Zero-Poisson-ratio telescopic buffering energy-absorbing structure

Abstract

The invention relates to a zero-Poisson-ratio telescopic buffering energy-absorbing structure, and belongs to the technical field of metamaterials. The structure is formed by periodically arranging a plurality of basic unit cells, and the basic unit cells are formed by performing primary mirroring on microstructure unit cells; the cross section of each microstructure unit cell comprises a first connecting beam, a second connecting beam, a third connecting beam and a fourth connecting beam which are connected in sequence; the first connecting beam, the second connecting beam, the third connecting beam and the fourth connecting beam respectively have specific node distribution and geometric constraint; the microstructure unit cells have out-of-plane depths perpendicular to the cross sections of the microstructure unit cells; and each basic unit cell is of a rhombic structure enclosed by two mutually symmetrical micro-structure unit cells. According to the invention, the transverse deformation is mutually counteracted during axial stress, the zero Poisson's ratio effect is realized, meanwhile, the impact energy is absorbed by utilizing the elastic buckling of the rhombic grids, and the comprehensive properties of constant transverse size, stable positioning point and high buffering efficiency are achieved.

Description

Technical Field

[0001] This invention belongs to the field of metamaterials technology, specifically relating to a zero Poisson's ratio stretchable buffer energy absorption structure. Background Technology

[0002] Buffer structures are critical components in engineering used to absorb impact energy and protect core components from damage; their performance directly determines the reliability and service life of equipment. With the rapid development of aerospace, precision manufacturing, and intelligent equipment, the requirements for buffer structures are becoming increasingly stringent: they not only need to have excellent expandable buffering capacity, but also need to meet the requirement of no lateral deformation during expansion and contraction.

[0003] The existing buffer structures generally suffer from the following drawbacks: 1. Non-zero Poisson's ratio leads to lateral deformation: Traditional cushioning materials (such as rubber, foam, and springs) all have a positive Poisson's ratio. When stretched or compressed axially, they will produce significant lateral contraction or expansion, which can easily interfere with or squeeze surrounding components, leading to the displacement or damage of core components. 2. Poor positioning stability during extension and retraction: Most existing telescopic buffer structures are asymmetrical designs, which are prone to overall displacement and torsion during axial extension and retraction. They cannot maintain the constant position of key positioning points (such as the mounting surface of core components and connection reference points), making it difficult to meet the positioning protection requirements of precision equipment. 3. It is difficult to balance cushioning performance and structural stability: Although some materials (such as honeycomb structures and woven materials) can suppress lateral deformation, they have low energy absorption efficiency and limited extension stroke; while elastic structures with high cushioning performance often lack dimensional stability and cannot achieve the synergistic effect of "zero Poisson's ratio-constant position-high cushioning" at the same time.

[0004] There are no natural materials in nature that simultaneously possess both "zero Poisson's ratio and high stretchability and cushioning" properties. Existing artificial structures often focus on a single performance characteristic, failing to achieve synergistic optimization of multiple properties. Therefore, developing a structurally sound and performance-balanced zero Poisson's ratio stretchable cushioning structure is key to overcoming these technical bottlenecks. Summary of the Invention

[0005] To address the problems of lateral deformation, positioning misalignment, and difficulty in balancing buffering and stability in existing buffer structures, this invention provides a zero Poisson's ratio stretchable buffer energy-absorbing structure, which is composed of several basic unit cells arranged periodically and symmetrically. The basic unit cells are mirror images of microstructure unit cells with irregular polygonal configurations. Through the length ratio of each side and the node layout of the microstructure unit cells, the lateral deformation of the structure cancels each other out when subjected to axial force, achieving a zero Poisson's ratio effect. At the same time, the elastic buckling of the rhomboid mesh within the basic unit cells absorbs impact energy, thus possessing comprehensive performance of constant lateral dimensions, stable positioning points, and high buffering efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a zero Poisson's ratio stretchable buffer energy absorption structure, which is composed of multiple basic unit cells arranged periodically, wherein the basic unit cells are formed by mirroring a microstructure unit cell once; The cross-section of the microstructure unit cell includes a first connecting beam, a second connecting beam, a third connecting beam, and a fourth connecting beam connected in sequence; a Cartesian coordinate system is established with the centroid of the cross-section of the microstructure unit cell as the origin, with the x-axis pointing horizontally to the right and the y-axis pointing vertically upward; the microstructure unit cell has an out-of-plane depth perpendicular to its cross-section; The outline of the first connecting beam includes nodes A, B, C, M, and N distributed in sequence, wherein AB and MN are parallel to the y-axis direction of the Cartesian coordinate system, and BC and AN are parallel to the x-axis direction of the Cartesian coordinate system. The outline of the second connecting beam includes nodes C, D, L, and M distributed in sequence, wherein CD∥LM; The outline of the third connecting beam includes nodes D, E, J, K, and L distributed in sequence, wherein DE and JK are parallel to the y-axis direction of the Cartesian coordinate system, and LK is parallel to the x-axis direction of the Cartesian coordinate system. The outline of the fourth connecting beam includes nodes E, F, G, H, I, and J distributed in sequence, wherein EF and HI are parallel to the x-axis of the Cartesian coordinate system, GH is parallel to the y-axis of the Cartesian coordinate system, and FG∥IJ; the second and fourth connecting beams are both located on the same side of the third connecting beam and extend in different inclination directions relative to the third connecting beam, and GH and AB are on the same straight line; The basic unit cell consists of a rhomboid structure formed by two mutually symmetrical microstructural units.

[0007] Furthermore, the microstructure unit cell satisfies the following geometric relationships: AB=KJ, CD=GF=IJ=LM, NM=DE, BC=LK=DE=EF, and the distance between DE and JK is equal to the distance between AB and NM.

[0008] Furthermore, the basic unit cell is formed by mirroring the microstructure unit cell along the y-axis of the Cartesian coordinate system.

[0009] Furthermore, the basic unit cells are arrayed along the x-axis and y-axis directions to obtain a zero Poisson's ratio stretchable buffer energy absorption structure formed by the periodic arrangement of multiple basic unit cells.

[0010] Furthermore, the microstructure unit cell is made of a cushioning material with high elastic modulus and high toughness.

[0011] Furthermore, the elastic modulus of the buffer material is 210 GPa, and its toughness is 100 MPa·m. 1 / 2 .

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. Significant zero Poisson's ratio characteristic: When the frame structure is subjected to axial force, the lateral deformations cancel each other out, resulting in a smaller lateral strain of the overall structure. This effectively avoids interference of lateral deformation with surrounding components and protects the dimensional stability of core components.

[0013] 2. Excellent stretchable buffer performance: It adopts highly elastic buffer material, which absorbs impact energy through deformation and is suitable for different impact energy scenarios.

[0014] 3. Wide adaptability: Flexible material selection, different materials can be replaced according to the temperature, strength and weight requirements of the application scenario, applicable to multiple fields such as aerospace, automotive, electronics, and precision manufacturing. Attached Figure Description

[0015] Figure 1 This is a front view of the zero Poisson's ratio stretchable buffer energy-absorbing structure of the present invention and a schematic diagram of the microstructure unit cell size under this view. Figure 2 This is a three-dimensional structural diagram of a microstructure unit cell in this invention; Figure 3 This is a schematic diagram of the basic unit cell of the present invention; Figure 4 This is a three-dimensional view of the zero Poisson's ratio stretchable buffer energy-absorbing structure in the embodiment; Figure 5 This is a load-displacement energy absorption curve diagram of the zero Poisson's ratio stretchable buffer energy absorption structure described in an embodiment of the present invention; In the figure, 100 represents the basic unit cell, and 200 represents the microstructure unit cell. 1. First connecting beam, 2. Second connecting beam, 3. Third connecting beam, 4. Fourth connecting beam. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the embodiments, but this should not be construed as limiting the invention in any way.

[0017] like Figure 1 As shown, the zero Poisson's ratio scalable buffer energy-absorbing structure is composed of multiple basic unit cells arranged periodically, and its front view is as follows. Figure 1 As shown in (a), its three-dimensional view is as follows: Figure 4 As shown. The basic unit cell 100 structure is as follows. Figure 3 As shown, it has a rhomboid structure 5 inside, and the basic unit cell 100 is composed of... Figure 1 (b) shows an axisymmetric structure obtained by mirroring the microstructure unit cell 200 once. The rhomboid structure 5 is formed by two symmetrical microstructure unit cells 200 enclosing each other.

[0018] Since the microstructure unit cell 200 is the most basic building block of the zero Poisson's ratio stretchable buffer energy-absorbing structure described in this invention, it will be surrounded by... Figure 1 (b) illustrates the structure of the microstructure unit cell 200.

[0019] The cross-section of the microstructure unit cell 200 includes a first connecting beam 1, a second connecting beam 2, a third connecting beam 3, and a fourth connecting beam 4 connected in sequence; a Cartesian coordinate system is established with the centroid of the cross-section of the microstructure unit cell 200 as the origin, with the x-axis pointing horizontally to the right and the y-axis pointing vertically upward.

[0020] The outline of the first connecting beam 1 includes nodes A, B, C, M, and N distributed in sequence, wherein AB and MN are parallel to the y-axis direction of the Cartesian coordinate system, and BC and AN are parallel to the x-axis direction of the Cartesian coordinate system.

[0021] The outline of the second connecting beam 2 includes nodes C, D, L, and M distributed in sequence, wherein CD∥LM.

[0022] The outline of the third connecting beam 3 includes nodes D, E, J, K, and L distributed in sequence, wherein DE and JK are parallel to the y-axis direction of the Cartesian coordinate system, and LK is parallel to the x-axis direction of the Cartesian coordinate system.

[0023] The outline of the fourth connecting beam 4 includes nodes E, F, G, H, I, and J distributed in sequence, wherein EF and HI are parallel to the x-axis of the Cartesian coordinate system, GH is parallel to the y-axis of the Cartesian coordinate system, and FG∥IJ.

[0024] The second connecting beam 2 and the fourth connecting beam 4 are both located on the same side of the third connecting beam 3, and extend in different inclination directions relative to the third connecting beam 3, and GH and AB are on the same straight line.

[0025] The front side (i.e., cross-section) of the microstructure unit cell 200, such as... Figure 1 (b) is mirror-symmetric along the y-axis, resulting in the following: Figure 3 The basic unit cell 100 shown has two microstructure units 200 sharing line segments AB and GH, thus forming a rhombus structure 5. The basic unit cells 100 are then periodically arrayed along the x-axis and y-axis to obtain a two-dimensional multi-cell structure. Adjacent basic unit cells 100 in the two-dimensional multi-cell structure share boundary nodes, forming a continuous and complete periodic structure. Then, the obtained two-dimensional multi-cell structure is stretched to a certain depth h along the z-axis to obtain... Figure 4 The three-dimensional multicellular structure shown is the zero Poisson's ratio stretchable buffer energy absorption structure described in this invention. Example 2

[0026] Based on Example 1, this example provides a specific value for the dimensional parameters.

[0027] The microstructure unit cell 200 satisfies the following geometric relationships: AB=KJ, with a length of l1; CD=GF=IJ=LM, with a length of l2; NM=DE, with a length of l3; the distance between CD and LM is equal to the distance between GF and IJ, and this distance is taken as the wall thickness t1 of the microstructure unit cell 200; the distance between DE and JK is equal to the distance between AB and NM, and this distance is taken as the wall thickness t2 at the intermediate connection; BC=LK=DE=EF, with a length of t3; HI is the bottom width t4 of the microstructure unit cell 200.

[0028] In this embodiment, the microstructure unit cell 200 adopts high elastic modulus (E≥180GPa) and high toughness (KIC≥80MPa·m). 1 / 2 The material is made of low-carbon steel with an elastic modulus of 210 GPa and a Poisson's ratio of v = 0.3. This material has both good elastic deformation capacity and toughness, and can absorb energy through elastic buckling under impact loads and return to its original shape after unloading, thus achieving reusable cushioning protection.

[0029] The zero Poisson's ratio stretchable buffer energy-absorbing structure described in Example 1 was constructed using low-carbon steel. It comprises four basic unit cells along the x-axis and three basic unit cells along the y-axis. The dimensions are: l1 = 11.76 mm, l2 = 18.81 mm, l3 = 3.45 mm, t1 = 5 mm, t2 = 0.75 mm, t3 = 4.11 mm, t4 = 5.61 mm, and h = 35 mm. Based on the intercellular relationships, the model was analyzed using ABAQUS with C3D8R elements selected.

[0030] Simulation conditions: A compressive load is applied to the structure along the negative y-axis, and the load-displacement curve of the structure is obtained, such as... Figure 5 As shown in the figure, the structure exhibits a continuous and stable plateau during compression, indicating that it can smoothly absorb energy within a large deformation range.

[0031] The zero Poisson's ratio stretchable buffer energy-absorbing structure of this invention has good designability. By adjusting the following parameters, performance can be adjusted as needed for different application scenarios: (1) Unit cell size: Adjusting the length parameters such as l1, l2, l3 can change the geometry of the rhombic mesh, thereby affecting the stiffness and energy absorption characteristics of the structure; (2) Wall thickness distribution: Adjusting the values ​​of t1, t2, t3 and t4 can optimize the local stiffness matching of the structure and improve the overall mechanical performance; (3) Number of array layers: By changing the number of array layers in the x-axis and y-axis directions, different spatial dimensions and load-bearing requirements can be adapted; (4) Out-of-plane depth: Adjusting the stretching depth h can change the overall thickness and energy absorption capacity of the structure.

[0032] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the specific implementation of the present invention with reference to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the pending claims.

Claims

1. A zero Poisson's ratio stretchable buffer energy-absorbing structure, composed of multiple basic unit cells arranged periodically, characterized in that, The basic unit cell is formed by mirroring a microstructure unit cell once. The cross-section of the microstructure unit cell includes a first connecting beam, a second connecting beam, a third connecting beam, and a fourth connecting beam connected in sequence; a Cartesian coordinate system is established with the centroid of the cross-section of the microstructure unit cell as the origin, with the x-axis pointing horizontally to the right and the y-axis pointing vertically upward; the microstructure unit cell has an out-of-plane depth perpendicular to its cross-section; The outline of the first connecting beam includes nodes A, B, C, M, and N distributed in sequence, wherein AB and MN are parallel to the y-axis direction of the Cartesian coordinate system, and BC and AN are parallel to the x-axis direction of the Cartesian coordinate system. The outline of the second connecting beam includes sequentially distributed nodes C, D, L, and M, where CD∥LM; The outline of the third connecting beam includes nodes D, E, J, K, and L distributed in sequence, wherein DE and JK are parallel to the y-axis direction of the Cartesian coordinate system, and LK is parallel to the x-axis direction of the Cartesian coordinate system. The outline of the fourth connecting beam includes nodes E, F, G, H, I, and J distributed in sequence, wherein EF and HI are parallel to the x-axis of the Cartesian coordinate system, GH is parallel to the y-axis of the Cartesian coordinate system, and FG∥IJ; the second and fourth connecting beams are both located on the same side of the third connecting beam and extend in different inclination directions relative to the third connecting beam, and GH and AB are on the same straight line; The basic unit cell consists of a rhomboid structure formed by two mutually symmetrical microstructural units.

2. The zero Poisson's ratio stretchable buffer energy-absorbing structure according to claim 1, characterized in that, The microstructure unit cell satisfies the following geometric relationships: AB=KJ, CD=GF=IJ=LM, NM=DE, BC=LK=DE=EF, and the distance between DE and JK is equal to the distance between AB and NM.

3. The zero Poisson's ratio stretchable buffer energy-absorbing structure according to claim 1, characterized in that, The basic unit cell is formed by mirroring the microstructure unit cell along the y-axis of the Cartesian coordinate system.

4. The zero Poisson's ratio stretchable buffer energy-absorbing structure according to claim 1, characterized in that, The basic unit cells are arrayed along the x-axis and y-axis to form a zero Poisson's ratio stretchable buffer energy absorption structure through periodic arrangement of multiple basic unit cells.

5. The zero Poisson's ratio stretchable buffer energy-absorbing structure according to claim 1, characterized in that, The microstructure unit cells are made of a cushioning material with high elastic modulus and high toughness.

6. The zero Poisson's ratio stretchable buffer energy-absorbing structure according to claim 5, characterized in that, The elastic modulus of the buffer material is E≥180GPa, and the toughness is KIC≥80 MPa·m. 1 / 2 .

Images