Deformable wing based on discrete assembly chained metamaterial structure

Abstract

The invention discloses a transformable wing based on a discrete assembly chained metamaterial structure, relates to the technical field of chained structures, and solves the problems of complex manufacturing process and limited material selection of the transformable wing. A chained metamaterial interlayer is packaged in a sealing shell and arranged on a wing framework, and a skin is arranged outside the wing framework and the chained metamaterial interlayer; the chained metamaterial interlayer comprises a pressure-torsion chained metamaterial, a microcrystal chained metamaterial and a spherical chained metamaterial, and the pressure-torsion chained metamaterial, the microcrystal chained metamaterial and the spherical chained metamaterial are connected in sequence; the pressure-torsion chained metamaterial is arranged at the root of the wing framework, and the spherical chained metamaterial is arranged at the tip of the wing framework; the metamaterial further comprises an auxetic chain type metamaterial and replaces the compression-torsion chain type metamaterial. According to the invention, flexible expansion of the chained metamaterial is realized through discrete assembly, and manufacturing of the large-size chained metamaterial is completed; the chained metamaterial is applied to the interior of a wing, and dynamic deformation of the wing can be achieved through vacuum degree adjustment.

Description

Technical Field

[0001] The present invention relates to the technical field of chain structures, and in particular to a deformable wing based on a discretely assembled chain metamaterial structure. Background Art

[0002] Morphing wings have achieved numerous successes, but they also face numerous challenges. NASA and MIT have developed a small-scale demonstrator, the Madcat V0, and a large-scale flying wing model. Composed of volume elements, a flexible skin, and a drive system, these wings offer significant advantages, but they face challenges such as complex manufacturing processes and limited material selection. The US VCCW project has produced bench and large-scale models and conducted wind tunnel and flight tests. This wing utilizes a compliant mechanism to achieve distributed deformation, but its heating and recovery characteristics remain to be studied.

[0003] Particle-blocking chain metastructures are a type of metamaterial that achieves reversible and continuous control of structural stiffness by manipulating the contact state between hard particles. Their notable features include lightweight and high strength, reversible deformation, shape adaptability, and rapid stiffness adjustment. Currently, these materials have been successfully applied in high-end equipment such as military protective equipment, robotic end effectors, and smart wearables.

[0004] Existing particle-blocking chain superstructures typically use selective laser sintering integrated molding technology. However, due to high manufacturing costs and equipment size limitations, it is difficult to achieve personalized customization and large-scale production, which seriously restricts its engineering process. Summary of the Invention

[0005] To address the aforementioned challenges of complex manufacturing processes and limited material selection in existing morphing wings, this invention proposes a morphing wing based on a discretely assembled chain metamaterial structure. This discrete assembly of components allows for flexible expansion of the chain metamaterial, overcoming equipment size limitations and enabling the fabrication of large-scale chain metamaterials. Application of this chain metamaterial within the wing allows for dynamic wing deformation through controlled vacuum levels. Upon evacuation, the partially shaped chain metamaterial will undergo bending deformation.

[0006] The present invention proposes a deformable wing based on a discretely assembled chain metamaterial structure, which specifically includes a skin, a wing frame and a chain metamaterial sandwich. The chain metamaterial sandwich is encapsulated in a sealed shell and arranged on the wing frame, and a skin is arranged outside the wing frame and the chain metamaterial sandwich; the chain metamaterial sandwich includes a compression-torsion chain metamaterial, a microcrystalline chain metamaterial and a spherical chain metamaterial, which are connected in sequence; the compression-torsion chain metamaterial is arranged at the root of the wing frame, and the spherical chain metamaterial is arranged at the tip of the wing frame.

[0007] Furthermore, the compression-twist chain metamaterial includes a plurality of compression-twist cells, the compression-twist cells are a frame-like structure, and the plurality of compression-twist cells are interconnected.

[0008] Furthermore, the compression-torsion cell includes two square rings, which are connected by four inclined straight rod parts; the square ring includes four straight rod parts and four spherical connecting parts, and the four straight rod parts are connected end to end by the spherical connecting parts to form a ring structure.

[0009] Furthermore, the micro-crystal chain metamaterial includes a plurality of micro-crystal cells, the micro-crystal cells are an octahedral framework structure, and the plurality of micro-crystal cells are interconnected.

[0010] Furthermore, the microcrystal cell includes eight straight rod parts and six spherical connecting parts, and the straight rod parts are connected to each other through the spherical connecting parts.

[0011] Furthermore, the spherical chain metamaterial includes a plurality of spherical cells, each of which is a spherical frame structure, and the plurality of spherical cells are interconnected.

[0012] Furthermore, the spherical cell includes four curved rod parts and two spherical connecting parts, and the curved rod parts are connected to each other through the spherical connecting parts.

[0013] Furthermore, a valve is provided on the sealing shell, and the valve is connected to the vacuum pump; the sealing shell has a thickness of 0.2 mm and is made of thermoplastic polyurethane.

[0014] A deformable wing based on a discretely assembled chain metamaterial structure specifically comprises a chain metamaterial sandwich, the aforementioned skin, and a wing frame. The chain metamaterial sandwich is encapsulated in a sealed shell and arranged on the wing frame, and a skin is arranged externally to the wing frame and the chain metamaterial sandwich. The chain metamaterial sandwich comprises a tensile chain metamaterial, the aforementioned microcrystalline chain metamaterial, and a spherical chain metamaterial. The tensile chain metamaterial, the microcrystalline chain metamaterial, and the spherical chain metamaterial are connected in sequence. The tensile chain metamaterial is arranged at the root of the wing frame, and the spherical chain metamaterial is arranged at the tip of the wing frame.

[0015] Furthermore, the auxetic chain metamaterial includes a plurality of auxetic cells, each of which is a centrally symmetrical structure and is interconnected; the auxetic cell includes six spherical connecting parts and twelve curved rod parts, the spherical connecting parts are arranged according to the vertex positions of the octahedron, and the spherical connecting parts are connected by curved rod parts.

[0016] The beneficial effects of the morphing wing based on the discrete assembly chain metamaterial structure described in the present invention are: (1) The present invention relates to a deformable wing based on a discretely assembled chain metamaterial structure. The wing structure is made of several different chain metamaterials, which can achieve flexible expansion of size and realize the construction of large-sized wings. At the same time, according to the characteristic that some configurations of chain metamaterials will bend and deform after vacuuming, the dynamic deformation of the wing at different angles can be achieved by adjusting the vacuum degree, thereby achieving the effect of dynamically switching the wing shape under different flight scenarios.

[0017] (2) The present invention discloses a deformable wing based on a discretely assembled chain metamaterial structure. By assembling three modular functional parts prepared by the fused deposition modeling process into a chain metamaterial, the problem of high cost of the traditional selective laser sintering method is solved. By changing the number of the three types of modular functional parts and their spatial position relationship, a cellular structure with differentiated mechanical response is assembled. The chain metamaterial formed by the interlocking of these cellular structures can meet the stiffness and deformation requirements in different scenarios. Moreover, the parts can be quickly replaced after being damaged, and can be recycled, which is conducive to saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] In the attached figure: Figure 1 This is a front view of a deformable wing (skin omitted) based on a discretely assembled chain metamaterial structure in a flat state under low vacuum according to the present invention; Figure 2 This is a side view of a deformable wing (skin omitted) based on a discretely assembled chain metamaterial structure in a flat state under low vacuum; Figure 3 This is a top view of a deformable wing (skin omitted) based on a discretely assembled chain metamaterial structure in a flat state under low vacuum; Figure 4 This is a front view of a deformable wing (skin omitted) based on a discrete assembly chain metamaterial structure according to the present invention in a bent state under high vacuum; Figure 5 This is a side view of a deformable wing (skin omitted) based on a discretely assembled chain metamaterial structure according to the present invention in a bent state under high vacuum; Figure 6 This is a top view of a deformable wing (skin omitted) based on a discretely assembled chain metamaterial structure according to the present invention in a bent state under high vacuum; Figure 7This is a front view of a compression-torsion chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 8 It is a side view of a compression-torsion chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 9 It is a top view of a compression-torsion chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 10 This is a schematic structural diagram of a compression-torsion cell of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 11 This is a front view of a micro-crystal chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 12 It is a side view of a micro-crystal chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 13 It is a top view of a micro-crystal chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 14 This is a schematic structural diagram of a micro-crystal cell of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 15 This is a front view of a spherical chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 16 It is a side view of a spherical chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 17 It is a top view of a spherical chain metamaterial of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 18 This is a schematic structural diagram of a spherical cell of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 19 This is a front view of a auxetic chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 20 It is a side view of a auxetic chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 21 It is a top view of a auxetic chain metamaterial for a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 22This is a schematic structural diagram of an auxetic cell of a deformable wing based on a discretely assembled chain metamaterial structure according to the present invention; Figure 23 This is a schematic structural diagram of a spherical connection part of a deformable wing based on a discrete assembly chain metamaterial structure according to the present invention; Figure 24 This is a schematic structural diagram of a straight rod component of a deformable wing based on a discrete assembly chain metamaterial structure according to the present invention; Figure 25 This is a schematic structural diagram of a bent rod component of a deformable wing based on a discrete assembly chain metamaterial structure according to the present invention; Among them: 1-spherical connecting parts, 101-circular holes and grooves, 2-straight rod parts, 201-straight rod tenons, 3-bent rod parts, 301-bent rod tenons, 4-compression-torsion cells, 5-tension cells, 6-microcrystal cells, 7-spherical cells, 8-compression-torsion chain metamaterials, 9-microcrystal chain metamaterials, 10-spherical chain metamaterials, 11-wing skeleton, 12-tension chain metamaterials. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Specific implementation method 1: See Figures 1-10 、 Figure 23-Figure 25 This embodiment is described in detail. The morphing wing based on a discretely assembled chain metamaterial structure described in this embodiment specifically comprises a skin, a wing frame 11, and a chain metamaterial interlayer. The chain metamaterial interlayer is encapsulated within a sealed shell and positioned on the wing frame 11. The skin is positioned externally to the wing frame 11 and the chain metamaterial interlayer. The chain metamaterial interlayer comprises a compression-torsion chain metamaterial 8, a microcrystalline chain metamaterial 9, and a spherical chain metamaterial 10, which are sequentially interlocked. The compression-torsion chain metamaterial 8 is positioned at the base of the wing frame 11, while the spherical chain metamaterial 10 is positioned at the tip of the wing frame 11. After evacuation, the compression-torsion chain metamaterial 8 remains straight and does not bend, while its stiffness is significantly enhanced, serving as the rigid support region closest to the fuselage. The microcrystalline chain metamaterial 9 undergoes slight bending deformation after evacuation, serving as a transition region in the mid-section of the wing. After evacuation, the spherical chain metamaterial 10 undergoes significant bending deformation, serving as the deformation zone at the distal end of the wing. The three chain metamaterials are interlocked sequentially according to the wing configuration requirements to form a chain metamaterial sandwich within the wing. This sandwich is enclosed in a sealed shell made of 0.2mm thick thermoplastic polyurethane (TPU) film. A valve is installed on the shell and connected to a vacuum pump with a pressure gauge via a hose, which regulates the air pressure within the sealed shell. A wing skeleton 11 is positioned beneath the chain metamaterial sandwich within the sealed shell. When the vacuum level in the sealed shell decreases, the skeleton 11 automatically drives the wing to return to a straight position. A flexible skin is then applied to the outer sides of the skeleton 11 and the chain metamaterial sandwich, forming a complete aerodynamic shape. By manipulating the vacuum level, the wing's shape can be controlled, ultimately achieving the fabrication of a deformable wing.

[0025] The compression-torsion chain metamaterial 8 comprises a plurality of compression-torsion cells 4, each of which is a cubic frame structure and interconnected. When subjected to positive pressure, the compression-torsion cells 4 undergo stable and significant torsion. The compression-torsion cells 4 comprise two square rings connected by four tilted straight rods 2, with the angle between the square rings and the tilted straight rods 2 being 45 degrees. The square rings comprise four straight rods 2 and four spherical connecting elements 1, which are connected end-to-end by the spherical connecting elements 1 to form a ring structure.

[0026] The microcrystal chain metamaterial 9 comprises a plurality of microcrystal cells 6, each of which has an octahedral framework structure and is interconnected. Each microcrystal cell 6 comprises eight straight rods 2 and six spherical connecting elements 1. The spherical connecting elements 1 are arranged according to the vertices of the octahedron, with one spherical connecting element 1 located at the top and bottom of the structure, and the remaining four spherical connecting elements 1 located in the middle layer, distributed symmetrically around the center. The eight straight rods 2 each extend from the top and bottom spherical connecting elements, four of which connect to the four spherical connecting elements 1 in the middle layer.

[0027] The spherical chain metamaterial 10 comprises a plurality of spherical cells 7, each of which is a spherical frame structure and is interconnected. Each spherical cell 7 comprises four curved rod components 3 and two spherical connecting components 1, with the spherical connecting components 1 located at the top and bottom of the structure, respectively. The top and bottom spherical connecting components 1 are connected by four curved rod components 3.

[0028] The spherical connection part 1 is a small rhombus truncated semicube, and a circular hole groove 101 is provided on the square surface of the spherical connection part 1, and the circular hole groove 101 runs through the entire spherical connection part 1; the straight rod part 2 is a cylindrical structure, and a straight rod tenon 201 is provided at both ends of the straight rod part 2. The straight rod part 2 is inserted into the circular hole groove 101 through the straight rod tenon 201 at its end to achieve an interference fit connection with the spherical connection part 1; the bent rod part 3 is a rod-shaped structure of 1 / 2 a circular ring, and a bent rod tenon 301 is provided at both ends of the bent rod part 3. The bent rod part 3 is inserted into the circular hole groove 101 through the bent rod tenon 301 provided at its end to achieve an interference fit connection with the spherical connection part 1; the spherical connection part 1, the straight rod part 2 and the bent rod part 3 are all prepared by a low-cost and high-efficiency fused deposition molding process. By changing the number of these three types of modular functional parts and their spatial position relationship, a cellular structure with differentiated mechanical response is assembled to meet the needs of different usage scenarios.

[0029] Specific implementation method 2: See Figures 19-25This embodiment is described in detail. The morphing wing based on a discretely assembled chain metamaterial structure described in this embodiment specifically comprises a skin, a wing frame 11, and a chain metamaterial interlayer. The chain metamaterial interlayer is encapsulated within a sealed shell and positioned on the wing frame 11. The skin is positioned externally to the wing frame 11 and the chain metamaterial interlayer. The chain metamaterial interlayer comprises an auxetic chain metamaterial 12, a microcrystalline chain metamaterial 9, and a spherical chain metamaterial 10. The auxetic chain metamaterial 12 replaces the compression-torsion chain metamaterial 8. The auxetic chain metamaterial 12, the microcrystalline chain metamaterial 9, and the spherical chain metamaterial 10 are sequentially interlocked. The auxetic chain metamaterial 12 is positioned at the base of the wing frame 11, while the spherical chain metamaterial 10 is positioned at the tip of the wing frame 11. After evacuation, the auxetic chain metamaterial 12 remains straight and does not bend, and its stiffness is significantly enhanced, serving as the rigid support region of the wing closest to the fuselage.

[0030] The auxetic chain metamaterial 12 comprises a plurality of auxetic cells 5, each of which is centrally symmetrical and interconnected. Each auxetic cell 5 comprises six spherical connecting elements 1 and twelve curved rod elements 3. The spherical connecting elements 1 are arranged at the vertices of an octahedron. The four outwardly facing inclined surfaces of each spherical connecting element 1 are aligned with the curved rod elements 3 to form the auxetic cell 5.

[0031] The other components and connection relationships of this embodiment are the same as those of the first embodiment.

[0032] To summarize the above implementation cases, the deformable wing based on a discretely assembled chain metamaterial structure described in the present invention, which is made of a wing structure made of several different chain metamaterials, can achieve flexible expansion of size and realize the construction of large-scale wings. At the same time, according to the characteristic that some configurations of chain metamaterials will bend and deform after vacuuming, the dynamic deformation of the wing at different angles can be achieved by adjusting the vacuum degree, and the effect of dynamically switching the wing shape under different flight scenarios can be achieved. The deformable wing based on a discretely assembled chain metamaterial structure described in the present invention solves the high cost problem of traditional selective laser sintering methods by assembling three types of modular functional parts prepared by the fused deposition modeling process into a chain metamaterial. By changing the number of the three types of modular functional parts and their spatial positional relationship, a cellular structure with differentiated mechanical response is assembled. The chain metamaterial formed by the interlocking of these cellular structures can meet the stiffness and deformation requirements in different scenarios. In addition, if the parts are damaged, they can be quickly replaced, achieving recycling, which is conducive to saving resources.

[0033] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is merely a specific embodiment of the present invention and is not intended to limit the invention. Reasonable combinations of the features described in the above embodiments are also possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A morphing wing based on a discretely assembled chain metamaterial structure, characterized by: The invention comprises a skin, a wing frame (11) and a chain metamaterial sandwich, wherein the chain metamaterial sandwich is encapsulated in a sealed shell and arranged on the wing frame (11), and a skin is arranged outside the wing frame (11) and the chain metamaterial sandwich; the chain metamaterial sandwich comprises a compression-torsion chain metamaterial (8), a microcrystalline chain metamaterial (9) and a spherical chain metamaterial (10), and the compression-torsion chain metamaterial (8), the microcrystalline chain metamaterial (9) and the spherical chain metamaterial (10) are connected in sequence; the compression-torsion chain metamaterial (8) is arranged at the root of the wing frame (11), and the spherical chain metamaterial (10) is arranged at the tip of the wing frame (11).

2. The morphing wing based on discrete assembly chain metamaterial structure according to claim 1, characterized in that: The compression-twist chain metamaterial (8) comprises a plurality of compression-twist cells (4), the compression-twist cells (4) being a frame-like structure, and the plurality of compression-twist cells (4) being interconnected and linked.

3. The morphing wing based on discrete assembly chain metamaterial structure according to claim 2, characterized in that: The compression-torsion cell (4) comprises two square rings, which are connected by four inclined straight rod parts (2); the square ring comprises four straight rod parts (2) and four spherical connecting parts (1), and the four straight rod parts (2) are connected end to end by the spherical connecting parts (1) to form a ring structure.

4. The morphing wing based on discrete assembly chain metamaterial structure according to claim 1, characterized in that: The microcrystal chain metamaterial (9) comprises a plurality of microcrystal cells (6), the microcrystal cells (6) being an octahedral framework structure, and the plurality of microcrystal cells (6) being interconnected.

5. The morphing wing based on discrete assembly chain metamaterial structure according to claim 4, characterized in that: The microcrystal cell (6) comprises eight straight rod parts (2) and six spherical connection parts (1), and the straight rod parts (2) are connected to each other via the spherical connection parts (1).

6. The morphing wing based on discrete assembly chain metamaterial structure according to claim 1, characterized in that: The spherical chain metamaterial (10) comprises a plurality of spherical cells (7), the spherical cells (7) being a spherical frame structure, and the plurality of spherical cells (7) being interconnected in a loop.

7. The morphing wing based on discrete assembly chain metamaterial structure according to claim 6, characterized in that: The spherical cell (7) comprises four curved rod parts (3) and two spherical connecting parts (1), and the curved rod parts (3) are connected to each other via the spherical connecting parts (1).

8. The morphing wing based on a discretely assembled chain metamaterial structure according to any one of claims 1 to 7, characterized in that: The sealing shell is provided with a valve which is connected to the vacuum pump; the sealing shell has a thickness of 0.2 mm and is made of thermoplastic polyurethane.

9. A morphing wing based on a discretely assembled chain metamaterial structure, characterized by: The invention comprises a chain metamaterial sandwich and the skin and wing frame (11) as claimed in claim 1, wherein the chain metamaterial sandwich is encapsulated in a sealed shell and arranged on the wing frame (11), and the wing frame (11) and the chain metamaterial sandwich are provided with a skin outside; the chain metamaterial sandwich comprises a tensile chain metamaterial (12) and the microcrystalline chain metamaterial (9) and the spherical chain metamaterial (10) as claimed in claim 1, and the tensile chain metamaterial (12), the microcrystalline chain metamaterial (9) and the spherical chain metamaterial (10) are connected in sequence; the tensile chain metamaterial (12) is arranged at the root of the wing frame (11), and the spherical chain metamaterial (10) is arranged at the tip of the wing frame (11).

10. The morphing wing based on discrete assembly chain metamaterial structure according to claim 9, characterized in that: The auxetic chain metamaterial (12) includes a plurality of auxetic cells (5), the auxetic cells (5) are of a centrally symmetrical structure, and the plurality of auxetic cells (5) are interconnected; the auxetic cells (5) include six spherical connecting parts (1) and twelve curved rod parts (3), the spherical connecting parts (1) are arranged according to the vertex positions of an octahedron, and the spherical connecting parts (1) are connected by curved rod parts (3).

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