A three-dimensional bionic fishbone negative Poisson's ratio lattice and honeycomb combined structure

Abstract

The present invention relates to the technical field of negative Poisson's ratio lattice, and in particular to a three-dimensional bionic fishbone negative Poisson's ratio lattice and a honeycomb combination structure. The three-dimensional bionic fishbone negative Poisson's ratio lattice comprises a plurality of evenly distributed pillars connected by nodes; the pillars comprise a bottom plate, a side plate and a top plate; the bottom plate and the top plate are respectively connected to the first end and the second end of the top plate; the top plate and the bottom plate are respectively located on both sides of the top plate, and an angle exists between the top plate, the bottom plate and the top plate. The present invention adopts a lattice connection method different from the traditional structure in the connection method of the honeycomb lattice, so that the lattice can not produce macroscopic tilt due to uneven force after deformation under uniaxial compression.

Description

Technical Field

[0001] The present invention relates to the technical field of negative Poisson's ratio lattice, in particular to a three-dimensional bionic fishbone negative Poisson's ratio lattice and a honeycomb combined structure. Background Art

[0002] The concept of Poisson's ratio (v), first proposed by French scientist Siméon Denis Poisson in 1829, can be understood as the lateral displacement and deformation characteristic of a material perpendicular to the direction of the applied force, also known as the lateral deformation coefficient. Materials with negative mechanical properties are called mechanical metamaterials, among which negative Poisson's ratio metamaterials are particularly prominent.

[0003] Negative Poisson's ratio mechanical metamaterials possess unique properties that differ from those of ordinary materials, including high energy absorption, high specific stiffness, impact resistance, and vibration isolation. However, despite the continuous efforts of scientists, research on innovative single negative Poisson's ratio structures has become extremely difficult. Combining negative Poisson's ratio metamaterial structures with structures in other fields is a primary trend in future development.

[0004] Lattice structures, due to their light weight, low density, high strength, and high specific energy absorption, have been widely used in the automotive, shipbuilding, aerospace, and marine engineering sectors. With the continuous development of additive manufacturing technology, irregular metal structures can also be easily manufactured, making metal lattice structures possible beyond finite element simulations and into experimental applications. "Made in China 2025" states that 3D printing using SLM technology will be a key development focus in the intelligent manufacturing industry. The lattice structure, proposed by Gibson of MIT and Ashby of Cambridge University, can effectively compensate for this shortcoming of the negative Poisson's ratio honeycomb structure.

[0005] Currently, the types of common negative Poisson's ratio structures are still very limited (especially three-dimensional negative Poisson's ratio structures), and the application of negative Poisson's ratio structures in actual engineering is not very extensive. Moreover, they are relatively stable and prone to collapse during compression and tension. Summary of the Invention

[0006] The first object of the present invention is to provide a three-dimensional bionic fishbone negative Poisson's ratio lattice, which can solve the problem that the negative Poisson's ratio structure in the prior art is relatively stable and easily collapses during compression and stretching;

[0007] The second object of the present invention is to provide a honeycomb composite structure comprising the three-dimensional bionic fishbone negative Poisson's ratio lattice as described above.

[0008] To achieve the above objectives, the present invention provides a three-dimensional bionic fishbone negative Poisson's ratio lattice, which includes three evenly distributed pillars connected by nodes;

[0009] The pillar includes a bottom plate, side plates and a top plate;

[0010] The bottom plate and the top plate are connected to the first end and the second end of the side plate respectively;

[0011] The top plate and the bottom plate are respectively located on both sides of the side plate, and an angle is formed between the top plate, the bottom plate and the side plate.

[0012] Preferably, the length of the bottom plate is c=84.4 mm, the length of the side plate is b=94.5 mm, and the length of the top plate is a=20.7 mm.

[0013] Preferably, the included angle between the top plate and the side plate is α=60°, the projection angle between the two top plates is γ=120°, and the projection angle between the two bottom plates is δ=210°.

[0014] Preferably, the three-dimensional bionic fishbone negative Poisson's ratio lattice comprises three evenly distributed columns, and the lattice is a bilaterally symmetrical structure, and the angle between adjacent side plates is θ=128°.

[0015] A honeycomb composite structure comprising the three-dimensional bionic fishbone negative Poisson's ratio lattice as described in any one of the above;

[0016] The honeycomb composite structure is formed by stacking lattice lattices.

[0017] Preferably, in the lattice lattices stacked in the vertical direction, the angle between the lattice lattice bottom plate located on the upper side and the lattice top plate located on the lower side is σ.

[0018] Preferably, two adjacent three-dimensional bionic fishbone negative Poisson's ratio lattice lattices are connected in sequence through the joint surface formed between the bottom plate and the side plate and arranged in a honeycomb shape, and the joint surface is shared to form a honeycomb structure, and then a honeycomb combination structure is formed by stacking up and down, and the arrangement and combination are expanded in the horizontal and vertical directions in this way.

[0019] Preferably, the lattice lattice size, dimensions and materials constituting the honeycomb composite structure are consistent.

[0020] Preferably, the lattice lattice and honeycomb combined structure is made by an additive manufacturing process.

[0021] Beneficial effects:

[0022] 1. Improved stability of negative Poisson's ratio structures. Traditional negative Poisson's ratio honeycomb structures often exhibit macroscopic instability under uniaxial compression. This invention utilizes a lattice connection method different from traditional structures in the connection of the honeycomb lattice, which prevents the lattice from macroscopic tilting due to uneven force after deformation under uniaxial compression.

[0023] 2. The present invention is a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combination structure that integrates a lattice structure and a negative Poisson's ratio structure, wherein each three-dimensional structural cell is the same size, which enables the three-dimensional structural cells in each cross section to deform synchronously during the impact process, thereby improving energy absorption efficiency and improving the smoothness of the impact resistance process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1a 、 Figure 1b This is a schematic diagram of the dimensional parameters of the three-dimensional bionic fishbone negative Poisson's ratio structure in the present invention;

[0026] Figure 2 Schematic diagram of the three-dimensional bionic fishbone negative Poisson's ratio structure of the present invention;

[0027] Figure 3 Schematic diagram of an array structure formed by stacking three-dimensional bionic fishbone negative Poisson's ratio structures in the present invention;

[0028] Figure 4 This is a front view of a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combination structure in the present invention;

[0029] Figure 5 This is a schematic diagram of a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combined structure connection method in the present invention;

[0030] Figure 6 This is a top view of a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combination structure in the present invention;

[0031] Figure 7 This is an isometric view of a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combination structure in the present invention;

[0032] Figure 8 This is a schematic diagram of the compression deformation of a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combination structure in the process of strain ε=0.0~0.5 in the present invention. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0036] like Figures 1a to 7 As shown, the present invention provides a three-dimensional bionic fishbone negative Poisson's ratio lattice, which includes three evenly distributed pillars, and the pillars are connected through nodes.

[0037] The support column includes a bottom plate, a side plate and a top plate, wherein the bottom plate and the side plate are connected to the first end and the second end of the side plate respectively.

[0038] The top plate and the bottom plate are respectively located on both sides of the side plate, and there is an angle between the top plate, the bottom plate and the side plate.

[0039] Specifically, the length of the bottom plate is c=84.4 mm, the length of the side plate is b=94.5 mm, and the length of the top plate is a=20.7 mm.

[0040] The included angle between the top plate and the side plate is α=60°, the projection angle between the two top plates is γ=120°, and the projection angle between the two bottom plates is δ=210°.

[0041] The three-dimensional bionic fishbone negative Poisson's ratio lattice is a bilaterally symmetrical structure, and the angle between adjacent two side plates is θ=128°.

[0042] In this embodiment, a honeycomb composite structure is further provided, which includes the three-dimensional bionic fishbone negative Poisson's ratio lattice as described above, and the honeycomb composite structure is formed by stacking the lattice lattices.

[0043] In the lattice lattices stacked in the vertical direction, the angle between the lattice bottom plate located on the upper side and the lattice top plate located on the lower side is σ.

[0044] Two adjacent three-dimensional bionic fishbone negative Poisson's ratio lattice lattices are connected in sequence through the joint surface formed between the bottom plate and the side plate and arranged in a honeycomb shape, and the joint surface is shared to form a honeycomb structure, and then a honeycomb combination structure is formed by stacking up and down. In this way, the arrangement and combination are expanded in the horizontal and vertical directions. This connection method of the lattice lattice improves the stability of the negative Poisson's ratio structure. Traditional negative Poisson's ratio honeycomb structures often show macroscopic instability under uniaxial compression. The present invention adopts a lattice connection method different from the traditional structure in the connection method of the honeycomb lattice, so that the lattice can not produce macroscopic tilt due to uneven force after deformation under uniaxial compression.

[0045] The lattice lattices constituting the honeycomb composite structure are consistent in size, dimensions and material.

[0046] The combined structure is a three-dimensional bionic fishbone negative Poisson's ratio lattice and its honeycomb combined structure that integrates a lattice structure and a negative Poisson's ratio structure. Each three-dimensional structural cell is the same size, which enables the three-dimensional structural cells in each cross-section to deform synchronously during the impact process, thereby improving energy absorption efficiency and improving the smoothness of the impact resistance process.

[0047] The lattice and honeycomb combined structures are made by additive manufacturing processes.

[0048] In summary, the lattice lattice and honeycomb combined structure provided by this embodiment has the following advantages:

[0049] By combining a lattice lattice structure with a honeycomb structure, a negative Poisson's ratio structure with excellent negative Poisson's ratio performance was designed. The honeycomb lattice connection method, which is different from the traditional lattice connection method, makes the lattice more stable during compression.

[0050] The combined structure can achieve a relatively obvious negative Poisson's ratio characteristic when compressed and deformed.

[0051] The honeycomb composite structure has multi-directional negative Poisson's ratio characteristics in local units, and also has multi-directional negative Poisson's ratio characteristics in the overall structure.

[0052] The combination method of the honeycomb structure is different from the dot matrix connection method of the traditional structure. In this way, the arrangement and combination are expanded horizontally and vertically.

[0053] like Figure 8 As shown in the figure, in the process of strain ε=0.0~0.5, the overall structure generally undergoes a relatively obvious compression, thinning and narrowing negative Poisson's ratio characteristic, which is more significant than the classic honeycomb structure.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A honeycomb composite structure, characterized in that: The honeycomb composite structure is formed by stacking three-dimensional bionic fishbone negative Poisson's ratio lattice lattices; the three-dimensional bionic fishbone negative Poisson's ratio lattice lattice includes three evenly distributed pillars, and the pillars are connected by nodes; The pillar includes a bottom plate, side plates and a top plate; The bottom plate and the top plate are connected to the first end and the second end of the side plate respectively; The top plate and the bottom plate are respectively located on both sides of the side plate, and there is an angle between the top plate, the bottom plate and the side plate; The angle between the top plate and the side plate is α = 60°, the projection angle between the two top plates is γ = 120°, and the projection angle between the two bottom plates is δ = 210°; The three-dimensional bionic fishbone negative Poisson's ratio lattice is a bilaterally symmetrical structure, and the angle between adjacent side plates is θ=128°; For lattice lattices stacked in the vertical direction, the angle between the bottom plate of the lattice lattice on the upper side and the top plate of the lattice lattice on the lower side is σ; Two adjacent three-dimensional bionic fishbone negative Poisson's ratio lattice lattices are connected in sequence through the joint surface formed between the bottom plate and the side plate and arranged in a honeycomb shape, and the joint surface is shared to form a honeycomb structure, and then a honeycomb combination structure is formed by stacking up and down, and the arrangement and combination are expanded in the horizontal and vertical directions in this way.

2. The honeycomb composite structure according to claim 1, characterized in that: The length of the bottom plate is c=84.4 mm, the length of the side plate is b=94.5 mm, and the length of the top plate is a=20.7 mm.

3. The honeycomb composite structure according to claim 1, characterized in that: The lattice lattices constituting the honeycomb composite structure have the same size, dimensions and materials.

4. The honeycomb composite structure according to claim 1, characterized in that: The lattice lattice and honeycomb combined structure is made by an additive manufacturing process.

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