A poisson ratio each direction controllable energy absorption enhanced lattice structure and design method

Abstract

The application discloses a kind of poisson ratio each direction controllable energy-absorbing enhanced lattice structure and design method, it is related to honeycomb structure field, method includes: S1, constructs the poisson ratio of two-dimensional honeycomb structure cell that can be adjusted according to inner and outer rib thickness;S2, the in-plane direction of two two-dimensional honeycomb structure cell is mutually coincident and placed 90 degrees, carries out Boolean intersection operation, obtains four three-dimensional honeycomb units;S3, the four intermediate vertices of each three-dimensional honeycomb unit are sequentially connected into quadrilateral rib, the upper vertex of four three-dimensional honeycomb units is sequentially connected into quadrilateral rib, and its lower vertex is sequentially connected into quadrilateral rib, to obtain three-dimensional honeycomb structure cell;S4, array obtains three-dimensional lattice structure;When being compressed in in-plane direction, show the same poisson ratio polarity as the in-plane direction corresponding two-dimensional honeycomb structure cell.The two-dimensional honeycomb structure cell constructed by the application improves the overall stiffness of structure, and generates new three-dimensional lattice structure with poisson ratio sign anisotropy by Boolean operation.

Description

Technical Field

[0001] This invention relates to the field of cellular structure technology, and in particular to an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio and its design method. Background Technology

[0002] Porous structures exhibit a stable energy absorption deformation mode under compressive loads, demonstrating high energy absorption efficiency, and are therefore widely used in aerospace, automotive engineering, and protective equipment. Traditional porous structures, however, undergo outward lateral diffusion under compressive loads, exhibiting a positive Poisson's ratio. This leads to a decrease in local material density and a reduction in dent resistance, limiting their application in scenarios requiring suppressed deformation or enhanced energy absorption. Carefully designed negative Poisson's ratio porous structures exhibit an anomalous tensile dilatation effect under compressive loads, possessing superior fracture toughness, dent resistance, and excellent energy absorption capabilities. These unique mechanical properties make negative Poisson's ratio honeycomb structures a promising candidate for applications in ballistic protective layers, variable-wing aircraft skins, and naval decks.

[0003] Currently, two-dimensional honeycomb structures can achieve designs that balance strength and controllable mechanical properties. However, these designs inevitably increase the porosity of the porous structure, limiting its widespread application in lightweighting. Furthermore, honeycomb structures are generally limited by the finite design space of their two-dimensional configuration, typically only able to control mechanical behavior in a single dimension. Therefore, inspired by crystal lattices in materials science, researchers have designed a series of three-dimensional lattice structures, which offer a higher dimensional design space than two-dimensional honeycombs, giving them the potential to control multi-dimensional mechanical behavior. However, this biomimetic lattice design method struggles to simultaneously achieve low density, high strength, and controllable mechanical properties, especially the anisotropy of the Poisson's ratio. Moreover, existing traditional design methods cannot break through the dimensional barriers of existing two-dimensional honeycomb structures, allowing their unique mechanical properties to be manifested in three-dimensional structures. Summary of the Invention

[0004] To address the above problems, this invention proposes an energy-absorbing and enhanced lattice structure and design method with anisotropically adjustable Poisson's ratio. By constructing a two-dimensional honeycomb structure cell that mixes convex and concave hexagonal honeycombs, the overall stiffness of the structure is improved. Furthermore, by using Boolean operations on two two-dimensional honeycomb structure cells, a novel three-dimensional lattice structure with anisotropic Poisson's ratio is generated based on the different Poisson's ratio characteristics of the two-dimensional honeycomb structure cells, which can effectively reduce the porosity of the structure. The two-dimensional honeycomb structure cell can be controlled by the thickness difference between the inner and outer ribs and the Poisson's ratio characteristics.

[0005] On the one hand, a design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio is described, with the following specific steps:

[0006] S1, construct a two-dimensional honeycomb structure cell; the two-dimensional honeycomb structure cell includes two horizontal outer ribs, four oblique outer ribs, two horizontal inner ribs and four oblique inner ribs;

[0007] Two horizontal outer ribs and four oblique outer ribs form a convex hexagon as the outer contour of the two-dimensional honeycomb structure cell; four oblique inner ribs and two horizontal outer ribs form a concave hexagon; one end of one horizontal inner rib is connected to the left vertex of the convex hexagon, and the other end is connected to the vertex of the left dominant angle of the concave hexagon; one end of another horizontal inner rib is connected to the right vertex of the convex hexagon, and the other end is connected to the vertex of the right dominant angle of the concave hexagon.

[0008] S2, place two two-dimensional honeycomb structure cells of the same height at 90 degrees to each other in the in-plane direction, perform Boolean union and intersection operation, retain the structure where the two two-dimensional honeycomb structure cells intersect at the oblique outer rib and oblique inner rib, and obtain four three-dimensional honeycomb units.

[0009] S3, connect the four middle vertices of each three-dimensional honeycomb unit to form quadrilateral ribs in sequence, connect the upper vertices of the four three-dimensional honeycomb units to form quadrilateral ribs in sequence, and connect the lower vertices of the four three-dimensional honeycomb units to form quadrilateral ribs in sequence to obtain a three-dimensional honeycomb structure cell.

[0010] S4, the three-dimensional honeycomb cell array is used to obtain a three-dimensional lattice structure; when the three-dimensional lattice structure is compressed in the in-plane direction, it exhibits the same Poisson's ratio polarity as the corresponding two-dimensional honeycomb cell in the in-plane direction.

[0011] Preferably, in S2, the honeycomb material composed of the two two-dimensional honeycomb cells both exhibit a positive Poisson's ratio when subjected to pressure.

[0012] Preferably, in S2, the honeycomb material composed of the two two-dimensional honeycomb structure cells both exhibit a negative Poisson's ratio when subjected to pressure.

[0013] Preferably, in S2, the honeycomb material composed of one two-dimensional honeycomb cell exhibits a negative Poisson's ratio when subjected to pressure, while the honeycomb material composed of the other two-dimensional honeycomb cell exhibits a positive Poisson's ratio when subjected to pressure.

[0014] Preferably, by setting the thickness of the inner and outer oblique ribs, the honeycomb structure composed of the two-dimensional honeycomb cells exhibits a positive or negative Poisson's ratio when subjected to pressure.

[0015] Preferably, the thickness of the four oblique outer ribs is equal; the thickness of the four oblique inner ribs is equal; the thickness difference coefficient is greater than or equal to the first thickness difference coefficient threshold to obtain a honeycomb structure that produces a positive Poisson's ratio effect under pressure; the thickness difference coefficient is less than the second thickness difference coefficient threshold to obtain a honeycomb structure that produces a negative Poisson's ratio effect under pressure.

[0016] The thickness difference coefficient is expressed as:

[0017] ;

[0018] in, Indicates the thickness difference coefficient; Indicates the thickness of the oblique outer rib; This indicates the thickness of the diagonal inner rib.

[0019] Preferably, the first thickness difference coefficient threshold is 0.04; the second thickness difference coefficient threshold is -0.04. On the other hand, a Poisson's ratio-tunable energy-absorbing enhanced lattice structure is obtained according to a Poisson's ratio-tunable energy-absorbing enhanced lattice structure design method.

[0020] On the other hand, an energy-absorbing enhanced lattice structure with an isotropically adjustable Poisson's ratio is obtained according to the above-mentioned design method for an energy-absorbing enhanced lattice structure with an isotropically adjustable Poisson's ratio.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The two-dimensional honeycomb structure cell constructed in this invention uses a hybrid design of positive and negative Poisson ratio honeycombs. The opposite mechanical deformation behaviors of the two configurations under load generate mutual balance within the cell, which significantly improves the overall stiffness of the structure. At the same time, the Boolean operation fusion strategy effectively reduces the porosity of the structure, and significantly improves the specific strength and load-bearing capacity of the structure while ensuring the lightweight advantage of the material.

[0023] (2) This invention simplifies the complex three-dimensional modeling and performance control problem into a two-dimensional plane parametric design through the Boolean operation dimensionality reduction design strategy, enabling designers to independently customize the mechanical response of the three-dimensional structure in different principal plane directions (such as the Poisson's ratio sign, etc.), effectively solving the problem of severe parameter coupling and difficulty in precise control in traditional three-dimensional structure design; at the same time, since the three-dimensional structure directly inherits the geometric characteristics of the two-dimensional hybrid honeycomb, its mechanical performance exhibits strong transferability and predictability, ensuring that the three-dimensional lattice can robustly achieve the expected deformation mode and performance index under complex loads, providing an efficient and reliable standardized design paradigm for the performance customization of porous structures in the engineering field;

[0024] (3) By cross-intersecting two-dimensional hybrid honeycombs and using Boolean operations to extract their overlapping parts, this invention successfully breaks the limitation that traditional porous structures can only control the mechanical behavior of a single dimension. This method can retain the mechanical characteristics of the two-dimensional configuration and map them to three-dimensional space, so that the structure can independently exhibit positive or negative Poisson ratio effects in different principal plane directions, and realize the anisotropic distribution of the Poisson ratio sign. Attached Figure Description

[0025] The present invention will now be described in further detail with reference to the accompanying drawings;

[0026] Figure 1 This is a schematic diagram illustrating the design method of the energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0027] Figure 2 A schematic diagram of a two-dimensional HR-cell honeycomb unit cell for the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the thickness difference coefficient-Poisson's ratio in the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of a homogeneous two-dimensional honeycomb structure for a Poisson's ratio-tunable energy-absorbing and enhanced lattice structure design method according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of a homogeneous novel three-dimensional lattice for the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0031] Figure 6 The nominal stress-strain comparison curves of two-dimensional honeycomb and novel lattice structures in the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention are shown.

[0032] Figure 7 This is a schematic diagram of an HR-N two-dimensional honeycomb unit cell for the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram of a novel three-dimensional lattice unit cell of the HR-NN, which is a method for designing an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0034] Figure 9 The image shows a comparison of the Poisson's ratio and strain of the HR-N two-dimensional honeycomb and the HR-NN novel three-dimensional lattice structure, representing the design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0035] Figure 10 This is a schematic diagram of an HR-P two-dimensional honeycomb unit cell for the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0036] Figure 11 A schematic diagram of the HR-PP novel three-dimensional lattice unit cell for the design method of an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0037] Figure 12 The image shows a comparison of the Poisson's ratio and strain of the HR-P two-dimensional honeycomb and the HR-PP novel three-dimensional lattice structure, representing the design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0038] Figure 13 This is a schematic diagram of a novel three-dimensional lattice unit cell of the HR-NP energy-absorbing and enhanced lattice structure design method with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0039] Figure 14 The HR-NN novel three-dimensional lattice structure Poisson's ratio-strain diagram of the design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to an embodiment of the present invention.

[0040] Reference numerals: 1. Planar honeycomb structure cell with adjustable Poisson's ratio; 11. Horizontal outer rib; 12. Oblique outer rib; 13. Oblique inner rib; 14. Horizontal inner rib. Detailed Implementation

[0041] The present invention will be further described below through specific embodiments.

[0042] like Figure 1 As shown, a design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio is presented, and the specific steps are as follows:

[0043] S1, constructing two-dimensional honeycomb structure cells.

[0044] like Figure 2 As shown, the two-dimensional honeycomb structure cell can be viewed as a hybrid two-dimensional honeycomb that fuses hexagonal positive Poisson's ratio units with concave negative Poisson's ratio units. By fusing the hexagonal honeycomb and the concave honeycomb, their opposing mechanical behaviors create a mutual balance within the cell. Specifically, the planar honeycomb structure cell 1 with adjustable Poisson's ratio includes two horizontal outer ribs 11, four oblique outer ribs 12, two horizontal inner ribs 14, and four oblique inner ribs 13; the two horizontal outer ribs 11 and the four oblique outer ribs 12 form a convex hexagon as the outer contour of the two-dimensional honeycomb structure cell; the four oblique inner ribs 13 and the two horizontal outer ribs 11 form a concave hexagon; one end of one horizontal inner rib 14 is connected to the left vertex of the convex hexagon, and the other end is connected to the vertex of the left dominant angle of the concave hexagon formed by the two oblique inner ribs 13 (the dominant angle of the concave hexagon is an interior angle greater than 180 degrees and less than 360 degrees); one end of another horizontal inner rib 14 is connected to the right vertex of the convex hexagon, and the other end is connected to the vertex of the right dominant angle of the concave hexagon formed by the other two oblique inner ribs 13.

[0045] Furthermore, the thickness difference between the inner and outer ribs is introduced as a key control variable. By adjusting the thickness ratio of the inner and outer ribs, the deformation mode of the structure is changed, achieving continuous and flexible control of the Poisson's ratio from positive to negative. Specifically:

[0046] Introducing a thickness difference coefficient, expressed as:

[0047] ;

[0048] in, Indicates the thickness difference coefficient; Indicates the thickness of the oblique outer rib; This indicates the thickness of the diagonal inner rib.

[0049] The relationship between the thickness difference coefficient and Poisson's ratio is shown in [reference]. Figure 3 As shown, when the thickness difference coefficient is greater than or equal to 0.04, the honeycomb structure composed of two-dimensional honeycomb cells exhibits a positive Poisson's ratio under pressure; when the thickness difference coefficient is less than -0.04, the honeycomb structure composed of two-dimensional honeycomb cells exhibits a negative Poisson's ratio under pressure; when the thickness difference coefficient is between -0.04 and 0.04 or is -0.04, the honeycomb structure composed of two-dimensional honeycomb cells first exhibits a positive Poisson's ratio under pressure, and then exhibits a negative Poisson's ratio.

[0050] S2, place two two-dimensional honeycomb structure cells of the same height with their in-plane directions (i.e., the pressure-bearing directions corresponding to the faces of the honeycomb array) overlapping each other at 90 degrees, perform Boolean union and intersection operations, retain the structure where the two two-dimensional honeycomb structure cells intersect at the oblique outer rib and oblique inner rib, and obtain four three-dimensional honeycomb units.

[0051] Two two-dimensional honeycombs with specific mechanical properties are arranged in a cross shape, and their overlapping spatial regions are extracted through Boolean operations. This preserves the geometric information and mechanical characteristics of the two-dimensional honeycombs and transforms them into corresponding three-dimensional lattice structures.

[0052] S3, connect the four middle vertices of each 3D honeycomb unit to form quadrilateral ribs in sequence, connect the upper vertices of the four 3D honeycomb units to form quadrilateral ribs in sequence, and connect the lower vertices of the four 3D honeycomb units to form quadrilateral ribs in sequence to obtain a three-dimensional honeycomb structure cell.

[0053] S4, the three-dimensional honeycomb cell array is used to obtain a three-dimensional lattice structure; when the three-dimensional lattice structure is compressed in the in-plane direction, it exhibits the same Poisson's ratio polarity as the corresponding two-dimensional honeycomb cell in the in-plane direction.

[0054] In summary, this method aims to address the design strategy of automatically generating anisotropic three-dimensional lattice structures with adjustable Poisson's ratio based on a two-dimensional honeycomb structure using Boolean operations. This strategy solves the problems of high porosity and limited design space (only one dimension for adjustment) in existing two-dimensional honeycomb structures, as well as the technical shortcomings of existing three-dimensional lattice structures that, while achieving lightweighting, struggle to simultaneously achieve high strength and flexible adjustment of the Poisson's ratio sign (positive / negative). This strategy involves placing two two-dimensional honeycombs in a cross shape and using Boolean operations to retain the overlapping portions. This method preserves the geometric information of the two-dimensional honeycombs in both directions, thus transforming the two-dimensional honeycomb structure into a corresponding three-dimensional lattice structure while retaining the mechanical properties of the two-dimensional honeycomb. Furthermore, the introduction of specific differences in the thickness of the inner and outer ribs as control variables enables flexible control of the Poisson's ratio sign from positive to negative and accurate control of the Poisson's ratio magnitude. By controlling the mechanical behavior of the two-dimensional honeycombs in various directions, anisotropic distribution of the Poisson's ratio in multiple dimensions is achieved, endowing the structure with the ability to exhibit differentiated deformation modes (such as lateral expansion or tensile effects) in different directions. Furthermore, by combining hybrid configurations with Boolean operations, the porosity of the porous structure is significantly reduced, overcoming the limitation of traditional three-dimensional lattice structure design where lightweighting and flexible mechanical performance control are difficult to achieve simultaneously, thus improving the overall load-bearing capacity and energy absorption efficiency of the structure. At the same time, by mapping the mechanical characteristics of the two-dimensional hybrid honeycomb structure using Boolean operations and automatically generating a three-dimensional lattice structure, the dimensional space of mechanical design is effectively broadened. This provides the engineering field with a porous structure solution that combines ultra-lightweight design, high specific strength, and multi-dimensional mechanical controllability.

[0055] An energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio is obtained through the aforementioned design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio.

[0056] Example 1:

[0057] The HR two-dimensional honeycomb unit and HR three-dimensional lattice structure used in this embodiment are homogeneous in size, meaning that the thickness of each outer wall is equal to the thickness of each inner wall, and the thickness difference coefficient is 0. Both samples have a porosity of 8.87%, and the same length, width, and height of 50mm, 50mm, and 30mm, respectively, as shown below. Figure 4 and Figure 5 As shown.

[0058] This embodiment compares the mechanical properties of two-dimensional honeycomb structures and three-dimensional lattice structures. Samples of HR two-dimensional honeycomb cells and HR three-dimensional lattice honeycomb cells were taken. Experimental results are available in [reference needed]. Figure 6As shown, experimental results indicate that under quasi-static load, the novel three-dimensional lattice structure improves energy absorption per unit mass by 289.47% compared to the two-dimensional honeycomb structure. This demonstrates that the Boolean operation fusion strategy significantly enhances the specific strength and load-bearing capacity of the structure while ensuring material lightweighting. This demonstrates that the structure in this embodiment balances ultra-lightweight design with superior structural strength.

[0059] Example 2:

[0060] The two-dimensional cellular unit used in this embodiment is an HR-N structure. Specifically, the outer wall thickness of the HR-N structure is smaller than the inner wall thickness, and its detailed parameters are as follows: Figure 7 As shown, the length of the horizontal outer rib 11 is ( or The length of the oblique outer rib is 11.25mm, and the length of the oblique outer rib is 12 ( or The thickness of the oblique inner rib 13 is 7.5mm. or The thickness of the outer diagonal rib 12 is 1.3mm. or The thickness is 0.7 mm, and the angle formed by the horizontal inner rib 14 and the oblique inner rib 13 is 60 degrees. and ,or and The thickness difference coefficient of the HR-N structure is -0.26. The HR-N structure constitutes a two-dimensional honeycomb structure. When subjected to compressive load, its deformation mode is mainly controlled by the inner wall, so the deformation exhibits a negative Poisson's ratio mode.

[0061] Using a Poisson's ratio-tunable energy-absorbing enhanced lattice structure design method, two HR-N two-dimensional cells are used to generate an HR-NN structure through Boolean operations. (See [link to relevant documentation]). Figure 8 As shown.

[0062] Through simulation experiments, the following results were obtained: Figure 9 A schematic diagram of Poisson's ratio. The Poisson's ratio curves of the novel HR-NN lattice structure in two dimensions (in-plane direction) are similar to those of its corresponding two-dimensional honeycomb HR-N, and both exhibit negative Poisson's ratio modes in their deformation behavior.

[0063] Example 3:

[0064] The two-dimensional cellular unit used in this embodiment is an HR-P structure. The outer wall thickness of the HR-P is greater than the inner wall thickness, and its detailed parameters are as follows: Figure 10 As shown, the length of the horizontal outer rib 11 is ( or The length of the oblique outer rib is 11.25mm, and the length of the oblique outer rib is 12 ( or The thickness of the oblique inner rib 13 is 7.5mm. or The thickness of the outer diagonal rib 12 is 0.7mm. or The thickness is 1.3mm, and the angle formed by the horizontal inner rib 14 and the oblique inner rib 13 is 60 degrees. and ,or and The thickness difference coefficient of the HR-N structure is 0.26. The HR-P structure constitutes a two-dimensional honeycomb structure. The deformation mode is mainly controlled by the outer wall, so the deformation exhibits a positive Poisson's ratio mode.

[0065] Using a Poisson's ratio-tunable energy-absorbing enhanced lattice structure design method, two HR-P two-dimensional honeycomb structures are converted into an HR-PP structure through Boolean operations. (See [link to relevant documentation]). Figure 11 As shown;

[0066] Through simulation experiments, the following results were obtained: Figure 12 A schematic diagram of Poisson's ratio. The Poisson's ratio curves of the novel HR-PP lattice structure in two dimensions are similar to those of its corresponding two-dimensional cellular HR-P, exhibiting a positive Poisson's ratio mode.

[0067] Combining Embodiments 2 and 3, it is shown that the novel lattice structure, by inheriting the geometric characteristics of two-dimensional honeycomb, exhibits extremely strong transferability and predictability in its mechanical behavior, ensuring that the three-dimensional lattice can robustly achieve the expected deformation mode and mechanical properties under complex loads.

[0068] Example 4:

[0069] This embodiment employs two two-dimensional honeycomb HR-N and HR-P structures with different Poisson ratios (parameters are the same as in Embodiments 2 and 3). A novel HR-NP lattice structure is generated through a design method for an energy-absorbing and enhanced lattice structure with an anisotropically adjustable Poisson ratio. (See [link to relevant documentation]). Figure 13 As shown, HR-N is stretched along the X-axis direction (normal direction of the ZY plane), and HR-P is stretched along the Z-axis direction (normal direction of the XY plane).

[0070] Compression simulation experiments were conducted on the novel HR-NP three-dimensional lattice structure, and the results were obtained. Figure 14 The Poisson's ratio curves show that the HR-NP novel three-dimensional lattice structure exhibits a significant negative Poisson's ratio in the ZY plane and a significant positive Poisson's ratio in the XY plane under compressive loading. Compression simulation experiments demonstrate that this lattice structure possesses tunable anisotropy.

[0071] In summary, the novel three-dimensional lattice structure generated by the design method of an anisotropically adjustable energy-absorbing enhanced lattice structure retains the mechanical characteristics of the two-dimensional configuration and maps them to three-dimensional space. This allows the structure to independently exhibit positive or negative Poisson's ratio effects in different dimensions, achieving anisotropic distribution of the Poisson's ratio sign. Simultaneously, the thickness difference between the inner and outer ribs can be utilized to realize a novel two-dimensional honeycomb structure with anisotropic Poisson's ratio. Boolean operations are then used to automatically generate a novel three-dimensional lattice structure with anisotropic Poisson's ratio sign. This effectively reduces the porosity of the structure and achieves anisotropic control of the Poisson's ratio, specifically manifested in the flexible switching between positive and negative Poisson's ratios in multiple dimensions and the accurate control of the Poisson's ratio magnitude, providing a new approach for the optimization design of porous structures in the engineering field.

[0072] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio, characterized in that, Includes the following steps: S1, construct a two-dimensional honeycomb structure cell; the two-dimensional honeycomb structure cell includes two horizontal outer ribs, four oblique outer ribs, two horizontal inner ribs and four oblique inner ribs; Two horizontal outer ribs and four oblique outer ribs form a convex hexagon as the outer contour of the two-dimensional honeycomb structure cell; four oblique inner ribs and two horizontal outer ribs form a concave hexagon; one end of one horizontal inner rib is connected to the left vertex of the convex hexagon, and the other end is connected to the vertex of the left dominant angle of the concave hexagon; one end of another horizontal inner rib is connected to the right vertex of the convex hexagon, and the other end is connected to the vertex of the right dominant angle of the concave hexagon. S2, place two two-dimensional honeycomb structure cells of the same height at 90 degrees to each other in the in-plane direction, perform Boolean union and intersection operation, retain the structure where the two two-dimensional honeycomb structure cells intersect at the oblique outer rib and oblique inner rib, and obtain four three-dimensional honeycomb units. S3, connect the four middle vertices of each three-dimensional honeycomb unit to form quadrilateral ribs in sequence, connect the upper vertices of the four three-dimensional honeycomb units to form quadrilateral ribs in sequence, and connect the lower vertices of the four three-dimensional honeycomb units to form quadrilateral ribs in sequence to obtain a three-dimensional honeycomb structure cell. S4, the three-dimensional honeycomb cell array is used to obtain a three-dimensional lattice structure; when the three-dimensional lattice structure is compressed in the in-plane direction, it exhibits the same Poisson's ratio polarity as the corresponding two-dimensional honeycomb cell in the in-plane direction.

2. The design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 1, characterized in that, In S2, the honeycomb material composed of two two-dimensional honeycomb structure cells both exhibit a positive Poisson's ratio when subjected to pressure.

3. The design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 1, characterized in that, In S2, the honeycomb material composed of two two-dimensional honeycomb cells exhibits a negative Poisson's ratio when subjected to pressure.

4. The design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 1, characterized in that, In S2, the honeycomb material composed of one two-dimensional honeycomb cell exhibits a negative Poisson's ratio when subjected to pressure, while the honeycomb material composed of another two-dimensional honeycomb cell exhibits a positive Poisson's ratio when subjected to pressure.

5. The design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 1, characterized in that, By setting the thickness of the inner and outer oblique ribs, the honeycomb structure composed of the two-dimensional honeycomb cells can exhibit a positive or negative Poisson's ratio when subjected to pressure.

6. The design method for an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 5, characterized in that, The four outer oblique ribs have equal thickness; the four inner oblique ribs have equal thickness. By making the thickness difference coefficient greater than or equal to the first thickness difference coefficient threshold, a honeycomb structure that produces a positive Poisson's ratio effect under pressure is obtained; by making the thickness difference coefficient less than the second thickness difference coefficient threshold, a honeycomb structure that produces a negative Poisson's ratio effect under pressure is obtained. The thickness difference coefficient is expressed as: ； in, Indicates the thickness difference coefficient; Indicates the thickness of the oblique outer rib; This indicates the thickness of the diagonal inner rib.

7. The method for designing an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio according to claim 6, characterized in that, The first thickness difference coefficient threshold is 0.04; the second thickness difference coefficient threshold is -0.

04.

8. A Poisson's ratio-tunable, energy-absorbing, enhanced lattice structure, characterized in that, The method for designing an energy-absorbing and enhanced lattice structure with an isotropically adjustable Poisson's ratio is obtained according to any one of claims 1-7.

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