A three-dimensional negative Poisson's ratio honeycomb structure with interlaced triangular inward-folded cylindrical cells

Abstract

This invention provides a negative Poisson's ratio honeycomb structure for aero-engines, relating to the field of aerospace technology, to address the technical problem of poor impact intrusion resistance in existing aero-engine structures. The honeycomb structure includes a ring structure formed by multiple sub-cells arranged circumferentially. Each sub-cell is surrounded by two mirror-symmetrical first faces and two mirror-symmetrical bent faces. The two bent faces bend in a direction approaching each other, and each bent face is formed by two mirror-symmetrical second faces. Each first and second face is triangular in shape and shares a common first vertex. The second vertices of each first and second face are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the ring structure. The second vertex refers to any vertex of each first and second face other than the first vertex. This honeycomb structure improves the impact intrusion resistance of traditional structures.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and more particularly to a negative Poisson's ratio honeycomb structure for aircraft engines and aircraft engines. Background Technology

[0002] Negative Poisson's ratio (NPR) structures exhibit unique counterintuitive deformation behavior, expanding laterally under axial tension and contracting internally under compression. NPR structures have broad application prospects in aerospace, civil engineering, automotive engineering, structural protection, and impact protection.

[0003] When a high-bypass turbofan engine blade misses and damages an aircraft, it needs to penetrate both the engine casing and the engine nacelle. Due to the complex load conditions of aero engines, negative Poisson's ratio structures can provide protection for the engine casing and nacelle. However, most existing negative Poisson's ratio structures are two-dimensional, with poor overall mechanical properties, and cannot effectively resist impact intrusion. Summary of the Invention

[0004] The purpose of this invention is to provide a negative Poisson's ratio honeycomb structure for aero engines and aero engines, so as to solve the technical problem of poor overall mechanical performance of existing aero engine structures.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a negative Poisson's ratio honeycomb structure for an aero-engine, comprising a ring structure formed by multiple sub-cells arranged circumferentially, wherein the sub-cells are formed by two mirror-symmetrical first surfaces and two mirror-symmetrical bent surfaces.

[0007] The two bending surfaces bend toward each other, and each bending surface is formed by two mirror-symmetric second surfaces; each of the first and second surfaces is triangular in shape and has a common first vertex;

[0008] The second vertices of each of the first and second faces are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the annular structure; wherein, the second vertex refers to the other vertices of each of the first and second faces besides the first vertex;

[0009] The first vertex of each of the sub-cells faces the central axis of the annular structure.

[0010] According to at least one embodiment of the present invention, the concavity angle θ of the sub-cell satisfies: 0° < θ < 60°; the concavity angle refers to the angle between the first surface and the first plane;

[0011] The first plane is perpendicular to the central axis of the subcell.

[0012] According to at least one embodiment of the present invention, the thickness of both the first surface and the second surface is t and satisfies: 0.25mm≤t<2R;

[0013] Where R is the radius of the cylindrical surface.

[0014] According to at least one embodiment of the present invention, the honeycomb structure includes cells, wherein the cells are a plurality of ring structures connected along a first direction, and adjacent ring structures are staggered in the circumferential direction; wherein, the first direction refers to the axial direction of the ring structures;

[0015] The phase difference between two adjacent ring structures in the circumferential direction is 180° / N, where N is the number of sub-cells in the same ring structure, and N is a positive integer greater than 1.

[0016] According to at least one embodiment of the present invention, the number N of the sub-cells in the same ring structure satisfies: 3≤N≤16.

[0017] According to at least one embodiment of the present invention, the cell has two end faces, the shape of the end faces being a preset shape, the preset shape being: the shape of the annular structure intersecting with the second plane;

[0018] The second plane is perpendicular to the first direction and passes through the center point of the annular structure.

[0019] According to at least one embodiment of the present invention, the cellular structure includes a plurality of cells, which are arranged in an array and connected along a second direction and a third direction;

[0020] Along the second direction, multiple cells are sequentially connected to form a cell group;

[0021] Along the third direction, the multiple cell groups are staggered;

[0022] In the second direction, the distance between corresponding cells in two adjacent cell groups is R.

[0023] According to at least one embodiment of the present invention, the honeycomb structure is made of one of the following materials: shape memory alloy, aluminum alloy, titanium alloy, stainless steel, high-temperature alloy, polylactic acid, and thermoplastic polyurethane.

[0024] According to at least one embodiment of the present invention, the Poisson's ratio of the honeycomb structure ranges from -0.8 to -0.2.

[0025] In a second aspect, the present invention also provides an aircraft engine, wherein the casing and / or nacelle of the aircraft engine includes the honeycomb structure described in the first aspect.

[0026] In one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0027] The negative Poisson's ratio honeycomb structure for aero-engines, an exemplary embodiment of the present invention, comprises a ring structure formed by multiple sub-cells arranged in a circumferential array. This ring structure has a cylindrical surface passing through the second vertex of each sub-cell, with each sub-cell situated on the same cylindrical surface; that is, the outer contour of the ring structure is a cylindrical surface. Each sub-cell is enclosed by two mirror-symmetrical first faces and two mirror-symmetrical bent faces. The two bent faces bend in a direction approaching each other, and each bent face is formed by two mirror-symmetrical second faces. Each first and second face is triangular in shape and shares a common first vertex. Thus, the sub-cell can be considered a quadrangular pyramidal tube with a cavity and an opening. After the first faces and bent faces alternately enclose the structure, each bent face is recessed into the pyramid at the point where the two second faces meet, thereby forming a hexagonal pyramidal tube with a pyramidal structure. The first vertex of each sub-cell (each first and second face is triangular in shape and shares a common first vertex) is inside the ring structure and faces the central axis of the ring structure, while the openings of each sub-cell are all located on the outer contour of the ring structure. The central axis of each sub-cell extends radially along the ring structure. Simulated compressive load experiments and actual load experiments demonstrate that the honeycomb structure for aero-engines according to the exemplary embodiment of this invention exhibits significant negative Poisson's ratio performance and good stability without instability, thus improving the overall mechanical performance of the aero-engine structure.

[0028] Furthermore, the cavity features (with sub-cells being conical structures) of the honeycomb structure for aero-engines in the exemplary embodiments of the present invention can achieve structural lightweighting and enhance overall structural stability by leveraging the negative Poisson's ratio effect, making it suitable for the weight-sensitive aerospace field. Attached Figure Description

[0029] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0030] Figure 1 This is an axonometric structural diagram of a cell in a honeycomb structure according to an embodiment of the present invention;

[0031] Figure 2 This is an axonometric structural diagram of a cell in a honeycomb structure according to an embodiment of the present invention;

[0032] Figure 3 This is a front view schematic diagram of a ring structure according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the concave angle of a subcell according to an embodiment of the present invention;

[0034] Figure 5 This is an isometric structural diagram of a honeycomb structure according to an embodiment of the present invention;

[0035] Figure 6 This is a top view schematic diagram of a honeycomb structure according to an embodiment of the present invention;

[0036] Figure 7 This is a deformation cloud diagram of a honeycomb structure according to an embodiment of the present invention under static compressive load;

[0037] Figure 8 This is a curve showing the relationship between Poisson's ratio and concave angle of a honeycomb structure under static compressive load according to an embodiment of the present invention.

[0038] Figure 9 This is a curve showing the relationship between Poisson's ratio and the radius of the annular structure under static compressive load according to an embodiment of the present invention.

[0039] Reference numerals: 10, sub-cell; 11, first face; 12, second face; 31, first vertex; 32, second vertex; 40, cylindrical face; 41, first plane; 100, ring structure; 200, cell. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0041] Figure 1 This is an axonometric structural diagram of a cell in a honeycomb structure according to an embodiment of the present invention; Figure 2 This is an axonometric structural diagram of a cell in a honeycomb structure according to an embodiment of the present invention;

[0042] Figure 3 This is a front view schematic diagram of the ring structure according to an embodiment of the present invention. Figures 1-3As shown, the negative Poisson's ratio honeycomb structure for an aero-engine provided by an exemplary embodiment of the present invention includes an annular structure 100 formed by a plurality of sub-cells 10 arranged circumferentially. Each sub-cell 10 is formed by two mirror-symmetrical first surfaces 11 and two mirror-symmetrical bent surfaces. The two bent surfaces are bent in a direction that approaches each other, and each bent surface is formed by two mirror-symmetrical second surfaces 12. The shape of each first surface 11 and each second surface 12 is triangular and has a common first vertex 31. The second vertices 32 of each first surface 11 and each second surface 12 are all located on the same cylindrical surface 40, and the central axis of the cylindrical surface 40 coincides with the central axis of the annular structure 100. The second vertex 32 refers to the other vertices of each first surface 11 and each second surface 12 besides the first vertex 31. The first vertices 31 of each sub-cell 10 are all oriented towards the central axis of the annular structure 100.

[0043] In practical applications, the honeycomb structure includes sub-cells 10 arranged in an array along the circumference to form a roughly ring-shaped ring structure 100. Multiple ring structures 100 are staggered along the axial direction to form a cylindrical cell 200. Specifically, the sub-cell 10 is a cone-shaped structure with six faces, all of which share a common first vertex 31. The opening of the sub-cell 10 faces outward from the ring structure 100. The six faces include two first faces 11 that are mirror-symmetrical about a first plane of symmetry (the face passing through the first vertex 31), and two bent faces (each bent face is formed by splicing two second faces 12, for a total of four second faces 12). The two second faces 12 are mirror-symmetrical about a second plane of symmetry (the face passing through the first vertex 31) and are connected to form bent faces, meaning that the two second faces 12 are not on the same plane. The other two second faces 12 form bent faces that are mirror-symmetrical to the bent faces mentioned above, and the two bent faces are mirror-symmetrical about a third plane of symmetry (the face passing through the first vertex 31). The first, second, and third planes of symmetry are all perpendicular to each other and all pass through the first vertex 31.

[0044] The two bent surfaces bend in a direction that brings them closer to each other; that is, the distance between the second vertices 32 of the two bent surfaces that are not shared with the first surface 11 is less than the distance between the two second vertices 32 shared by the first surface 11. Figure 2 As shown, the cone-shaped structure of the subcell 10 can be regarded as a pyramidal structure with two concave sides and two flat sides.

[0045] For example, the second vertices 32 of each of the first surfaces 11 and the second surfaces 12 are all located on the same cylindrical surface 40, and the central axis of the cylindrical surface 40 coincides with the central axis of the annular structure 100. That is, the first vertices 31 are all facing the central axis of the cylindrical surface 40, while the second vertices 32 are all away from the central axis of the cylindrical surface 40.

[0046] For example, in each sub-cell 10, the first surface 11 between two adjacent sub-cells 10 in the same annular structure 100 is a shared surface (which can be regarded as the first surface 11 of each sub-cell 10 being a wall surface with 1 / 2 wall thickness, and the first surface 11 of two adjacent sub-cells 10 being a wall surface with a full wall thickness).

[0047] Figure 4 This is a schematic diagram of the concave angle of a daughter cell according to an embodiment of the present invention. For example... Figure 4 As shown, the dotted circular line represents a top view of the cylindrical surface 40 (virtual), with a radius of R. This cylindrical surface 40 passes through the second vertex 32 of each sub-cell 10, meaning that the distance between the second vertex 32 of each sub-cell 10 and the central axis of the annular structure 100 or the cylindrical surface 40 is the same. In other words, the projections of the second vertices 32 of each sub-cell 10 onto a preset plane lie on the same circle, and this preset plane is a plane perpendicular to the central axis of the annular structure 100. It can be understood that the cylindrical surface 40 is a virtual, thicknessless cylindrical surface, also known as a toroidal surface.

[0048] The first plane 41 is also a virtual plane. Figure 4 The straight dashed line is a top view of the schematic diagram. It is perpendicular to the radial direction of the cylindrical surface 40, that is, perpendicular to the central axis of the sub-cell 10. It can be understood that the extension direction of the central axis is the radial direction of the cylindrical surface 40. The first plane 41 is parallel to or coincides with the tangent plane of the cylindrical surface 40 at the sub-cell 10.

[0049] Continue as Figure 4 As shown, the angles between the two first surfaces 11 and the first plane 41, i.e., the concave angles θ, are the same. The value of θ is in the range of 0° < θ < 60°, for example, it can be 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or any two of the above values. Within the range of the above concave angles, the Poisson's ratio and stiffness of the entire honeycomb structure can be flexibly adjusted to adapt to the needs of different application scenarios, control the number of basic sub-cells 10, and optimize the density of the honeycomb structure.

[0050] Continue as Figure 3As shown, in some embodiments, the thickness of each first surface 11 and second surface 12 is the same, that is, the thickness t of the wall surface (both the first surface 11 and the second surface 12 can be referred to as the wall surface) of the cone-shaped structure is in the range of 0.25mm≤t<2R. For the ring structure 100, the first surface 11 of the sub-cell 10 and the adjacent sub-cell 10 share a wall surface, which can be regarded as the wall thickness of the first surface 11 of each sub-cell 10 being t / 2. Within the above-mentioned range of wall thickness, the Poisson's ratio and stiffness of the entire honeycomb structure can be flexibly adjusted to adapt to the needs of different application scenarios. The number of basic units (sub-cells 10) can be controlled according to specific application requirements to optimize the structural density.

[0051] like Figure 1 As shown, in some embodiments, the cellular structure includes cells 200, which are multiple ring structures 100 connected along a first direction, with adjacent ring structures 100 staggered in the circumferential direction; wherein, the first direction refers to the axial direction of the ring structure 100; the phase difference between two adjacent ring structures 100 in the circumferential direction is 180° / N, wherein, N is the number of sub-cells 10 in the same ring structure 100, and N is a positive integer.

[0052] The cell 200 of the honeycomb structure is composed of multiple ring structures 100 arranged along a first direction, wherein adjacent ring structures 100 are staggered. Figure 1 Taking the vertical direction (first direction) as an example, the phase difference between the ring structure 100 in the upper layer and the ring structure 100 in the lower layer in the circumferential direction is 180° / N.

[0053] For example, when the ring structure 100 is formed by 6 sub-cells 10, the circumferential phase difference between the ring structure 100 of the upper layer and the ring structure 100 of the lower layer is 30°, and so on. Thus, the second vertex 32 of the bending surface of the upper layer that does not intersect with the first surface 11 coincides with the first vertex 31 of the first surface 11 of the lower layer; the second vertex 32 of the first surface 11 of the upper layer coincides with the second vertex 32 of the bending surface of the lower layer that does not intersect with the first surface 11, thereby forming two connected ring structures 100.

[0054] For example, the number N of sub-cells 10 in the same ring structure 100 satisfies: 3 ≤ N ≤ 10000. For example, N can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 50, 100, 200, 500, 1000, 2000, 3000, 5000, 7000, 8000, or 9000.

[0055] Figure 5 This is an isometric structural diagram of a honeycomb structure according to an embodiment of the present invention. (Combined with...) Figure 1 and Figure 5As shown, cell 200 has two end faces, and the shape of the end faces is a preset shape. The preset shape refers to the shape of the ring structure 100 intersecting with the second plane; wherein, the second plane is perpendicular to the first direction and passes through the center point of the ring structure 100.

[0056] In practical applications, the two end faces of cell 200 are two-dimensional planes, which can be used as load-bearing parts. The parts located at both ends of cell 200 can be regarded as the upper and lower parts of the ring structure 100 in the middle of the axial direction. That is, the two ends of cell 200 are half of the ring structure 100 in the axial direction, or the parts located at both ends of cell 200 are half of the ring structure, not the whole ring structure, while the parts located in the middle of cell 200 are the whole ring structure.

[0057] In some embodiments, the cellular structure includes a plurality of cells 200, which are arranged in an array and connected along a second direction and a third direction; along the second direction, the plurality of cells 200 are connected in sequence to form a group of cells 200; along the third direction, the groups of cells 200 are staggered, wherein, in the second direction, the distance between corresponding cells 200 in two adjacent groups of cells 200 is R.

[0058] Figure 6 This is a top view schematic diagram of a honeycomb structure according to an embodiment of the present invention. (Combined with...) Figures 5-6 As shown, cell 200 consists of multiple ring structures 100 arranged along the first direction, while the honeycomb structure is formed by connecting multiple cell arrays 200. In the second direction, each cell array 200 is arranged and connected to form a cell group 200, with a distance R between adjacent cells 200. In the third direction, each cell group 200 is arranged in an array. Specifically, adjacent cell groups 200 are staggered, and the distance R between corresponding cells 200 in different cell groups 200 forms an interconnected and complete honeycomb structure.

[0059] In some embodiments, the honeycomb structure provided by the exemplary embodiments of the present invention can be made of one of the following materials: shape memory alloy, aluminum alloy, titanium alloy, stainless steel, polylactic acid, and thermoplastic polyurethane. The shape memory alloy can be nickel-based shape memory alloy, iron-based shape memory alloy, copper-based shape memory alloy, etc. The honeycomb structure can also be made of other superelastic materials or metals.

[0060] For example, the honeycomb structure provided in the exemplary embodiment of the present invention can be prepared by additive manufacturing 3D printing technology. The integrated molding technology of additive manufacturing can reduce assembly steps and improve the overall rigidity of the honeycomb structure.

[0061] For example, the Poisson's ratio of the honeycomb structure provided in the exemplary embodiment of the present invention ranges from -0.8 to -0.2, and can be, for example, -0.2, -0.3, -0.4, -0.5, -0.6, -0.7, -0.8 or within any two of the above values.

[0062] Calculation Example

[0063] In the preprocessing module of Ansys finite element software, material parameters are first set for the honeycomb structure, the finite element mesh of the structure is generated, the analysis step, boundary conditions and load conditions are set, and the contact properties are set, so as to perform out-of-plane quasi-static compression simulation calculation of the honeycomb structure.

[0064] The honeycomb structure is formed by 36 cells 200 stacked and connected in a 6×6 honeycomb pattern. Each cell 200 is formed by 7 layers of ring structures 100 and two loading parts (half ring structures 100) respectively located at both ends of the first direction. The end face is flat. Each layer of ring structure 100 is formed by 6 sub-cells 10 stacked in a circumferential array. The phase difference between two adjacent layers of ring structures 100 in the circumferential direction is 60°. The wall thickness t of the ring structure 100 is 0.5 mm.

[0065] Material parameters were set in Ansys finite element simulation software. A photocurable resin was selected as the research object, with an elastic modulus E = 2.7 GPa and a Poisson's ratio μ = 0.38.

[0066] Experimental Example

[0067] The honeycomb structure is formed by 36 cells 200 stacked in a 6×6 honeycomb pattern. Each cell 200 is formed by 7 layers of ring structures 100 and two loading parts (half ring structures 100) at both ends. The end face is flat. Each layer of ring structure 100 is formed by 6 sub-cells 10 stacked in a circumferential array. The phase difference between two adjacent layers of ring structures 100 in the circumferential direction is 60°. The wall thickness t of the ring structure 100 is 0.5 mm.

[0068] Honeycomb structures with different concave angles or different annular radii were prepared by additive manufacturing 3D printing technology (using high-toughness thermoplastic polyurethane elastomer material (TPU)), and the Poisson's ratio of each honeycomb structure under static compressive load in the first direction was measured.

[0069] Figure 7 This is a deformation contour plot of a honeycomb structure according to an embodiment of the present invention under static compressive load. See also Figure 7As shown in the figure, the deformation cloud diagram of the honeycomb structure in the calculation example under static compressive load (compressive load is applied in the axial direction (first direction) of cell 200) (the black line of the outer frame is the outline of the undeformed model) clearly shows that the honeycomb structure provided by the exemplary embodiment of the present invention has significant negative Poisson ratio performance and good stability without instability.

[0070] Figure 8 This is a curve showing the relationship between Poisson's ratio and concavity angle of a honeycomb structure under static compressive load according to an embodiment of the present invention. Figure 8 As shown, under static compressive load, when the concavity angle θ increases from 25° to 40°, the Poisson's ratio of the honeycomb structure provided by the exemplary embodiment of the present invention decreases from -0.42 to -0.71, exhibiting a significant negative Poisson's ratio characteristic. Meanwhile, the experimental values ​​(concavity angles θ of 30° and 35°) verify the accuracy of the Poisson's ratio values.

[0071] Figure 9 This is a curve showing the relationship between Poisson's ratio and the radius of the annular structure 100 under static compressive load according to an embodiment of the present invention. Figure 9 As shown in the exemplary embodiment of the present invention, under static compressive load, when the radius R of the annular structure 100 increases from 5 mm to 20 mm, the Poisson's ratio of the honeycomb structure first decreases and then increases, ranging from -0.32 to -0.62, exhibiting a significant negative Poisson's ratio characteristic. Meanwhile, the experimental values ​​(radius R of 10 mm and 15 mm) verify the accuracy of the Poisson's ratio values.

[0072] An exemplary embodiment of the present invention also provides an aircraft engine, wherein the casing and / or nacelle of the aircraft engine include the honeycomb structure of the above embodiments.

[0073] The aforementioned aero-engine casing and / or nacelle are constructed using a multi-layered structure combining localized reinforcing ribs, Kevlar winding, and a honeycomb structure to enhance their penetration resistance and provide primary protection. The engine nacelle often employs a honeycomb sandwich structure in areas such as the air intake cowling and fan shroud, providing supplementary containment. The honeycomb structure is lightweight, highly rigid, and deforms under impact loads, exhibiting a strong energy absorption effect.

[0074] Since high-bypass turbofan engine blades can cause damage to aircraft when they fly off, it is necessary to penetrate the two-layer structure of the engine casing and engine nacelle. The engine casing and engine nacelle formed by the honeycomb structure of the exemplary embodiment of the present invention have a negative Poisson's ratio structure that can meet the requirements of complex stress environment in actual working conditions in three-dimensional space applications, and greatly improve the anti-intrusion effect.

[0075] The other technical advantages of the aforementioned aero-engine compared to the prior art are the same as the technical advantages of the honeycomb structure in the above-described embodiments, and will not be repeated here.

[0076] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A negative Poisson's ratio honeycomb structure for aircraft engines, characterized in that, It includes a ring structure formed by multiple sub-cells arranged circumferentially, wherein each sub-cell is formed by two mirror-symmetrical first surfaces and two mirror-symmetrical bent surfaces; The two bending surfaces bend toward each other, and each bending surface is formed by two mirror-symmetric second surfaces; each of the first and second surfaces is triangular in shape and has a common first vertex; The second vertices of each of the first and second faces are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the central axis of the annular structure; wherein, the second vertex refers to the other vertices of each of the first and second faces besides the first vertex; The concavity angle θ of the sub-cell satisfies: 0° < θ < 60°; the concavity angle refers to the angle between the first surface and the first plane; Wherein, the first plane is perpendicular to the central axis of the sub-cell; The thickness of both the first and second surfaces is t and satisfies: 0.25mm ≤ t < 2R; Where R is the radius of the cylindrical surface; The honeycomb structure includes cells, which are multiple ring structures connected along a first direction, with adjacent ring structures staggered in the circumferential direction; wherein, the first direction refers to the axial direction of the ring structure; The phase difference between two adjacent ring structures in the circumferential direction is 180° / N, where N is the number of sub-cells in the same ring structure, and N is a positive integer greater than 1.

2. The honeycomb structure according to claim 1, characterized in that, The number N of the sub-cells in the same ring structure satisfies: 3 ≤ N ≤ 10000.

3. The honeycomb structure according to claim 1, characterized in that, The cell has two end faces, and the shape of the end faces is a preset shape, which refers to the shape of the annular structure intersecting with the second plane; The second plane is perpendicular to the first direction and passes through the center point of the annular structure.

4. The honeycomb structure according to any one of claims 1-3, characterized in that, The cellular structure includes a plurality of cells, which are arranged in an array and connected along a second direction and a third direction. Along the second direction, multiple cells are sequentially connected to form a cell group; Along the third direction, the multiple cell groups are staggered; In the second direction, the distance between corresponding cells in two adjacent cell groups is R.

5. The honeycomb structure according to claim 4, characterized in that, The honeycomb structure is made of one of the following materials: shape memory alloy, aluminum alloy, titanium alloy, stainless steel, polylactic acid, and thermoplastic polyurethane.

6. The honeycomb structure according to claim 5, characterized in that, The Poisson's ratio of the honeycomb structure ranges from -0.8 to -0.

2.

7. An aircraft engine, characterized in that, The casing and / or nacelle of the aircraft engine include the honeycomb structure as described in any one of claims 1-6.

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