A tensile structure-based negative poisson's ratio metamaterial unit cell structure

Abstract

The application discloses a kind of negative Poisson's ratio metamaterial cell structure based on tension structure, including three-pronged rod assembly, three elastic link assemblies and three first springs, three elastic link assemblies are evenly distributed along three-pronged rod assembly circumference, and each elastic link assembly end is rotationally connected with three-pronged rod assembly end;Every middle part of each elastic link assembly is connected with the middle part of three-pronged rod assembly by first spring.The application utilizes the characteristics of tension integral structure, such as light weight, self-stabilizing, self-adapting and stiffness adjustable, combines with metamaterial cell structure, can improve rigidity and self-stabilizing, improve mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of negative Poisson's ratio metamaterial structures, and more particularly to a negative Poisson's ratio metamaterial cell structure based on a tension structure. Background Art

[0002] Negative Poisson's ratio metamaterials, a key branch of mechanical metamaterials, have become a highly sought-after new material due to their negative Poisson's ratio effect, which can enhance mechanical properties such as shear modulus, fracture toughness, thermal shock strength, and indentation resistance. As a non-naturally occurring material, metamaterials' properties are determined by their structural characteristics rather than their chemical composition.

[0003] Currently, a variety of metamaterial cell structures have been proposed to achieve negative Poisson's ration characteristics, but all of them have unreasonable geometric and topological shape designs, which are mainly manifested in poor self-stability, and the rigidity and mechanical properties need to be improved.

[0004] Therefore, providing a negative Poisson's ratio metamaterial cell structure based on a tensile structure with improved mechanical properties is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a negative Poisson's ratio metamaterial cellular structure based on a tensile structure, which has the characteristics of programmability, stability and adjustable stiffness.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A negative Poisson's ratio metamaterial cell structure based on a tension structure includes a tripod assembly, three elastic link assemblies and three first springs. The three elastic link assemblies are evenly distributed along the circumference of the tripod assembly, and the end of each elastic link assembly is rotatably connected to the end of the tripod assembly; the middle of each elastic link assembly is connected to the middle of the tripod assembly via the first spring.

[0008] By adopting the above scheme, the beneficial effects of the present invention are:

[0009] By utilizing the characteristics of the tensegrity structure, such as light weight, self-stability, self-adaptation and adjustable stiffness, and combining it with the metamaterial cellular structure, it is possible to enhance the stiffness and self-stability and improve the mechanical properties.

[0010] Furthermore, the tripod assembly includes a first tripod and a second tripod which are parallel and cross-distributed up and down, and the middle of the first tripod is rotatably connected to the middle of the second tripod to form a first central rotation point; one end of the three elastic link assemblies are respectively rotatably connected to the three first support rod ends of the first tripod, and the other end of the three elastic link assemblies are respectively rotatably connected to the three second support rod ends of the second tripod; the middle of the three elastic link assemblies are respectively connected to the first central rotation point through the three first springs.

[0011] Furthermore, the adjacent first support rods and the second support rods form an angle of 60°.

[0012] Furthermore, the elastic link assembly includes a first link, a second link, two second springs and two third springs, the first link and the second link are parallel and cross-distributed up and down, and the middle of the first link is rotatably connected to the middle of the second link to form a second center rotation point; the end of the first link is connected to the end of the second link close to it through the second spring, and the end of the first link is connected to the end of the second link away from it through the third spring; the ends of the three first support rods are respectively rotatably connected to one end of the three first links, and the ends of the three second support rods are respectively rotatably connected to one end of the three second links; the three second center rotation points are respectively connected to the first center rotation point through the three first springs.

[0013] The beneficial effect of adopting the above-mentioned further technical solution is that when the three elastic link assembly structures are subjected to forces in different directions, they can restrict each other's rotation in the axial direction, making the structure more stable, and under the constraints of three sets of springs with different elastic coefficients, they will always reach a balanced state at one position, thereby improving self-stability.

[0014] Furthermore, the angle between the first connecting rod and the second connecting rod is 60°.

[0015] Furthermore, the middle portion of the first tripod and the middle portion of the second tripod, the middle portion of the first connecting rod and the middle portion of the second connecting rod, the end portion of the first support member and the end portion of the first connecting rod, and the end portion of the second support member and the end portion of the second connecting rod are all connected by pins. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0017] Figure 1 The accompanying drawing is an axial side view of a negative Poisson's ratio metamaterial cell structure based on a tensile structure provided by the present invention;

[0018] Figure 2 The accompanying drawing is a front view of a negative Poisson's ratio metamaterial cell structure based on a tensile structure provided by the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] like Figure 1-2 As shown, an embodiment of the present invention discloses a negative Poisson's ratio metamaterial cellular structure based on a tensegrity structure, comprising a tripod assembly 1, three elastic link assemblies 2, and three first springs 3. The three elastic link assemblies 2 are all rectangular and evenly distributed along the circumference of the tripod assembly 1, with 120° between each other. The ends of each elastic link assembly 2 are rotatably connected to the ends of the tripod assembly 1; the middle portion of each elastic link assembly 2 is connected to the middle portion of the tripod assembly 1 via the first spring 3. The present invention utilizes the lightweight, self-stabilizing, adaptive, and stiffness-adjustable characteristics of the two-rod, four-cable and four-rod, two-cable tensegrity structures, combined with the metamaterial cellular structure, to enhance stiffness and self-stability, thereby improving mechanical properties.

[0021] Specifically, the tripod assembly 1 includes a first tripod 11 and a second tripod 12 that are parallel and cross-distributed up and down. The middle part of the first tripod 11 is rotatably connected to the middle part of the second tripod 12 to form a first central rotation point 4; one end of the three elastic link assemblies 2 are respectively rotatably connected to the ends of the three first support rods of the first tripod 11, and the other end of the three elastic link assemblies 2 are respectively rotatably connected to the ends of the three second support rods of the second tripod 12. In this embodiment, the adjacent first support rods and second support rods form a 60° angle between each other; the middle parts of the three elastic link assemblies 2 are respectively connected to the first central rotation point 4 through three first springs 3. When the three elastic link assemblies 2 are subjected to forces in different directions, they can restrict each other's rotation in the axial direction, making the structure more stable.

[0022] Specifically, the elastic link assembly 2 includes a first link 21, a second link 22, two second springs 23 and two third springs 24. The first link 21 and the second link 22 are parallel and cross-distributed up and down, and the middle part of the first link 21 is rotatably connected to the middle part of the second link 22 to form a second central rotation point 5. In this embodiment, the angle between the first link 21 and the second link 22 is 60°; the end of the first link 21 is connected to the end of the second link 22 close to it through the second spring 23, and the end of the first link 21 is connected to the end of the second link 22 away from it through the third spring 24; the ends of the three first support rods are respectively rotatably connected to one end of the three first links 21, and the ends of the three second support rods are respectively rotatably connected to one end of the three second links 22; the three second central rotation points 5 are respectively connected to the first central rotation point 4 through three first springs 3, and the first spring 3, the second spring 23 and the third spring 24 are all hook springs. In this embodiment, the first spring 3, the second spring 23 and the third spring 24 have different elastic coefficients, so that under the constraints of three groups of springs with different elastic coefficients, a balanced state can always be reached at one position, thereby improving self-stability.

[0023] Specifically, the middle of the first tripod 11 and the middle of the second tripod 12, the middle of the first connecting rod 21 and the middle of the second connecting rod 22, the end of the first support rod and the end of the first connecting rod 21, and the end of the second support rod and the end of the second connecting rod 22 are all connected by pins.

[0024] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0025] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A negative Poisson's ratio metamaterial cell structure based on a tensile structure, characterized in that: It includes a tripod assembly, three elastic link assemblies and three first springs, wherein the three elastic link assemblies are evenly distributed along the circumference of the tripod assembly, and each end of the elastic link assembly is rotatably connected to the end of the tripod assembly; the middle portion of each elastic link assembly is connected to the middle portion of the tripod assembly via the first spring; The tripod assembly includes a first tripod and a second tripod that are parallel and cross-distributed vertically. The middle portion of the first tripod is rotatably connected to the middle portion of the second tripod to form a first central rotation point. One end portion of the three elastic link assemblies is rotatably connected to the ends of the three first support members of the first tripod, and the other end portions of the three elastic link assemblies are rotatably connected to the ends of the three second support members of the second tripod. The middle portions of the three elastic link assemblies are respectively connected to the first central rotation point via three first springs. The adjacent first supporting rods form an angle of 60° between each other, and the adjacent second supporting rods form an angle of 60° between each other; The elastic link assembly includes a first link, a second link, two second springs and two third springs. The first link and the second link are parallel and cross-distributed up and down, and the middle of the first link is rotatably connected to the middle of the second link to form a second center rotation point; the two ends of the first link are respectively connected to the two ends of the second link close to it through the second springs, and the two ends of the first link are respectively connected to the two ends of the second link away from it through the third springs; the three ends of the first support rods are respectively rotatably connected to one end of the three first links close to the first support rod, and the three ends of the second support rods are respectively rotatably connected to one end of the three second links close to the second support rod; the three second center rotation points are respectively connected to the first center rotation point through the three first springs.

2. The negative Poisson's ratio metamaterial cell structure based on a tensile structure according to claim 1, characterized in that: The angle between the first connecting rod and the second connecting rod is 60°.

3. The negative Poisson's ratio metamaterial cell structure based on a tensile structure according to claim 1, characterized in that: The middle portion of the first tripod and the middle portion of the second tripod, the middle portion of the first connecting rod and the middle portion of the second connecting rod, the end portion of the first support member and the end portion of the first connecting rod close to the first support member, and the end portion of the second support member and the end portion of the second connecting rod close to the second support member are all connected by pins.

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