Grid stiffened wall plate for aircraft structure and forming mold and method of grid stiffened wall plate

Abstract

The invention belongs to the technical field of grating stiffened wall plates, and particularly relates to a grating stiffened wall plate for an aircraft structure and a forming mold and method.The grating stiffened wall plate comprises a grating frame, a skin plate is arranged on the grating frame, and the skin plate comprises an outer skin arranged on the bottom face of the grating frame and an inner skin arranged on the grating frame; the grille frame comprises a transverse rib core material and a longitudinal rib core material which are connected with each other, the inner skin is located between the transverse rib core material and the longitudinal rib core material, the connecting position between the transverse rib core material and the longitudinal rib core material is called as a connecting node, and each connecting node is provided with a forming block; the strength and the stability of the grating frame are effectively enhanced through the forming blocks. In addition, the transverse rib core materials and the longitudinal rib core materials are tightly fixed through flanging wrapping of the inner skin, and therefore the strength and the structural efficiency of the grating stiffened wall plate are remarkably improved. And the unique requirements of aircraft wall plate structures such as airplanes and the like on the aspects of transmitting and bearing large loads are met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of grid stiffened panels, and particularly relates to a grid stiffened panel for aircraft structure and a forming die and method thereof. BACKGROUND

[0002] In the design of modern aircraft, the fuselage door, landing gear door and other key structures usually adopt thin-walled integral stiffened panel structure. This structure combines thin walls with stiffening elements to improve the overall strength and stiffness. The traditional stiffened panel structure mainly relies on the mechanical connection between the stringers and the rib strips to form a typical stiffened panel. As the main load-bearing elements, the stringers and the rib strips are tightly combined through rivets, bolts or other mechanical connection methods to ensure the integrity and load-bearing capacity of the structure.

[0003] However, in practical applications, the existing stiffened panel structure has the problem of insufficient strength. Since the thin-walled structure is prone to deformation under external loads, the traditional mechanical connection method may loosen or be damaged during long-term use, resulting in a decline in the overall performance of the structure. In addition, with the continuous development of aviation technology, the requirements for lightweight and high-performance of the structure are becoming higher and higher, and the traditional stiffened panel structure has been difficult to meet the comprehensive demands of modern aircraft for strength, stiffness and durability. SUMMARY

[0004] The purpose of the present application is to overcome the above-mentioned deficiencies and provide a grid stiffened panel for aircraft structure and a forming die and method thereof.

[0005] To achieve the above-mentioned purpose, the present application provides a grid stiffened panel for aircraft structure, comprising a grid frame, a skin plate arranged on the grid frame, the skin plate comprising an outer skin arranged on the bottom surface of the grid frame and an inner skin arranged on the grid frame, the grid frame comprising connected horizontal core material and vertical core material, the inner skin being located between the horizontal core material and the vertical core material, the connection between the horizontal core material and the vertical core material being referred to as a connection node, a shaped block being arranged on the connection node, the shaped block being a preform composed of carbon fiber and resin, the shaped block comprising a reinforcing element distributed upward and downward, the reinforcing element comprising a top plate and a limiting block arranged at the bottom of the top plate, the limiting block forming a slot for inserting the horizontal core material and the vertical core material, and a cutout being arranged in the corner area of the inner skin.

[0006] Further, a limiting extension is arranged on the top plate, and the limiting extension is in contact with the top surface of the inner skin.

[0007] Further, twist strips are filled on both sides of the horizontal core material and the vertical core material, and the twist strips are located at the connection between the horizontal core material and the outer skin and between the vertical core material and the outer skin.

[0008] Further, the outer skin is provided with a reinforcing layer at a position corresponding to the connecting node.

[0009] The application further provides a forming die for the grid-reinforced wallboard, comprising a die body, the die body comprising a frame, an inner core module arranged on one side of the grid-reinforced wallboard, and a pressurizing cover plate arranged on one side of the grid-reinforced wallboard, a die cavity for forming the grid-reinforced wallboard being formed between the frame, the inner core module, and the pressurizing cover plate.

[0010] Further, the frame comprises a detachably connected horizontal frame and a vertical frame.

[0011] Further, the inner core module comprises a plurality of inner cores arranged between the horizontal core material and the vertical core material.

[0012] The application further provides a forming method for the grid-reinforced wallboard, comprising the following steps: a grid frame processing step of engaging the horizontal core material and the vertical core material with each other to form a grid frame; an inner skin pasting step of pasting the inner skin on the inner core module and clamping the grid frame into the inner core module; a twist strip filling step of filling the twist strip on the surface of the inner skin; a forming block installing step of inserting the forming block at the position of each connecting node; an outer skin pasting step of pasting the outer skin on the surface; a frame assembling step of assembling the frame and installing the pressurizing cover plate; a solidification forming step of performing bagging and then vacuumizing, and then solidifying; a demolding step of demolding after the solidification forming.

[0013] The technical solution provided by the application has at least the following technical effects: The grid-reinforced wallboard disclosed by the application is provided with a forming block at the connecting node of the horizontal core material and the vertical core material, which effectively enhances the strength and stability of the grid frame. In addition, the horizontal core material and the vertical core material are tightly fixed through the edge covering of the inner skin, thereby significantly improving the strength and structural efficiency of the grid-reinforced wallboard. The unique requirements of the wallboard structure of an aircraft or other aircraft in transmitting and bearing large loads are met. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0015] Figure 1 Structure diagram of the grid stiffened wallboard of the embodiment 1 of the present application; Figure 2 Exploded view of the grid stiffened wallboard of the embodiment 1 of the present application; Figure 3 Structure diagram of the reinforcing block of the embodiment 1 of the present application; Figure 4 Structure diagram of the twist bar distribution of the embodiment 1 of the present application; Figure 5 Unfolding and flanging diagram of the inner skin of the embodiment 1 of the present application; Figure 6 Structure diagram of the reinforcing layer distribution of the embodiment 1 of the present application; Figure 7 Structure diagram of the forming die of the embodiment 2 of the present application; Figure 8 Exploded view of the forming die of the embodiment 2 of the present application.

[0016] Main figure mark explanation: 1, transverse rib core material; 2, longitudinal rib core material; 3, outer skin; 4, inner skin; 5, reinforcing piece; 51, top plate; 52, limiting block; 53, insertion slot; 54, limiting extension; 6, twist bar; 7, transverse frame; 8, longitudinal frame; 9, inner core; 10, pressing cover plate; 11, shear opening; 12, flange; 13, reinforcing layer. DETAILED DESCRIPTION

[0017] The embodiments of the present application will be described in detail below, examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the embodiments of the present application, and cannot be understood as a limitation of the present application.

[0018] Embodiment 1: as shown in Figure 1 , Figure 2 , a grid stiffened wallboard for aircraft structure, comprising a grid frame, a skin plate is arranged on the grid frame. The skin plate is composed of an outer skin 3 arranged on the bottom surface of the grid frame and an inner skin 4 arranged on the grid frame. The grid frame is composed of transverse rib core material 1 and longitudinal rib core material 2 connected to each other, and the inner skin 4 is located between the transverse rib core material 1 and the longitudinal rib core material 2, and the inner skin 4 is specifically distributed in the square formed by the two. Through the flange 12 of the inner skin 4 and the covering of the outer skin 3, the transverse rib core material 1 and the longitudinal rib core material 2 are tightly fixed, thereby significantly improving the strength and structural efficiency of the grid stiffened wallboard, as shown in Figure 5 , each corner area of the inner skin 4 is provided with a shear opening 11, and the flange 12 in the direction of the transverse rib core material 1 and the longitudinal rib core material 2 is used to cover the transverse rib core material 1 and the longitudinal rib core material 2.

[0019] The connection between the cross rib core material 1 and the longitudinal rib core material 2 is called a connection node, and a shaped block is arranged on each connection node. The shaped block comprises a reinforcing member 5 distributed above and below, and the strength and stability of the lattice reinforced wallboard are further improved by fastening the connection node position through the reinforcing member 5. As shown in Figure 3 , in this embodiment, the reinforcing member 5 comprises a top plate 51 and a limiting block 52 arranged at the bottom of the top plate 51, and the limiting block 52 forms a slot 53 for inserting the cross rib core material 1 and the longitudinal rib core material 2. Specifically, four limiting blocks 52 are circumferentially distributed at the bottom of the top plate 51 to form a cross slot, and the cross rib core material 1 and the longitudinal rib core material 2 are inserted into the cross slot, so that the connection between the cross rib core material 1 and the longitudinal rib core material 2 is more stable under the action of the reinforcing member 5. Since the lattice reinforced wallboard in this embodiment is an orthogonal lattice wallboard, the slot 53 in this embodiment is a cross-shaped slot 53. However, in addition to the orthogonal lattice wallboard, the lattice reinforced wallboard can also be a special-shaped lattice wallboard, so the shape of the slot 53 can be changed accordingly according to the shape of the special-shaped connection node. In this embodiment, the reinforcing member 5 is made of a fiber resin material, which has excellent tensile and bending resistance. Specifically, it is a preform composed of carbon fibers and resin blocks. The preparation of the preform can adopt a unidirectional tape, and a corresponding mold is used for warm pressing to form a "pre" shape. The reinforcing member 5 is directly clamped into the gap between the cross rib core material 1, the longitudinal rib core material 2 and the skin plate, and the cross rib core material 1 and the longitudinal rib core material 2 are directly inserted into the slot 53. The whole is solidified at one time, and a force transmission node is formed.

[0020] As shown in Figure 3 , the top plate 51 is provided with a limiting extension 54, which is in contact with the top surface of the inner skin 4. The limiting extension 54 improves the stability of the connection between the inner skin 4 and the cross rib core material 1 and the longitudinal rib core material 2.

[0021] In order to further improve the overall strength of the lattice reinforced wallboard, twist strips 6 are filled on both sides of the cross rib core material 1 and the longitudinal rib core material 2. The twist strips 6 can be formed by pressing a unidirectional tape fiber through a mold. As shown in Figure 4 , these twist strips 6 are located at the connection parts of the cross rib core material 1 and the outer skin 3, and the longitudinal rib core material 2 and the outer skin 3. The function of the twist strip 6 is to fill the gap between the inner skin 4, the outer skin 3, the cross rib core material 1 and the longitudinal rib core material 2, so that the formation between the inner skin 4, the outer skin 3, the cross rib core material 1 and the longitudinal rib core material 2 is more stable, as shown in Figure 6 , the outer skin 3 is provided with a reinforcing layer 13 at the position corresponding to the connection node, so that the axial and shear strength of the connection node area in two directions is significantly improved.

[0022] Embodiment 2: as Figure 7 , Figure 8As shown, the embodiment discloses a mold for forming the grid reinforced wallboard of embodiment 1, which comprises a mold body. The mold body comprises a frame, an inner core module arranged on one side of the grid reinforced wallboard, and a pressing cover plate 10 arranged on the other side of the grid reinforced wallboard, and a mold cavity for forming the grid reinforced wallboard is formed between the three. The frame is composed of two detachably connected transverse frames 7 and longitudinal frames 8, and the transverse frames 7 and the inner core module can be detachably connected through bolts and other connectors. The inner core module contains a plurality of inner cores 9 arranged in the square between the horizontal rib core material 1 and the vertical rib core material 2. In the mold cavity formed by the frame, the pressing cover plate 10 and the inner core module, the grid reinforced wallboard described in embodiment 1 is integrally cured and formed.

[0023] Embodiment 3: The embodiment discloses a forming method of a grid reinforced wallboard, and the specific steps are as follows: First, the grid frame is processed. In this embodiment, four horizontal rib core materials 1 and three vertical rib core materials 2 are prepared. The horizontal rib core material 1 and the vertical rib core material 2 are engaged with each other through the clamping groove to form a grid frame.

[0024] Then, the inner skin 4 is laid. The inner cores 9 of the inner core module are arranged in order to ensure their flatness. Then, the inner skin 4 is evenly laid on the inner cores 9. Finally, the previously processed grid frame is clamped into the inner core module to ensure that it is firmly fixed on the inner skin 4.

[0025] Then, the twist bar 6 is filled. The twist bar 6 needs to be evenly filled on the surface of the inner skin 4. The twist bar 6 needs to be distributed on both sides of the horizontal rib core material 1 and the vertical rib core material 2 to ensure the stability and strength of the overall structure.

[0026] Then, the forming block is installed. The forming block is inserted into the insertion slot 53 of the horizontal rib core material 1 and the vertical rib core material 2 at each connection node position of the horizontal rib core material 1 and the vertical rib core material 2 to further strengthen the stability of the structure.

[0027] Then, the outer skin 3 is laid. The outer skin 3 needs to be evenly laid on the surface to form the outer surface of the wallboard.

[0028] Then, the frame is assembled. The frame needs to be assembled, specifically two transverse frames 7 and longitudinal frames 8 are assembled through bolts and other connectors, and the pressing cover plate 10 is installed to ensure the integrity and sealing of the overall structure.

[0029] Then, the curing is performed. The whole bag needs to be punched during the process, and then vacuumized to cure. The structural stability and strength of the wallboard are ensured.

[0030] Finally, demolding, after curing and molding, demolding is needed. After demolding, the top surface and edges of the wallboard are machined and edge sealed to ensure flatness and aesthetics. Finally, testing is performed to ensure that the quality of the wallboard meets the standards.

[0031] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A grid-reinforced wall panel for aircraft structure, characterized in that: The invention comprises a grid frame, wherein a skin plate is provided on the grid frame, wherein the skin plate comprises an outer skin (3) provided on the bottom surface of the grid frame and an inner skin (4) provided on the grid frame, wherein the grid frame comprises a transverse rib core material (1) and a longitudinal rib core material (2) connected to each other, wherein the inner skin (4) is located between the transverse rib core material (1) and the longitudinal rib core material (2), wherein the connection between the transverse rib core material (1) and the longitudinal rib core material (2) is called a connection node, and each connection node is provided with a forming block; the forming block is a preform composed of carbon fiber and resin block, wherein the forming block comprises reinforcing members (5) distributed up and down; the reinforcing member (5) comprises a top plate (51) and a limiting block (52) provided at the bottom of the top plate (51), wherein the limiting block (52) forms a slot (53) for inserting the transverse rib core material (1) and the longitudinal rib core material (2); and a notch (11) is provided at a corner area of ​​the inner skin (4).

2. The grid-reinforced wall panel for aircraft structure according to claim 1, characterized in that: A position-limiting extension portion (54) is provided on the top plate (51), and the position-limiting extension portion (54) is in contact with the top surface of the inner skin (4).

3. The grid-reinforced wall panel for aircraft structure according to claim 1, characterized in that: Both sides of the transverse reinforcement core material (1) and the longitudinal reinforcement core material (2) are filled with twist strips (6), and the twist strips (6) are located at the connection between the transverse reinforcement core material (1) and the outer skin (3), and the longitudinal reinforcement core material (2) and the outer skin (3).

4. The grid-reinforced wall panel for aircraft structure according to claim 1, characterized in that: A reinforcement layer (13) is provided at a position of the outer skin (3) corresponding to the connection node.

5. A forming die for the grid-reinforced wall panel according to any one of claims 1 to 4, characterized in that: The mold body comprises a frame, an inner core module arranged on one side of the grille reinforcement wall panel, and a pressurized cover plate (10) arranged on one side of the grille reinforcement wall panel, wherein a mold cavity for forming the grille reinforcement wall panel is formed between the frame, the inner core module and the pressurized cover plate (10).

6. The forming die according to claim 5, wherein: The frame comprises a detachably connected transverse frame (7) and a longitudinal frame (8).

7. The forming die according to claim 5, wherein: The inner core module comprises a plurality of inner cores (9) arranged between the transverse rib core material (1) and the longitudinal rib core material (2).

8. A method for forming a grid-reinforced wall panel using a forming mold according to any one of claims 5 to 7, characterized in that: The steps include: The grid frame processing steps include: interlocking the transverse reinforcement core material (1) and the longitudinal reinforcement core material (2) to form a grid frame; Inner skin (4) laying step: laying the inner skin (4) on the inner core module, and inserting the grid frame into the inner core module; The twist strip (6) filling step: filling the twist strip (6) on the surface of the inner skin (4); Steps for installing the forming blocks: insert the forming blocks at each connection node position; The outer skin (3) paving step: paving the outer skin (3) on the surface; Frame assembly step: assemble the frame and install the pressure cover (10); Curing and molding steps: bagging the whole thing and then vacuuming it; to solidify; Demolding step: After curing and molding, demolding is performed.

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