Method for producing opening part having reinforcing rib

Abstract

The invention relates to a method for manufacturing an opening part (10) made of a composite material comprising a skin (12), a rib extending in an associated extension direction, and at least one reinforcing rib (14) having a reinforcing head (22), the method comprising:-providing a first fibrous preform (PF1) for forming the body of the skin and the rib; -providing a second fibrous preform (PF2) for forming a reinforcing head of the reinforcing rib; -placing the assembly formed by the first fibrous preform and the second fibrous preform in a moulding device (30) comprising a base body (32) shaped to form a rib of the component; and-hot pressing the assembly to form a component; and the first preform comprises discontinuous fibers (PF12) for forming the body and the second preform comprises continuous fibers oriented in the direction of extension.

Description

Technical Field

[0001] This invention relates to the field of components made of composite materials, particularly turbine engine components, formed from fiber-reinforced materials densified through a matrix. In particular, the invention is applicable to hot-pressing manufacturing methods for components, such as ribbed composite panels including openings forming reinforcing ribs. Background Technology

[0002] The technical background includes document EP 3 950 292 A1.

[0003] Open-type reinforced composite panels typically consist of composite skins assembled into an intermediate structure, unlike sandwich composite panels which consist of two composite skins assembled on either side of the intermediate structure. This reduces panel costs and simplifies panel manufacturing, as well as decreasing panel weight, which is particularly important for aerospace applications.

[0004] Examples of applications include thrust reverser flaps for aircraft nacelles, components of thrust reverser grilles, and reinforced internal or external passageway panels.

[0005] Composite skins typically contain woven or unstructured organic or mineral fibers, such as carbon or glass, embedded in a polymer or resin matrix.

[0006] To maintain good flexural stiffness, such open panels typically include a structure formed by reinforcing ribs extending from the inner surface of the composite skin. These ribs may be oriented in the same direction or intersect each other.

[0007] The applicant's patent application FR 2 112 191 discloses an open panel with increased flexural stiffness and improved resistance to deformation, enabling a significant reduction in panel mass and simplifying panel manufacturing. More specifically, the open composite panel includes a composite skin having an inner surface and an outer surface, and a plurality of reinforcing ribs. Each rib extends from the inner surface of the skin to a top opposite the inner surface and also extends along a corresponding extension direction. Furthermore, at least one of the ribs is reinforced. For this purpose, each reinforcing rib forms a reinforcement and includes at least one elongated reinforcing portion extending along the top of the reinforcing rib, the reinforcing portion comprising fibers extending substantially along the extension direction of the reinforcing rib.

[0008] It is known that various turbine engine components (especially aircraft turbine engine components) can be made of composite materials to improve their thermomechanical drag resistance and reduce their mass.

[0009] Some composite materials typically consist of fiber reinforcement materials and a matrix.

[0010] Several techniques have been identified for manufacturing parts made of composite materials, including RTM (resin transfer molding), thermoplastic injection, and hot pressing. In most cases, RTM injection requires fiber-reinforced materials with continuous fibers. Thermoplastic injection with fiber-reinforced materials containing long or short fibers (fibers in the resin and pre-emptied mold) enables the very rapid and high-yield production of parts.

[0011] Hot pressing allows for the densification of fiber-reinforced materials that have been pre-impregnated with a matrix by applying pressure and heat treatment at high temperatures.

[0012] The object of this invention is to provide a method for making the hot-pressing manufacturing of ribbed panels with such optimized structure easier and more robust. Summary of the Invention

[0013] The present invention relates to a method for manufacturing an open component made of a composite material, the open component comprising a skin and at least one rib, each rib comprising a body and a head, the body extending from an inner surface of the skin to the head, each rib extending along an associated extension direction, the component comprising at least one rib referred to as a reinforcing rib having a reinforcing head, characterized in that the method comprises the following steps: - The step of providing at least one first fiber preform, said at least one first fiber preform being configured to form a body with a skin and at least one rib; - The step of providing at least one second fiber preform, said at least one second fiber preform being configured to form a reinforcing head with at least one reinforcing rib; - The step of placing an assembly formed from a first fiber preform and a second fiber preform in a molding apparatus including a punch and a matrix, wherein the second fiber preform is disposed between the matrix and the first fiber preform, and the matrix is ​​shaped to form at least one rib of an open portion; and - The step of hot-pressing the components to form open parts; - The step of demolding the component to form an open part; Furthermore, the first fiber preform includes at least discontinuous fibers (PF12) to form at least the body of the rib, and the second fiber preform includes at least continuous fibers oriented along an extension direction associated with at least one rib.

[0014] Therefore, the present invention provides a simple solution to at least some of the aforementioned disadvantages. The present invention proposes a method for making the manufacture of such ribbed components easier and more robust through hot pressing, particularly structurally optimized ribbed panels that include a reinforcing structure at the top of the ribs.

[0015] Such components or panels have increased strength and flexural stiffness due to the heads of the ribs. The heads of the ribs can be easily added to the panel using the method described in this invention.

[0016] "Extending essentially in one direction" means forming an angle of less than 10°, preferably less than 5° with that direction.

[0017] Similarly, a "rib" is any out-of-plane height of a panel, and a "reinforcing member" or "reinforcing rib" is a rib that includes a reinforcing head, i.e., a reinforcing structure at the top of its body.

[0018] The method according to the invention may include one or more of the following features, used individually or in any technically possible combination: -The opening component is the opening panel; - The first preform includes a continuous fiber layer to form a skin, and discontinuous fibers are arranged in clusters on one of the continuous fiber layers to form the body of at least one rib; - The first preform includes an additional layer of continuous fibers to form a skin, the additional layer including slots, each slot extending along an associated extension direction of at least one rib, and discontinuous fibers arranged in clusters between the continuous fiber layer and the additional layer of continuous fibers in a manner perpendicular to the slots of the additional layer. - The at least one reinforcing rib or each reinforcing rib extends along at least two different extension directions and intersects at the intersection, and the second preform includes continuous unidirectional fiber strips extending along at least two extension directions and alternately stacked at the intersection; - The second preform includes at least one additional layer of continuous fiber material for each reinforcing head of the reinforcing rib, the additional layer of continuous fiber material being arranged to cover at least one unidirectional fiber strip among unidirectional fiber strips extending in the extension direction associated with the reinforcing rib head, the additional layer having an elongated shape in the extension direction of the associated reinforcing rib head, the continuous fibers of the additional layer extending in a direction different from the extension direction of the associated reinforcing rib head, and the additional layer being shaped to cover at least one longitudinal fiber strip and, after hot pressing, at least partially cover the body associated with the reinforcing rib head of the opening member; - The first segment of the continuous fibers of the additional layer is oriented at an angle between 30° and 60° relative to the extension direction of the associated reinforcing rib head, and the second segment of the continuous fibers of the additional layer is oriented at an angle between -30° and -60° relative to the extension direction of the associated reinforcing rib head. - The additional layer has a width in a direction perpendicular to the extension direction of the associated reinforcing rib head, such that after hot pressing, the additional layer covers the body to an overlap height greater than at least three times the thickness of the additional layer, preferably greater than at least five times the thickness of the additional layer; - The matrix includes a main surface and a cavity, the cavity extending from the main surface and being shaped to form at least one rib forming an opening component, the placement step including: placing a second fiber preform at the bottom of the cavity, and then placing a first fiber preform on the main surface before the hot pressing step; - The matrix includes a main surface and a cavity, the cavity extending from the main surface and being shaped to form at least one rib forming an opening member. The step of providing at least one first fiber preform includes the step of providing a fiber preform, referred to as a skin preform, configured to form a skin, and the step of providing a fiber preform, referred to as a body preform, configured to form a body with at least one rib. The step of placing the preform in the molding apparatus includes: placing a second fiber preform in the cavity, then placing a fiber body preform on the main surface perpendicular to the cavity, and then placing a fiber skin preform on top of the fiber body preform. - Before placing the skin preform, the fiber body preform is compressed to at least partially creep into the cavity to form at least 80%, preferably at least 90%, and even more preferably at least 95% filling of at least one rib; - The first fiber preform and the second fiber preform are pre-impregnated with resin. Attached Figure Description

[0019] The invention will be better understood from the following detailed description, and other features and advantages will become apparent. This detailed description includes embodiments given illustratively and as non-limiting examples with reference to the accompanying drawings, which can serve to complete the understanding of the invention and its embodiments, and, where appropriate, contribute to the definition of the invention, thereby: - Figure 1 This is a schematic cross-sectional view of the first open panel obtained by the manufacturing method according to the present invention; - Figure 2 This is a three-dimensional schematic diagram of a second example of a panel obtained by the method according to the invention; - Figure 3 This is a block diagram illustrating a method for manufacturing a component according to the present invention; - Figure 4 The schematic diagram illustrates the process used in manufacturing prior to the hot pressing step. Figure 1 or Figure 3 A cross-sectional view of the molding apparatus or mold for the component shown; - Figure 5This schematically illustrates the process when the mold closes during hot pressing. Figure 4 A cross-sectional view of the molding apparatus; - Figure 6 A perspective view of a first preform used in the manufacturing method according to the invention is shown schematically; - Figure 7 The illustration shows exactly when the lid is closed. Figure 6 A cross-sectional view of the previous molding device on the substrate of the first preform; - Figure 8 It shows Figure 6 The result of the first fiber preform after hot pressing; - Figure 9 A perspective view of another first preform used in the manufacturing method according to the invention is shown schematically; - Figure 10 The illustration shows exactly when the lid is closed. Figure 9 A cross-sectional view of the previous molding device on the substrate of the first preform; - Figure 11 It shows Figure 9 The result of the first fiber preform after hot pressing; - Figure 12 A perspective view schematically illustrating a second preform used in the manufacturing method according to the invention; and - Figure 13 It shows the result of Figure 12 A partial cross-section of a component manufactured from the second prefabricated part.

[0020] Elements that have the same function in different embodiments have the same reference numerals in the drawings.

[0021] The accompanying drawings are not shown to scale. In particular, the thickness has been increased to make the drawings easier to read. Detailed Implementation

[0022] Figure 1 A schematic cross-sectional view is shown of a first example of an opening component (particularly an opening panel 10) that can be obtained by the method according to the invention. A panel refers to any surface component that can also be non-planar and non-developable.

[0023] Examples of applications include thrust reverser flaps for aircraft nacelles, components of thrust reverser grilles, and reinforced internal or external passageway panels.

[0024] The open panel 10 includes a composite skin 12 and at least one reinforcing rib 14 (also referred to as a reinforcement). The open panel 10 may also include non-reinforcing ribs, i.e., ribs with non-reinforcing heads.

[0025] As mentioned above, "rib" refers to any out-of-plane height of the panel, and "reinforcement" refers to a rib including a reinforcing head, i.e., a reinforcing structure at the top of its body.

[0026] The skin 12 extends along the extension plane XY and defines an outer surface 16 and an inner surface 18 spaced apart in the thickness direction Z perpendicular to the extension plane XY.

[0027] For example, once panel 10 is in place, outer surface 16 is configured to face the passenger compartment and is visible, while inner surface 18 may be invisible, depending on the installation of the components.

[0028] The rib, whether or not it is reinforced, includes a body 20 and a head 22. The body 20 protrudes from the inner surface 18 of the skin along the thickness direction Z to the corresponding head 22 of the reinforcement 14.

[0029] Furthermore, each rib body 20, whether or not it is reinforced, extends along an associated extension direction on the inner surface 18 of the skin 12. For example, the rib bodies 20 all extend in the same direction X and are parallel to each other, as shown in... Figure 1 In the example shown.

[0030] Ribs, whether or not they are reinforced, can be regularly spaced along a transverse direction Y perpendicular to the extension direction X and the thickness direction Z.

[0031] Each rib body, whether or not reinforced, includes two sides 24 extending between the inner surface 18 and the head 22 of the rib, whether or not reinforced, and these two sides 24 are opposite each other in the transverse direction Y.

[0032] For each reinforcement 14, the head 22 of the rib is reinforced relative to the body 20 of the rib, that is, the head 22 has greater rigidity and thus enables the panel 10 to be reinforced.

[0033] The head 22 extends along the body 20 of the reinforcing rib 14.

[0034] Each reinforcing head is a rigid structure extending along the extension direction of the body of the reinforcing rib 14 (i.e., direction X in the example shown), in the form of a rod, made of a rigid material, specifically, the elastic stiffness of which is greater than or equal to the elastic stiffness of the material constituting the body of the rib.

[0035] Figure 2 It shows a ratio Figure 1 The first example is a schematic three-dimensional view of another example of a more complex panel, which can also be obtained using the methods described in this invention.

[0036] In this example, panel 10 includes ribs that project relative to the skin (body and head) and extend in multiple different directions. Specifically, in the example shown, three reinforcing ribs 14A extend along a first extending direction X, two reinforcing ribs 14B extend along a second extending direction Y, and three reinforcing ribs 14C extend along an intermediate extending direction between the first extending direction X and the second extending direction Y.

[0037] All extension directions form an angle between 15° and 165°, which is specifically equal to 90° in the example shown with respect to the first extension direction X and the second extension direction Y.

[0038] The reinforcing ribs 14 intersect at at least one intersection 26. Two reinforcing members 14 form the intersection 26 and are fixed to each other at the intersection of their reinforcing heads.

[0039] Reference Figure 3 A detailed description of a method 100 for manufacturing components (particularly open panels) made of composite materials according to the present invention. Figure 3 This is a flowchart illustrating the steps in the method.

[0040] The method includes step 110: supplying or providing at least one first fiber preform PF1, which is configured to form the body 20 of the skin 12 and the reinforcement 14.

[0041] The first fiber preform PF1 may comprise continuous and / or discontinuous fiber FDCs to form the body of the skin and reinforcement. Short fibers are fibers less than 1 mm in length, as opposed to long fibers with lengths of tens of millimeters. The first fiber preform PF1 may be in the form of layers or stacks of unidirectional fibers, such as “Non-Crimp Fabrics” as abbreviated NFC. Alternatively, the first fiber preform PF1 may be in the form of a fabric or pad referred to as SMC (Sheet Molding Compound). In a known manner, such a pad comprises continuous or discontinuous fibers that are randomly distributed primarily in the extended plane of the pad. Alternatively, the first fiber preform PF1 may be in the form of a bulk material (such as “Bulk Molding Compound” as abbreviated BMC), which comprises fibers with a finished length typically less than 50 mm.

[0042] Preferably, the fibers of the first fiber preform PF1 are pre-impregnated with an impregnating polymer resin (or matrix). In other words, the first preform PF1 is made of a composite material known as a prepreg, i.e., containing fibers embedded in a resin. The impregnating resin particularly includes thermoplastic or thermosetting resins. Examples of thermoplastic resins are polyamides, polyetheretherketones, polyetherketoneketones, polyphenylene sulfides, or polyaryletherketones. Thermosetting resins include, for example, epoxides or polyimides. The fibers are organic, mineral, metallic, thermoplastic polymer, or thermosetting polymer fibers, or mixtures of these fibers. Examples of fibers are carbon fibers, glass fibers, or polyaramid fibers.

[0043] The method includes step 120: providing or supplying at least one second fiber preform PF2, the at least one second fiber preform PF2 being configured to form a head 22 of a reinforcement, i.e., a reinforcing head of a reinforcing rib.

[0044] The second fiber preform PF2 includes at least long fibers FC oriented along the extension direction associated with the reinforcing member 14.

[0045] Oriented long continuous fibers are unidirectional continuous fibers that are approximately tens of millimeters long.

[0046] Preferably, the second fiber preform PF2 is also made of a composite material known as a prepreg, i.e., containing fibers embedded in a resin. Preferably, the resin used for the second fiber preform PF2 is the same as the resin used for the first fiber preform PF1.

[0047] Advantageously, the oriented long fibers of the second fiber preform PF2, which is configured to form the reinforcing head 22 of the reinforcing rib 14, are primarily or solely in the form of multiple unidirectional fiber strips, typically denoted by UD as "unidirectional". Each unidirectional fiber strip comprises an assembly of continuous filaments parallel to each other. Thus, the continuous filaments are arranged longitudinally along the entire length of the head 22 of the reinforcing member 14.

[0048] When the component to be manufactured includes a reinforcing member 14 extending in multiple dissimilar directions and intersecting at intersection 26 (see...) Figure 2 When the second preform PF2 is used, it advantageously includes continuous longitudinal fiber strips that extend in all directions and are alternately stacked at the intersections.

[0049] Figure 12A second preform PF2 is shown, which is configured to form the head 22 of the reinforcement 14, particularly at the intersection 26. In the example shown, reinforcement 14A extends along a first extending direction X, and reinforcement 14B extends along a second extending direction Y. The second preform PF2 includes a first longitudinal fiber strip RA extending along the first extending direction X and a second longitudinal fiber strip RB extending along the second extending direction Y. The first strip RA and the second strip RB intersect alternately at the intersection 26. At the intersection 26, the result is the following stacking: first strip RA, then second strip RB, then first strip RA again, and so on.

[0050] Advantageously, this construction, in which the strips alternate along different directions of extension of the reinforcing member, enables an increase in the mechanical bonding of the fibers in different directions, and thus enhances the mechanical strength of the intersection (also known as the inter-reinforcing member node if desired).

[0051] Advantageously, these strips can be applied using a method for depositing strips into a geometry using mechanized layup.

[0052] Preferably, the width L of the strip in the longitudinal fiber strip bundle of UD is slightly less than or equal to the width of the head of the reinforcement 14 of the part to be manufactured. The width refers to the dimension transverse to the extension direction of the reinforcement and therefore transverse to the extension direction of the strip, which is also the dimension perpendicular to the longitudinal fiber of the strip.

[0053] Advantageously, the second preform PF2, which is configured to form the head of the reinforcement, includes at least one additional layer PF21 of long or continuous fiber material for each reinforcement head.

[0054] The additional layer PF21 is arranged to cover at least one unidirectional UD fiber strip among the unidirectional UD fiber strips extending along the extension direction associated with the head 22 of the reinforcement member, more precisely, to cover the bundle of unidirectional UD fiber strips RA and RB, such as Figure 12 As shown. One or more additional layers PF21 have an elongated shape in the extending direction of the reinforcing head 22 of the associated reinforcing member.

[0055] One or more additional layers of PF21 have continuous fibers that extend in a direction different from the extension direction of the associated reinforcement head, i.e., in a direction that is transverse to or non-collinear with the extension direction of the reinforcement.

[0056] In addition, one or more additional layers PF21 are shaped to cover at least one strip RA, RB of unidirectional UD fibers and, after hot pressing, at least partially cover the body 20 associated with the head of the component's reinforcement.

[0057] The one or more additional layers PF21 improve stress transfer between the longitudinal fibers of the head and the body of the reinforcement.

[0058] Preferably, each additional layer PF21 is arranged vertically on each independent linear segment of the associated reinforcing head. Each additional layer protrudes laterally on either side of the longitudinal strip to form a U-shaped fiber continuity in a plane orthogonal to the extension direction after forming and hot pressing, thereby covering the unidirectional UD fibers of the reinforcing head and a portion of the body of the reinforcing member. In other words, the width L' of each additional layer PF21 is greater than the width L of the strip in the bundle of unidirectional UD fiber strips to be covered. Preferably, the width L' of the additional layer PF21 is sufficient to extend an overlap height H along the side 24 of the reinforcing member, which overlap height H is greater than three times its thickness E, and even more preferably at least five times its thickness E. Thickness E refers to the thickness of the additional layer PF21 before curing.

[0059] Figure 13 A partial cross-sectional view is shown of an embodiment of a component, particularly manufactured from this second preform PF2, wherein the additional layer PF21 of the preform is thicker than the body thickness of the reinforcing member (i.e., the dimension of the body in the transverse direction Y). In an alternative mode, the thickness of the body of the reinforcing member remains constant, and the additional layer PF21 of the preform replaces a portion of the material of the rib body at the overlap height H.

[0060] This second preform PF2 can be manufactured by arranging continuous fiber sheets in a layup form to form one or more additional layers PF21, and then stacking unidirectional UD fiber strips on one or more additional layers PF21.

[0061] Alternatively, this second preform PF2 can be manufactured by first depositing a unidirectional UD fiber strip and then depositing at least one continuous fiber layer on top of the unidirectional UD fiber strip, the at least one continuous fiber layer extending with a small width on either side of the deposition width of the unidirectional UD fiber strip.

[0062] Each additional layer PF21 may be a fabric in which the fibers are preferably oriented between + / -30° and + / -60° relative to the extension direction of the associated reinforcement. In other words, the fabric comprises a first fiber oriented between +30° and +60° relative to the extension direction and a second fiber oriented between -30° and -60° relative to the extension direction, the second fiber being symmetrical with respect to the extension direction of the associated reinforcement with respect to the first fiber. The fabric is formed by two-dimensionally weaving the first fiber, into which the second fiber is woven.

[0063] Alternatively, each additional layer PF21 may be a stack of at least two unidirectional fiber layers, the unidirectional fibers extending in a direction symmetrical with respect to the extension direction of the associated reinforcement and extending at an angle between + / -30° and 90° with respect to the extension direction of the associated reinforcement.

[0064] Then, the method includes step 130: forming an assembly (such as a first fiber preform PF1 and a second fiber preform PF2) from the first fiber preform PF1 and the second fiber preform PF2. Figure 4 (As shown) is placed in the molding device 30.

[0065] Figure 4 The schematic diagram illustrates the process used in manufacturing prior to the hot pressing step. Figure 1 or Figure 2 A cross-sectional view of the molding apparatus or mold 30 for the component shown.

[0066] The device 30 includes a base 32 and a cover or punch 34, which is mounted to slide vertically in the Z direction within the base and together with the base defines a compression chamber 36.

[0067] The base 32 has a main surface 38 facing the cover 34. This main surface 38 has irregularities and, more specifically, extends from the main surface 38 and is shaped into cavities 40 forming reinforcements for the open panel. The shape and arrangement of the cavities 40 correspond to the shape and arrangement of the reinforcements 14 on the component to be manufactured. Thus, each cavity 40 extends from the main surface 38 to the bottom 42.

[0068] The second fiber preform PF2 is arranged between the matrix 32 and the first fiber preform PF1.

[0069] In the first embodiment, the first fiber preform PF1 and the second fiber preform PF2 are assembled to form an assembly by stacking one on top of the other, and the assembly is then mounted in a molding apparatus such that the continuous fibers of the second preform, configured to form the head of the reinforcement, are positioned perpendicular to the cavity. The molding apparatus 30 is then closed.

[0070] Of course, if the preform PF2 includes a complementary layer PF21, these complementary layers are stacked as the outer layer of the assembly so that they first contact the surface 38 of the molding device.

[0071] According to the first variant, the second fiber preform PF2, configured to form the head of the reinforcement, is first individually positioned in the molding apparatus 30 such that each strip or bundle of strips associated with the head of the reinforcement is engaged in a corresponding cavity 40 of the matrix 32 of the molding apparatus 30. Then, prior to the hot pressing step, the first fiber preform PF1 is placed on top of the second preform, specifically on the main surface 38 of the matrix 32.

[0072] Advantageously, the molding device 30 may include another punch shaped to partially press each strip or bundle of strips associated with the head of the reinforcement into the corresponding cavity 40 or into the bottom 42 of the corresponding cavity. This step of pressing the second preform PF2 into the cavity is even more advantageous because, as described above, the second preform PF2 includes at least one additional layer PF21 to facilitate control over the pressing of the second preform PF2 centered on each cavity and the juxtaposition of the additional layer PF21 along the side 24 of the associated reinforcement.

[0073] According to the second variation, step 130 for placing in the molding apparatus 30 includes: - Place the second fiber preform PF2 such that each strip or bundle of strips associated with the head of the reinforcing member is at least partially engaged in the corresponding cavity 40 toward the bottom 42 of the corresponding cavity 40, and then, - The fiber-bonded preform PF12 is placed on the main surface 38 perpendicular to the cavity. Preferably, the fiber-bonded preform PF12 is compressed to creep at least partially into the cavity 40. This creep can achieve at least 80% filling of the reinforcement, preferably at least 90%, and even more preferably at least 95%.

[0074] The placement step 130 continues by placing the fiber skin preform PF11 on top of the fiber body preform PF12, followed by a step of closing the molding device for hot pressing the final assembly to form the final part.

[0075] The method then proceeds to step 140: hot-pressing the component to form an open panel, such as... Figure 5 As shown.

[0076] Figure 5 This schematically illustrates the process when the mold closes during hot pressing. Figure 4 Cross-sectional view of the molding device 30.

[0077] This hot-pressing step ensures that the second fiber preform PF2 is positioned at the head of the reinforcement 14. Hot pressing also allows material to creep at least partially from the first fiber preform PF1 to form the body 20 of the reinforcement 14, ensuring that the first fiber preform fully fills the tool cavity. Therefore, hot pressing enables the two preforms PF1 and PF2 to be bonded together through co-consolidation. In the case of thermosetting resins, the fiber preforms are cured by chemical crosslinking or polymerization; in the case of thermoplastic matrices, the fiber preforms are cured by heating and cooling.

[0078] Therefore, the reinforcing head 22 of the reinforcing member 14 is fixed to the corresponding body 20 of the reinforcing member, and is more precisely bonded to the corresponding body by the polymer matrix of the composite material forming the head.

[0079] The method may also include step 150 of demolding the manufactured part, followed by step 160 of finishing the part to obtain the final part.

[0080] According to the first variant, the method according to the invention differs from the aforementioned method in that, during step 110 of supplying or providing at least one first fiber preform PF1, the first fiber preform PF1 comprises continuous fibers FC forming a skin and discontinuous fibers FDC forming a body of a reinforcement.

[0081] For example, the continuous fiber FC that is constructed to form the skin of a component is a layup of unidirectional UD fibers or a multi-axial, multi-layered fabric or pad - or a bulk material BMC as described and defined above.

[0082] Discontinuous fibers can be uniformly distributed on the continuous fiber layer. Advantageously, the discontinuous fibers can be arranged in clusters or piles on the skin, near the base of the reinforcement, thereby reducing the creep length of the material of the first preform PF1 to fill the cavity and form the body of the reinforcement.

[0083] This step is in Figures 6 to 8 As shown in the image. Figure 6 A perspective view of the first preform PF1 is shown schematically. The first fiber preform PF1 includes a fiber preform PF11, which is configured to form the skin 12 and is referred to as the "skin preform", and a fiber preform PF12, which is configured to form the body of the reinforcement 14 and is referred to as the "body preform".

[0084] The skin preform PF11 comprises multiple layers of continuous fibers, which are three layups in the example shown.

[0085] The main preform PF12 is formed from discontinuous fiber clusters arranged in a cluster on the skin 12 near the base of the reinforcement 14. In the example shown, the clusters are triangular in shape to form reinforcements of the same shape.

[0086] Advantageously, step 110 may include a hot-pressing step to form a first fiber preform PF1 from the skin preform PF11 and the body preform PF12, so as to bind the first preform PF1 and the second preform PF2 together and ensure their bonding before step 130, in which the assembly formed by the first preform PF1 and the second preform PF2 is placed in the molding apparatus 30. The same molding apparatus 30 may be used for both hot-pressing steps.

[0087] Figure 7 A schematic cross-section of the molded device is shown just before the lid 34 closes onto the base 32, while Figure 8 The result of this hot pressing is shown, namely, the first fiber preform PF1.

[0088] Preferably, the skin preform PF11 includes an additional layer of continuous fibers PF111. Figure 9 A perspective view of this first prefabricated member PF1 is schematically shown. The additional layer PF111 includes slots 50 for each reinforcement 14, each slot 50 extending along an associated extension direction of the reinforcement 14. In the example shown, the slots 50 are triangular in shape to form reinforcements of the same shape.

[0089] like Figure 10 and Figure 11 As shown, the discontinuous fibers of the main preform PF12 are arranged in clusters between the layers of the skin preform and the additional layer of the skin preform in a manner perpendicular to the slot 50 of the additional layer PF111. Figure 10 A schematic cross-sectional view of the first preform PF1, configured to be inserted into a molding apparatus, is shown. Figure 11 The result of hot pressing is shown, namely, the first fiber preform PF1, in which the body 20 of the reinforcing member 14 is formed at least partially.

[0090] Advantageously, the presence of an additional layer PF111 of continuous fibers with slots 50 perpendicular to the discontinuous fiber clusters enables the movement of the discontinuous fiber elements and ensures the continuity of the fiber layer on the surface of the component at the base of the reinforcement 14.

[0091] Advantageously, the invention as described makes it easier and more robust to manufacture such ribbed components, particularly structurally optimized ribbed panels, by hot pressing.

[0092] Of course, the present invention is not limited to the embodiments described above, which are provided merely as examples. The present invention encompasses various modifications, alternatives, and other variations that can be conceived by those skilled in the art within the framework of the present invention, particularly all combinations of the various embodiments described above, which may be employed individually or in combination.

[0093] Specifically, as described, the present invention implements a composite material referred to as a prepreg, i.e., comprising fibers embedded in resin to form a fiber preform assembly. However, the method can also be applied to so-called "dry" fiber preforms, i.e., fiber preforms comprising fibers held together by an adhesive. In this case, resin is applied to the preform, for example by a resin film arranged between the cover and the first fiber preform, before the molding apparatus is closed, and the preform is impregnated during hot pressing. Alternatively, resin can be injected into the compression chamber of the molding apparatus after the molding apparatus is closed.

Claims

1. A method (100) for manufacturing an opening component (10) made of a composite material, the opening component comprising a skin (12) and at least one rib, each rib comprising a body (20) and a head, the body extending from an inner surface (18) of the skin to the head, each rib extending in an associated extension direction, the component comprising at least one rib referred to as a reinforcing rib (14) having a reinforcing head (22), characterized in that, The method includes the following steps: - The step (110) of providing at least one first fiber preform (PF1), said at least one first fiber preform being configured to form the body of the skin and said at least one rib; - The step (120) of providing at least one second fiber preform (PF2), said at least one second fiber preform being configured to form a reinforcing head (22) of at least one reinforcing rib (14). - Step (130) of placing the assembly formed by the first fiber preform and the second fiber preform in a molding apparatus (30) including a punch (34) and a matrix (32), wherein the second fiber preform is disposed between the matrix and the first fiber preform, and the matrix is ​​shaped to form at least one rib of the opening member; and - Step (140) of hot pressing the component to form the opening part. - The step of demolding the component to form the opening part; Furthermore, the first fiber preform includes at least discontinuous fibers (PF12) to at least form the body of the rib, and the second fiber preform includes at least continuous fibers oriented along an extension direction associated with the at least one rib.

2. The method according to claim 1, wherein, The first preform (PF1) includes a continuous fiber layer (PF11) to form the skin, and the discontinuous fibers (PF12) are arranged in clusters on one of the continuous fiber layers to form the body of the at least one rib.

3. The method according to claim 2, wherein, The first preform (PF1) includes an additional layer (PF111) of continuous fibers to form the skin, the additional layer including slots (50), each slot extending along an associated extension direction of the at least one rib, the discontinuous fibers being arranged in clusters between the continuous fiber layer and the additional layer of continuous fibers in a manner perpendicular to the slots of the additional layer.

4. The method according to any one of the preceding claims, wherein, The at least one reinforcing rib (14) or each reinforcing rib extends along at least two different extension directions (X, Y) and intersects at an intersection (26), wherein the second preform (PF2) comprises continuous unidirectional fiber strips (RA, RB) extending along at least two extension directions and alternately stacked at the intersection.

5. The method according to claim 4, wherein, The second preform (PF2) includes at least one additional layer (PF21) of continuous fiber material for each reinforcing head of the reinforcing rib, the additional layer of continuous fiber material being arranged to cover at least one unidirectional fiber strip among unidirectional fiber strips extending in the extension direction associated with the reinforcing rib head, the additional layer having an elongated shape in the extension direction of the associated reinforcing rib head, the continuous fibers of the additional layer extending in a direction different from the extension direction of the associated reinforcing rib head, and the additional layer being shaped to cover at least one longitudinal fiber strip and, after hot pressing, at least partially cover the body associated with the reinforcing rib head of the opening member.

6. The method according to claim 5, wherein, The first segment of the continuous fibers of the additional layer (PF21) is oriented at an angle between 30° and 60° relative to the extension direction of the associated reinforcing rib head, and the second segment of the continuous fibers of the additional layer is oriented at an angle between -30° and -60° relative to the extension direction of the associated reinforcing rib head.

7. The method according to claim 5 or 6, wherein, The additional layer (PF21) has a width in a direction perpendicular to the extension direction of the associated reinforcing rib head, such that after hot pressing, the additional layer covers the body to an overlap height greater than at least three times the thickness of the additional layer, preferably greater than at least five times the thickness of the additional layer.

8. The method according to any one of the preceding claims, wherein, The substrate (32) includes a main surface (38) and a cavity (40) extending from the main surface and being shaped to form at least one rib of the opening member, wherein the placement step includes: placing the second fiber preform (PF2) at the bottom of the cavity, and then placing the first fiber preform (PF1) on the main surface prior to the hot pressing step.

9. The method according to any one of claims 1 to 7, wherein, The substrate (32) includes a main surface (38) and a cavity (40) extending from the main surface and being shaped to form at least one rib of the opening member. The step of providing at least one first fiber preform includes the step of providing a fiber preform, referred to as a skin preform, configured to form the skin, and the step of providing a fiber preform, referred to as a body preform, configured to form the body of the at least one rib. And the step of placing it in the molding device (30) includes: - Place the second fiber preform (PF2) into the cavity (40), and then, - Place the fiber body preform (PF12) on the main surface (38) perpendicular to the cavity, and then, - Place the fiber skin preform (PF11) on top of the fiber body preform (PF12).

10. The method according to the preceding claim, wherein, Before placing the skin preform (PF11), the fiber body preform (PF12) is compressed to creep into the cavity (40) at least partially to form at least 80%, preferably at least 90%, and even more preferably at least 95% of the filling of the at least one rib.

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