A positive and negative poisson's ratio structure chimeric type reinforced cushion material

Abstract

The application belongs to the technical field of cushioning materials, and provides a positive and negative Poisson ratio structure chimeric reinforced cushioning material, four negative Poisson ratio microcell elements are connected at the end in space to form a closed three-dimensional negative Poisson ratio cell element, two positive Poisson ratio microcell elements are crossed to form a cross-shaped three-dimensional positive Poisson ratio cell element, and the cross-shaped three-dimensional positive Poisson ratio cell element is chimeric into the closed three-dimensional negative Poisson ratio cell element to form a positive and negative Poisson ratio structure chimeric cell element. The positive and negative Poisson ratio structure chimeric reinforced cushioning material can obtain a positive and negative Poisson ratio chimeric design metamaterial by copying and connecting the positive and negative Poisson ratio structure chimeric cell element in space. When the metamaterial deforms under impact load, the internal concave structure will shrink and deform, and the honeycomb structure will expand and deform. Through the coupling effect of the two completely opposite deformations, the impact resistance of the metamaterial can be improved.

Description

Technical Field

[0001] This invention belongs to the field of cushioning material technology, and in particular relates to a positive and negative Poisson's ratio interlocking reinforced cushioning material. Background Technology

[0002] Shock is a common and harsh environment in the aerospace field, and reducing shock loads is crucial for ensuring the reliability and safety of equipment components. Currently, using cushioning materials to absorb shock energy is the mainstream shock reduction method in aerospace engineering, with common cushioning materials including rubber cushioning pads and aluminum honeycomb structures. However, rubber cushioning pads suffer from high strain rate sensitivity and severe nonlinear hardening, while aluminum honeycomb structures have poor deformation performance and excessively high impact stress, which are not conducive to cushioning requirements. Cushioning materials in the aerospace field should meet the performance requirements of lightweight, high energy absorption, and low impact, making the design of new cushioning materials that meet these requirements of great significance.

[0003] Mechanical metamaterials are defined as periodic artificial structures with special mechanical properties. Compared with traditional cushioning materials, mechanical metamaterials have the advantage of being able to modify their deformation modes through the design of their internal microstructures, thereby constructing ideal structures that meet practical needs. Negative Poisson's ratio materials are a typical class of mechanical metamaterials. Unlike traditional positive Poisson's ratio materials, which deform in the opposite way, negative Poisson's ratio materials contract inward under impact loads, thus enhancing their impact stress. Common negative Poisson's ratio materials include concave structures, double-arrow structures, star-shaped structures, and chiral structures. These negative Poisson's ratio materials have been widely used in cushioning and energy absorption engineering applications.

[0004] Existing negative Poisson's ratio metamaterials have high porosity and a single deformation mode, making it difficult to completely absorb impact energy. Therefore, researchers have conducted numerous innovative designs to enhance the compressive strength and energy absorption performance of negative Poisson's ratio materials. Current research focuses on innovative designs of negative Poisson's ratio structures at both the mesoscopic and macroscopic levels as the main means to improve the structural buffering and energy absorption performance. For example, at the mesoscopic level, researchers have proposed methods such as adding additional support beams to microcells and setting up multi-level cell designs; at the macroscopic level, researchers have proposed methods such as coupling cell wall structures with negative Poisson's ratio structures and employing layered gradient designs.

[0005] However, adding extra cell walls to induce deformation mode conversion at the two-dimensional scale often only enhances the stress in the middle and later stages of metamaterials, and has a limited effect on improving the overall specific energy absorption of the material; the complexity of multi-level design microcells is significantly increased, which puts forward higher requirements for manufacturing precision; the coupling design at the macro level is mostly based on the combination of negative Poisson ratio structure and macro structure (homogeneous material or thin-walled tube), and its spatial scalability and coupling strength need to be improved.

[0006] Therefore, to improve the compressive strength and energy absorption performance of traditional negative Poisson's ratio metamaterials, the following three technical problems should be addressed:

[0007] 1. Metamaterials should possess high lightweight and high specific energy absorption properties;

[0008] 2. Avoid significantly increasing the complexity of metamaterials;

[0009] 3. Metamaterials should have good spatial scalability. Summary of the Invention

[0010] This invention provides a positive and negative Poisson's ratio interlocking reinforced cushioning material, which aims to solve the following problem.

[0011] This invention is implemented as follows: a positive and negative Poisson's ratio structure-interlocking reinforced buffer material includes multiple positive and negative Poisson's ratio structure-interlocking cells. Each positive and negative Poisson's ratio structure-interlocking cell includes four negative Poisson's ratio microcells and two positive Poisson's ratio microcells. The four negative Poisson's ratio microcells are connected end-to-end in space to form an enclosed three-dimensional negative Poisson's ratio cell. The two positive Poisson's ratio microcells intersect to form a cross-shaped three-dimensional positive Poisson's ratio cell. The cross-shaped three-dimensional positive Poisson's ratio cell is interlocked within the enclosed three-dimensional negative Poisson's ratio cell to form a positive and negative Poisson's ratio structure-interlocking cell.

[0012] Preferably, the negative Poisson's ratio microcell includes two first horizontal cell walls, four first inclined cell walls, and two first connecting cell walls. The two first horizontal cell walls are parallel to each other and spaced apart. Each end of the two first horizontal cell walls is provided with a first inclined cell wall. The inner ends of the two first inclined cell walls on the same side are connected and the connection point forms an inwardly concave angle. The two first horizontal cell walls and the four first inclined cell walls form an hourglass-shaped structure. The two first connecting cell walls are respectively provided at the connection points of the two first inclined cell walls on both sides.

[0013] Preferably, within an enclosed three-dimensional negative Poisson's ratio cell, a first connecting cell wall of each negative Poisson's ratio microcell is connected to a first connecting cell wall of an adjacent negative Poisson's ratio microcell.

[0014] Preferably, the positive Poisson's ratio microcell includes two second horizontal cell walls, four second inclined cell walls, and two second connecting cell walls. The two second horizontal cell walls are parallel to each other and spaced apart. Both ends of the two second horizontal cell walls are provided with second inclined cell walls. The inner ends of the two second inclined cell walls on the same side are connected and the connection point forms an outwardly convex angle. The two second horizontal cell walls and the four second inclined cell walls form a hexagonal structure. The two second connecting cell walls are respectively provided at the connection points of the two second inclined cell walls on both sides.

[0015] Beneficial effects

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a positive and negative Poisson's ratio structured interlocking reinforced buffer material. A negative Poisson's ratio microcell 4 is rotated and replicated in space, so that the resulting four negative Poisson's ratio microcells 4 are interconnected to form a closed loop, resulting in an enclosed three-dimensional negative Poisson's ratio cell 2. A positive Poisson's ratio microcell 5 is rotated and replicated in space, so that the resulting two cells are arranged in a cross-shaped arrangement, resulting in a cross-shaped three-dimensional positive Poisson's ratio cell 3. The resulting cross-shaped three-dimensional positive Poisson's ratio cell 3 is placed within the enclosed three-dimensional negative Poisson's ratio cell 2, such that the second connecting cell wall 53 of each positive Poisson's ratio microcell 5 is located at the center of the negative Poisson's ratio microcell 4, resulting in a positive-negative Poisson's ratio structured interlocking cell 1. By replicating and connecting the positive-negative Poisson's ratio structure interlocking cell 1 in space, a positive-negative Poisson's ratio interlocking design metamaterial can be obtained. When the invented metamaterial deforms under impact load, its internal concave structure will shrink and its honeycomb structure will expand. Through the coupling effect of the two completely opposite deformations, the impact resistance of the metamaterial can be improved.

[0017] The positive-negative Poisson's ratio interlocking design buffer material involves a three-dimensional cell structure, which has higher lightweight characteristics compared with the existing two-dimensional structure. The enclosed three-dimensional negative Poisson's ratio cell 2 and the cross-shaped three-dimensional positive Poisson's ratio cell 3 can both have their mechanical properties changed through parameter design, and have high designability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the positive and negative Poisson's ratio chimeric cell in this invention;

[0020] Figure 3 This is a schematic diagram of the structure of the negative Poisson's ratio microcell in this invention;

[0021] Figure 4 This is a schematic diagram of the structure of the positive Poisson's ratio microcell in this invention;

[0022] Figure 5 This is a schematic diagram of the enclosed three-dimensional negative Poisson's ratio cell in this invention;

[0023] Figure 6 This is a schematic diagram of the cross-shaped three-dimensional positive Poisson's ratio cell in this invention.

[0024] In the figure: 1-Chimeric cell with positive and negative Poisson's ratio structure, 2-Enclosed three-dimensional negative Poisson's ratio cell, 3-Cross-shaped three-dimensional positive Poisson's ratio cell, 4-Negative Poisson's ratio micro cell, 41-First horizontal cell wall, 42-First inclined cell wall, 43-First connecting cell wall, 5-Poisson's ratio micro cell, 51-Second horizontal cell wall, 52-Second inclined cell wall, 53-Second connecting cell wall. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] Please see Figure 1-3 The present invention provides a technical solution: a positive and negative Poisson's ratio structure-interlocking reinforced buffer material, comprising a plurality of positive and negative Poisson's ratio structure-interlocking cells 1, each of the positive and negative Poisson's ratio structure-interlocking cells 1 comprising four negative Poisson's ratio micro cells 4 and two positive Poisson's ratio micro cells 5, the four negative Poisson's ratio micro cells 4 being connected end-to-end in space to form an enclosed three-dimensional negative Poisson's ratio cell 2, the two positive Poisson's ratio micro cells 5 intersecting to form a cross-shaped three-dimensional positive Poisson's ratio cell 3, the cross-shaped three-dimensional positive Poisson's ratio cell 3 being interlocked within the enclosed three-dimensional negative Poisson's ratio cell 2 to form the positive and negative Poisson's ratio structure-interlocking cells 1.

[0027] In this embodiment, negative Poisson's ratio microcell 4 and positive Poisson's ratio microcell 5 are interlocked in space. Through the completely opposite deformation trends of the two structures and the interlocking arrangement strategy, the two structures will produce a significant coupling effect under impact load. Since the coupling effect is determined by the microcell topology, the coupling effect exists in the entire material space, which will significantly improve the coupling effect strength.

[0028] Furthermore, the negative Poisson's ratio microcell 4 includes two first horizontal cell walls 41, four first inclined cell walls 42, and two first connecting cell walls 43. The two first horizontal cell walls 41 are parallel to each other and spaced apart. Each end of the two first horizontal cell walls 41 is provided with a first inclined cell wall 42. The inner ends of the two first inclined cell walls 42 on the same side are connected and the connection point forms an inwardly concave angle. The two first horizontal cell walls 41 and the four first inclined cell walls 42 form an hourglass-shaped structure. The two first connecting cell walls 43 are respectively provided at the connection points of the two first inclined cell walls 42 on both sides.

[0029] In this embodiment, the negative Poisson's ratio microcell 4 is composed of 8 cell walls, of which the four first inclined cell walls 42 are of equal length, and are represented by l 11 This indicates that the four included angles formed by the first inclined cell wall 42 and the first horizontal cell wall 41 are equal, denoted by θ1, and θ1 is less than 90 degrees, so that the connection between two connected first inclined cell walls 42 forms an indentation. The two first horizontal cell walls 41 are parallel to each other and of equal length, denoted by l. 12 This indicates that the two first connecting cell walls 43 are parallel to each other and connected to the first inclined cell wall 42, with a length of L. 12 / 2; The height of the entire microcell is h, the length is s, the cell wall width is b1, and the cell wall thickness is t1.

[0030] Furthermore, within an enclosed three-dimensional negative Poisson's ratio cell 2, a first connecting cell wall 43 of each negative Poisson's ratio microcell 4 is connected to a first connecting cell wall 43 of an adjacent negative Poisson's ratio microcell 4.

[0031] In this embodiment, four negative Poisson's ratio microcells 4 are connected end to end, and the two first connecting cell walls 43 in each negative Poisson's ratio microcell 4 are respectively connected to one first connecting cell wall 43 of two adjacent negative Poisson's ratio microcells 4.

[0032] Furthermore, the positive Poisson's ratio microcell 5 includes two second horizontal cell walls 51, four second inclined cell walls 52, and two second connecting cell walls. The two second horizontal cell walls 51 are parallel to each other and spaced apart. The two ends of the two second horizontal cell walls 51 are provided with second inclined cell walls 52. The inner ends of the two second inclined cell walls 52 on the same side are connected and the connection point forms an outward convex angle. The two second horizontal cell walls 51 and the four second inclined cell walls 52 form a hexagonal structure. The two second connecting cell walls 53 are respectively provided at the connection points of the two second inclined cell walls 52 on both sides.

[0033] Poisson's ratio cell 5 consists of 8 cell walls, of which four second inclined cell walls 52 are of equal length, represented by l. 21 The angle between the two adjacent second inclined cell walls 52 and the second horizontal cell wall 51 is denoted by θ2, and θ2 is greater than 90 degrees, causing the connection point of the two adjacent second inclined cell walls 52 to form an outward convexity; the two second horizontal cell walls 51 are parallel to each other and of equal length, and their length is denoted by l. 22 This indicates that the two second connecting cell walls 53 are parallel to each other and connected to the second inclined cell wall 52, with a length of l. 12 / 2; The height of the entire microcell is h, the length is s, the cell wall width is b2, and the cell wall thickness is t2.

[0034] That is, the positive Poisson's ratio cell 5 and the negative Poisson's ratio cell 4 have the same overall height and the same length.

[0035] The negative Poisson's ratio microcell 4 is rotated and replicated in space, so that the four resulting negative Poisson's ratio microcells 4 are interconnected to form a closed loop, resulting in an enclosed three-dimensional negative Poisson's ratio microcell 2. The positive Poisson's ratio microcell 5 is rotated and replicated in space, so that the two resulting cells are arranged in an intersecting pattern, resulting in a cross-shaped three-dimensional positive Poisson's ratio microcell 3. The resulting cross-shaped three-dimensional positive Poisson's ratio microcell 3 is placed inside the enclosed three-dimensional negative Poisson's ratio microcell 2, so that the second connecting cell wall 53 of each positive Poisson's ratio microcell 5 is located at the center of the negative Poisson's ratio microcell 4, resulting in a positive-negative Poisson's ratio structured interlocking cell 1. By replicating and connecting the positive-negative Poisson's ratio structured interlocking cell 1 in space, a positive-negative Poisson's ratio interlocking design metamaterial can be obtained. When the invented metamaterial deforms under impact load, its internal concave structure will undergo contraction deformation, and its honeycomb structure will undergo expansion deformation. Through the coupling effect of these two completely opposite deformations, the impact resistance of the metamaterial can be improved.

[0036] The positive-negative Poisson's ratio interlocking design buffer material involves a three-dimensional cell structure, which has higher lightweight characteristics compared with the existing two-dimensional structure. The enclosed three-dimensional negative Poisson's ratio cell 2 and the cross-shaped three-dimensional positive Poisson's ratio cell 3 can both have their mechanical properties changed through parameter design, and have high designability.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reinforced cushioning material with a positive and negative Poisson's ratio interlocking structure, characterized in that: It includes multiple positive and negative Poisson ratio structure chimeric cells (1), each of the positive and negative Poisson ratio structure chimeric cells (1) includes four negative Poisson ratio micro cells (4) and two positive Poisson ratio micro cells (5). The four negative Poisson ratio micro cells (4) are connected end to end in space to form an enclosed three-dimensional negative Poisson ratio cell (2). The two positive Poisson ratio micro cells (5) intersect each other to form a cross-shaped three-dimensional positive Poisson ratio cell (3). The cross-shaped three-dimensional positive Poisson ratio cell (3) is embedded in the enclosed three-dimensional negative Poisson ratio cell (2) to form a positive and negative Poisson ratio structure chimeric cell (1).

2. The positive and negative Poisson's ratio interlocking reinforced cushioning material as described in claim 1, characterized in that: The negative Poisson's ratio microcell (4) includes two first horizontal cell walls (41), four first inclined cell walls (42), and two first connecting cell walls (43). The two first horizontal cell walls (41) are parallel to each other and spaced apart. Each of the two first horizontal cell walls (41) has a first inclined cell wall (42) at both ends. The inner ends of the two first inclined cell walls (42) on the same side are connected and the connection point forms an inwardly concave angle. The two first horizontal cell walls (41) and the four first inclined cell walls (42) form an hourglass-shaped structure. The two first connecting cell walls (43) are respectively located at the connection point of the two first inclined cell walls (42) on both sides.

3. The positive and negative Poisson's ratio interlocking reinforced cushioning material as described in claim 2, characterized in that: Within an enclosed three-dimensional negative Poisson's ratio cell (2), a first connecting cell wall (43) of each negative Poisson's ratio microcell (4) is connected to a first connecting cell wall (43) of the adjacent negative Poisson's ratio microcell (4).

4. The positive and negative Poisson's ratio interlocking reinforced cushioning material as described in claim 1, characterized in that: The positive Poisson's ratio microcell (5) includes two second horizontal cell walls (51), four second inclined cell walls (52), and two second connecting cell walls. The two second horizontal cell walls (51) are parallel to each other and spaced apart. The two ends of the two second horizontal cell walls (51) are provided with second inclined cell walls (52). The inner ends of the two second inclined cell walls (52) on the same side are connected and the connection point forms an outward convex angle. The two second horizontal cell walls (51) and the four second inclined cell walls (52) form a hexagonal structure. The two second connecting cell walls (53) are respectively provided at the connection point of the two second inclined cell walls (52) on both sides.

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