 220 of the foot portion 201 of the preform 200 has an area that does not increase in at least one direction of the longitudinal direction D L Thus, each sub-portion 221, 222, 223 of the external surface 220 of the foot portion 201 must have a maximum cross-section less than or equal to the minimum cross-section of the preceding sub-portion along the longitudinal direction DL .

[0045] The preform 200 is assembled with a metal sleeve 500 such that the foot portion 201 of said preform 200 is inserted into the metal sleeve 500. The foot portion 201 of the preform 200 can be completely covered by the metal sleeve 500. The metal sleeve 500 does not cover, even partially, the transition portion 202 of the preform 200. The metal sleeve 500 does not cover, even partially, the aerodynamic profile portion of the preform 200.

[0046] The metal sleeve 500 includes an internal surface 510. The internal surface 510 of the sleeve 500 covers the external surface 220 of the foot portion 201 of the preform 200. The geometry of the internal surface 510 of the sleeve 500 corresponds to the geometry of the external surface 220 of the foot portion 201 of the preform 200. In particular, the geometry of the internal surface 510 of the sleeve 500 and the geometry of the external surface 220 of the foot portion 201 of the preform 200 are configured to be able to slide relative to each other in at least one direction along the longitudinal direction D L .

[0047] For example, according to a first embodiment, the internal surface 510 of the sleeve 500 can slide relative to the external surface 220 of the foot portion 201 of the preform 200 in both directions of the longitudinal direction D LThis is the case, for example, when the internal surface 510 of the sleeve 500 and the external surface 220 of the foot portion 201 of the preform 200 are straight cylinders, for example, cylinders of revolution. This first embodiment has the advantage of offering a geometry that is easy to implement.

[0048] According to a second embodiment, the geometry of the internal surface 510 of the sleeve 500 and the geometry of the external surface 220 of the foot portion 201 of the preform 200 can be configured to slide relative to each other in only a first direction of the longitudinal direction D L , according to which the free end of the foot portion 201 of the preform 200 can slide along the longitudinal direction D Lalong the entire length of the sleeve 500. In this second embodiment, the cross-section of the external surface 220 of the foot portion 201 is larger at the junction between the foot portion 201 and the transition portion 202 than at the free end of the foot portion 201.

[0049] According to a third embodiment illustrated in the figures, the geometry of the internal surface 510 of the sleeve 500 and the geometry of the external surface 220 of the foot portion 201 of the preform 200 can be configured to slide relative to each other in only a second direction of the longitudinal direction D L , according to which the junction between the foot portion 201 of the preform 200 and the transition portion 202 of the preform 200 can slide along the longitudinal direction D Lalong the entire length of the sleeve 500. In this third embodiment, the cross-section of the external surface 220 of the foot portion 201 is larger at the free end of the foot portion 201 than at the junction between the foot portion 201 and the transition portion 202, as illustrated in the figures. This third embodiment allows for maintaining an optimal foot geometry with respect to the actual mechanical stresses of a blade or propeller blade.

[0050] The internal surface 510 of the metal sleeve 500 can also be formed by sub-portions 511, 512, 513 along the longitudinal direction D LEach sub-portion 511, 512, 513 of the internal surface 510 of the sleeve 500 corresponds to one of the sub-portions 221, 222, 223 of the external surface 220 of the foot portion 201. Thus, each sub-portion 511, 512, 513 of the internal surface 510 of the sleeve 500 covers one of the sub-portions 221, 222, 223 of the external surface 220 of the foot portion 201. Each sub-portion 511, 512, 513 of the internal surface 510 of the sleeve 500 has the same geometry as the sub-portion 221, 222, 223 of the external surface 220 it covers.

[0051] Each sub-portion 511, 512, 513 of the inner surface 510 of the sleeve 500 can be a cylinder, for example a cylinder of revolution, or a portion of a cone, for example a portion of a cone of revolution. In the illustrated example, the first sub-portion 511, the second sub-portion 512, and the third sub-portion 513 of the inner surface 510 of the sleeve 500 respectively cover the first sub-portion 221, the second sub-portion 222, and the third sub-portion 223 of the outer surface 220 of the foot portion 201 of the preform 200. In the illustrated example, the first sub-portion 511 of the inner surface 510 of the sleeve 500 is a cylinder, in particular a cylinder of revolution. In the illustrated example, the second sub-portion 512 of the internal surface 510 of the sleeve 500 is a portion of a cone, in particular a portion of a cone of revolution.In the illustrated example, the third sub-portion 513 of the internal surface 510 of the sleeve 500 is a cylinder, in particular a cylinder of revolution.

[0052] The cross-section of the internal surface geometry 510 of the sleeve 500 has an area that remains constant or decreases in at least one direction of the longitudinal direction D L In other words, the cross-section of the internal surface geometry 510 of the sleeve 500 has an area that does not increase in at least one direction of the longitudinal direction D L Thus, each sub-portion 511, 512, 513 of the internal surface 510 of the sleeve 500 must have a maximum cross-section less than or equal to the minimum cross-section of the preceding sub-portion along the longitudinal direction D L .

[0053] The 500 metal sleeve is classically made of titanium or Inconel.

[0054] The metal sleeve 500 is made in one piece. Therefore, the metal sleeve 500 lacks fasteners for joining multiple sections of said metal sleeve 500, such as bolts, jaws, or clamps. The metal sleeve 500 may, however, include means for connecting to other parts of the turbomachine, in particular means for connecting it to a rotor disc. For this purpose, the metal sleeve 500 may, for example, have a thread and / or a flange. The metal sleeve 500 may be manufactured, for example, by casting.

[0055] An anti-adherent agent 6 is interposed between the inner surface 510 of the sleeve 500 and the outer surface 220 of the foot portion 201 of the preform 200. A layer of anti-adherent agent 6 is schematically illustrated with an exaggerated thickness in the figures.

[0056] To facilitate the implementation of the process, the anti-adherent agent 6 is preferably applied to the internal surface 510 of the sleeve 500 before its assembly with the fibrous blank(s) 101, 102. It is of course not outside the scope of the invention if the anti-adherent agent 6 is applied to the surface of the fibrous blank 101 intended to form the external surface 220 of the foot portion 201 of the preform 200 before its assembly with the sleeve 500.

[0057] The anti-adhesive agent 6 can be applied to the entire inner surface 510 of the sleeve 500. The anti-adhesive agent 6 can be applied to the entire outer surface 220 of the foot portion 201 of the preform 200. Indeed, by applying the anti-adhesive agent 6 to the entire contact surface between the sleeve 500 and the foot portion 201 of the preform 200, the removal of the sleeve 500 is greatly facilitated.

[0058] The anti-adherent agent can be applied in the form of a silicone-based or polyvinyl alcohol (PVA) solution.

[0059] In particular, the release agent can be applied as a non-aqueous solution. Specifically, the release agent can be a solvent-based polymer formulated to cure at room temperature. For this purpose, Loctite® Frekote® B-15™, Loctite® Frekote® 700-NC™, or Loctite® Frekote® 44-NC™ can be used, for example.

[0060] The release agent can also be applied as a solvent-free aqueous solution. For this purpose, Zyvax® Departure™ can be used, for example.

[0061] The solution can be applied by spraying, soaking, brushing, or using a cloth.

[0062] The anti-adhesive agent can also be applied in the form of an adhesive tape. Such a tape comprises an adhesive surface and an anti-adhesive surface bearing the anti-adhesive agent. The adhesive surface is positioned opposite the anti-adhesive surface. The anti-adhesive agent comprises polytetrafluoroethylene, polyethylene, or silicone rubber. Such a tape is applied by placing the adhesive surface on the inner surface 510 of the sleeve 500 or on the outer surface 220 of the foot portion 201 of the preform 200.

[0063] The anti-adhesive agent can also be applied partly in the form of an adhesive tape and partly in the form of a solution.

[0064] The preform 200 is then densified by at least one matrix to obtain a part made of composite material 300.

[0065] The propeller blade 300 comprises a root portion 301, a transition portion 302, and an airfoil portion 303. The transition portion 302 of the part 300 connects the root portion 301 to the airfoil portion 303 along the longitudinal direction D L The foot portion 301 extends along the longitudinal direction D L between the junction between the foot part 301 and the transition part 302 and a free end of said foot part 301.

[0066] As explained previously, the aerodynamic profile section 303 of part 300 is not necessarily complete. Indeed, if the analyses and checks to be carried out on the specimen only concern the root area, it is not necessary for the blade or propeller blade produced to be complete in terms of the aerodynamic profile.

[0067] The fibrous reinforcement of the root portion 301 of the blade or the blade 300 is formed by the root portion 201 of the preform 200. The fibrous reinforcement of the transition portion 302 of the blade or the blade 300 can be formed by the transition portion 202 of the preform 200. The fibrous reinforcement of the airfoil portion 303 of the blade or the blade 300 can be formed by the airfoil portion 203 of the preform 200.

[0068] The external surface of the foot portion 301 of the blade or the blade 300 has the same shape, dimensions and geometry as the external surface 220 of the foot portion 201 of the preform 200.

[0069] After densification of the preform 200, the metal sleeve 500 is removed from the blade or propeller blade 300. The metal sleeve 500 is removed by sliding it along the foot portion 301 of the blade or propeller blade 300. The metal sleeve 500 is removed from the blade or propeller blade 300 without damaging said sleeve 500. The metal sleeve 500 remains in one piece when removed from the blade or propeller blade 300. In particular, the metal sleeve 500 is neither cut nor disassembled.

[0070] In the first and second embodiments described above, it is not necessary to cut the blade or propeller blade 300 to allow the removal of the metal sleeve 500. Indeed, in the first and second embodiments, the free end of the root portion 301 of the blade or propeller blade 300 can slide along the longitudinal direction D Lalong the entire length of the sleeve 500. Thus, the sleeve 500 can be easily removed by sliding the free end of the foot part 301 of the blade or the blade 300 inside the sleeve 500, until the entire foot part 301 of the blade or the blade 300 is freed.

[0071] In the third embodiment, illustrated in the figures, it may be necessary to cut the blade or propeller blade 300 to allow the removal of the metal sleeve 500. Indeed, in the third embodiment, the free end of the root portion 301 of the blade or propeller blade 300 cannot slide along the longitudinal direction D L in the sleeve 500. Thus, if the blade or propeller blade 300 is not cut, the aerodynamic profile part 303, or even the transition part 302, can block the removal of the sleeve 500.

[0072] Thus, in the third embodiment, a cutting step can be performed on the blade or propeller blade 300 before the removal of the metal sleeve 500, as illustrated in Figure 4. This cutting is preferably carried out at the transition portion 302 of the blade or propeller blade 300. This cut allows the root portion 301 to be separated from the airfoil portion 303 of the blade or propeller blade 300. This cut can be made, for example, by sectioning, milling, or waterjet cutting. The resulting cut part 300c consists of the root portion 301 of the blade or propeller blade 300 and optionally a portion of the transition portion 302 of the blade or propeller blade 300.

[0073] The cut part 300c is able to slide along the longitudinal direction DL in the metal sleeve 500. The cut part 300c extends along the longitudinal direction DL between the free end of the foot portion 301 and a cut surface. The cut surface is able to slide along the longitudinal direction D L along the entire length of the sleeve 500. Thus, the metal sleeve 500 can easily be removed from the cut piece 300c, as illustrated in Figure 5.

[0074] In all embodiments, the presence of the anti-adherent agent 6 allows the sleeve 500 to slide relative to the foot portion 301. The sleeve 500 can be withdrawn manually or automatically, for example, by means of a jack. The withdrawal of the sleeve 500 can be initiated by applying a force along the longitudinal direction D. L The removal of sleeve 500 can be initiated by vibration. The removal of sleeve 500 can also be achieved by applying a force along the longitudinal direction D. L The removal of sleeve 500 can be achieved by vibration.

[0075] The metal sleeve 500 can be reused after removal. Therefore, the removed metal sleeve 500 can be used for a new part, particularly for a new blade or propeller blade. A cleaning step can be carried out on the metal sleeve 500 after its removal, for example, to remove any traces of the anti-adherent agent 6 or any matrix residue.

[0076] After removing the sleeve 500, the foot portion 301 of the blade or propeller blade 300 can form a test specimen in itself. After removing the sleeve 500, the foot portion 301 of the blade or propeller blade 300 can also be cut to obtain one or more test specimens. For example, the foot portion 301 of the blade or propeller blade 300 can be cut into one or more washers along one or more cutting planes perpendicular to the longitudinal direction D LEach of these washers can form a test specimen. According to another example, the foot portion 301 of the blade or propeller blade 300 can be cut along a cutting plane including the longitudinal direction D L Such a longitudinal section can allow for measurements of the volumetric fiber content or measurements to determine the glass transition temperature.

[0077] The resulting specimen(s) may be subjected to one or more analyses. For example, the analysis(s) may include visual analysis, ultrasonic analysis, X-ray analysis, or a combination thereof. In particular, the analysis(s) may include tomography. Specifically, the analysis(s) may focus on the composite material of the foot portion 301. The analysis(s) may allow for the determination of the fiber volume fraction. The analysis(s) may allow for the determination of the glass transition temperature.

Claims

Demands

1. A method for manufacturing a part configured to be subjected to analysis, comprising: - the assembly of one or more fibrous blanks (101, 102) with a metal sleeve (500) so as to obtain a preform (200) comprising along a longitudinal direction (D L) a foot portion (201), an aerodynamic profile portion (203), and a transition portion (202) connecting the foot portion (201) to the aerodynamic profile portion (203), the foot portion (201) of the preform (200) being inserted into the metal sleeve (500), the metal sleeve (500) comprising an inner surface (510) covering the outer surface (220) of the foot portion (201) of the preform (200), an anti-adhesive agent (6) being interposed between the inner surface (510) of the metal sleeve (500) and the outer surface (220) of the foot portion (201) of the preform (200), the geometry of the outer surface (220) of the foot portion (201) of the preform (200) and the geometry of the inner surface (510) of the sleeve (500) being configured so that they can slide relative to each other in at least one direction along the longitudinal direction (D L ), - the densification of the preform (200) by a matrix so as to obtain a blade or propeller blade (300) comprising an aerodynamic profile part (303), a transition part (302) and a root part (301) formed respectively by the aerodynamic profile portion (203), by the transition portion (202) and by the root portion (201) of the preform (200) densified by the matrix, then - the removal of the metal sleeve (500) by sliding along the root part (301) of the blade or propeller blade (300).

2. A manufacturing method according to claim 1, the method further comprising cutting at least a portion of the foot part (301) of the blade or propeller blade (300) for analysis after removal of the metal sleeve (500).

3. A manufacturing method according to claim 1 or 2, wherein the cross-section of the external surface of the root portion (301) of the blade or propeller blade (300) is larger at the free end of said root portion (301) than at the junction between the root portion (301) and the transition portion (302) of the blade or propeller blade (300), the method further comprising a step of cutting the blade or propeller blade (300) at the transition portion so as to separate the root portion (301) from the airfoil portion (303) of the blade or propeller blade (300) before the sleeve (500) is removed, the sleeve (500) being removed by sliding said sleeve (500) away from the free end of the root portion (301) of the blade or the propeller blade (300).

4. A manufacturing method according to any one of claims 1 to 3, wherein the anti-adherent agent (6) is applied at least in part in the form of an aqueous or non-aqueous solution.

5. A manufacturing method according to claim 4, wherein the anti-adherent agent (6) is applied by spraying, dipping, brushing or using a cloth.

6. A manufacturing method according to any one of claims 1 to 5, wherein the anti-adherent agent (6) is applied at least in part in the form of a tape comprising an adhesive surface and an anti-adherent surface having the anti-adherent agent.

7. A manufacturing method according to claim 6, wherein the anti-adherent agent (6) comprises polytetrafluoroethylene, polyethylene or silicone rubber.

8. A manufacturing method according to any one of claims 1 to 7, wherein the foot portion (201) of the preform (200) has a three-dimensional weave.

9. Method for analyzing a portion of the root (301) of a propeller blade or fan blade (300), comprising: - the manufacture of a part according to any one of claims 1 to 8, then - the analysis of said part.

10. Analytical method according to claim 9, wherein the analysis is carried out by X-rays or by ultrasound.

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