CN218935121U

CN218935121U - Concave barbell auxetic open pore structure with negative poisson ratio

Info

Publication number: CN218935121U
Application number: CN202223383807.7U
Authority: CN
Inventors: 张祺; 朱一林; 邓夕胜; 赵翔; 邵永波; 于超
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2022-12-16
Filing date: 2022-12-16
Publication date: 2023-04-28
Anticipated expiration: 2032-12-16

Abstract

The embodiment of the utility model provides an inner concave barbell auxetic open pore structure with negative poisson ratio, which relates to the field of auxetic materials, and comprises a plurality of basic units; the basic unit is a sheet member arranged in a plane and is formed by combining three elliptic sheet members in a mode of mutually overlapping a part of each structure; the basic unit is axisymmetric about the connecting line of the center points of the three elliptical plate members; the structure formed by the rotationally symmetrical array of the plurality of basic units has a stronger negative poisson's ratio effect in an elastic range when being subjected to unidirectional tensile load.

Description

Concave barbell auxetic open pore structure with negative poisson ratio

Technical Field

The utility model relates to the field of auxetic materials, in particular to an inward concave barbell auxetic open-cell structure with negative poisson ratio.

Background

The mechanical metamaterial is a material designed manually and has specific physical properties which are not possessed by natural materials in nature. Because of their unique properties, there is an increasing interest in mechanical metamaterials, and a large number of which are currently being designed and manufactured. Auxetic materials, as one of the mechanical metamaterials, have now been found to exhibit physical properties that are superior to conventional materials, such as shear resistance, fracture resistance, indentation resistance, sound absorption, energy absorption, and the like. With the benefit of the characteristics, the auxetic material can be widely applied to the fields of textiles, biomedicine, aerospace, sports, automobiles, civil engineering and the like. Auxetic materials are of many types, but there is little research into the auxetic properties of auxetic materials after different shaped opening operations.

Disclosure of Invention

The utility model aims at providing an indent barbell auxetic open-cell structure with negative poisson ratio, which has simple structure, strong auxetic effect in elastic range when being acted by unidirectional tensile load, and can meet the pursuit of novel structure with good physical properties in various fields in the market, namely, a novel structure with negative poisson ratio effect.

Embodiments of the utility model may be implemented as follows:

the embodiment of the utility model provides an inner concave barbell auxetic open-cell structure with negative poisson ratio, which comprises a plurality of basic units;

the base unit is formed by combining a first elliptic plate member, a second elliptic plate member and a third elliptic plate member in a mode of overlapping a part of each structure.

In addition, the concave barbell auxetic open-cell structure with negative poisson ratio provided by the embodiment of the utility model can also have the following additional technical characteristics:

optionally, the edge of the second oval plate member passes through the center point of the first oval plate member and the third oval plate member.

Optionally, the center points of the first elliptical plate member, the second elliptical plate member and the third elliptical plate member are on the same straight line.

Optionally, the line connecting the center points of the first, second and third elliptical plate members is the symmetry axis of the base unit.

Optionally, the arc lengths of the first arc edge and the sixth arc edge of the base unit are equal.

Optionally, the arc lengths of the second arc edge, the third arc edge, the seventh arc edge and the eighth arc edge of the base unit are equal.

Optionally, the arc length of the fourth arc edge and the fifth arc edge of the base unit is equal.

Optionally, the plurality of base units are distributed in a rotationally symmetric array.

The concave barbell auxetic open-cell structure with negative poisson ratio of the embodiment of the utility model has the beneficial effects that the concave barbell auxetic open-cell structure with negative poisson ratio comprises, for example:

the structure includes a plurality of base units; the basic unit is a sheet member arranged in a plane and is formed by combining three elliptic sheet members in a mode of mutually overlapping a part of each structure; the basic unit is axisymmetric about the connecting line of the center points of the three elliptical plate members; the structure formed by the rotationally symmetrical array of the plurality of basic units has a stronger negative poisson's ratio effect in an elastic range when being subjected to unidirectional tensile load.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a basic unit structure in an open-cell structure of a concave barbell with negative poisson ratio according to the present embodiment;

fig. 2 is a diagram of a rotationally symmetrical array of a plurality of base units in a concave barbell auxetic open cell structure with negative poisson's ratio according to the present embodiment;

fig. 3 is a schematic structural diagram of an open-cell structure of a concave barbell with negative poisson's ratio according to the present embodiment;

fig. 4 is a schematic diagram showing a comparison between the structure before and after deformation when being axially stretched in the concave barbell auxetic open-cell structure with negative poisson ratio according to the present embodiment;

fig. 5 is a schematic diagram showing a comparison of structural strain and poisson's ratio when the concave barbell auxetic open-cell structure with negative poisson's ratio is axially stretched according to the present embodiment.

Icon: 10-a concave barbell auxetic open pore structure; 100-base unit; 110-a first oval plate member; 120-a second oval plate member; 130-a third oval plate member; 111-a first circular arc edge; 112-a second circular arc edge; 113-a third arc edge; 121-a fourth arc edge; 122-a fifth arc edge; 131-sixth circular arc edge; 132-seventh rounded edges; 133-eighth circular arc edge.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, if the terms "upper", "lower", "inner", "outer", and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present utility model and simplifying the description, and it is not indicated or implied that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus it should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, if any, are used merely for distinguishing between descriptions and not for indicating or implying a relative importance.

It should be noted that the features of the embodiments of the present utility model may be combined with each other without conflict.

The concave-barbell auxetic open-cell structure 10 with negative poisson's ratio provided in this embodiment is described in detail below with reference to fig. 1 to 5.

Referring to fig. 1, an embodiment of the present utility model provides a concave barbell auxetic open cell structure 10 with negative poisson's ratio, comprising a plurality of base units 100; the base unit 100 is formed by combining the first elliptical plate member 110, the second elliptical plate member 120, and the third elliptical plate member 130 in such a manner that a part of the respective structures are overlapped with each other; the edge of the second oval plate member 120 passes through the center points of the first oval plate member 110 and the third oval plate member 130; the first and second

oval plate members

110, 120 are collinear with the center point of the third oval plate member 130.

"Negative Poisson's Ratio" means that the material expands laterally within the elastic range when stretched; while the transverse direction of the material instead contracts when compressed. "the edge of the second oval plate member 120 passes through the center points of the first oval plate member 110 and the third oval plate member 130; the first and second

oval plate members

110, 120 are collinear with the center point of the third oval plate member 130. By "is meant that the base unit is made up of three oval plate members that overlap one another in a portion such that they fit closely together, and must not lie in intersecting planes.

Referring to fig. 2 and 3, a plurality of base units are connected by rotationally symmetrical arrays according to the drawing, and the opening operation is performed on the base units, so as to obtain the concave barbell auxetic open-cell structure 10 with negative poisson ratio according to the embodiment of the present utility model.

Referring to fig. 4, as can be seen from a comparison of the front and rear of the structure, the deformation of the elongated interconnection formed by the opening operation is greatest when the concave barbell auxetic open-cell structure 10 is rotationally symmetric in an array of a plurality of base units when being subjected to axial load stretching; the concave barbell auxetic open cell structure 10 is under tension in the direction of the arrows shown in the drawings, causing the structure to expand laterally when subjected to axial load tension, i.e., a negative poisson's ratio effect.

Referring to fig. 5, it can be seen that the concave barbell auxetic open cell structure 10 has a strong negative poisson's ratio effect, and can maintain good auxetic performance under large deformation.

With continued reference to fig. 1, in the present embodiment, the second circular arc side 112, the third circular arc side 113, the seventh circular arc side 132 and the eighth circular arc side 133 of the base unit 100 have the same arc length, and they are controlled by changing the ratio of the major axis and the minor axis of the first elliptical plate member 110 to the third elliptical plate member 130. By adjusting the magnitude of the ratio, a negative poisson's ratio effect different from the present embodiment can be obtained.

Specifically, in the present embodiment, the ratio of the major axis and the minor axis of the first elliptical plate member 110 to the third elliptical plate member 130 is 3.3.

Specifically, the ratio of the major axis and the minor axis of the first elliptical plate member 110 to the third elliptical plate member 130 ranges in size from 2 to 5. For example 2.5, 3, 3.5, 4, 4.5.

With continued reference to fig. 1, by adjusting the ratio of the major axis to the minor axis of the second elliptical plate member 120, a negative poisson's ratio effect different from the present embodiment can be obtained.

Specifically, in the present embodiment, the ratio of the major axis to the minor axis of the second elliptical plate member 120 is 3.3.

Specifically, the ratio of the major axis to the minor axis of the second elliptical plate member 120 ranges in size from 2 to 5. For example 2.5, 3, 3.5, 4, 4.5.

The concave barbell auxetic open-cell structure 10 with negative poisson ratio provided in this embodiment has at least the following advantages:

the ratio of the major axis and the minor axis of the first elliptical plate member 110 to the third elliptical plate member 130 of the base unit 100 for opening the holes is adjustable in magnitude to obtain different negative poisson's ratio effects.

The ratio of the major axis to the minor axis of the second oval plate member 120 of the base unit 100 for opening the aperture is adjustable in magnitude to achieve different negative poisson's ratio effects.

By adjusting the shortest distance between adjacent base units 100 that make up the concave barbell auxetic open structure 10, different negative poisson's ratio effects can be obtained.

The concave barbell auxetic open cell structure 10 obtained by rotationally symmetric array and perforation of the plurality of base units 100 has a strong negative poisson's ratio effect.

By designing the concave shape of the multi-rounded edges of the base unit 100 for the opening operation, the concave barbell auxetic open-cell structure 10 is pre-stored with a certain amount of deformation, with better deformability, which helps to improve the auxetic performance of the structure.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present utility model should be included in the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A concave barbell auxetic open cell structure with negative poisson's ratio, comprising:

a plurality of base units (100);

the base unit (100) is formed by combining a first elliptical plate member (110), a second elliptical plate member (120) and a third elliptical plate member (130) in a manner of overlapping a part of each structure.

2. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 1, wherein: the edge line of the second elliptical plate member (120) passes through the center points of the first elliptical plate member (110) and the third elliptical plate member (130).

3. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 2, wherein: the center points of the first elliptic plate member (110), the second elliptic plate member (120) and the third elliptic plate member (130) are on the same straight line.

4. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 3, wherein: the lines of the central points of the first elliptic plate member (110), the second elliptic plate member (120) and the third elliptic plate member (130) are symmetry axes of the base unit (100).

5. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 1, wherein: the arc length of the first arc edge (111) and the arc length of the sixth arc edge (131) of the basic unit (100) are equal.

6. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 1, wherein: the arc lengths of the second arc edge (112), the third arc edge (113), the seventh arc edge (132) and the eighth arc edge (133) of the base unit (100) are equal.

7. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 1, wherein: the arc length of the fourth arc side (121) and the arc length of the fifth arc side (122) of the basic unit (100) are equal.

8. The concave barbell auxetic open cell structure with negative poisson's ratio according to claim 1, wherein: the plurality of base units (100) are distributed in a rotationally symmetric array.