WO2016181085A1

WO2016181085A1 - Part made of a composite material, comprising a t-shaped stiffener and method for producing such a part

Info

Publication number: WO2016181085A1
Application number: PCT/FR2016/051131
Authority: WO
Inventors: Simon VERGER; Laurent Dubois; Zoheir ABOURA; Justine BIGAUD
Original assignee: Universite De Technologie De Compiegne (Utc)
Priority date: 2015-05-12
Filing date: 2016-05-12
Publication date: 2016-11-17
Also published as: FR3036060A1; FR3036060B1

Abstract

The invention relates to a part (10) made of a composite material, comprising a T-shaped stiffener (12) mounted on a supporting face (14) of a base (16), the stiffener (12) comprising a first L-shaped element (18a) and a second L-shaped element (18b), said part (10) comprising a core (30) which is housed in a cavity (28) defined by an area for the joining of the L-shaped elements (18a, 18b) and the base (16), characterised in that the core (30) is enveloped in at least one fibrous central ply (32) which is connected to the base (16) by at least one first mechanical connection (L1), said first mechanical connection (L1) being designed to transmit forces between the base (16) and the stiffener (12).

Description

COMPOSITE MATERIAL PART COMPRISING A T-STIFFENER AND METHOD OF MANUFACTURING SUCH A PART

The invention relates to a composite material part comprising a T-stiffener mounted on a bearing surface of a base.

The invention also relates to a method for manufacturing such a part.

In general, the present patent application relates to the field of manufacture of composite material parts with stiffener, especially for aeronautics.

For reasons of mass and cost savings, it is interesting to replace metal parts with composite parts, in particular structural parts with complex geometry.

Most composite parts are made from bi-directional fabric stacking, often called "pleats", for example carbon fibers or glass fibers. Depending on the manufacturing process, these fabrics may be dry, the resin being provided by injection or infusion in a second time, or pre-impregnated. The resin is then polymerized by raising the temperature.

This technology is generally satisfactory for monolithic parts solicited according to their plan, but may be unsuitable for structures solicited "off plan".

Thus, it is known to equip some parts with a stiffener, of T-section for example, which is positioned perpendicularly or at an angle to the main plane of the part.

The stiffener is generally formed by a first L-shaped element and a second L-shaped composite material element which are arranged back to back to form a T.

More particularly, each stiffener comprises a sole which is extended on the bearing surface of the base of the piece, and a rib which extends from the associated sole to form the core of the stiffener.

The rib and the sole of each L-shaped element are connected by a connecting portion.

The junction zone of the L-shaped elements and the base of the room, in the vicinity of the connecting portions of the L-shaped elements, delimits generally a cavity which is filled with resin, or which forms a disturbance of the flatness of the folds which tend to fill this cavity.

This junction zone may constitute a mechanical weakening which may cause unfolding of the folds of the connecting portion of the L-shaped elements, delamination of the folds between each L-shaped element, and delamination of the folds between each element L and the base of the room.

To reinforce the part, it is known to make seams to bind the plies together, especially to bind the L-shaped elements on the base of the room. This type of process and part is for example described in the documents FR-A-2993492 and EP-A-2540479.

Also, WO-A-2009140555 proposes a composite material part comprising a core which is arranged in the cavity delimited by the junction zone of the elements constituting the composite part.

Although this type of core prevents the cavity from being filled exclusively with resin and prevents the deformation of the connection portions of the L-shaped elements, the part described in the document WO-A-2009140555 does not seem to guarantee either a sufficient mechanical strength of the various plies the room between them, nor sufficient mechanical strength of the folds and the core.

The present invention aims in particular to solve these disadvantages and relates for this purpose to a composite material part comprising a T-shaped stiffener mounted on a bearing surface of a base, the stiffener comprising a first element L and a second element in L of composite material which are arranged back to back to form a T, said piece having a core which is housed in a cavity delimited by a junction zone of the L-shaped elements, and of the base, the first L-shaped element and the second L-shaped element comprising:

- a first sole and a second sole respectively, which are extended on the support face of the base,

- a first rib and a second rib respectively which extend back to back from the associated sole to form a stiffener core, and

a first coupling portion and a second connecting portion respectively that connect said ribs to said associated soles,

characterized in that the core is wrapped in at least one fibrous central fold which is connected on the base by at least a first link mechanical, said first mechanical connection being adapted to transmit forces between the base and the stiffener.

Advantageously, the core of the part according to the invention makes it possible to prevent the formation of a resin pocket in the junction zone of the L-shaped elements and the base of the part.

In addition, the mechanical connection makes it possible to reinforce the part and to prevent delamination of the part.

Preferably, the first mechanical connection extends in the extension of the core of the stiffener to promote the recovery of forces between the base and the stiffener.

In addition, the central fold which envelops the core has at least two sides which extend between said ribs of the L-shaped elements and which are interconnected by at least one second mechanical connection.

Similarly, the first rib and the second rib of the L-shaped elements are interconnected by at least one third mechanical connection.

The third mechanical connection makes it possible in particular to link each element L between them and to bind the elements in L on the central fold.

In addition, the first coupling portion and the second connecting portion of the L-shaped elements are each connected to the base by at least one fourth mechanical connection which extends generally radially along the radius of curvature of the associated coupling portion.

The fourth mechanical connection makes it possible, in particular, to link each L-shaped element to the base in order to promote the transmission of forces between the L-shaped elements and the base and to reinforce the part.

Also, the first sole and the second sole of the elements in

L are each connected to the base by at least one fifth mechanical connection.

According to an alternative embodiment of the invention, the central core comprises a first portion and a second portion and the central fold comprises a first portion and a second portion, each portion of the core being enveloped by an associated portion of the central fold, each portion central fold being connected to the base by at least a first mechanical connection.

Preferably, each mechanical connection is of the stitching type.

Also, the core is deformable to substantially match the shape of the elements in L. The invention also relates to a method for manufacturing a composite material part of the type described above, characterized in that it comprises at least:

a first step of connecting the central fold, which consists in connecting the central fold on the base of the workpiece with at least a first mechanical connection,

a step of enveloping the core, which consists in wrapping the core by means of the central fold, and

- A step of draping each L-shaped element to form the T-stiffener, which step consists of forming the first sole and the second sole, which are extended on the bearing face of the base, and to form the first rib and the second rib which extend back to back, the core being housed in the cavity defined by the junction zone of the L-shaped elements and the base of the piece.

In one embodiment, the first step of binding the central fold consists of:

- place the center fold flat on the bearing face of the base of the piece,

- connect the central fold on the base of the part by the first mechanical connection,

and the step of wrapping the core consists of:

depositing the core on the central fold so that the central fold has two sections arranged on either side of the core,

- Fold the two folds of the central fold against each other to wrap the core.

According to an alternative embodiment of the method, the central core comprises a first portion and a second portion and the central fold comprises a first portion and a second portion, the first central fold binding step consisting of:

- Deposit the first portion and the second portion of the central fold on the support face of the base of the part,

- connect each portion of the central fold on the base of the workpiece with at least a first mechanical connection,

and the step of wrapping the core consists of:

depositing the first portion and the second portion of the core on the first portion and the second portion of the central fold respectively, so each of said portions of the central fold has two faces arranged on either side of the part of the associated core,

- fold the two sections of each portion of the central fold against each other to wrap each part of the core.

Also, the method comprises a second step of connecting the central folded sections which consists of connecting the central folded sections by a second mechanical connection to enclose the core in the central fold, the second linkage step being performed before the step of draping.

In addition, the method may comprise a third bonding step which consists in connecting the first rib and the second rib of the L-shaped elements by the third mechanical connection, the third bonding step being performed after the draping step.

In addition, the method may comprise a fourth connecting step which consists of connecting the first coupling portion and the second connecting portion of the L-shaped elements on the base of the workpiece, each with a fourth mechanical connection which extends radially generally. according to the radius of curvature of the associated coupling portion, the fourth bonding step being performed after the draping step.

Finally, the method may comprise a fifth connection step which consists in connecting the first sole and the second sole of the L-shaped elements on the basis of the part each with a fifth mechanical connection, the fifth connection step being carried out after the step draping.

Other features and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

- Figure 1 is a perspective view of a section of a composite material part comprising a T-stiffener mounted on a bearing surface of a base, according to the invention;

FIGS. 2a to 2h are diagrammatic cross-sectional views, which illustrate the manufacturing process of the part of FIG. 1 with a one-part core, according to a first embodiment;

FIGS. 3a to 3d are diagrammatic cross-sectional views, which illustrate the manufacturing process of the part of FIG. 1 with a two-part core, according to a second embodiment; FIGS. 4a to 4j are diagrammatic cross-sectional views, which illustrate the method of manufacturing the part of FIG. 1 with a two-part core, according to a third embodiment.

In the description and the claims, the terms "upper", "lower" and "low", "high" will be used in a nonlimiting manner with reference to the upper part and the lower part respectively of FIGS. 1 to 4.

Moreover, to clarify the description and the claims, the longitudinal, vertical and transverse terminology will be adopted in a nonlimiting manner with reference to the L, V, T trihedron indicated in the figures.

In all of these figures, identical or similar references represent identical or similar organs or sets of members.

To facilitate the understanding of the description, the identical and symmetrical elements along the plane P of symmetry are indicated by the same numerical references distinguished by the letters "a" or "b".

FIG. 1 shows a piece 10 made of composite material comprising a T-shaped stiffener 12 mounted on a horizontal bearing face 14 of a base 16 of the part 10.

The term "composite material" refers to a material having fibrous folds, such as fiberglass folds or folds of carbon fibers, and a resin. The resin is preferably of the polymer type, for example an epoxy-based polymer.

The part 10 can be used for various applications to support loads and / or to reinforce a structural element. By way of nonlimiting example, the part 10 can be used to be part of a nacelle component frame or beam.

The stiffener 12 includes a first L-shaped element 18a and a second L-shaped composite material member 18b that are arranged back to back and extend longitudinally to form an inverted T-section profile.

The piece 10 has a plane of symmetry P of general design, illustrated in Figure 1, which extends vertically and longitudinally between the two L-shaped elements 18a, 18b.

In addition, the first element L 18a and the second element L

18b comprise a first sole 20a and a second sole 20b respectively, which are extended on the bearing face 14 of the base 16, and a first rib 22a and a second rib 22b respectively which extend perpendicularly to the base 16, back to back, from the sole 20a, 20b associated for form a core 24 of the stiffener 12 T.

The first rib 22a and the second rib 22b are connected on the first sole 20a and the second sole 20b respectively by a first connecting portion 26a and a second connecting portion 26b curves respectively.

As can be seen in FIG. 1, the two L-shaped elements 18a, 18b and the base 16 have a central Z-junction zone, which delimits a longitudinal central cavity 28 of generally triangular cross-section.

The part 10 comprises a core 30 which is housed in the cavity 28, and which is deformable so as to adapt to the volume of the cavity during the draping and compacting of the folds of the L-shaped elements 18a and 18b. This core will marry the shape of the central Z junction zone created by the assembly of these elements with the base, which will prevent the appearance in the fittings 26a and 26b of resin-rich areas or localized creases that are commonly observed when using braided cores and which are areas of local weakness. This core may optionally consist of unidirectional wicks of carbon fiber, glass or other. This deformable core makes it possible to improve the positioning and the curvature of the folds in these zones of connections 26a and 26b with respect to a non-deformable core, and consequently makes it possible to obtain a better material health and a better mechanical behavior of this sensitive zone. .

The core has a cross-section of generally triangular shape which is complementary to the shape of the cavity 28 and which is delimited by a lower surface in vertical support on the base 16 of the part 10, and two lateral faces arranged opposite the portions of fitting 26a, 26b of the L-shaped elements 18a, 18b.

According to the invention, the core 30 is wrapped in at least one fibrous central fold 32 which is connected to the base 16 by a first mechanical connection L1.

The term "mechanical connection" means a link having a mechanical element reported other than an element of the glue or resin type. A mechanical connection here is preferably a sewing-type connection which is made by means of fibers or threads. This connection is for example a loop seam known by the English name "tufting", or a seam perpendicular to the general orientation of the plies known under the name "z-pinning", or any other type of seam adapted to the composite material .

It will be noted that each mechanical connection comprises one or more seams.

More particularly, the central fold 32 has two sides 34a, 34b which are folded symmetrically on either side of the side faces of the core 30 and which extend vertically between the ribs 22a, 22b of the L-shaped elements 18a, 18b, according to the plane of symmetry P.

The first mechanical link L1 comprises one or more vertical seams which extend longitudinally, and which each connect the base 16 of the workpiece 10 to a portion of the central fold 32 arranged under the lower face of the core 30, as can be seen at Figure 1.

The first mechanical link L1 is designed to transmit forces between the base 16 and the stiffener 12, in particular vertical forces, and to promote the recovery of forces between the base 16 and the stiffener 12. It strengthens the mechanical strength by off plan of the central zone by creating a direct force recovery between the central fold 32 vertically connected to the ribs 22a and 22b and the folds of the base 16, and delaying the occurrence of delamination type damage at the level of the bearing surface 14. This resumption of effort is direct on the one hand because the central fold 32 which is part of the stack of the core 24 of the stiffener is directly placed against the upper fold of the base 16, and on the other hand because the mechanical connection L1 is vertical and therefore oriented in the axis of the stiffener 12.

The central fibrous fold 32 connected to the base 16 by the mechanical link L1 also makes it possible to prevent the shifting or transverse sliding of the core 30 which it envelopes. It therefore participates in controlling the positioning of the folds of the connectors 26a and 26b, and the interfaces between these connectors 26a and 26b with the base 16, which will facilitate the introduction of the other mechanical connections.

The two sections 34a, 34b of the central fold 32 may be interconnected by a second mechanical connection L2 which is arranged directly on the above the core 30, to enclose the core 30 in the pocket thus formed by the central fold 32.

With reference to FIG. 1, the first rib 22a and the second rib 22b of the L-shaped elements 18a, 18b are interconnected by a third mechanical link L3 which here comprises three seams each extending longitudinally. The number of these seams can be variable (one or more).

Also, the first connecting portion 26a and the second connecting portion 26b of the L-shaped elements 18a, 18b are connected to the base 16 each by a fourth mechanical connection L4 which extends generally for example radially along the radius of curvature of the associated fitting portion. Depending on the position and the direction of the mechanical connection L4 of the first connector 26a and the mechanical connection L4 of the second connector 26b, these can cross below, inside, or above the element 30. .

In addition, the first sole 20a and the second sole 20b of the L-shaped elements 18a, 18b are each connected to the base 16 by a fifth mechanical link L5.

According to an alternative embodiment of the invention, described in more detail below, the central core 30 includes a first portion 30a and a second portion 30b and the central fold 32 has a first portion 32a and a second portion 32b which surround the first part 30a and the second part 30b respectively of the core 30.

According to this variant embodiment, each portion 32a, 32b of the central fold 32 is connected to the base 16 by a first mechanical connection L1.

This embodiment enhances the force transfer capacity between the core of the stiffener and the base 16 in that each portion of the central fold 32a and 32b has its inner side perfectly in the axis of the core 24 of the stiffener and directly connected to the base.

The manufacture of the previously described part 10 is carried out according to a method described below.

The method according to the invention comprises a first central ply binding step 32, a core wrapping step 30, a draping step of each L-shaped element 18a, 18b to form the T-stiffener 12 and a plurality of bonding steps the different elements constituting the piece 10.

According to a first embodiment of the method, represented in FIGS. 2a to 2h, the first step of connecting the central fold 32, illustrated in FIGS. FIGS. 2a, 2b and 2c consist, successively, of depositing the central fold 32 flat on the bearing face 14 of the base 16 of the workpiece 10 and of connecting the central fold 32 to the base 16 of the workpiece 10 by the first mechanical connection L1.

The first bonding step is followed by a step of wrapping the core 30 which successively consists of depositing the core 30 on the central fold 32, so that the central fold 32 has two sides 34a, 34b arranged on either side of the core 30, as can be seen in Figure 2d.

The wrapping step also consists in folding the two panels 34a, 34b of the central fold 32 against each other to envelop the core 30, according to FIG. 2e.

According to the first embodiment, the method comprises a second step of connecting the sections 34a, 34b of the central ply 32 which consists in connecting the central ply sections by the second mechanical connection L2, illustrated in FIG. 2e, to enclose the core 30 in the central fold 32.

Also, the method comprises a step of draping each L-shaped element 18a, 18b to form the stiffener 12 T, illustrated in Figure 2f.

The draping step consists of forming the first sole 20a and the second sole 20b, which are extended on the bearing face 14 of the base 16, and forming the first rib 22a and the second rib 22b which extend backwards. back, depositing wrinkles on the base 16 and the core 30.

Following the draping step, the core 30 is trapped in the cavity 28 which is delimited by the junction zone of the L-shaped elements 18a, 18b and the base 16 of the part 10.

Also, following the draping step, the method comprises a third connecting step which consists in connecting the first rib 22a and the second rib 22b of the L-shaped elements 18a, 18b by the third mechanical link L3, illustrated in FIG. Figure 2f.

The third connecting step is followed by a fourth connecting step, illustrated in FIG. 2g, which consists in connecting the first connecting portion 26a and the second connecting portion 26b of the L-shaped elements 18a, 18b on the base 16 of the piece 10, each by a fourth mechanical connection L4.

Each fourth mechanical connection L4 extends radially generally along the radius of curvature of the associated connecting portion 26a, 26b. Finally, the fourth connecting step is followed by a fifth connecting step, illustrated in Figure 2h, which consists of connecting the first sole 20a and the second sole 20b of the L-shaped elements 18a, 18b on the base 16 of the piece 10 each by a fifth mechanical link L5.

The manufacturing method according to the invention has a second embodiment and a third embodiment, which are suitable for the manufacture of the part 10 made according to the embodiment variant described above, according to which the central core comprises a first part. 30a and a second portion 30b and the central fold 32 has a first portion 32a and a second portion 32b which envelop the first portion 30a and the second portion 30b respectively of the core 30.

According to the second embodiment of the method, represented in FIGS. 3a to 3j, the first step of connecting the central ply 32 consists successively of depositing the first portion 32a of the central ply 32 on the bearing surface 14 of the base 16 of the part 10, according to FIG. 3b, connect the first portion 32a of the central fold 32 on the base 16 of the piece 10 by at least one seam of the first mechanical connection L1, according to FIG. 3c, fold the first portion 32a at the right of the seam of the first mechanical connection L1, according to FIG. 3d, depositing the second portion 32b of the central ply 32 on the bearing surface 14 of the base 16 of the part 10, according to FIG. 3d, so that each portion 32a , 32b of the central fold 32 has a section bearing on the bearing surface 14 of the base 16 and a section which extends above the base 16, connecting the second portion 32b of the central fold 32 on the base 16 of the piece 10 by a seam of the first mechanical connection L1 so that the seams of the first portion 32a and the second portion 32b are adjacent, according to Figure 3e, fold the second portion 32b to the right of the seam of the first mechanical link L1.

Still according to the second embodiment of the method, the first bonding step is followed by a step of wrapping the core 30 in two parts, which successively consists in depositing the first part 30a and the second part 30b of the core 30 on the first part. portion 32a and the second portion 32b of the central fold 32 respectively, so that each of the portions of the central fold 32 has two sections arranged on either side of the portion 30a, 30b of the associated core 30, as can be seen on 3f, and fold down the two faces of each portion 32a, 32b of the central fold 32 one against each other to wrap each portion 30a, 30b of the core 30, as can be seen in Figure 3g.

The manufacturing method according to the second embodiment comprises a second linkage step illustrated in FIG. 3g, a layup step illustrated in FIG. 3h, a third linkage step illustrated in FIG. 3h, a fourth linkage step illustrated in FIG. Figure 3i and a fifth linkage step illustrated in Figure 3j, which are identical to the previously described steps for the first embodiment of the method and which will not be described in more detail not to unnecessarily burden the description.

Finally, according to the third embodiment of the method, shown in Figures 4a to 4j, the first connecting step of the central fold 32 consists successively to bind the two portions 32a, 32b of the central fold 32 between it by a link 36 which can be consisting of one or more seams, according to Figure 4b, deposit the central fold 32 thus formed on the bearing surface 14 of the base 16 of the part 10, according to Figures 4c and 4d, so that each portion 32a , 32b of the central fold 32 has a section bearing on the bearing surface 14 of the base 16 and a section which extends above the base 16, connecting the seam which links the first portion 32a and the second portion 32b the central fold 32 on the base 16, by means of a seam of the first mechanical connection L1 according to Figure 4c.

According to a variant illustrated in FIG. 4d, instead of connecting the seam which links the first portion 32a and the second portion 32b of the central fold 32 on the base 16, it is possible to directly connect the first portion 32a and / or the second portion 32b of the central fold 32 directly on the base 16 by a seam of the first mechanical link L1.

Still according to the third embodiment of the method, the first bonding step is followed by a step of wrapping the core 30 in two parts, which successively consists in depositing the first portion 30a and the second portion 30b of the core 30 on the first portion 32a and the second portion 32b of the central fold 32 respectively, so that each of the portions of the central fold 32 has two sections arranged on either side of the portion 30a, 30b of the associated core 30, as can be seen on Figure 4f, and fold down the two faces of each portion 32a, 32b of the central fold 32 against each other to wrap each portion 30a, 30b of the core 30, as can be seen in Figure 4g. The manufacturing method according to the third embodiment comprises a second linkage step illustrated in FIG. 4g, a layup step illustrated in FIG. 4h, a third linkage step illustrated in FIG. 4h, a fourth linkage step illustrated in FIG. Figure 4i and a fifth linkage step illustrated in Figure 4j, which are identical to the previously described steps for the first embodiment of the method and will not be described in more detail not to unnecessarily burden the description.

Claims

1. Composite material part (10) having a T-shaped stiffener (12) mounted on a bearing face (14) of a base (16), the stiffener (12) having a first L-shaped element (18a) and a second an L-shaped element (18b) of composite material which are arranged back to back to form a T, said part (10) having a core (30) which is housed in a cavity (28) delimited by a junction zone of the L-shaped elements (18a, 18b) and the base (16), the first L-shaped element (18a) and the second L-shaped element (18b) comprising:

- a first sole (20a) and a second sole (20b) respectively, which are extended on the bearing face (14) of the base (16),

a first rib (22a) and a second rib (22b) respectively extending back to back from the associated sole (20a, 20b) to form a core (24) of the stiffener (12), and

a first coupling portion (26a) and a second connecting portion (26b) respectively which connect said ribs (22a, 22b) to said associated soles (20a, 20b),

characterized in that the core (30) is wrapped in at least one fibrous central fold (32) which is connected on the base (16) by at least a first mechanical connection (L1), said first mechanical connection (L1) being adapted for transmitting forces between the base (16) and the stiffener (12).

2. Part (10) of composite material comprising a stiffener (12) T according to claim 1, characterized in that the first mechanical connection (L1) extends in the extension of the core (24) of the stiffener (12). ) to promote the recovery of forces between the base (16) and the stiffener (12).

3. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the central fold (32) which surrounds the core (30) has at least two sides (34a , 34b) which extend between said ribs (22a, 22b) of the L-shaped elements (18a, 18b) and which are interconnected by at least one second mechanical connection (L2).

4. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the first rib (22a) and the second rib (22b) of the L-shaped elements are connected between they by at least one third mechanical connection (L3).

5. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the first connecting portion (26a) and the second connecting portion (26b) of the elements L (18a, 18b) are connected to the base (16) each by at least one fourth mechanical connection (L4) which extends radially generally along the radius of curvature of the associated connecting portion (26a, 26b).

6. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the first sole (20a) and the second sole (20b) of the elements L (18a, 18b) are each connected to the base (16) by at least one fifth mechanical connection (L5).

7. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the central core (30) comprises a first portion (30a) and a second portion (30b). and the central fold (32) has a first portion (32a) and a second portion (32b), each portion (30a, 30b) of the core (30) being enveloped by an associated portion (32a, 32b) of the central fold (32b). ), each portion (32a, 32b) of the central fold (32) being connected to the base (16) by at least a first mechanical connection (L1).

8. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that each mechanical connection (L1, L2, L3, L4, L5) is of the seam type.

9. Part (10) of composite material comprising a stiffener (12) T according to any one of the preceding claims, characterized in that the core is deformable to substantially conform to the shape of the L-shaped elements (18a, 18b).

A method for manufacturing a composite material part (10) having a T-shaped stiffener (12) mounted on a bearing face (14) of a base (16) according to any of the preceding claims. characterized in that it comprises at least:

a first step of connecting the central fold (32), which consists in connecting the central fold (32) on the base (16) of the workpiece (10) by at least a first mechanical connection (L1),

a step of wrapping the core (30) which consists in wrapping the core (30) by means of the central fold (32), and - A step of draping each L-shaped element (18a, 18b) to form the stiffener (12) T, which consists in forming the first sole (20a) and the second sole (20b), which are extended on the face supporting (14) the base (16), and forming the first rib (22a) and the second rib (22b) which extend back to back, the core (30) being housed in the cavity (28) delimited by the junction zone of the L-shaped elements (18a, 18b) and the base (16) of the workpiece (10).

1 1. Method according to claim 10, characterized in that the first step of connecting the central fold (32) consists of:

- place the center fold (32) flat on the support face (14) of the base

(16) of the piece (10),

- connect the central fold (32) on the base (16) of the workpiece (10) by the first mechanical connection (L1),

and in that the step of wrapping the core (30) consists of: - depositing the core (30) on the central fold (32) so that the central fold (32) has two sections (34a, 34b) arranged on both sides of the core (30),

- Fold the two pieces (34a, 34b) of the central fold (32) against each other to wrap the core (30).

12. The method of claim 10, characterized in that the central core (30) comprises a first portion (30a) and a second portion (30b) and the central fold (32) comprises a first portion (32a) and a second portion (32b), the first central fold binding step (32) comprising:

depositing the first portion (32a) and the second portion (32b) of the central fold (32) on the bearing face (14) of the base (16) of the workpiece (10),

- connect each portion of the central fold (32) on the base (16) of the workpiece (10) by at least a first mechanical connection (L1),

and in that the step of wrapping the core (30) comprises:

depositing the first portion (30a) and the second portion (30b) of the core (30) on the first portion (32a) and the second portion (32b) of the central fold (32) respectively, so that each of said portions (32a) , 32b) of the central fold (32) has two faces arranged on either side of the portion (30a, 30b) of the associated core (30),

- Fold the two sections of each portion (32a, 32b) of the central fold (32) against each other to wrap each portion (30a, 30b) of the core (30).

13. Method according to one of claims 1 1 and 12, characterized in that the method comprises a second step of connecting the sections (34a, 34b) of the central fold (32) which consists of connecting the panels (34a, 34b) central fold (32) by a second mechanical connection (L2), for enclosing the core (30) in the central fold (32), the second connecting step being performed before the draping step.

14. Method according to any one of claims 10 to 13, characterized in that the method comprises a third connecting step which consists in connecting the first rib (22a) and the second rib (22b) of the L-shaped elements (18a, 18b) by the third mechanical connection (L3), the third connecting step being performed after the draping step.

15. A method according to any one of claims 10 to 14, characterized in that the method comprises a fourth connecting step which consists of connecting the first connecting portion (26a) and the second connecting portion (26b) of the elements. L (18a, 18b), on the base (16) of the workpiece (10), each with a fourth mechanical connection (L4) extending generally radially along the radius of curvature of the connecting portion (26a, 26b) associated, the fourth binding step being performed after the draping step.

16. A method according to any one of claims 10 to 15, characterized in that the method comprises a fifth bonding step which consists in connecting the first sole (20a) and the second sole (20b) of the elements L (18a, 18b) on the base (16) of the workpiece (10) each by a fifth mechanical connection (L5), the fifth connecting step being performed after the draping step.