Cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure, application and control method

Abstract

The present invention relates to the field of structural technology, and in particular to a honeycomb lattice structure with a negative Poisson's ratio and a cubic bipolar ligament. The structure comprises a plurality of honeycomb cells, which are assembled in a mutually linked manner. The honeycomb cells comprise two symmetrically arranged straight edges, each of which is connected to a cubic bipolar ligament at each end. The four cubic bipolar ligaments are symmetrical, and the opposite ends of the two cubic bipolar ligaments on the same side are connected to the linked edges. The two linked edges are symmetrical and lie in the same plane. The two straight edges, the four cubic bipolar ligaments, and the two linked edges constitute an interconnected linked structure. The present invention aims to provide a honeycomb lattice structure with a negative Poisson's ratio and a cubic bipolar ligament, which modifies the oblique straight ligaments of the traditional concave hexagonal cells into cubic bipolar curved ligaments, thereby enhancing the potential for optimizing energy absorption and impact resistance.

Description

Technical Field

[0001] The present invention relates to the field of structural technology, in particular to a cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure, and its application and control method. Background Art

[0002] Negative Poisson's ratio metamaterials, also known as auxetic materials, are a branch of mechanical metamaterials distinguished by their negative Poisson's ratio—when subjected to axial tension, they exhibit lateral expansion. This counterintuitive mechanical response stems from the unique geometric configuration of their unit cells. Based on their structural topology, auxetic designs can be categorized into five main categories: concave honeycomb structures, chiral structures, rotationally rigid polygonal structures, corrugated lamellar structures, and porous lamellar structures. The advantages of auxetic materials are multifaceted: their negative Poisson's ratio significantly improves their fracture resistance, indentation resistance, and energy absorption capacity, yielding significant potential for load buffering. For example, in protective engineering, auxetic structures have been successfully used in helmet design and collision energy absorption devices. In aerospace, they are integrated into sandwich panels to reduce the risk of vibration and fatigue failure. Furthermore, their synchronized bending curvature allows auxetic materials to conform to the contours of the body, demonstrating excellent conformability in biomedical devices such as vascular stents and wearable sensors.

[0003] However, conventional auxetic materials—particularly those employing linear ligament configurations, such as concave honeycomb structures—have inherent flaws in their deformation mechanisms. Under compressive loads, the rigid hinges and linear ligaments of these structures produce localized stress concentrations at the nodes, leading to non-uniform deformation. This instability stems from the geometric constraints of the linear ligaments, which hinder stress redistribution and exacerbate premature buckling and collapse of the structure, thereby reducing the reliability of such structures in dynamic applications such as impact protection or vibration damping. Furthermore, the energy absorption capacity of conventional auxetic materials is limited by their instability under compressive loads. Although their negative Poisson's ratio behavior theoretically enhances energy absorption through synchronous bending deformation, linear ligament designs are prone to buckling and often collapse before the structure is fully densified.

[0004] To overcome these limitations, recent studies have begun to explore the use of curved ligaments to replace traditional straight-line configurations. For example, sinusoidal, wavy, elliptical, and arc-shaped ligament configurations have been proposed, which reduce stress concentration at nodes through more uniform stress field distribution. Simulation models in these literatures show that curvature design can delay buckling and improve energy absorption by controlling the bending of the ligament. However, existing designs are mostly based on fixed curvature geometries (such as arcs or sine curves), which makes it difficult to fine-tune structural responses for specific application requirements. In addition, biomimetic, self-similar, and hierarchical designs are used to promote sequential buckling and stabilize deformation paths, thereby improving energy absorption capacity. However, such designs usually require complex geometric configurations, which not only rely on high-performance computing resources for optimization, but also significantly increase manufacturing costs.

[0005] Therefore, it is urgent to propose a new design method for negative Poisson's ratio honeycomb lattice structure to overcome the poor compression stability and low energy absorption characteristics of the existing structure. Summary of the Invention

[0006] In response to the above-mentioned defects, the purpose of the present invention is to propose a cubic bipole ligament negative Poisson's ratio honeycomb lattice structure, which modifies the oblique straight ligaments of the traditional concave hexagonal unit cell into cubic bipole curved ligaments, thereby enhancing the optimization potential of energy absorption and impact resistance.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure includes a plurality of honeycomb unit cells, and the plurality of honeycomb unit cells are assembled in linkage with each other;

[0009] The honeycomb unit cell includes two symmetrically arranged straight edges, each end of the two straight edges is connected to a three-dimensional double-pole ligament, the four three-dimensional double-pole ligaments are symmetrical to each other, and the opposite ends of the two three-dimensional double-pole ligaments on the same side are connected to a linkage edge, and the two linkage edges are symmetrical to each other and are in the same plane;

[0010] Two straight edges, four triple bipolar ligaments and two linkage edges constitute an interconnected linkage structure.

[0011] Furthermore, the three-fold double-pole ligament is in an "N" shape, including a first curved section, a first pole, a second curved section, a second pole, and a third curved section;

[0012] One end of the first curved segment is connected to one end of the straight edge, and the other end is connected to one end of the second curved segment. The position where the first curved segment and the second curved segment are connected is the first pole; the other end of the second curved segment is connected to one end of the third curved segment, and the position where the second curved segment and the third curved segment are connected is the second pole; the other section of the third curved segment is connected to the linkage edge.

[0013] Furthermore, the honeycomb unit cells are connected vertically by sharing straight edges and horizontally by interconnected links, so as to form a honeycomb lattice structure with multiple honeycomb unit cells.

[0014] On the other hand, a regulation method for a cubic double-pole ligament negative Poisson's ratio honeycomb lattice structure is proposed. This method is used for the cubic double-pole ligament negative Poisson's ratio honeycomb lattice structure and includes the following steps:

[0015] S1. Set parameter constraints, and the parameter constraints are limited as follows:

[0016] ;

[0017] ;

[0018] ;

[0019] ;

[0020] To meet the target geometric requirements, the main constraint conditions specify that a3 > 0 and Δ > 0 to ensure the existence of two independent extreme points;

[0021] Here, x1 and x2 respectively represent the abscissas of the two extreme points of the function;

[0022] The secondary constraint conditions force 0 < x1, x2 < (l1 - h1) / 2, thereby limiting the extreme coordinates within the design domain. At the same time, f(x1) < h2 / 2 and f(x2) ≥ 0 are restricted to ensure compatibility;

[0023] The continuity constraint at the structural node is achieved through the conditional equation a1 = h2 / (l1 - h1) – [a2(l1 - h1)] / 2 – [a3(l1 - h1)²] / 4;

[0024] The honeycomb unit cell dimensions include a straight edge length of l1, a link spacing of h1, a straight edge spacing of h2, and a thickness of the straight edge of t; a1, a2, and a3 are the three coefficients of the cubic function. a1 is obtained through the conditional equation, while a2 and a3 are input according to the requirements of Young's modulus and Poisson's ratio. The cubic function is defined as a polynomial function in the form of y = a1x + a2x 2 + a3x 3 The coordinate origin is defined at the vertical center O point of the link. The positive x-axis direction is defined horizontally to the right along the link, and the positive y-axis direction is defined vertically upward perpendicular to the link. Since the cubic double-pole ligament passes through the coordinate origin O point, a0 = 0, where a1 is the first-order term coefficient, a2 is the second-order term coefficient, and a3 is the third-order term coefficient;

[0025] S2. Input the honeycomb unit cell size and determine whether the honeycomb unit cell size parameters meet the parameter constraints. If the honeycomb unit cell size does not meet the parameter constraints, it needs to be adjusted and re-entered;

[0026] S3. Prediction of Young's modulus and Poisson's ratio. If the unit cell size parameters satisfy the parameter constraints, the honeycomb unit cell size data that meets the parameter constraints is substituted into the Young's modulus and Poisson's ratio prediction formula to predict the Young's modulus and Poisson's ratio of the honeycomb unit cell of the data.

[0027] S4, Young's modulus and Poisson's ratio control, the honeycomb unit cell size parameters used in the prediction are adjusted by controlling the Young's modulus and Poisson's ratio;

[0028] Adjustment of Young's modulus: increase Young's modulus by increasing h2, or increasing a2 and decreasing a3, or decreasing l1, or increasing t; decrease Young's modulus by decreasing h2, or decreasing a2 and increasing a3, or increasing l1, or decreasing t;

[0029] Poisson's ratio regulation: increase h2; or increase a2 and decrease a3; or decrease l1; or decrease h1 to improve the effect of negative Poisson's ratio; decrease h2; or decrease a2 and increase a3; or increase l1; or increase h1 to reduce the effect of negative Poisson's ratio.

[0030] Under quasi-static compression, it exhibits stable compression deformation and gradually enhanced stress-strain behavior, significantly improving energy absorption characteristics; it has excellent impact energy absorption and acceleration peak attenuation capabilities;

[0031] Furthermore, in step S3, Castigliano's second theorem is used to derive the prediction formula of the effective Young's modulus and Poisson's ratio of the honeycomb unit cell under small deformation:

[0032] ;

[0033] ;

[0034] Among them, E y is the effective elastic modulus; v xy is Poisson's ratio; E s Elastic modulus of the parent material.

[0035] Thirdly, a flipper with a negative Poisson's ratio honeycomb lattice structure using cubic bipolar ligaments is proposed as the skeleton of the flipper's blade structure.

[0036] One of the above technical solutions includes the following beneficial effects: compared with the traditional design solution, the tertiary ligament significantly enhances the optimization potential of energy absorption and impact resistance. In addition, compared with the traditional concave hexagonal unit cell structure, this solution has a larger adjustment space. The cubic bipole ligament negative Poisson's ratio honeycomb lattice structure of the present invention can change the mechanical properties, energy absorption characteristics and deformation degree through parameter adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the traditional concave hexagonal unit cell;

[0038] Figure 2 Schematic diagram of the mechanical model of the cubic bipolar ligament negative Poisson's ratio honeycomb unit cell structure of the present invention;

[0039] Figure 3 Schematic diagram of a model of a cubic bipolar ligament negative Poisson's ratio honeycomb structure of the present invention;

[0040] Figure 4 This is a schematic diagram of the distribution of the effective elastic modulus of the honeycomb unit cell with the cubic ligament shape parameters of this scheme;

[0041] Figure 5 This is a schematic diagram of the distribution of the Poisson's ratio of the honeycomb unit cell with the cubic ligament shape parameters in this scheme;

[0042] Figure 6 This is one of the schematic diagrams of experimental and simulation results of a 4×3 lattice structure under different compressive strains;

[0043] Figure 7 This is the second schematic diagram of the experimental and simulation results of the 4×3 lattice structure under different compressive strains;

[0044] Figure 8 This is the third schematic diagram of the experimental and simulation results of the 4×3 lattice structure under different compressive strains;

[0045] Figure 9 Schematic diagram of stress-strain curves (a) and specific energy absorption-strain curves (b) for six groups of 4×3 lattice structures with different ligament shape parameters;

[0046] Figure 10 Schematic diagram of stress-strain curves (a) and specific energy absorption-strain curves (b) of six 4×3 lattice structures with different h1 parameters;

[0047] Figure 11 Schematic diagram of stress-strain curves (a) and specific energy absorption-strain curves (b) of three 4×3 lattice structures with different h2 parameters;

[0048] Figure 12 This is a schematic diagram of the impact simulation of four honeycomb lattice structures;

[0049] Figure 13 (a) The acceleration-time curves and (b) the impact responses of the four lattice structures under an impact energy of 60 J.

[0050] Figure 14 Acceleration-time curves (a) and impact responses (b) of four lattice structures under impact energy of 240J;

[0051] Figure 15 Acceleration-time curves (a) and impact responses (b) of four lattice structures under impact energy of 540J.

[0052] Among them: straight edge 100, triple double pole ligament 200, linkage edge 300. DETAILED DESCRIPTION

[0053] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0054] like Figure 2 and Figure 3 As shown, the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure includes a plurality of honeycomb unit cells, and the plurality of honeycomb unit cells are assembled in linkage with each other;

[0055] The honeycomb unit cell includes two symmetrically arranged straight edges 100, each of which is connected to a three-dimensional double-pole ligament 200 at each end. The four three-dimensional double-pole ligaments 200 are symmetrical to each other, and the opposite ends of the two three-dimensional double-pole ligaments 200 on the same side are connected to a linkage edge 300. The two linkage edges 300 are symmetrical to each other and are in the same plane.

[0056] The two straight edges 100, the four triple bipolar ligaments 200 and the two linkage edges 300 constitute an interconnected linkage structure.

[0057] Compared with traditional design schemes, the triple double-pole ligament 200 significantly enhances the optimization potential of energy absorption and impact resistance. In addition, compared with the traditional concave hexagonal unit cell structure, this scheme has a larger adjustment space. The triple double-pole ligament negative Poisson's ratio honeycomb lattice structure of the present invention can change the mechanical properties, energy absorption characteristics and deformation degree through parameter adjustment.

[0058] The triple double-pole ligament is in an "N" shape, including a first curved segment, a first pole, a second curved segment, a second pole, and a third curved segment;

[0059] One end of the first bending section is connected to one end of the straight edge, and the other end is connected to one end of the second bending section. The position where the first bending section and the second bending section are connected is the first pole; the other end of the second bending section is connected to one end of the third bending section. The position where the second bending section and the third bending section are connected is the second pole; the other section of the third bending section is connected to the linkage edge.

[0060] Compared with the traditional hexagonal unit cell structure, the triple double-pole ligament has an additional pair of ligament shape parameters a2 and a3. By regulating the ligament shape parameters a2 and a3, the mechanical properties, energy absorption characteristics and deformation degree of the honeycomb lattice structure can be regulated within a large range.

[0061] Among them, the honeycomb unit cells are connected up and down by sharing the straight edge, and are connected to each other on the left and right sides by the linkage edge, so that multiple honeycomb unit cells form a honeycomb lattice structure.

[0062] The overall honeycomb unit cell structure is a closed-loop linkage structure. Multiple honeycomb unit cells form a honeycomb lattice structure and are connected to each other through the linkage edge. Combined with the fact that the honeycomb unit cells share the straight edge up and down, when the entire honeycomb lattice structure is subjected to impact or tension, multiple honeycomb unit cells can jointly process the impact or torque.

[0063] This solution also proposes a regulation method for the triple double-pole ligament negative Poisson's ratio honeycomb lattice structure. This method is used for the triple double-pole ligament negative Poisson's ratio honeycomb lattice structure; it includes the following steps:

[0064] S1. Set parameter constraints. The parameter constraints are limited as follows:

[0065] ;

[0066] ;

[0067] ;

[0068] ;

[0069] To meet the target geometric requirements, the main constraint conditions stipulate that a3 ≥ 0 and Δ > 0 to ensure the existence of two independent extreme points;

[0070] Here, x1 and x2 respectively represent the abscissas of the two extreme points of the function;

[0071] The secondary constraint conditions force 0 < x1, x2 < (l1 - h1) / 2, thereby limiting the extreme value coordinates within the design domain, and at the same time restricting f(x1) < h2 / 2 and f(x2) ≥ 0 to ensure compatibility;

[0072] The continuity constraint at the structural nodes is realized by the conditional formula a1=h2 / (l1-h1)–[a2(l1-h1)] / 2–[a3(l1-h1)²] / 4;

[0073] The dimensions of a honeycomb cell include the straight side length l1, the linkage side spacing h1, the straight side spacing h2, and the straight side thickness t; a1, a2, and a3 are the three coefficients of the cubic function. a1 is calculated by the conditional expression, and a2 and a3 are input according to the requirements of Young's modulus and Poisson's ratio. The cubic function is defined as y=a1x+a2x 2 +a3x 3 The polynomial function defines the origin of the coordinate system at the vertical center of the linkage edge, O. The horizontal rightward direction along the linkage edge is defined as the positive direction of the x-axis, and the vertical upward direction perpendicular to the linkage edge is defined as the positive direction of the y-axis. Since the cubic bipolar ligament passes through the origin of the coordinate system, O, a0=0, where a1 is the coefficient of the linear term, a2 is the coefficient of the quadratic term, and a3 is the coefficient of the cubic term.

[0074] S2. Input the honeycomb unit cell size and determine whether the honeycomb unit cell size parameters meet the parameter constraints. If the honeycomb unit cell size does not meet the parameter constraints, it needs to be adjusted and re-entered;

[0075] S3. Prediction of Young's modulus and Poisson's ratio. If the unit cell size parameters satisfy the parameter constraints, the honeycomb unit cell size data that meets the parameter constraints is substituted into the Young's modulus and Poisson's ratio prediction formula to predict the Young's modulus and Poisson's ratio of the honeycomb unit cell of the data.

[0076] S4, Young's modulus and Poisson's ratio control, the honeycomb unit cell size parameters used in the prediction are adjusted by controlling the Young's modulus and Poisson's ratio;

[0077] Adjustment of Young's modulus: increase Young's modulus by increasing h2, or increasing a2 and decreasing a3, or decreasing l1, or increasing t; decrease Young's modulus by decreasing h2, or decreasing a2 and increasing a3, or increasing l1, or decreasing t;

[0078] Poisson's ratio regulation: increase h2; or increase a2 and decrease a3; or decrease l1; or decrease h1 to improve the effect of negative Poisson's ratio; decrease h2; or decrease a2 and increase a3; or increase l1; or increase h1 to reduce the effect of negative Poisson's ratio.

[0079] Under quasi-static compression, it exhibits stable compression deformation and gradually enhanced stress-strain behavior, significantly improving energy absorption characteristics; it has excellent impact energy absorption and acceleration peak attenuation capabilities;

[0080] Among them, in step S3, Castigliano's second theorem is used to derive the prediction formula of the effective Young's modulus and Poisson's ratio of the honeycomb unit cell under small deformation:

[0081] ;

[0082] ;

[0083] Among them, E y is the effective elastic modulus; v xy is Poisson's ratio; E s Elastic modulus of the parent material.

[0084] Figure 4 It can be seen that E y / E s It is closely related to a2 and a3. As a3 decreases and a2 increases, E y / E s Increase; Figure 5 In the figure, it can be seen that no matter how the parameters change, the structure shows a negative Poisson's ratio characteristic. a2 and a3 have an important influence on the adjustment of the Poisson's ratio. Reducing a3 or increasing a2 can reduce the Poisson's ratio value. Figure 4-5 It is shown that changing the values ​​of the ligament shape parameters a2 and a3 can significantly affect the elastic mechanical properties of the cubic double-pole ligament negative Poisson's ratio honeycomb unit cell structure, thereby regulating the load-bearing capacity and energy absorption characteristics of the cubic double-pole ligament negative Poisson's ratio honeycomb lattice structure.

[0085] by Figure 3 Quasi-static compression experiments and finite element simulations were conducted on the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure. Figure 6-Figure 8 The paper presents experimental and simulation results of a 4×3 lattice structure under different compression levels. As the compression progresses, the simulation and experimental results exhibit consistent deformation behavior. The simulation results accurately capture the deformation during the compression experiment, verifying the effectiveness of the simulation model.

[0086] exist Figure 4 and Figure 5 Six different ligament shape parameter groups were selected from the lattice, named NAS-2-A to NAS-2-F, and finite element simulations were established for each of them. It can be seen that compared with the traditional concave hexagonal lattice structure, the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure shows a self-contact enhancement phenomenon as compression progresses, specifically manifested as a progressively enhanced stress-strain behavior. This phenomenon significantly improves the compressive stability of the structure and enhances energy absorption, such as Figure 9 As shown in (b), the superiority of the structure of this scheme is verified.

[0087] The influence of different height parameters h1 and h2 on the mechanical properties and energy absorption of the negative Poisson's ratio honeycomb lattice structure of the cubic bipolar ligament is shown in Figure 2. Figure 10As can be seen in Figure (a), when h1=0.9, the unit cell ligaments intersect at one point, and their compression deformation pattern is similar to that of a triangular lattice structure, specifically characterized by a high initial peak and a short platform. As h1 increases, the initial stress peak gradually decreases, and the unit cell gradually becomes wider, with a larger concave deformation space, so the platform gradually becomes longer. For energy absorption, such as Figure 10 As shown in Figure (b), since a small h1 has a large stress level, the energy absorption gradually decreases as h1 increases. Figure 11 It can be seen that the influence of h2 on the structural performance is relatively consistent. As h2 increases, its load-bearing capacity and capacity absorption gradually deteriorate.

[0088] In order to further illustrate the protection practicability of the proposed structure, the inventors established Figure 12 The impact simulation model shown in Figure 1 is a 30kg protective structure subjected to different initial impact velocities. By continuously monitoring and recording the response of the center point on the upper surface of the structure, the energy dissipation and buffering capacity of four different honeycomb lattice structures are quantitatively evaluated, as shown in Figure 1. Figure 13-15 As shown. Figure 13 From the acceleration response curve of (a)-15, it can be seen that the new lattice structure (h2=18, h2=14, h1=0.9) has higher energy dissipation efficiency than the traditional honeycomb structure (NAS-1-F) under impact load. These innovative structures extend the impact buffering stage and greatly improve the buffering performance of protective applications. Figure 13 As can be seen in Figure (b)-15, although the energy absorption capabilities of the four honeycomb structures are similar, the three new designs consistently show significant improvements in mitigating peak acceleration as the impact energy increases. Notably, the honeycomb structure with h1 = 0.9 performs exceptionally well in both impact energy absorption and peak acceleration attenuation, demonstrating its high impact cushioning and energy absorption capabilities.

[0089] This proposal also proposes a fin using the above-mentioned cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure. The fin uses the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure as the blade structure, and one side of the blade structure is covered with an elastic paddling surface layer.

[0090] The entire triple bipolar ligament negative Poisson's ratio honeycomb lattice structure is used as the blade of the fin. Under the same tensile force, the honeycomb lattice structure will produce deformation compared to the blade without honeycomb, so that the area of ​​the blade is increased and the paddling efficiency is improved. Under the same weight, the use of honeycomb lattice structure as the blade skeleton to make the fin blade can improve the paddling propulsion efficiency of the blade.

[0091] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. Cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure, characterized by: It includes multiple honeycomb unit cells, and the multiple honeycomb unit cells are assembled in a linked manner with each other; The honeycomb unit cell includes two symmetrically arranged straight edges, and the two ends of the two straight edges are respectively connected to a cubic double-pole ligament. The four cubic double-pole ligaments are respectively symmetric, and the relative ends of the two cubic double-pole ligaments on the same side are connected to the linkage edge. The two linkage edges are symmetric and in the same plane; The two straight edges, the four cubic double-pole ligaments and the two linkage edges form a linked structure that is interconnected; The cubic double-pole ligament is in an "N" shape and includes a first bending section, a first pole, a second bending section, a second pole and a third bending section; One end of the first bending section is connected to one end of the straight edge, and the other end is connected to one end of the second bending section. The position where the first bending section and the second bending section are connected is the first pole; the other end of the second bending section and one end of the third bending section are connected, and the position where the second bending section and the third bending section are connected is the second pole; the other section of the third bending section is connected to the linkage edge; The honeycomb unit cells are connected up and down by sharing straight edges, and are connected to each other on the left and right sides by the linkage edges, so that multiple honeycomb unit cells form a honeycomb lattice structure.

2. A control method for a cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure, characterized in that: This method is used for the cubic double-pole ligament negative Poisson's ratio honeycomb lattice structure described in claim 1; it includes the following steps: S1. Set parameter constraints, and the parameter constraints are limited as follows: To meet the target geometric requirements, the main constraint conditions stipulate that a3>0 and Δ>0 to ensure the existence of two independent extreme points; Here, x1 and x2 respectively represent the abscissas of the two extreme points of the function; The secondary constraint conditions force 0<x1,x2<(l1-h1) / 2, so as to limit the extreme value coordinates within the design domain range, and at the same time accompany the restrictions f(x1)<h2 / 2 and f(x2)≥0 to ensure compatibility; By the conditional expression a1=h2 / (l1-h1)–[a2(l1-h1)] / 2–[a3(l1-h1) 2 ] / 4 implements continuity constraints at structural nodes; The dimensions of a honeycomb cell include the straight side length l1, the linkage side spacing h1, the straight side spacing h2, and the straight side thickness t; a1, a2, and a3 are the three coefficients of the cubic function. a1 is calculated by the conditional expression, and a2 and a3 are input according to the requirements of Young's modulus and Poisson's ratio. The cubic function is defined as y=a1x+a2x 2 +a3x 3 The polynomial function defines the origin of the coordinate system at the vertical center O of the linkage edge, the horizontal rightward direction along the linkage edge is defined as the positive direction of the x-axis, and the vertical upward direction perpendicular to the linkage edge is defined as the positive direction of the y-axis; S2. Input the honeycomb unit cell size, and judge whether the honeycomb unit cell size parameters meet the parameter constraints. If the honeycomb unit cell size does not meet the parameter constraints, it needs to be adjusted and re-input; S3. Prediction of Young's modulus and Poisson's ratio. If the honeycomb unit cell size parameters meet the parameter constraints, substitute the honeycomb unit cell size data that meets the parameter constraints into the Young's modulus and Poisson's ratio prediction formulas to predict the Young's modulus and Poisson's ratio of the honeycomb unit cell of this data; S4. Regulation of Young's modulus and Poisson's ratio. Adjust the honeycomb unit cell size parameters used in the prediction through the Young's modulus and Poisson's ratio regulation method; Adjustment of Young's modulus. Increase Young's modulus by increasing h2; or increasing a2 and decreasing a3; or decreasing l1; or increasing t; decrease Young's modulus by decreasing h2; or decreasing a2 and increasing a3; or increasing l1; or decreasing t; Regulation of Poisson's ratio. Increase the effect of negative Poisson's ratio by increasing h2; or increasing a2 and decreasing a3; or decreasing l1; or decreasing h1; decrease the effect of negative Poisson's ratio by decreasing h2; or decreasing a2 and increasing a3; or increasing l1; or increasing h1.

3. The control method of the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure according to claim 2, characterized in that: In step S3, the prediction formulas for the effective Young's modulus and Poisson's ratio of the honeycomb unit cell under small deformation are derived by using the second Castigliano's theorem: Among them, E y is the effective elastic modulus; v xy is Poisson's ratio; E s Elastic modulus of the parent material.

4. A fin using a cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure, characterized in that: The device uses the cubic bipolar ligament negative Poisson's ratio honeycomb lattice structure described in claim 1 as a blade structure, and one side of the blade structure is covered with an elastic paddling surface layer.

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