Internal stress self-loading two-rod two-cable tension metamaterial negative Poisson's ratio structure

Abstract

The invention belongs to the field of material science and metamaterials, and particularly relates to an internal stress self-loading two-rod two-cable tension characteristic negative poisson ratio metamaterial structure which comprises an internal stress self-loading two-rod two-cable tension metamaterial cell element structure and a rotating hinge. The two-rod and two-cable tensioning metamaterial cell element structure capable of automatically loading the internal stress comprises a rigid shell part, a T-shaped rod piece, a pressed elastic assembly, a tensioned elastic assembly and a hydrogel driving assembly. The characteristics of self-stabilization, self-recovery, self-adjustment and the like of the overall tensioning structure are combined, the unique deformation mechanism of the negative Poisson's ratio material is reserved, the local stress concentration effect of a traditional material is overcome, the limitation that the tensioning structure depends on external loading internal stress is broken through, the energy absorption, shock absorption, impact resistance and other performance of the negative Poisson's ratio material are improved, and the tensile strength of the negative Poisson's ratio material is improved. The method is expected to be developed vigorously and can realize application value in multiple fields.

Description

Technical Field

[0001] The present invention belongs to the field of material science and metamaterials, and specifically relates to a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, which is suitable for the fields of energy absorption, shock absorption, impact resistance and high-performance engineering materials. Background Art

[0002] Due to their special deformation behavior, negative Poisson's ratio materials have shown significant application prospects in many engineering fields. Unlike traditional materials, the lateral dimensions of negative Poisson's ratio materials will increase when stretched. This unique deformation mechanism enables them to have higher energy absorption, shock absorption and impact resistance. However, existing negative Poisson's ratio materials still have certain shortcomings in terms of strength and stability. When the stress or strain borne by the material exceeds a certain critical value, stress concentration is likely to occur in local areas, which in turn causes local collapse or structural instability, significantly affecting the overall mechanical properties of the material. This problem of local stress concentration limits the widespread application of negative Poisson's ratio materials in some high stress and high strain environments.

[0003] To address this problem, a tensegrity structure is proposed to improve the local stress concentration effect of negative Poisson's ratio materials, thereby improving the mechanical properties of negative Poisson's ratio materials. That is, through the synergistic effect of the tension and compression forces of the tensegrity structure, the uniform distribution of stress can be effectively achieved, avoiding the problem of local stress concentration. This structural design allows the material to undergo delocalized deformation under the action of external loads, thereby preventing overall failure caused by excessive deformation in local areas. However, traditional tensegrity structures usually rely on external loading to generate internal prestress, which places additional requirements on the control and operation of the system.

[0004] Therefore, how to develop a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress is an urgent problem to be solved by technicians in this field. Summary of the invention

[0005] To this end, the purpose of the present invention is to develop a two-rod and two-cable tensile metamaterial with negative Poisson's ratio that can self-load internal stress, self-stabilize, self-recover and self-regulate. The material combines the mechanical properties of the tensegrity structure, retains the unique deformation mechanism of the negative Poisson's ratio material, overcomes the local stress concentration effect of traditional materials, breaks through the limitation of the tensile structure relying on external loading to control internal stress, and improves the energy absorption, shock absorption and impact resistance of traditional negative Poisson's ratio materials.

[0006] The invention provides a two-rod two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, comprising a two-rod two-cable tensioned metamaterial cell structure with self-loaded internal stress and a rotary hinge.

[0007] The two-rod and two-cable tensile metamaterial cellular structure with self-loaded internal stress has a total of nine groups, and the two-rod and two-cable tensile metamaterial cellular structure with self-loaded internal stress includes two groups of rigid shell components, two groups of T-shaped rods, two groups of elastic components and hydrogel driving components. The rotary hinge is a symmetrical four-petal-shaped plate. Among them, the rigid shell, the T-shaped rod and the rotary hinge are made of polylactic acid material, the elastic component is made of thermoplastic polyurethane material, and the hydrogel driving component is synthesized by 3-sulfopropyl acrylate potassium salt through chemical cross-linking method.

[0008] The two-rod and two-cable tension metamaterial negative Poisson's ratio structure with self-loaded internal stress is placed in a water environment, and the two groups of T-shaped rods and the two groups of compressed elastic components are pushed by the hydrogel driving component to slide along the channel direction of the shell component. The two groups of T-shaped rods reach self-balance under the common constraint of the two groups of elastic components, and finally complete the self-loading of internal stress. When subjected to external loads, the two-rod and two-cable tension metamaterial negative Poisson's ratio structure with self-loaded internal stress deforms abnormally, absorbs external energy, and resists energy impact. The two-rod and two-cable tension metamaterial cellular structure with self-loaded internal stress is delocalized, distributively carries excessive stress, and enhances the stability of the structure; when the external load is removed, the two-rod and two-cable tension metamaterial negative Poisson's ratio structure with self-loaded internal stress will remain in a deformed state; when subjected to opposite external loads, the two-rod and two-cable tension metamaterial negative Poisson's ratio structure with self-loaded internal stress will restore the initial state, restore toughness and energy absorption capacity, and improve the service life of the structure.

[0009] It can be known from the above technical solutions that, compared with the prior art, the present invention discloses a two-rod and two-cable tensile metamaterial negative Poisson's ratio that can self-load internal stress, self-stabilize, self-recover and self-regulate. This material combines the delocalized deformation characteristics of the tensile overall structure with the excellent toughness and mechanical properties of the negative Poisson's ratio material, overcomes the limitations of traditional negative Poisson's ratio materials in local stress concentration, and breaks through the shackles of the tensile structure relying on external loading to control internal stress. The present invention provides a two-rod and two-cable tensile metamaterial negative Poisson's ratio structure that self-loads internal stress, which utilizes the unique deformation mechanism of the negative Poisson's ratio material, combines the mechanical properties of the tensile overall structure, overcomes the local stress concentration effect of traditional materials, breaks through the limitation of the tensile structure relying on external loading to control internal stress, and improves the energy absorption, shock absorption and impact resistance of traditional negative Poisson's ratio materials.

[0010] Furthermore, the two groups of shell components are respectively a first shell component and a second shell component. The main bodies of the first shell component and the second shell component are both rectangular structures, with 6 water inlet channels in the middle of the main body, channels in the inner extension direction, limited structures at both ends, and 4 positioning and mounting holes at the 4 corners. Grooves are also provided on both sides of the main structure of the second shell component, so that the first shell component and the second shell component can be assembled in an inlaid manner. Four triangular fixing buckles are provided in the middle of the second shell channel, which are arranged symmetrically. The water inlet channel can maintain the synchronous changes of the internal structure with the external environment, providing a basic guarantee for the response drive inside the structure.

[0011] Furthermore, the two groups of T-shaped rods include an H-shaped frame and a telescopic rod connected as one body, four symmetrically distributed fixing grooves are provided on both sides of the H-shaped frame with the telescopic rod as the center, four axial holes are provided at both ends of the H-shaped frame along its width direction, and a square limit baffle is constructed at the extended end of the telescopic rod along its length direction; the two groups of T-shaped rods are symmetrically distributed on both sides of the long end of the shell component, and the telescopic rod of the T-shaped rod can slide inside the channel formed by the two groups of shell components. The square limit baffle at the end of the telescopic rod effectively prevents excessive sliding, ensures the controllable movement of the component in the channel, and thus improves the adjustment accuracy and overall stability of the structure.

[0012] The elastic components are respectively two groups of compressive elastic components and two groups of tensile elastic components. The two groups of compressive elastic components are in the shape of a hollow four-pointed star, and are connected by sliding inside the channel composed of two groups of shell components. The two groups of compressive elastic components finally reach balance and are fixed in the triangular fixing buckle of the second shell component after the self-driving process; the two groups of tensile elastic components include a serpentine tensile member and two groups of T-shaped fixing members connected as one. The two groups of T-shaped fixing members are respectively connected through the fixing grooves of the H-shaped frame; the hydrogel driving component is located at the center position inside the channel composed of the two groups of shell components, and can expand along the channel direction to push the two groups of compressive elastic components to slide. The compressive elastic component slides to the equilibrium position and is fixed under the drive of hydrogel expansion, providing reliable self-driving and self-balancing capabilities. The combination of the serpentine tensile member and the T-shaped fixing member ensures the stability of the tensile elastic component, and further improves the durability and adaptability of the entire structure.

[0013] The beneficial effect of adopting the technical solution of the above step is that the two-rod and two-cable tensioned metamaterial cellular structure with self-loaded internal stress self-loads internal stress under the driving force provided by the hydrogel driving component, thereby improving the structure's light weight and high strength, impact resistance and energy absorption, precise deformation control and adaptive performance.

[0014] Furthermore, the rotary hinge is a symmetrical four-petal-shaped plate, and axial holes are respectively provided at its four corners. The two-rod and two-cable tensioned metamaterial cellular structure with self-loaded internal stress is connected to the rotary hinge through the axial hole, and the rotary hinge undergoes translational rotation under the common constraint of four adjacent groups of the two-rod and two-cable tensioned metamaterial cellular structures with self-loaded internal stress.

[0015] The beneficial effect of adopting the above-mentioned technical solution is that the two-rod two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress benefits from the self-stabilization, self-recovery and self-regulation characteristics of the two-rod two-cable tensioned metamaterial cellular structure with self-loaded internal stress, and delocalized deformation will occur under external load, avoiding the overall failure of the material caused by excessive deformation in the local area, and further improving the energy absorption, shock absorption and impact resistance of traditional negative Poisson's ratio materials. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0017] Figure 1 The accompanying drawing is a front view of a two-rod and two-cable tensioned metamaterial cell structure with self-loaded internal stress provided by the present invention.

[0018] Figure 2 The accompanying drawing is an exploded schematic diagram of a two-rod and two-cable tensioned metamaterial cellular structure with self-loaded internal stress provided by the present invention.

[0019] Figure 3 The accompanying drawing is a perspective view of an initial state of a two-rod and two-cable tensioned metamaterial cell structure with self-loaded internal stress provided by the present invention.

[0020] Figure 4 The accompanying drawing is a perspective view of a two-rod and two-cable tensioned metamaterial cell structure in a driven state with self-loaded internal stress provided by the present invention.

[0021] Figure 5 The accompanying drawing is a front view of an initial state of a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress provided by the present invention.

[0022] Figure 6 The accompanying drawing is a front view of a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure in a driven state with self-loaded internal stress provided by the present invention.

[0023] Among them, 1000-a two-rod and two-cable tensioned metamaterial cellular structure with self-loaded internal stress; 100-rigid shell component; 110-first shell component; 120-second shell component; 200-T-shaped rod; 300-elastic component; 310-compressive elastic component; 320-tensile elastic component; 400-hydrogel drive component; 2000-rotating hinge. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two groups of components or the interaction relationship between two groups of components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0028] When the stress or strain of a negative Poisson's ratio material exceeds a certain critical value, it will cause stress concentration in local areas, which will cause local collapse or structural instability.

[0029] In view of this, the embodiment of the present invention discloses a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, as shown in the attached drawings. Figure 1-2 , including: a two-rod two-cable tensile metamaterial cellular structure 1000 with self-loaded internal stress and a rotary hinge 2000; the two-rod two-cable tensile metamaterial cellular structure 1000 with self-loaded internal stress has nine groups in total, including a shell component 100, a T-shaped rod 200, an elastic component 300 and a hydrogel driving component 400. The nine groups of the two-rod two-cable tensile metamaterial cellular structure 1000 with self-loaded internal stress are perpendicular to each other, arranged in an alternating manner, and connected to the rotary hinge 2000 through an axial hole to form a two-rod two-cable tensile metamaterial negative Poisson's ratio structure with self-loaded internal stress. The structure utilizes the self-stabilization, self-recovery and self-regulation characteristics of the tensegrity structure, which can enable the material to withstand greater loads and deformations, thereby improving the mechanical properties of the material.

[0030] See attached Figure 1-4 , the two groups of shell components 100 described in the embodiment of the present invention are respectively a first shell component 110 and a second shell component 120. The main bodies of the first shell component 110 and the second shell component 120 are both rectangular structures, and 6 water inlet channels are opened in the middle of the main body. Channels are opened in the direction of the internal extension, and limiting structures are left at both ends. Four positioning and mounting holes are opened at the positions of the four corners. Grooves are also opened on both sides of the main structure of the second shell component 120, so that the first shell component 110 and the second shell component 120 can be assembled in an inlaid manner. Four triangular fixing buckles are left in the middle of the second shell channel, which are arranged symmetrically. The water inlet channel can maintain the synchronous changes of the internal structure with the external environment, providing a basic guarantee for the response drive inside the structure.

[0031] In a preferred embodiment of the present invention, the two groups of T-shaped rods 200 include an H-shaped frame and a telescopic rod connected as one body, four symmetrically distributed fixing grooves are provided on both sides of the H-shaped frame with the telescopic rod as the center, four axial holes are provided at both ends of the H-shaped frame along its width direction, and a square limit baffle is constructed at the extended end of the telescopic rod along its length direction; the two groups of T-shaped rods 200 are symmetrically distributed on both sides of the long end of the shell component 100, and the telescopic rods of the T-shaped rods 200 can slide inside the channel formed by the two groups of shell components 100. The square limit baffle at the end of the telescopic rod effectively prevents excessive sliding, ensures the controllable movement of the component in the channel, and thus improves the adjustment accuracy and overall stability of the structure.

[0032] In a preferred embodiment of the present invention, the elastic components 300 are respectively two groups of compressive elastic components 310 and two groups of tensile elastic components 320. The two groups of compressive elastic components 310 are in the shape of a hollow four-pointed star, and are connected by sliding inside the channel formed by two groups of shell components 100. The two groups of compressive elastic components 310 finally reach balance and are fixed in the triangular fixing buckle of the second shell component 120 after the self-driving process; the two groups of tensile elastic components 320 include a serpentine tensile member connected as one and two groups of T-shaped fixing members. The two groups of T-shaped fixing members are connected through the fixing grooves of the H-shaped frame respectively; the hydrogel driving component 400 is located at the center position inside the channel formed by the two groups of shell components 100, and can expand along the channel direction to push the two groups of compressive elastic components 310 to slide. The compressive elastic component 310 slides to the equilibrium position and is fixed under the drive of hydrogel expansion, providing reliable self-driving and self-balancing capabilities. The combination of the serpentine tension member and the T-shaped fixing member ensures the stability of the tension elastic component 320, and further improves the durability and adaptability of the entire structure.

[0033] See attached Figure 5-6 In the embodiment of the present invention, the rotary hinge 2000 is a symmetrical four-petal-shaped plate, and axial holes are respectively provided at its four corners. The two-rod and two-cable tensioned metamaterial cellular structure 1000 with self-loaded internal stress is connected to the rotary hinge 2000 through the axial hole, and the rotary hinge 2000 undergoes translational rotation under the common constraint of four adjacent groups of the two-rod and two-cable tensioned metamaterial cellular structures 1000 with self-loaded internal stress.

[0034] The working modes of the embodiments provided by the present invention are mainly 1. Active environmental response to self-loading internal stress, the hydrogel swells in a wet environment to provide driving force, the common constraints of the two sets of elastic components 300 achieve self-balance, and finally complete the self-loading of internal stress; 2. Absorption and diffusion of external energy and load, when subjected to external load, the two-rod two-cable tension metamaterial negative Poisson's ratio structure 1000 of self-loading internal stress deforms abnormally, absorbs external energy, and resists energy impact. The two-rod two-cable tension metamaterial cellular structure 1000 of self-loading internal stress is delocalized, distributively carries excessive stress, and enhances the stability of the structure; when the external load is removed, the two-rod two-cable tension metamaterial negative Poisson's ratio structure 1000 of self-loading internal stress will remain in a deformed state; when subjected to an opposite external load, the two-rod two-cable tension metamaterial negative Poisson's ratio structure 1000 of self-loading internal stress will restore the initial state, restore toughness and energy absorption capacity, and improve the service life of the structure.

[0035] The invention improves the problems of negative Poisson's ratio materials, such as weak mechanical strength, poor stability, easy stress concentration and local collapse or structural instability. The invention provides a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, which combines the self-stabilization, self-recovery and self-regulation characteristics of the tensioned overall structure, retains the unique deformation mechanism of negative Poisson's ratio materials, overcomes the local stress concentration effect of traditional materials, breaks through the limitation of tensioned structures relying on external loading to control internal stress, improves the energy absorption, shock absorption and impact resistance of negative Poisson's ratio materials, and is expected to be vigorously developed and can realize its application value in many fields.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0037] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, characterized in that: include: A two-rod two-cable tensioned metamaterial cellular structure (1000) with self-loaded internal stress and a rotary hinge (2000); the two-rod two-cable tensioned metamaterial cellular structure (1000) with self-loaded internal stress comprises nine groups, including a rigid shell component (100), a T-shaped rod (200), an elastic component (300) and a hydrogel drive component (400); the two groups of shell components (100) are respectively a first shell component (110) and a second shell component (120); the first shell component (110) and the second shell component (120) are both rectangular structures, with six water inlet channels provided in the middle of the main body, channels provided in the inner extension direction, limiting structures left at both ends, and four positioning and mounting holes provided at the four corners; grooves are also provided on both sides of the main structure of the second shell component (120), so that the first shell component (110) and the second shell component (120) can be assembled in an inlaid manner; four triangular fixing buckles are provided in the middle of the second shell channel, and are symmetrically arranged.

2. According to claim 1, a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, characterized in that: In the self-loaded internal stress two-rod two-cable tensioned metamaterial cellular structure (1000), the two groups of T-shaped rods (200) comprise an H-shaped frame and a telescopic rod connected as one body, four symmetrically distributed fixing grooves are provided on both sides of the H-shaped frame with the telescopic rod as the center, four axial holes are provided at both ends of the H-shaped frame along its width direction, and a square limit baffle is constructed at the extended end of the telescopic rod along its length direction; the two groups of T-shaped rods (200) are respectively symmetrically distributed on both sides of the long end of the shell component (100), and the telescopic rods of the T-shaped rods (200) can slide inside the channel formed by the two groups of shell components (100).

3. According to claim 2, a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, characterized in that: In the two-rod and two-cable tensioned metamaterial cellular structure (1000) with self-loaded internal stress, the elastic components (300) are respectively two groups of compression elastic components (310) and two groups of tension elastic components (320); the two groups of compression elastic components (310) are in the shape of a hollow four-pointed star and are connected by sliding inside a channel formed by two groups of shell components (100); the two groups of compression elastic components (310) finally reach equilibrium and are fixed in the triangular fixing buckle of the second shell component (120) after a self-driving process; the two groups of tension elastic components (320) include a serpentine tension member and two groups of T-shaped fixing members connected as one body; the two groups of T-shaped fixing members are respectively connected through fixing grooves of the H-shaped frame; the hydrogel driving component (400) is located at the center of the channel formed by the two groups of shell components (100), and can expand along the channel direction to push the two groups of compression elastic components (310) to slide.

4. According to claim 3, a two-rod and two-cable tensioned metamaterial negative Poisson's ratio structure with self-loaded internal stress, characterized in that: The rotary hinge (2000) is a symmetrical four-petal-shaped plate, with axial holes respectively provided at its four corners; the two-rod and two-cable tensioned metamaterial cellular structure (1000) with self-loaded internal stress is connected to the rotary hinge (2000) via the axial holes, and the rotary hinge (2000) undergoes translational rotation under the joint constraint of four adjacent groups of the two-rod and two-cable tensioned metamaterial cellular structures (1000) with self-loaded internal stress.

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