Catenary level concave honeycomb cell and multi-cell structure

Abstract

This invention belongs to the field of mechanical metamaterials technology and discloses a catenary-level concave honeycomb cell and multi-cell structure. It includes catenary-level units, each comprising two curved catenary edges and one straight edge. The two curved catenary edges are symmetrically arranged on both sides of the straight edge, and the ends of the curved catenary edges connect to the ends of the straight edge. The honeycomb cell is a symmetrical, concave hexagonal structure, including two horizontal cell walls and four inclined cell walls, which are formed by sequentially connecting multiple catenary-level units. The multi-cell honeycomb structure is composed of multiple honeycomb cells arranged in a periodic array in a plane. The catenary-level concave honeycomb structure provided by this application exhibits stable deformation and load-bearing capacity, enhances the negative Poisson's ratio effect, and significantly improves load-bearing and energy absorption performance.

Description

Technical Field

[0001] This invention relates to the field of mechanical metamaterials technology, specifically to a catenary-level concave honeycomb cell and multi-cell structure. Background Technology

[0002] Honeycomb structure is a new type of structure with high porosity and lightweight. It has advantages such as high specific strength, specific stiffness, vibration reduction and noise reduction, impact energy absorption and designability. It has broad application prospects in fields such as construction, automobiles, railway vehicles, ships, aerospace, satellites, packaging and medical implants.

[0003] The mechanical properties of honeycomb structures can be adjusted by modifying their unit cell structure and arrangement. Traditional honeycomb structures are regular hexagons; when converted to concave hexagons, they exhibit a unique negative Poisson's ratio effect: the material widens perpendicular to the stretching direction when stretched and narrows perpendicular to the compression direction when compressed. This special deformation characteristic indicates that the structure possesses lightweight, vibration isolation, high energy absorption, and high damping properties. However, traditional concave honeycomb structures rely solely on plastic hinges at the nodes to absorb energy, resulting in low energy absorption efficiency, which cannot meet the energy absorption requirements for impact protection.

[0004] In recent years, researchers have further improved the impact resistance of concave honeycomb structures by mimicking the circular hierarchical structure of biological tissues. However, the goal of biological evolution is primarily to enhance strength and stiffness for defense, rather than energy absorption through large deformation. During compression, the circular hierarchical units of the circular concave honeycomb undergo tensile deformation, disrupting the rotational deformation of the cell walls around the nodes and weakening the negative Poisson effect. This weaker negative Poisson ratio effect cannot fully compress the hierarchical units to absorb energy, resulting in the hierarchical units' energy absorption potential not being fully released. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, a catenary-level concave honeycomb cell and multi-cell structure is provided, which solves the problem of insufficient energy absorption performance of existing concave-level honeycomb structures.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A catenary-level concave honeycomb cell includes a catenary-level unit, wherein the catenary-level unit includes two catenary curved edges and one straight edge, the two catenary curved edges are symmetrically arranged on both sides of the straight edge, and the two ends of the catenary curved edges are connected to the two ends of the straight edge. The honeycomb cell is a concave hexagonal structure that is symmetrical in all directions, including two horizontal cell walls and four inclined cell walls. The horizontal cell walls and inclined cell walls are formed by connecting multiple catenary hierarchical units in sequence.

[0007] According to the above technical solution, the catenary curved edge is an axially non-stretchable homogeneous component with a uniform cross-section.

[0008] According to the above technical solution, the curved edge and straight edge of the catenary have the same cross-section.

[0009] According to the above technical solution, the length of the horizontal cell wall is at least twice the length of the inclined cell wall.

[0010] According to the above technical solution, the horizontal cell wall comprises six catenary hierarchical units.

[0011] According to the above technical solution, the inclined cell wall includes three catenary hierarchical units.

[0012] According to the above technical solution, the cell is made by stamping, extrusion or 3D printing.

[0013] According to the above technical solution, the material for preparing the honeycomb cells is metallic aluminum.

[0014] This application also provides a catenary-level concave honeycomb multicell structure, comprising a plurality of the above-described honeycomb cells, wherein the plurality of honeycomb cells are periodically arrayed in a plane.

[0015] According to the above technical solution, in the vertical direction, the upper and lower honeycomb cells share a horizontal cell wall; in the horizontal direction, multiple honeycomb cells are interconnected by sharing an inclined cell wall.

[0016] The present invention has the following beneficial effects: 1. This invention proposes a catenary hierarchical concave honeycomb structure composed of multiple catenary hierarchical units. The catenary hierarchical units exhibit high load-bearing capacity, with deformation in the low strain range primarily characterized by the rotation of interlayer cell walls around their endpoints. This avoids random bending of the cell walls during compression, achieving overall ordered deformation and demonstrating stable deformation and load-bearing capacity. Furthermore, it enhances the negative Poisson's ratio effect, which accelerates material convergence towards the impact region, thereby forcing the catenary hierarchical units to deform through mutual compression, significantly improving load-bearing and energy absorption performance.

[0017] 2. The catenary-level concave honeycomb multi-cell structure proposed in this invention has the advantages of high energy absorption and high load-bearing capacity, and can be used in high-end equipment protection scenarios such as aircraft landing buffer, special vehicle explosion protection armor, and battlefield defense structures. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the construction of the catenary hierarchical unit in an embodiment of the present invention; Figure 2 This is a schematic diagram of a cellular cell in an embodiment of the present invention; Figure 3 This is a schematic diagram of the honeycomb multicell structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the deformation modes of the honeycomb multicell structure under different strains in an embodiment of the present invention; Figure 5 These are stress-strain diagrams of the honeycomb multicell structure and the traditional concave honeycomb structure under low-speed impact in the embodiments of the present invention. Figure 6 This is a dynamic Poisson's ratio diagram of the honeycomb multicell structure and the traditional concave honeycomb structure under low-speed impact in an embodiment of the present invention.

[0019] In the figure: 1. Catenary hierarchical unit; 11. Curved edge; 12. Straight edge; 2. Horizontal cell wall; 3. Inclined cell wall; 4. Honeycomb cell; 5. Fixing plate; 6. Impact plate; 7. Traditional concave honeycomb structure. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Reference Figures 1-6 As shown, the present invention provides a catenary-level concave honeycomb cell and multi-cell structure.

[0022] Example 1 The structure includes a catenary hierarchical unit 1, which comprises two catenary curved edges 11 and one straight edge 12. The two catenary curved edges 11 are symmetrically arranged on both sides of the straight edge 12, and the two ends of the catenary curved edges 11 are connected to the two ends of the straight edge. The honeycomb cell 4 is a concave hexagonal structure that is symmetrical in all directions, including two horizontal cell walls 2 and four inclined cell walls 3. The horizontal cell walls 2 and the inclined cell walls 3 are formed by connecting multiple catenary hierarchical units 1 in sequence.

[0023] Furthermore, a catenary refers to a flexible, inextensible chain, fixed at both ends, with uniform thickness and mass distribution, which forms a curve after reaching equilibrium under gravity. When using the catenary configuration to design arched structures, its unique pure compressive force structural characteristics can achieve high load-bearing capacity. Therefore, architects have built numerous arched structures over the centuries, such as arched bridges, arched doorways, and arched roofs. Inspired by the high load-bearing capacity of catenary structures, this application proposes a catenary hierarchical unit to achieve efficient energy absorption in catenary hierarchical concave honeycomb structures.

[0024] Furthermore, the parametric equation of the catenary curve is:

[0025] In the formula, cosh is the hyperbolic cosine function. It is a constant related to the catenary function.

[0026] in, Satisfy the following formula:

[0027] In the formula, This represents the distance between two suspension points on the catenary curve. This represents the total length of the catenary.

[0028] It should be noted that, according to the catenary equation, once the length of the straight side 12 is determined, the shape of the curved side 11 can only be adjusted by changing its length.

[0029] Furthermore, the catenary curved edge 11 is an axially non-stretchable homogeneous component with a uniform cross-section, and the catenary curved edge 11 and the straight edge 12 have the same cross-section.

[0030] Furthermore, such as Figure 2 As shown, the honeycomb cell 4 consists of two horizontal cell walls 2 and four inclined cell walls 3, specifically a concave hexagonal structure that is symmetrical vertically and horizontally. The length of the horizontal cell wall 2 is defined as... The length of the inclined cell wall 3 is The distance between the two horizontal cell walls 2 is The angle between the horizontal cell wall 2 and the inclined cell wall 3 is Then, the following geometric relationship exists for cell 4: , The length of the horizontal cell wall 2 is at least twice the length of the inclined cell wall 3. This is to ensure that the honeycomb cell 4 can be completely deformed under pressure until the two horizontal cell walls 2 come into contact, thus ensuring the buffering and energy absorption effect.

[0031] Furthermore, the material used to prepare the honeycomb cell 4 is metallic aluminum.

[0032] Furthermore, the cellular cell 4 is made by stamping, extrusion or 3D printing.

[0033] This embodiment also provides a catenary-level concave honeycomb multi-cell structure, including multiple honeycomb cells 4, which are periodically arrayed in a plane. In the vertical direction, the upper and lower honeycomb cells 4 share a horizontal cell wall 2; in the horizontal direction, the multiple honeycomb cells 4 are interconnected by sharing an inclined cell wall 3, and the distance between two adjacent honeycomb cells 4 is half the height of the honeycomb cell 4.

[0034] Example 2 The principle and technical solution of Embodiment 2 are basically the same as those of Embodiment 1. The difference is that a specific honeycomb multi-cell structure is given and compared with the traditional concave honeycomb structure 7.

[0035] Furthermore, such as Figure 3 As shown, the cross-sections of the catenary curved edge 11 and straight edge 12 are preferably rectangular. The length of the horizontal cell wall 2 is preferably six catenary hierarchical units 1, and the length of the inclined cell wall 3 is preferably three catenary hierarchical units 1. The included angle between the horizontal cell wall 2 and the inclined cell wall 3 is preferably 70°. A honeycomb cell 4 is formed by combining two horizontal cell walls 2 and four inclined cell walls 3. The material of the honeycomb cell 4 is set to aluminum, and the wall thickness is set to 0.1 mm. The honeycomb cell 4 is arrayed in 13 and 10 arrays in the x and y directions, respectively, to obtain a honeycomb multi-cell structure. Using finite element analysis software, the honeycomb multi-cell structure is placed between a fixed plate 5 and an impact plate 6, which impacts the honeycomb multi-cell structure at a speed of 3 m / s. It should be noted that in the finite element model, there is overlap of the catenary hierarchical units 1 at the connection between the horizontal cell wall 2 and the inclined cell wall 3.

[0036] Furthermore, such as Figure 4 As shown, the traditional concave honeycomb structure 7 exhibits local deformation and unstable deformation during in-plane compression. However, the honeycomb multi-cell structure of this application, due to the high load-bearing capacity of the catenary hierarchical unit 1, mainly undergoes rotational deformation of the horizontal cell wall 2 and the inclined cell wall 3 around their endpoints before the strain reaches 0.6, achieving overall orderly deformation and demonstrating stable deformation and load-bearing capacity, thus exhibiting better deformation stability.

[0037] Furthermore, the energy absorption performance of a structure refers to the energy absorbed by the structure during plastic deformation; therefore, a higher stress-strain curve indicates superior energy absorption performance. For example... Figure 5 As shown in the figure, the stress-strain curve of the honeycomb multicell structure of this application is much higher than that of the traditional concave honeycomb structure 7, indicating that the load-bearing capacity and energy absorption capacity of the honeycomb multicell structure are significantly improved. Furthermore, as... Figure 6 As shown, the negative Poisson's ratio effect of the honeycomb multicell structure in this application is also superior to that of the traditional concave honeycomb structure 7. In summary, introducing catenary hierarchical units 1 into the traditional concave honeycomb structure 7 can significantly improve mechanical properties.

[0038] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A catenary-level concave honeycomb cell, characterized in that: It includes a catenary hierarchical unit, which includes two catenary curved edges and one straight edge. The two catenary curved edges are symmetrically arranged on both sides of the straight edge, and the two ends of the catenary curved edges are connected to the two ends of the straight edge. The honeycomb cell is a concave hexagonal structure that is symmetrical in all directions, including two horizontal cell walls and four inclined cell walls. The horizontal cell walls and inclined cell walls are formed by connecting multiple catenary hierarchical units in sequence.

2. The catenary-level concave honeycomb cell according to claim 1, characterized in that: The catenary curve is an axially non-stretchable homogeneous component with a uniform cross-section.

3. The catenary-level concave honeycomb cell according to claim 1, characterized in that: The curved and straight sides of the catenary have the same cross-section.

4. The catenary-level concave honeycomb cell according to claim 1, characterized in that: The length of the horizontal cell wall is at least twice the length of the inclined cell wall.

5. A catenary-level concave honeycomb cell according to claim 4, characterized in that: The horizontal cell wall comprises six catenary hierarchical units.

6. A catenary-level concave honeycomb cell according to claim 4, characterized in that: The inclined cell wall comprises three catenary hierarchical units.

7. A catenary-level concave honeycomb cell according to claim 1, characterized in that: The cell is made by stamping, extrusion or 3D printing.

8. A catenary-level concave honeycomb cell according to claim 1, characterized in that: The cell material used to prepare the honeycomb cells is aluminum.

9. A catenary-level concave honeycomb multicellular structure, characterized in that: It includes a plurality of cellular cells as described in any one of claims 1-8, wherein the plurality of cellular cells are periodically arrayed in a plane.

10. A catenary-level concave honeycomb multicellular structure according to claim 9, characterized in that: In the vertical direction, the upper and lower honeycomb cells share a horizontal cell wall; in the horizontal direction, multiple honeycomb cells are interconnected by sharing an inclined cell wall.

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