A negative stiffness bistable metamaterial cell structure based on tensile structure

Abstract

The present invention discloses a negative stiffness bistable metamaterial cellular structure based on a tensioned structure. The structure comprises a flat plate, two L-shaped rod groups, two gear groups, and multiple springs. The two L-shaped rod groups are located on either side of the top of the flat plate; the two gear groups are located at the bottom of the flat plate and correspond to the positions of the two L-shaped rod groups. The L-shaped rod groups and the corresponding gear groups are connected by a key extending through the flat plate; the two gear groups are connected by a transmission gear group; and the two adjacent L-shaped rods of each L-shaped rod group are connected by a spring. By combining the tensioned structure with the metamaterial cellular structure, the present invention improves the stability, self-adaptation, and self-stabilization properties of the cellular structure. Furthermore, by combining the characteristics of gears, the structure achieves more stable deformation and greater load-bearing capacity.

Description

Technical Field

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

[0002] Metamaterials are a class of artificial materials with special properties that do not exist in nature. They possess unique properties, such as allowing light and electromagnetic waves to change their normal properties, which is impossible to achieve with traditional materials.

[0003] The stiffness properties of traditional materials are difficult to change or adjust during operation, while this kind of tunable elasticity is highly desirable for robots and intelligent machines. While metamaterials exist that can achieve similar functions, continuous adjustability in existing designs is plagued by problems such as structural instability, weak robustness, plastic failure, and slow response.

[0004] Therefore, it is an urgent problem for those skilled in the art to provide a negative stiffness bistable metamaterial cell structure based on a tensile structure that has multistability, programmability, high stability, and fast response. Summary of the Invention

[0005] In view of this, the present invention provides a negative stiffness bistable metamaterial cellular structure based on a tensile structure, which has continuously adjustable elastic properties while maintaining stability and robust maneuverability and high load-bearing capacity.

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

[0007] A negative stiffness bistable metamaterial cell structure based on a tension structure includes a flat plate, two L-shaped rod groups, two gear groups and multiple springs, wherein the two L-shaped rod groups are respectively located on both sides of the top of the flat plate; the two gear groups are both located at the bottom of the flat plate and correspond to the positions of the two L-shaped rod groups respectively; the L-shaped rod group and the gear group corresponding to their positions are connected by a key passing through the flat plate; the two gear groups are connected by a transmission gear group; and the two L-shaped rods adjacent to each other along the circumference of each L-shaped rod group are connected by the springs.

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

[0009] By combining the tensile structure with the metamaterial cellular structure, the stability, adaptability, and self-stabilization performance of the cellular structure are improved. At the same time, combined with the gear characteristics, the deformation is made more stable and the load-bearing capacity is stronger.

[0010] Furthermore, the two L-shaped rod groups are symmetrically distributed.

[0011] The beneficial effect of adopting the above-mentioned further technical solution is that when a tension cell rotates and the spring length is shortened, the adjacent tension cell is stretched in the opposite direction, the spring length increases, and a reverse pulling force is provided to realize energy storage and release, so that the cell structure has a bistable state.

[0012] Furthermore, each of the L-shaped rod groups includes four L-shaped rods, which are evenly distributed along the circumference and the rotation angle between two circumferentially adjacent L-shaped rods is 90°; the inner end of each L-shaped rod is connected to the corresponding gear group through the key, and the outer ends of two circumferentially adjacent L-shaped rods are connected through the spring.

[0013] Furthermore, the gear set includes five gears arranged in a cross shape, and the gear located in the middle is respectively meshed with the four gears on its periphery; the inner end of each L-shaped rod is connected to the corresponding gear center through the key; the transmission gear set includes three transmission gears arranged horizontally and meshed in sequence; the two gears located on the inner side of the two gear sets are connected through the three transmission gears.

[0014] The beneficial effect of adopting the above-mentioned further technical solution is that, through the synchronous transmission of the gears, the relative angle of the L-shaped rod is guaranteed to remain unchanged when it rotates, thereby controlling the length of the springs in the same group to be equal, so that the tension in the tensioning structure can be controlled. At the same time, the use of the gear structure can make the rotation process smoother. Since the gears have a large load-bearing capacity, this structure can also further improve the load-bearing capacity of the cellular structure.

[0015] Furthermore, the two sections of each L-shaped rod are equal in length, and the length from the end of the L-shaped rod to the center is equal to the distance between the centers of the two gears distributed in the horizontal direction.

[0016] The beneficial effect of adopting the above-mentioned further technical solution is that the L-shaped rod is used to control the deformation scale of the spring, so that the overall tension of the material fluctuates during the deformation process, providing a basis for the bistability of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 A top view of a negative stiffness bistable metamaterial cell structure based on a tensile structure provided by the present invention;

[0019] Figure 2 This is a bottom view of a negative stiffness bistable metamaterial cell structure based on a tension structure provided by the present invention. DETAILED DESCRIPTION

[0020] 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.

[0021] like Figure 1 、 2 As shown, an embodiment of the present invention discloses a negative stiffness bistable metamaterial cellular structure based on a tensile structure, comprising a flat plate 1, two L-shaped rod groups 2, two gear groups 3, and a plurality of springs 4. The two L-shaped rod groups 2 are located on either side of the top of the flat plate 1; the two gear groups 3 are located at the bottom of the flat plate 1 and correspond to the positions of the two L-shaped rod groups 2 respectively; the L-shaped rod groups 2 and the gear groups 3 corresponding to their positions are connected by a key passing through the flat plate, and of course, the flat plate 1 has a keyway corresponding to the key; the two gear groups 3 are connected by a transmission gear group 5; the two L-shaped rods 21 adjacently distributed along the circumference of each L-shaped rod group 2 are connected by a spring 4, and finally the four springs 4 on each L-shaped rod group 2 are combined to form a square. The present invention improves the stability, self-adaptation, and self-stabilization performance of the cellular structure by combining the tensile structure with the metamaterial cellular structure. At the same time, combined with the characteristics of the gears, the deformation is more stable and the load-bearing capacity is stronger.

[0022] Specifically, the two L-shaped rod groups 2 are symmetrically distributed, that is, mirror images, so that when one tension cell rotates and the length of the spring 4 is shortened, the adjacent tension cells are stretched in the opposite direction, the spring length increases, and a reverse pulling force is provided to realize the storage and release of energy, so that the cell structure has a bistable state.

[0023] Specifically, each L-shaped rod group 2 includes four L-shaped rods 21, which are evenly distributed along the circumference and the rotation angle between two adjacent L-shaped rods 21 along the circumference is 90°; the inner end of each L-shaped rod 21 is connected to the corresponding gear group 3 through a key, and the outer ends of two adjacent L-shaped rods 21 along the circumference are connected through a spring 4.

[0024] Specifically, the gear set 3 includes five gears 31 arranged in a cross shape, and the gear 31 located in the middle is respectively engaged with the four gears 31 on its periphery, and the five gears 31 are the same size; the inner end of each L-shaped rod 21 is connected to the center of the corresponding gear 31 through a key; the transmission gear set 5 includes three transmission gears 51 arranged horizontally and meshed in sequence; the two gears 31 located on the inner side of the two gear sets 3 are connected by three transmission gears 51. Through the synchronous transmission of the gears 31, the relative angle of the L-shaped rod 21 remains unchanged when rotating, thereby controlling the length of the springs 4 in the same group to be equal, so that the tension in the tensioning structure is controllable. At the same time, the use of the gear 31 structure can make the rotation process smoother. Since the gear 31 has a large load-bearing capacity, this structure can further improve the load-bearing capacity of the cellular structure.

[0025] Specifically, the two sections of each L-shaped rod 21 are equal in length, and the length from the end of the L-shaped rod 21 to the center is equal to the center distance of the two gears 31 distributed along the horizontal direction. The L-shaped rod 21 is used to control the deformation scale of the spring 4, so that the overall tension of the material fluctuates during the deformation process, providing a basis for the bistability of the cell.

[0026] 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.

[0027] 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 stiffness bistable metamaterial cell structure based on a tensile structure, characterized in that: The invention comprises a plate, two L-shaped rod groups, two gear groups and a plurality of springs, wherein the two L-shaped rod groups are respectively located on both sides of the upper surface of the plate; the two gear groups are respectively located on the lower surface of the plate and correspond to the positions of the two L-shaped rod groups; the L-shaped rod groups and the gear groups corresponding to their positions are connected by a key passing through the plate; the two gear groups are connected by a transmission gear group; and the two L-shaped rods adjacent to each other along the circumference of each L-shaped rod group are connected by the springs; The two L-shaped rod groups are symmetrically distributed left and right; Each of the L-shaped rod groups includes four L-shaped rods, which are evenly distributed along the circumference and the rotation angle between two adjacent L-shaped rods along the circumference is 90 degrees; the inner end of each L-shaped rod is connected to the corresponding gear group via the key, and the outer ends of two adjacent L-shaped rods along the circumference are connected via the spring. The gear set includes five gears arranged in a cross shape, and the gear located in the middle is respectively meshed with the four gears on its periphery; the inner end of each L-shaped rod is connected to the center of the corresponding gear via the key; the transmission gear set includes three transmission gears arranged horizontally and meshed in sequence; the two gears located on the inner side of the two gear sets are connected by the three transmission gears; The L-shaped rod includes a first rod pointing to the middle of the gear and a second rod perpendicular to the first rod, the end of the second rod away from the first rod is the outer end of the L-shaped rod, and the end of the first rod away from the second rod is the inner end of the L-shaped rod; The two sections of each L-shaped rod are equal in length, and the length from the end of the L-shaped rod to the center is equal to the center distance of two adjacent gears distributed in the horizontal direction.

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