Composite laminate, fuselage lifting surface comprising same and method of manufacturing same
By using a composite laminate with an interlaced layer design in the lifting surface of the composite fuselage, the sawtooth effect caused by high-deposition prepreg material was solved, achieving efficient and low-cost composite material manufacturing and ensuring high-quality bonding with other components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AIRBUS OPERATIONS SL
- Filing Date
- 2021-06-29
- Publication Date
- 2026-07-14
AI Technical Summary
In the manufacturing of composite fuselage lifting surfaces, existing technologies use highly deposited prepreg materials, which cause a sawtooth effect in the inclined areas, affecting surface quality and manufacturing efficiency, and leading to problems in the co-curing, co-bonding, and fastening processes.
A composite laminate design is adopted, comprising staggered layers arranged along the slope direction. The composite laminate formed by laying high-deposition prepreg material avoids the sawtooth effect in the slope area, ensures surface quality, and is co-cured, co-bonded or fastened to other components.
It achieves a high-quality beveled surface, reduces manufacturing costs and delivery time, improves production efficiency, and ensures the quality of engagement with other components.
Smart Images
Figure CN114104253B_ABST
Abstract
Description
Technical Field
[0001] This invention pertains to the field of composite laminates used in aerospace structures, and more specifically to those composite laminates including inclined surfaces. In particular, this invention provides a composite laminate with inclined surfaces having a fuselage lifting surface, a fuselage lifting surface including the composite laminate, and a method for manufacturing the composite laminate.
[0002] Therefore, the object of the present invention is to provide a laminate for improving the lifting surface of an aircraft fuselage, which is also suitable for being made of high deposition prepreg (HD impregnation) material and performs better than prior art laminates when used as an interface with other aircraft parts or components. Background Technology
[0003] like Figure 1 As shown, the composite fuselage lifting surface (1) is typically composed of a skin, which is in the form of a composite laminate (2) reinforced by a truss (8). This composite fuselage lifting surface (1) can be composed of a torsion box, a horizontal tail plane, a vertical tail plane, a rudder, an elevator, an aileron, a spoiler, or a flap.
[0004] Typically, these composite fuselage lifting surfaces are manufactured using standard prepreg materials via Automated Fiber Placement (AFP) or Automated Tape Placement (ATL) techniques. Both ATL and AFP processes are functionally similar, applying resin-impregnated fiber material (the so-called "prepreg"), although each is used differently to achieve specific structural goals, providing strength or stiffness when needed. The choice of one process over the other depends primarily on the geometric complexity of the part to be manufactured, with AFP allowing for higher curvature. However, in both methods, although the process is automated, the placement process still requires significant labor time. Therefore, in high-productivity scenarios, substantial investments in machinery and workshops are required to compensate for the significant delivery time involved in the placement process.
[0005] In the aerospace industry, high-deposition prepreg forms are known to significantly reduce the layup time required to obtain these composite structures. These high-deposition prepregs are pre-impregnated composite fiber materials in which a thermosetting polymer matrix or thermoplastic resin is already present. The technical design of these material forms allows for rapid layup of prepreg tapes (tows) because these tapes are provided in a wider (>1.5 inches wide - 3.81 cm) form than conventional standard prepreg forms; and in some cases, these tapes are thicker than conventional standard prepreg forms. However, due to irregularities and quality losses that occur after the composite laminate of the lifting surface cures, the use of high-deposition prepreg technology for the manufacture of current composite fuselage lifting surfaces is not currently considered.
[0006] Furthermore, due to the so-called sawtooth effect, the current design of most composite fuselage lifting surfaces, including the sloped sections, incorporates some irregularities in the sloped areas. A sawtooth effect occurs in the sloped regions when the ends of the strips corresponding to each layer of the laminated slope are not aligned or are not perpendicular to the slope direction, leaving triangular "sawtooth" patterns. See also Figure 2 The direction of the inclined plane should be understood as the direction in which the thickness of the layered pressing part decreases along the lifting surface.
[0007] Compared to the theoretical lifting surface, this serrated effect of the ramp will introduce deviations into the resulting composite fuselage lifting surface. When the fuselage lifting surface is manufactured using current material forms, the serrated effect is small. However, when the composite fuselage lifting surface is manufactured using a high-deposition prepreg form, the serrated effect worsens (in terms of both the depth and size of the serrations) because the width (and sometimes the thickness) of the strip conforming to this high-deposition prepreg form increases.
[0008] Therefore, frequently obtained low-quality surfaces may affect component design, thus failing to provide controlled surfaces for other parts or component interfaces. Figure 3 Examples of these irregular surfaces are shown, where section AA forms a peak and section BB forms a valley.
[0009] These interfaces between components or parts can be co-cured, co-bonded, or fastened. Irregular surfaces at the interfaces can cause compaction problems (porosity and wrinkles) during co-curing; irregular adhesive thickness distribution (bonding problems) during co-bonding; and fill irregular gaps in fastened interfaces, resulting in long delivery times and increased labor costs. Summary of the Invention
[0010] This invention provides a solution to the aforementioned problems through a composite laminate for fuselage lifting surfaces and a method for manufacturing such a composite laminate, which produces a composite material with a slope unaffected by the serrated effect. Therefore, the laminate of this invention can be made from a high-deposition prepreg material without compromising the surface quality of the slope.
[0011] In a first aspect, the present invention provides a composite laminate for a fuselage lifting surface, the composite laminate being made of a prepreg material and including at least two sides and a sloped region defined by a reduced number of staggered laminates extending along a slope direction. The composite laminate comprises a combination of the following:
[0012] -A first layer formed by strips arranged parallel to the direction of the inclined plane.
[0013] -A second layer formed by strips arranged orthogonally to the inclined plane.
[0014] - A third layer formed by strips arranged in a first laying direction, the first laying direction being different from the inclined plane direction and directions orthogonal to the inclined plane direction, and
[0015] - A fourth layer formed by a strip arranged in a second laying direction, the second laying direction being different from the slope direction, the direction orthogonal to the slope direction, and the first laying direction; and wherein, in the slope region, the strip forming the third layer and / or the fourth layer extends from one laminate side to another laminate side.
[0016] A composite laminate should be understood as a set of stacked sheets manufactured from a composite material, wherein each sheet is formed by strips laid along the same layup direction. In this invention, these strips forming the sheets are preferably high-deposition prepreg material. Preferably, the laying of these materials is performed by AFP (Advanced Photopolymerization).
[0017] In this document, a sheet (layer) should be understood as a single continuous region of a composite material formed by multiple strips laid (arranged) in the same direction. The continuous laying of sheets forms a stack or a set of stacked sheets that will eventually conform to the laminate.
[0018] The composite laminate of the present invention includes at least one beveled region at one of its ends, the end corresponding to a reduced number of staggered laminates along the bevel direction. The bevel direction D will be understood as the direction extending along the reduced number of staggered laminates, i.e., the direction defined from the free beveled portion of the laminate to the end of the beveled region of the laminate.
[0019] According to the present invention, the composite laminate has a different layout configuration in the sloped region relative to the rest of the laminate (non-sloped region or free sloped region).
[0020] The specific layout of the sloped region is determined by the strips of the third and / or fourth layers: in particular, the strips forming the third and / or fourth layers extend from one side of the laminate to another side of the laminate. Preferably, this other side of the laminate is the opposite side of the laminate.
[0021] Unlike conventional designs for composite fuselage lift surface laminates, this invention provides a novel laminate design without serrated edges in the sloped regions. Therefore, the laminate of this invention is compatible with high-deposition prepreg materials, thereby increasing the quality of the skin slopes. Consequently, this invention provides a superior surface that facilitates bonding between this composite laminate and other components through co-curing, co-bonding, or fastening. Furthermore, the laminate design ensures that the bolt interface areas with other components meet the required tolerances.
[0022] Furthermore, composite laminates manufactured using high-deposition prepreg materials reduce costs and delivery times because they can generate high productivity.
[0023] In a particular embodiment, each sheet has a strip width greater than 3.81 cm, thus conforming to sheet presses with high deposition prepreg material.
[0024] In a second aspect of the invention, the present invention provides a fuselage lifting surface including the above-described composite laminate, and comprising at least one of the following: a torsion box, a horizontal tail plane, a vertical tail plane, a rudder, an elevator, an aileron, a spoiler, or a flap.
[0025] In a third aspect of the invention, the present invention provides a method for manufacturing the aforementioned composite laminate for fuselage lifting surfaces, the method comprising the following steps:
[0026] a) Laying prepreg material to form a set of stacked sheets, said set of stacked sheets including at least one sloping region defined by a decreasing number of staggered sheets extending along a sloping direction.
[0027] b) Curing the stacked sheets obtained in step a)
[0028] c) Obtain a composite laminate for the fuselage lifting surface in the form of a cured composite laminate;
[0029] Step a) includes laying at least:
[0030] -A first layer formed by strips arranged parallel to the direction of the inclined plane.
[0031] -A second layer formed by strips arranged orthogonally to the inclined plane.
[0032] - A third layer formed by strips arranged in a first laying direction, the first laying direction being different from the inclined plane direction and the direction orthogonal to the inclined plane direction, and
[0033] - A fourth layer formed by strips arranged in a second laying direction, the second laying direction being different from the inclined plane direction, the direction orthogonal to the inclined plane direction, and the first laying direction;
[0034] - Furthermore, in the sloped region, strips forming the third and / or fourth layers are laid from one laminate side to another. Attached Figure Description
[0035] Referring to the accompanying drawings and in view of the detailed description of the invention, these and other features and advantages of the invention will become apparent from the preferred embodiments of the invention, which are given by way of example only and are not limited thereto.
[0036] Figure 1 This image shows a three-dimensional view of the fuselage's lifting surface.
[0037] Figure 2 This figure illustrates the sawtooth effect in existing laminates.
[0038] Figure 3 This figure shows the irregular surface of a prior art laminate.
[0039] Figure 4 This figure shows a schematic representation of a first embodiment of a composite laminate according to the present invention.
[0040] Figure 4A This image is... Figure 4 Detailed view.
[0041] Figure 5 This figure shows a schematic representation of a second embodiment of the composite laminate according to the present invention.
[0042] Figure 5A This image is... Figure 5 Detailed view.
[0043] Figure 6 This figure illustrates an aircraft comprising a composite laminate according to an embodiment of the present invention. Detailed Implementation
[0044] This invention provides an improved design for a composite laminate with beveled surfaces, intended for use as a lifting surface on an aircraft fuselage. This improvement allows the laminate to be manufactured using prepreg material without compromising the quality of the beveled surface.
[0045] Figure 1 A perspective view of a fuselage lifting surface (1) is shown, which includes a composite laminate (2) consisting of a set of stacked prepreg sheets. The composite laminate (2) includes a sloping region (2a) with reduced staggered laminates. This sloping region (2a) extends parallel to a sloping direction D corresponding to the direction of the reduced staggered laminates.
[0046] This composite laminate (2) has an elongated configuration, including a sloping region (2a) between the two longest opposite sides (2b, 2c) of the composite laminate.
[0047] This composite laminate (2) is made of Figure 4 and Figure 5 Any combination of the layers shown constitutes the structure.
[0048] Figure 1The fuselage lifting surface (1) shown further includes a plurality of reinforcing elements (8) positioned along the upper surface of the laminate (2) and bonded to the surface of this composite laminate. Specifically, the reinforcing elements (8) are trusses. In a particular example, the reinforcing elements (8) are co-cured with a new set of stacked layers of the composite laminate (2). In another example, the reinforcing elements (8) are co-bonded with the cured composite laminate (2).
[0049] Figure 4 and Figure 5 Two embodiments of the composite laminate (2) of the present invention are shown.
[0050] According to the present invention, the laminate (2) comprises a combination of the following layers:
[0051] -The first layer (21) is formed by strips (4) arranged parallel to the inclined plane direction (D).
[0052] -A second layer (22) formed by strips (4) arranged orthogonally to the inclined plane direction (D),
[0053] -A third layer (23) formed by strips (4) arranged in a first laying direction (O1), wherein the first laying direction (O1) differs from the slope direction (D) and the direction orthogonal to the slope direction (D), and
[0054] - A fourth layer (24) formed by strips (4) arranged in a second laying direction (O2), which is different from the slope direction (D), the direction orthogonal to the slope direction (D), and the first laying direction (O1).
[0055] Moreover, in the inclined region (2a),
[0056] - A strip (4) forming a third layer (23) and / or a fourth layer (24) extends from one laminate side (2b) to the opposite laminate side (2c).
[0057] according to Figure 4 and Figure 5 In the embodiments, Figure 4A and Figure 5A The combination of the above-mentioned layers is shown in detail in the figure.
[0058] Figure 4 A first embodiment of a composite laminate (2) with a specific layout configuration in a sloped region (2a) is shown, in which a strip (4) forming a third layer (23) and a fourth layer (24) extends from one laminate side (2b) to the opposite laminate side (2c), spanning the two laminate sides (2b, 2c).
[0059] Figure 5 A second embodiment of a composite laminate (2) with another specific layout configuration in the sloped region (3) is shown, in which the outermost shortest side (4a') of the strip forming the third layer (23) extends to the outermost longest side (4b') of the strip forming the fourth layer (24), and the outermost shortest side (4a') of the strip forming the fourth layer (24) extends to the outermost longest side (4b') of the strip forming the third layer (23).
[0060] like Figure 4 and Figure 5 As can be seen in the illustrated embodiments, the composite laminate (2) of the present invention avoids the jagged effect in the beveled region by moving the beveled region (2a) to the side of the laminate (2b, 2c). Thus, the present invention provides a flat surface in the aforementioned beveled region (2a), which is suitable as an interface with other components or parts to be co-cured, co-bonded, or fastened together. Specifically, this surface flatness avoids porosity and wrinkles during co-curing; adhesion problems during co-bonding; and irregular gaps during fastening.
[0061] When considering the first layer (21) and the second layer (22), both configurations can present some variations (embodiments). According to a preferred embodiment, the sloped region (2a) is composed of a third layer (23) and a fourth layer (24). That is, there is no first layer (21) and a second layer (22) in the sloped region (2a) because these layers are only laid to the beginning of the sloped region (2a). According to another preferred embodiment, the sloped region (2a) includes a first layer (21) and / or a second layer (22) that extend to the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) forming the sloped region (2a). According to another preferred embodiment, the slope region (2a) includes a first layer (21) and / or a second layer (22) that extend beyond the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) forming the slope region (2a).
[0062] exist Figure 4 and Figure 5In the specific embodiment shown, a strip (4) of the first layer (21) is laid in a direction at 0° relative to the maximum dimension direction of the laminate (2), which coincides with the inclined plane direction D; a second layer (22) is laid in a direction at ±90° relative to the maximum dimension direction of the laminate (2); a strip (4) of the third layer (23) is laid in a first laying direction (O1) at +45° relative to the maximum dimension direction of the laminate (2); and a strip (4) of the fourth layer (24) is laid in a second laying direction (O2) at -45° relative to the maximum dimension direction of the laminate (2).
[0063] In another preferred embodiment, the first layer (21) and the second layer (22) are stacked to form a stack with overlapping edges in the sloped region (2a). Preferably, the edges of the stacked layers coincide with the sides of the laminates (2b, 2c).
[0064] In a particular embodiment, each sheet has a strip width greater than 3.81 cm, thus constituting a high-deposition prepreg laminate.
[0065] The present invention further provides a method for manufacturing a composite laminate (2) for a fuselage lifting surface (1), the method comprising the following steps:
[0066] a) Laying prepreg material to form a set of stacked sheets, the set of stacked sheets including at least one sloping region (2a) defined by reduced staggered sheets extending along the sloping direction (D),
[0067] b) Curing the stacked layers obtained in step a).
[0068] c) Obtain a composite laminate (2) in the form of a cured composite laminate (2) for the fuselage lifting surface (1);
[0069] Step a) includes laying at least:
[0070] -The first layer (21) is formed by strips (4) arranged parallel to the inclined plane direction (D).
[0071] -A second layer (22) formed by strips (4) arranged orthogonally to the inclined plane direction (D),
[0072] -A third layer (23) formed by strips (4) arranged in a first laying direction (O1), wherein the first laying direction (O1) differs from the slope direction (D) and the direction orthogonal to the slope direction (D), and
[0073] - A fourth layer (24) formed by strips (4) arranged in the second laying direction (O2), which is different from the slope direction (D), the direction orthogonal to the slope direction (D), and the first laying direction (O1);
[0074] Furthermore, in the sloped region (2a), a strip (4) forming a third layer (23) and / or a fourth layer (24) is laid from one laminate side (2b) to another laminate side (2c).
[0075] According to a preferred embodiment, the laying in step a) is performed according to one of the following:
[0076] - Lay the first layer (21) and the second layer (22) up to the slope area (2a),
[0077] - Lay the first layer (21) and / or the second layer (22) until the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) unfolded on the slope region (2a),
[0078] - Lay the first layer (21) and / or the second layer (22) beyond the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) unfolded on the slope region (2a).
[0079] According to another preferred embodiment, step a) includes laying a strip (4) forming a third layer (23) and a fourth layer (24) across the two laminate sides (2b, 2c) from one laminate side (2b) to the opposite laminate side (2c) in the sloped region (2a). This preferred embodiment produces Figure 4 and Figure 4A The composite laminate shown.
[0080] According to another preferred embodiment, step a) includes, in the inclined region (2a):
[0081] - Lay out the shortest outermost side of the strip (4a') forming the third layer (23) until the longest outermost side of the strip (4b') forming the fourth layer (24), and
[0082] - Lay the outermost shortest side of the strip (4a”) that forms the fourth layer (24) until the outermost longest side of the strip (4b”) that forms the third layer (23).
[0083] This preferred embodiment produces Figure 5 and Figure 5A The composite laminate shown.
[0084] In obtaining Figure 4 and Figure 5In the specific example of the laminate shown, the laying will follow this order:
[0085] - The third layer (23) is formed by strips (4) arranged in the first laying direction (O1) at +45°.
[0086] - The fourth layer (24) is formed by strips (4) arranged in a second laying direction (O2) at -45°.
[0087] - The third layer (23) is formed by strips (4) arranged in the first laying direction (O1) at +45°.
[0088] - The fourth layer (24) is formed by strips (4) arranged in a second laying direction (O2) at -45°.
[0089] - The second layer (22) is formed by strips (4) arranged in a third laying direction at ±90° relative to the slope direction (D), and
[0090] - The two first layers (21) are formed by strips (4) arranged parallel to the slope direction (D).
[0091] The present invention further provides a method for manufacturing a fuselage lifting surface (1), the method comprising the following steps:
[0092] i. Providing at least one composite laminate (2) obtained in at least one step of the previously defined method,
[0093] ii. Provide reinforcing elements (8),
[0094] iii. Join the reinforcing element (8) to the composite laminate (2),
[0095] iv. Obtain the fuselage lifting surface (1).
[0096] In a specific example, the cured composite laminate (2) obtained in step c) of the previously defined method for manufacturing the composite laminate (2) is bonded to at least one reinforcing element (8) by a co-bonding process, wherein the reinforcing element (8) is bonded to the composite laminate (2) by adhesive lines. This is carried out in step iii) of the method for manufacturing the fuselage lifting surface (1).
[0097] In another specific example, a set of stacked sheets in the form of a fresh composite laminate (so-called "preform") obtained in step a) of the previously defined method for manufacturing composite laminates (2) are bonded to at least one reinforcing element (8), and the two parts are cured together in the same curing cycle by a co-curing process.
[0098] at last, Figure 6An aircraft (9) is shown, comprising multiple fuselage lifting surfaces (1), such as wing anti-torsion boxes (10), horizontal tail planes (11), vertical tail planes (12), and rudders (7). These fuselage lifting surfaces (1) are manufactured from composite laminates (2) according to the invention.
Claims
1. A composite laminate (2) for a fuselage lifting surface (1), said composite laminate (2) being made of prepreg material and comprising at least two sides (2b, 2b) and a sloped region (2a) defined by reduced staggered laminates extending along a slope direction (D), in, The composite laminate (2) comprises a combination of the following: -A first layer (21) formed by strips (4) arranged parallel to the inclined plane direction (D), -A second layer (22) formed by strips (4) arranged orthogonally to the inclined plane direction (D), -A third layer (23) formed by strips (4) arranged in a first laying direction (O1), wherein the first laying direction (O1) is different from the inclined plane direction (D) and the direction orthogonal to the inclined plane direction (D), and - A fourth layer (24) formed by a strip (4) arranged in a second laying direction (O2), which is different from the inclined plane direction (D), the direction orthogonal to the inclined plane direction (D), and the first laying direction (O1); Furthermore, in the inclined region (2a), the strip (4) forming the third layer (23) and / or the fourth layer (24) extends from one laminate side (2b) to another laminate side (2c).
2. The composite laminate (2) for the fuselage lifting surface (1) according to claim 1, wherein, The inclined region (2a) is composed of a third layer (23) and a fourth layer (24).
3. The composite laminate (2) for the fuselage lifting surface (1) according to claim 1, wherein, The sloped region (2a) includes a first layer (21) and / or a second layer (22), the first layer and / or the second layer extending to the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) forming the sloped region (2a).
4. The composite laminate (2) for the fuselage lifting surface (1) according to claim 1, wherein, The sloped region (2a) includes a first layer (21) and / or a second layer (22), the first layer and / or the second layer extending beyond the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) forming the sloped region (2a).
5. The composite laminate (2) for the fuselage lifting surface (1) according to claim 1, wherein, The first layer (21) and the second layer (22) are stacked to form a stack of overlapping edges in the slope region (2a).
6. The composite laminate (2) for the fuselage lifting surface (1) according to claim 5, wherein, The edges of the stacked sheets coincide with the sides of the laminate (2b, 2c).
7. The composite laminate (2) for the fuselage lifting surface (1) according to any one of claims 1 to 6, wherein, In the sloped region (2a), the strip (4) forming the third layer (23) and the fourth layer (24) extends from one laminate side (2b) to the opposite laminate side (2c), spanning the two laminate sides (2b, 2c).
8. The composite laminate (2) for the fuselage lifting surface (1) according to any one of claims 1 to 6, wherein, In the inclined region (2a), - Extend the outermost shortest side of the strip (4a') forming the third layer (23) to the outermost longest side of the strip (4b') forming the fourth layer (24), and - Extend the shortest outermost side of the strip (4a”) forming the fourth layer (24) to the longest outermost side of the strip (4b”) forming the third layer (23).
9. The composite laminate (2) for the fuselage lifting surface (1) according to any one of claims 1 to 6, wherein, The first laying direction (O1) is orthogonal to the second laying direction (O2).
10. The composite laminate (2) for the fuselage lifting surface (1) according to claim 9, wherein, The first laying direction (O1) is at +45° relative to the maximum direction of the laminate (2), and the second laying direction (O2) is at -45°.
11. The composite laminate (2) for the fuselage lifting surface (1) according to any one of claims 1 to 6, wherein, The direction of the inclined plane (D) is substantially parallel to the direction defined by the maximum dimension of the laminate (2).
12. A fuselage lifting surface (1) comprising a composite laminate (2) according to any one of claims 1 to 11, and consisting of at least one of the following: a torsion box, a horizontal tail plane, a vertical tail plane, a rudder, an elevator, an aileron, a spoiler, or a flap.
13. A method for manufacturing a composite laminate (2) for a fuselage lifting surface (1) according to any one of claims 1 to 11, the method comprising the following steps: a) Laying prepreg material to form a set of stacked sheets, the set of stacked sheets including at least one sloping region (2a) defined by reduced staggered sheets extending along the sloping direction (D), b) Curing the stacked sheets obtained in step a) c) Obtain a composite laminate (2) in the form of a cured composite laminate (2) for the fuselage lifting surface (1); Step a) includes laying at least: -A first layer (21) formed by strips (4) arranged parallel to the inclined plane direction (D), -A second layer (22) formed by strips (4) arranged orthogonally to the inclined plane direction (D), -A third layer (23) formed by strips (4) arranged in a first laying direction (O1), wherein the first laying direction (O1) is different from the inclined plane direction (D) and the direction orthogonal to the inclined plane direction (D), and - A fourth layer (24) formed by a strip (4) arranged in a second laying direction (O2), which is different from the inclined plane direction (D), the direction orthogonal to the inclined plane direction (D), and the first laying direction (O1); - Furthermore, in the sloped region (2a), a strip (4) forming the third layer (23) and / or the fourth layer (24) is laid from one laminate side (2b) to another laminate side (2c).
14. The method according to claim 13, wherein, The laying step a) includes one of the following: - Lay the first layer (21) and the second layer (22) until the sloped area (2a) is reached. - Lay the first layer (21) and / or the second layer (22) until the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) unfolded on the slope region (2a), - Lay the first layer (21) and / or the second layer (22) beyond the outermost ends (3, 5) of the third layer (23) and / or the fourth layer (24) unfolded on the slope region (2a).
15. The method according to any one of claims 13 to 14, wherein, Step a) includes laying a strip (4) forming the third layer (23) and the fourth layer (24) across the two laminate sides (2b, 2c) from one laminate side (2b) to the opposite laminate side (2c) in the sloped region (2a).
16. The method according to any one of claims 13 to 14, wherein, Step a) includes, in the inclined region (2a): - Lay out the shortest outermost side of the strip (4a') forming the third layer (23) until the longest outermost side of the strip (4b') forming the fourth layer (24), and - Lay the outermost shortest side of the strip (4a”) that forms the fourth layer (24) until the outermost longest side of the strip (4b”) that forms the third layer (23).