A process for one-step forming of a hot formed angle and aircraft structure
Patent Information
- Application Number
- CN202611407455.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-11
- Publication Date
- 2026-10-13
AI Technical Summary
[0002]复合材料板雕刻梁、肋结构与蒙皮粘接是中小型无人机常用的结构设计方案，但该方案中梁、肋因由板材直接雕刻成型而不具有缘条（翻边），导致梁、肋仅以其侧边（板厚方向）与蒙皮贴合形成胶接面，该胶接面积极小（受限于板材厚度），粘接强度严重不足，在服役载荷下极易发生界面脱粘，存在坠机隐患
本申请实施例通过设置具有形状记忆材料层的热成型角材，利用形状记忆材料层在折叠状态下被拉伸储能、受热后收缩回复的特性，在固化过程中自动将复合材料粘接层压合贴合于蒙皮的内表面，形成具有较大面积的翻边粘接结构，从而有效增大了梁或肋与蒙皮之间的胶接面积，提高了连接可靠性，避免了因胶接面积不足导致的界面脱粘和坠机隐患；同时，整个飞机结构仅需一次烘箱固化即可完成梁或肋与蒙皮的连接，无需涂抹脱模剂和打磨操作，显著缩短了制造周期，改善了作业环境，且避免了手工糊制带来的质量不一致问题，适用于中小型无人机结构的批量化制造。
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Figure CN122896945A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of aircraft structural design and manufacturing technology, and in particular to a thermoformed angle rod and a one-time forming process for aircraft structures. Background Technology
[0002] The bonding of composite material panels with carved beams and ribs to the skin is a common structural design for small and medium-sized UAVs. However, in this design, the beams and ribs are directly carved from the sheet material without flanges, resulting in the beams and ribs only having their sides (in the thickness direction) bonded to the skin. This bonding area is extremely small (limited by the sheet thickness), leading to severely insufficient bonding strength. Under service loads, interface debonding is highly likely, posing a crash hazard. To increase the bonding area, existing technologies attempt to manually apply fiber cloth at the intersection of the beams / ribs and the skin to form flanges. However, this process requires first applying a release agent to one side of the skin, then applying and curing the cloth to form the flange, followed by sanding to remove the release agent contamination layer, and then assembling it with the other side of the skin for a second curing. This process suffers from drawbacks such as long processing time due to two curing cycles, difficulty in applying the release agent and harsh working environment, and poor consistency in the quality of manual application. Summary of the Invention
[0003] This application provides a one-time forming process for thermoformed angle materials and aircraft structures, which solves the problems mentioned in the background art.
[0004] In a first aspect, embodiments of this application provide a thermoformed angle bracket for connecting beams or ribs to the skin in an aircraft structure, comprising: A molded part includes a substrate and a shape memory material layer, the substrate having a guiding structure connected to the substrate, and at least a portion of the guiding structure forming a deformable space with the remainder of the substrate, the shape memory material layer being disposed on the side of the guiding structure opposite to the substrate; A composite material adhesive layer is disposed on the side of the substrate away from the shape memory material layer, for bonding the beam or rib to the skin; The thermoformed angle has an unfolded state and a folded state. In the folded state, the substrate is folded along the guide structure, the deformable space protrudes outward and deforms, and the shape memory material layer is in a stretched state. When heated, the shape memory material layer shrinks, which causes the guide structure to deform, thereby causing the substrate to change from the folded state to the unfolded state, so that the composite material adhesive layer adheres to the inner surface of the skin to form a flanged adhesive structure.
[0005] In conjunction with the first aspect, in one possible implementation, the shape memory material layer is in a stretched state when it deforms as the deformable space bulges outward. Alternatively, the shape memory material layer is in a stretched state due to deformation based on the shape of the deformable space bulging outward when folded.
[0006] In conjunction with the first aspect, in one possible implementation, the guide structure is a movable portion in the middle of the substrate, with both ends of the movable portion connected to the substrate, and the deformable space formed between the middle of the movable portion and the substrate; and / or, an avoidance structure is provided at the connection between the guide structure and the substrate to prevent motion interference between the guide structure and the substrate in the folded state.
[0007] In conjunction with the first aspect, in one possible implementation, a notch is provided in the middle of the active part, and the shape memory material layer is suspended at the notch.
[0008] In conjunction with the first aspect, in one possible implementation, the two opposite sides of the notch have a predetermined included angle.
[0009] In conjunction with the first aspect, in one possible implementation, in the folded state, the interior angle corresponding to the outward convex deformation of the deformable space is less than or equal to 45°; And / or, the composite adhesive layer includes a composite material layer and an adhesive layer stacked together, the adhesive layer being disposed on the side of the composite material layer away from the substrate.
[0010] In conjunction with the first aspect, in one possible implementation, the shrinkage trigger temperature of the shape memory material layer is lower than the gelatinization temperature of the adhesive layer.
[0011] Secondly, embodiments of this application provide a one-piece molding process for aircraft structures, including the following steps: Provide thermoformed angles as described in any of the first aspects; Fold the thermoformed angle piece to a folded state, causing the guide structure to fold in the opposite direction, causing the deformable space to bulge outward and deform, causing the shape memory material layer to deform and be stretched. One side of the folded thermoformed angle is fixed to the web of the beam or rib, and the folded part of the thermoformed angle is aligned with the edge of the beam or rib, while the other side of the thermoformed angle is the free side. The skin is fastened to the beam or rib with thermoformed angle members and fixed to obtain the component assembly; Heating the component assembly causes the shape memory material layer to shrink due to heat, which in turn causes the guide structure to deform, thereby causing the substrate to change to an unfolded state. This pushes the inner surface of the free lateral skin of the thermoformed angle piece to move, so that the composite adhesive layer is pressed onto the inner surface of the skin and cured, forming a flanged adhesive structure between the beam or rib and the skin.
[0012] In conjunction with the second aspect, in one possible implementation, the shape memory material layer is stretched in the folded state by being passively stretched by the outward deformation of the deformable space; or, the shape memory material layer is pre-stretched and shaped before being fixed to the guide structure.
[0013] In conjunction with the second aspect, in one possible implementation, during the heating process, the shape memory material layer is first heated and rebounds to press the composite adhesive layer onto the inner surface of the skin, and then the composite adhesive layer is heated and cured.
[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects: This application embodiment utilizes a thermoformed corner piece with a shape memory material layer. Taking advantage of the shape memory material layer's ability to store energy when stretched in a folded state and shrink and recover upon heating, the composite adhesive layer is automatically pressed and bonded to the inner surface of the skin during the curing process, forming a flanged adhesive structure with a large area. This effectively increases the bonding area between the beams or ribs and the skin, improving connection reliability and avoiding interface debonding and crash hazards caused by insufficient bonding area. Simultaneously, the entire aircraft structure only requires one oven curing cycle to complete the connection between the beams or ribs and the skin, eliminating the need for mold release agents and sanding operations. This significantly shortens the manufacturing cycle, improves the working environment, and avoids the quality inconsistencies caused by manual pasting, making it suitable for the mass production of small and medium-sized UAV structures. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram of a beam rib frame with the thermoformed angle members pasted on, provided in an embodiment of this application. Figure 2 Schematic diagrams of cross-sections of cured thermoformed angles, beams, and skins provided in embodiments of this application; Figure 3 This is a partial schematic diagram of the cross-section of the cured thermoformed angle piece, beam, and skin provided in an embodiment of this application. Figure 4 This is a schematic diagram of a molded part with the shape memory material layer pasted on, provided in an embodiment of this application. Figure 5 This is a cross-sectional schematic diagram of a molded part with the shape memory material layer pasted on, provided in an embodiment of this application. Figure 6A schematic diagram of a substrate with a pre-formed notch provided in an embodiment of this application; Figure 7 This is a schematic diagram of a folded thermoformed corner piece provided in an embodiment of this application; Figure 8 This is a schematic cross-sectional view of the folded thermoformed angle piece provided in an embodiment of this application; Figure 9 This is a schematic diagram of the thermoformed angle piece after curing, provided in an embodiment of this application. Figure 10 This is a schematic cross-sectional view of the thermoformed angle piece after curing, provided in an embodiment of this application.
[0017] Icons: 1-Thermoformed angle; 11-Molded part; 111-Substrate; 1111-Guiding structure; 11111-Notch; 112-Shape memory material layer; 12-Composite adhesive layer; 121-Composite layer; 122-Adhesive layer; 13-Avoidance structure; 2-Beam; 3-Skin. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.
[0020] This application provides a thermoformed angle piece 1, such as... Figures 1 to 10As shown, the connection between beam 2 or rib and skin 3 in an aircraft structure includes a molded part 11 and a composite material adhesive layer 12.
[0021] The molded part 11 includes a substrate 111 and a shape memory material layer 112. The substrate 111 has a guide structure 1111, which is connected to the substrate 111. At least a portion of the guide structure 1111 forms a deformable space with the rest of the substrate 111. The shape memory material layer 112 is disposed on the side of the guide structure 1111 away from the substrate 111. The composite material adhesive layer 12 is disposed on the side of the substrate 111 away from the shape memory material layer 112 and is used to bond the beam 2 or rib to the skin 3. The thermoformed angle 1 has an unfolded state and a folded state. In the folded state, the substrate 111 is folded along the guide structure 1111, and the deformable space protrudes outward. The shape memory material layer 112 is in a stretched state. When heated, the shape memory material layer 112 shrinks, which causes the guide structure 1111 to deform, thereby causing the substrate 111 to change from the folded state to the unfolded state, so that the composite material adhesive layer 12 adheres to the inner surface of the skin 3 to form a flanged adhesive structure.
[0022] like Figure 4 and Figure 5 As shown, the molded part 11 includes a substrate 111 and a shape memory material layer 112. The substrate 111 has a guide structure 1111 connected to the substrate 111, and at least a portion of the guide structure 1111 forms a deformable space with the remainder of the substrate 111. The shape memory material layer 112 is disposed on the side of the guide structure 1111 facing away from the substrate 111.
[0023] like Figure 6 As shown, the substrate 111 has a pre-made notch 11111 for easy folding and separation. The substrate 111 is made of hollow corrugated paper, which is lightweight and has a certain rigidity, and also facilitates the pre-pressing of the notch 11111.
[0024] The composite adhesive layer 12 is disposed on the side of the substrate 111 away from the shape memory material layer 112, and is used to bond the beam 2 or rib to the skin 3. The composite adhesive layer 12 includes a composite material layer 121 and an adhesive layer 122 stacked together, with the adhesive layer 122 disposed on the side of the composite material layer 121 away from the substrate 111. The composite material layer 121 is a fiber prepreg, and the adhesive layer 122 is an adhesive film; the two are stacked together and bonded well.
[0025] like Figure 7 and Figure 8 As shown, the thermoformed angle member 1 has an unfolded state and a folded state. In the folded state, the substrate 111 folds along the guide structure 1111, the deformable space bulges outward, and the shape memory material layer 112 is in a stretched state. Figure 9 and Figure 10 As shown, the shape memory material layer 112 shrinks when heated, causing the guide structure 1111 to deform, which in turn causes the substrate 111 to change from a folded state to an unfolded state, so that the composite material adhesive layer 12 adheres to the inner surface of the skin 3 to form a flanged adhesive structure.
[0026] In this embodiment, the shape memory material layer 112 is in a stretched state when it deforms outward as the deformable space bulges outward; or, the shape memory material layer 112 is in a stretched state when it deforms based on the shape of the deformable space bulging outward when folded.
[0027] Specifically, the shape memory material layer 112 is stretched in the folded state in the following ways: the shape memory material layer 112 is passively stretched by the outward deformation driven by the deformable space; or, the shape memory material layer 112 is pre-stretched and shaped before being fixed to the guide structure 1111.
[0028] In the first method, the shape memory material layer 112 is attached to the guide structure 1111 in its natural state. When folding the thermoformed angle 1, the substrate 111 folds along the guide structure 1111, and the deformable space bulges outward. The shape memory material layer 112 undergoes tensile deformation along with the bulging deformation of the deformable space, changing from its natural state to a stretched state. After the folding operation is completed at room temperature or slightly above room temperature, cooling is performed to allow the thermoformed angle 1 to initially set its shape. At this time, the shape memory material layer 112 remains in a stretched state.
[0029] In the second method, the shape memory material layer 112 is pre-stretched and shaped to match the shape of the deformable space after it bulges outward in the folded state, and then the stretched and shaped shape memory material layer 112 is fixed to the guide structure 1111.
[0030] In this embodiment, the guide structure 1111 is a movable part in the middle of the substrate 111, with both ends of the movable part connected to the substrate 111, and a deformable space is formed between the middle of the movable part and the substrate 111; and / or, an avoidance structure 13 is provided at the connection between the guide structure 1111 and the substrate 111 to avoid motion interference between the guide structure 1111 and the substrate 111 in the folded state.
[0031] Optionally, the avoidance structure 13 may be a slotted or thinned area on the substrate 111 to ensure that there is no movement interference between the components during the folding process.
[0032] In this embodiment of the application, a notch 11111 is provided in the middle of the active part, and the shape memory material layer 112 is suspended at the notch 11111. Figure 5As shown, the shape memory material layer 112 is suspended at the notch 11111, providing space for stretching deformation during folding.
[0033] In a specific implementation, such as Figure 5 As shown, a notch 11111 is pre-formed on the substrate 111, which divides the substrate 111 into multiple foldable parts. The thickness of the substrate 111 is denoted as t. In the portion of the substrate 111 where the shape memory material layer 112 is fixed, the width of the two sides of the notch 11111 is... ·t. In the fully unfolded state of the molded part 11, the length of the suspended portion of the shape memory material layer 112 at the notch 11111 is 2t. When the thermoformed angle 1 is folded to a folded state, and the inner angle of the folded angle is less than or equal to 45°, the two sides of the notch 11111 of the substrate 111 come together, and the suspended portion of the shape memory material layer 112 at the notch 11111 is stretched to completely fit the two sides of the notch 11111. At this time, the length of the suspended portion is stretched to 2t. ·t, strain is -1. In this stretched state, the shape memory material layer 112 stores elastic potential energy. When heated, the shape memory material layer 112 contracts, causing the substrate 111 to return from a folded state to an unfolded state. Specifically, in the folded state, the interior angle corresponding to the outward convex deformation of the deformable space is the first convex deformation angle α, and α ≤ 45°; in the unfolded state, the interior angle corresponding to the outward convex deformation of the deformable space is the second convex deformation angle β. When the thermoformed angle 1 transitions from a folded state to an unfolded state, the interior angle corresponding to the outward convex deformation of the deformable space increases from α to β, i.e., α < β.
[0034] In this embodiment of the application, a predetermined angle is formed between the two opposite sides of the notch 11111. Optionally, the predetermined angle is 90°.
[0035] In this embodiment, the shrinkage trigger temperature of the shape memory material layer 112 is lower than the gelatinization temperature of the adhesive layer 122. The gelatinization temperature refers to the temperature at which the adhesive layer 122 begins to melt. The advantage of this setting is that during the heating process, the shape memory material layer 112 first reaches the shrinkage trigger temperature and rebounds, pressing the composite adhesive layer 12 onto the inner surface of the skin 3. Subsequently, the temperature is further increased to above the gelatinization temperature of the adhesive layer 122, and the adhesive layer 122 gelatinizes and solidifies, thereby ensuring that the shape memory material layer 112 completes the pressing action before the adhesive layer 122 is fully melted, achieving reliable bonding.
[0036] This application provides a one-piece molding process for aircraft structures, including the following steps: Provide thermoformed angle piece 1 as described above; Fold the thermoformed angle 1 to a folded state, causing the guide structure 1111 to fold in the opposite direction, causing the deformable space to bulge outward and deform, causing the shape memory material layer 112 to deform and be stretched. One side of the folded thermoformed angle 1 is fixed to the web of the beam 2 or rib, and the folded part of the thermoformed angle 1 is aligned with the edge of the beam 2 or rib. The other side of the thermoformed angle 1 is the free side. The skin 3 is fastened to the beam 2 or rib with the thermoformed angle piece 1 and fixed to obtain the component assembly; Heating the component assembly causes the shape memory material layer 112 to shrink due to heat, which in turn causes the guide structure 1111 to deform, thereby causing the substrate 111 to change to an unfolded state. This pushes the inner surface of the free side skin 3 of the thermoformed angle 1 to move, so that the composite material adhesive layer 12 is pressed onto the inner surface of the skin 3 and cured, forming a flanged adhesive structure between the beam 2 or rib and the skin 3.
[0037] Specifically, the composite material plates are first cut to manufacture beam 2, rib skeleton, and composite material skin 3.
[0038] Then, the aforementioned thermoformed angle member 1 is provided. The thermoformed angle member 1 is folded to a folded state, causing the guide structure 1111 to fold in the opposite direction, causing the deformable space to bulge outward and deform, thus stretching the shape memory material layer 112. After completing the folding operation at room temperature or slightly above room temperature, the thermoformed angle member 1 is cooled to initially set its shape, at which point the shape memory material layer 112 remains in a stretched state. The shape memory material layer 112 is stretched in the folded state in the following ways: the shape memory material layer 112 is passively stretched by the outward deformation of the deformable space; or, the shape memory material layer 112 is pre-stretched and shaped before being fixed to the guide structure 1111.
[0039] Next, one side of the folded thermoformed angle bracket 1 is fixed to the web of the beam 2 or rib, and the folded corner of the thermoformed angle bracket 1 is aligned with the edge of the beam 2 or rib, leaving the other side of the thermoformed angle bracket 1 as the free side. Figure 1 As shown, the thermoformed angle member 1 is glued and fixed along the web direction of the beam 2.
[0040] Then, the skin 3 is fastened to the beam 2 or rib on which the thermoformed angle member 1 is installed and fixed to obtain the component assembly. Specifically, the upper skin and the lower skin are fastened to the upper and lower sides of the beam 2 and rib frame on which the thermoformed angle member 1 is installed and fixed respectively.
[0041] Finally, the component assembly is heated, causing the shape memory material layer 112 to shrink due to heat, which in turn causes the guide structure 1111 to deform, thereby causing the substrate 111 to change to an unfolded state, pushing the inner surface of the free side skin 3 of the thermoformed angle 1 to move, so that the composite material adhesive layer 12 is pressed onto the inner surface of the skin 3 and cured, forming a flanged adhesive structure between the beam 2 or rib and the skin 3.
[0042] Specifically, during oven heating, when the temperature reaches the shrinkage trigger temperature of the shape memory material layer 112, the shape memory material layer 112 rebounds due to heat. Because it is in a stretched state when folded, although its elastic modulus is only 5-10 MPa, it is sufficient to generate enough force to cause the corner piece to rebound, pushing the free side of the thermoformed corner piece 1 towards the inner surface of the skin 3, thus pressing the composite adhesive layer 12 onto the inner surface of the skin 3. The gelatinization temperature of the adhesive layer 122 is slightly higher than the shrinkage trigger temperature of the shape memory material layer 112, but does not exceed the effective elastic range of the shape memory material layer 112. Therefore, the shape memory material layer 112 first rebounds due to heat, pressing the composite adhesive layer 12 onto the inner surface of the skin 3. Subsequently, the temperature further increases to above the gelatinization temperature of the adhesive layer 122, causing the adhesive layer 122 to gelatinize and solidify, bonding the composite material layer 121 and the skin 3 together.
[0043] like Figure 9 and Figure 10 As shown, after curing, the substrate 111 of the thermoformed angle 1 returns to its unfolded state, and the inner angle corresponding to the outward deformation of the deformable space changes from the first convex deformation angle α to the second convex deformation angle β, where the first convex deformation angle α is smaller than the second convex deformation angle β. The composite material adhesive layer 12 is attached to the inner surface of the skin 3 to form a flanged adhesive structure.
[0044] The resilience of the thermoformed angle 1 can also be adjusted by adjusting the thickness and width of the shape memory material layer 112 to adapt to different structural and process requirements.
[0045] like Figure 2 and Figure 3 As shown, the final beam 2 and skin 3 form a reliable large-area flanged bonding structure through the composite material bonding layer 12, ensuring a large bonding area.
[0046] Through the above process, the connection between beam 2 or rib and skin 3 can be completed in just one oven curing cycle. No release agent or sanding is required, which significantly shortens the manufacturing cycle and improves the working environment.
[0047] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.
[0048] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.
Claims
1. A thermoformed angle bracket for connecting beams (2) or ribs to skin (3) in an aircraft structure, characterized in that, include: The molded part (11) includes a substrate (111) and a shape memory material layer (112). The substrate (111) has a guide structure (1111) connected to the substrate (111), and at least a portion of the guide structure (1111) forms a deformable space with the remainder of the substrate (111). The shape memory material layer (112) is disposed on the side of the guide structure (1111) facing away from the substrate (111). A composite material adhesive layer (12) is disposed on the side of the substrate (111) away from the shape memory material layer (112) for bonding the beam (2) or rib to the skin (3). The thermoformed corner piece (1) has an unfolded state and a folded state. In the folded state, the substrate (111) is folded along the guide structure (1111), the deformable space protrudes outward and deforms, the shape memory material layer (112) is in a stretched state, and after being heated, the shape memory material layer (112) shrinks, which drives the guide structure (1111) to deform, thereby driving the substrate (111) to change from the folded state to the unfolded state, so that the composite material adhesive layer (12) adheres to the inner surface of the skin (3) to form a flanged adhesive structure.
2. The thermoformed angle metal according to claim 1, characterized in that, The shape memory material layer (112) is in a stretched state when it deforms outward as the deformable space bulges outward; Alternatively, the shape memory material layer (112) is in a stretched state based on the shape of the deformable space bulging outward when folded.
3. The thermoformed angle metal according to claim 1, characterized in that, The guide structure (1111) is a movable part in the middle of the substrate (111), with both ends of the movable part connected to the substrate (111), and the deformable space is formed between the middle of the movable part and the substrate (111); and / or, an avoidance structure (13) is provided at the connection between the guide structure (1111) and the substrate (111) to avoid motion interference between the guide structure (1111) and the substrate (111) in the folded state.
4. The thermoformed angle metal according to claim 3, characterized in that, A notch (11111) is provided in the middle of the active part, and the shape memory material layer (112) is suspended at the notch (11111).
5. The thermoformed angle metal according to claim 4, characterized in that, The notch (11111) has a predetermined angle between its two opposite sides.
6. The thermoformed angle metal according to claim 1, characterized in that, In the folded state, the interior angle corresponding to the outward bulge deformation of the deformable space is less than or equal to 45°; And / or, the composite adhesive layer (12) includes a composite material layer (121) and an adhesive layer (122) stacked together, the adhesive layer (122) being disposed on the side of the composite material layer (121) away from the substrate (111).
7. The thermoformed angle metal according to claim 6, characterized in that, The shrinkage triggering temperature of the shape memory material layer (112) is lower than the gelatinization temperature of the adhesive layer (122).
8. A one-piece molding process for aircraft structures, characterized in that, Includes the following steps: Provide a thermoformed angle (1) as described in any one of claims 1 to 7; Fold the thermoformed angle (1) to a folded state, so that the guide structure (1111) is folded in the opposite direction, so that the deformable space protrudes outward and deforms, so that the shape memory material layer (112) is deformed and stretched; One side of the folded thermoformed angle (1) is fixed to the web of the beam (2) or rib, and the folded part of the thermoformed angle (1) is aligned with the edge of the beam (2) or rib, while the other side of the thermoformed angle (1) is the free side. The skin (3) is fastened to the beam (2) or rib with the thermoformed angle (1) and fixed to obtain the component assembly; Heating the component assembly causes the shape memory material layer (112) to shrink due to heat, which in turn causes the guide structure (1111) to deform, thereby causing the substrate (111) to change to an unfolded state, which in turn causes the inner surface of the free side skin (3) of the thermoformed angle (1) to move, so that the composite adhesive layer (12) is pressed onto the inner surface of the skin (3) and cured, forming a flanged adhesive structure between the beam (2) or rib and the skin (3).
9. The one-piece molding process for aircraft structures according to claim 8, characterized in that, The shape memory material layer (112) is stretched in the folded state in the following ways: the shape memory material layer (112) is passively stretched by the outward deformation driven by the deformable space; or, the shape memory material layer (112) is pre-stretched and shaped and then fixed on the guide structure (1111).
10. The one-piece molding process for aircraft structures according to claim 8, characterized in that, During the heating process, the shape memory material layer (112) is heated and rebounds to press the composite adhesive layer (12) onto the inner surface of the skin (3), and then the composite adhesive layer (12) is heated and cured.