Rigidity-variable compression-torsion chiral metamaterial cell element based on integrated molding

Abstract

The invention discloses a variable-stiffness compression-torsion chiral metamaterial cell element based on integrated molding, and belongs to the technical field of mechanical metamaterials. The cell element comprises a top rigid end cover, a bottom rigid end cover, a chiral spiral rigid rod group, a rigidity adjusting knob group, a central elastic component and a rigidity adjusting limiting node group. The chiral spiral rigid rod group is obliquely arranged between the top rigid end cover and the bottom rigid end cover to realize pressure-torsion coupling motion; the central elastic component is formed by integrally pouring and curing a hyperelastic material, and two ends of the central elastic component are respectively connected with the top rigid end cover and the bottom rigid end cover; the rigidity adjusting knob set can adjust the effective working length and the pre-tightening state of the central elastic assembly. The rigidity adjusting limiting node set is selectively fixed to the top rigid end cover, and graded adjustment of rigidity is achieved. The cell enhances the bonding strength of a rigid-flexible interface through an integrated forming process, realizes flexible regulation and control of the rigidity, and is mainly applicable to application scenes such as aerospace, robots and intelligent equipment.

Description

Technical Field

[0001] This invention relates to the field of mechanical metamaterials technology, and in particular to a variable stiffness compressive-torsional metamaterial cell based on integral molding. Background Technology

[0002] Mechanical metamaterials are a class of novel materials that overcome the limitations of traditional materials and achieve unconventional mechanical properties through the artificial design of microscopic or macroscopic geometric topologies. Among them, chiral structures, due to their unique "compression-torsional coupling" effect—that is, they exhibit controllable rotational deformation under axial compressive loads or axial expansion and contraction under torsional loads—show great promise in applications such as aerospace deployment mechanisms, soft robot actuators, and high-performance shock absorption and cushioning.

[0003] However, existing chiral metamaterial cells still have significant limitations in structural design and manufacturing processes. To balance load-bearing capacity and large deformation requirements, rigid-flexible coupling structures have become the mainstream research direction. However, the rigid and flexible components of such structures are often assembled using simple adhesive or mechanical connections. Under repeated large deformations or high-load tension, the rigid-flexible interface region is prone to significant stress concentration, leading to interface delamination, debonding, or connection failure, severely limiting the service life and mechanical reliability of the structure.

[0004] Furthermore, once existing chiral cell structures are fabricated, their geometry, topology, and material properties are fixed, and their overall stiffness is determined, making flexible adjustment difficult. In practical applications, such as variable stiffness robotic arm end effectors or adaptive damping systems, structures are often required to exhibit variable mechanical responses under different operating conditions. For example, they should exhibit low stiffness compliance when in contact with weak objects, while transforming into high stiffness support under load. Most existing passive metamaterial structures lack active adjustment capabilities and struggle to adapt to complex and variable external load environments. Therefore, there is an urgent need for a compression-torsion chiral cell that can ensure the stability and reliability of the rigid-flexible interface through an integrated molding process, while also enabling flexible hierarchical stiffness control, to meet the pressing needs of modern engineering for high-performance metamaterials. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a variable stiffness compressive-torsional chiral metamaterial cell based on integral molding. This structure possesses excellent variable stiffness characteristics and compressive-torsional coupling motion capability, enabling efficient energy conversion and shape recovery under external pressure, and can be widely used in robotics and intelligent equipment.

[0006] It should be noted that the definitions and use of terms such as components or orientations in this invention are merely for the convenience and uniformity of description. Related terms can be replaced with equivalent terms or adjusted directionally according to the actual situation, and should not be construed as limiting this invention.

[0007] This invention proposes a variable stiffness compressive-torsional chiral metamaterial cell based on integrated molding, which mainly includes a top rigid end cap, a bottom rigid end cap, a chiral helical rigid rod assembly, a stiffness adjustment knob assembly, a central elastic component, and a stiffness adjustment limiting node assembly. The top and bottom rigid end caps are both triangular and symmetrically arranged. A chiral helical rigid rod assembly is positioned between them, allowing the structure to generate a preset torsional angle when an external force is applied to the metamaterial cell, thereby achieving compressive-torsional coupled motion characteristics. Specifically, the chiral helical rigid rod assembly includes a first chiral helical rigid rod, a second chiral helical rigid rod, and a third chiral helical rigid rod. Their inclined configuration allows the top rigid end cap to generate a preset torsional angle relative to the bottom rigid end cap when the cell is subjected to axial pressure, thus achieving compressive-torsional coupled motion characteristics and giving the overall structure good mechanical response characteristics during deformation.

[0008] The stiffness adjustment knob assembly includes a first adjustment knob, a second adjustment knob, and a third adjustment knob, which are evenly distributed on the upper surface of the top rigid end cap. The central elastic component is integrally cast and cured from a high-resilience superelastic material, and includes a first elastic cable, a second elastic cable, a third elastic cable, a first embedded anchor frame, a second embedded anchor frame, a third embedded anchor frame, a first embedded anchor end, a second embedded anchor end, a third embedded anchor end, a first rigid-flexible coupling node, a second rigid-flexible coupling node, a third rigid-flexible coupling node, a fourth rigid-flexible coupling node, a fifth rigid-flexible coupling node, a sixth rigid-flexible coupling node, a first embedded rigid reinforcement, a second embedded rigid reinforcement, a third embedded rigid reinforcement, a fourth embedded rigid reinforcement, a fifth embedded rigid reinforcement, a sixth embedded rigid reinforcement, a seventh embedded rigid reinforcement, an eighth embedded rigid reinforcement, and a ninth embedded rigid reinforcement.

[0009] It should be noted that the stiffness adjustment knob group can adjust the effective working length and preload state of the central elastic component by rotation, thereby controlling the overall stiffness of the metamaterial cell. The central elastic component is made of a hyperelastic material with high resilience, capable of effective tensile and compressive deformation under external axial pressure, converting mechanical energy into elastic potential energy. When the external load is removed, the component utilizes the stored elastic potential energy to generate a self-restoring force, driving the entire metamaterial cell structure to automatically return to its initial equilibrium position.

[0010] It should be noted that the upper ends of the first, second, and third elastic cables are fixed to the corresponding first, second, and third embedded anchor ends via molding processes. When the overall structure is subjected to an axial external load, the top rigid end cap moves towards the bottom rigid end cap, the chiral helical rigid rod assembly tilts, and the entire structure deforms. The first, second, and third elastic cables within the central elastic component convert mechanical energy into stored elastic potential energy. After the external load is removed, the stored elastic potential energy is transferred to the top and bottom rigid end caps through the first, second, third, fourth, fifth, and sixth rigid-flexible coupling nodes, restoring the entire structure to its initial equilibrium state.

[0011] It should be noted that the first, second, and third embedded anchor frames provide additional support and rigidity for the overall structure. Together with the first, second, and third elastic cables, they constitute the first, second, third, fourth, fifth, and sixth rigid-flexible coupling nodes, respectively. Furthermore, the first, second, and third embedded anchor frames are located inside the first, second, and third chiral helical rigid rods, further enhancing the structural stability and motion capability of the metamaterial cell.

[0012] The stiffness adjustment limiting node group includes a first adjusting limiting block, a second adjusting limiting block, a third adjusting limiting block, a fourth adjusting limiting block, a fifth adjusting limiting block, a sixth adjusting limiting block, a seventh adjusting limiting block, an eighth adjusting limiting block, and a ninth adjusting limiting block. The first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth adjusting limiting blocks can be selectively fixed in pre-set slots or countersunk holes on the surface of the top rigid end cap to achieve stiffness adjustment at different height positions. During the application of external force, by locking the adjusting limiting blocks at different positions, the effective elastic segment length participating in free deformation in the central elastic component can be changed, thereby achieving graded adjustment of the equivalent elastic modulus of the metamaterial cell under compressive torsional loads and further controlling its overall stiffness response. Meanwhile, the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth embedded rigid reinforcements are disposed inside the first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth adjusting limit blocks, increasing the overall structural connection stability and preventing slippage of the components under load.

[0013] It should be noted that by replacing the first, second, and third elastic cables with different elastic moduli or stiffness coefficients, the load-bearing capacity, shape recovery capacity, and energy absorption capacity of the cell can be adjusted to a certain extent in a proportional manner.

[0014] Beneficial Effects: This invention integrates the central elastic component with rigid-flexible coupling nodes, embedded anchoring skeleton, and embedded rigid reinforcement components through an integrated molding process, significantly improving the bonding strength and fatigue life of the rigid-flexible interface and effectively avoiding the interface peeling and failure problems easily caused by traditional adhesive or mechanical connection methods. Simultaneously, through the synergistic effect of the stiffness adjustment knob group and the stiffness adjustment limit node group, the effective working length and preload state of the central elastic component can be flexibly controlled, achieving graded adjustment of the overall stiffness of the metamaterial cell, enabling it to have variable mechanical response capabilities under different working conditions. Furthermore, the inclined configuration of the chiral helical rigid rod group endows the cell with excellent compressive-torsional coupling motion characteristics. When subjected to axial pressure, it can efficiently convert mechanical energy into elastic potential energy and automatically return to the initial equilibrium position after the load is removed, thus showing broad prospects in applications such as aerospace, robotics, and intelligent equipment. Attached Figure Description

[0015] To clearly illustrate the embodiments and related technical solutions of the present invention, the accompanying drawings involved in the embodiments will be briefly described below. It should be understood that the following drawings are only for illustrating some embodiments of the present invention. Those skilled in the art can also obtain other related technical solutions and drawings based on these drawings without any inventive effort.

[0016] Figure 1 I is a schematic diagram of the structure of a variable stiffness compressive-torsional metamaterial cell based on integral molding, provided in an embodiment of the present invention.

[0017] Figure 2 Schematic diagram II of the structure of the variable stiffness compressive-torsional metamaterial cell based on integral molding provided in the embodiments of the present invention.

[0018] Figure 3 Schematic diagram I of the central elastic component of a monolithically molded variable stiffness compressive-torsional metamaterial cell provided in an embodiment of the present invention.

[0019] Figure 4 Schematic diagram II of the central elastic component based on an integrally molded variable stiffness compressive-torsional metamaterial cell provided in an embodiment of the present invention.

[0020] Figure 5 Schematic diagram III of the central elastic component based on an integrally molded variable stiffness compressive-torsional metamaterial cell provided in an embodiment of the present invention.

[0021] Figure 6 Schematic diagram III of the structure of the integrally molded variable stiffness compressive-torsional metamaterial cell provided in the embodiment of the present invention.

[0022] Figure 7 A schematic diagram of axial compression deformation of a monolithically molded variable stiffness compressive-torsional metamaterial cell provided in an embodiment of the present invention.

[0023] Labeling Explanation: 1. Top Rigid End Cap; 2. Bottom Rigid End Cap; 3. Chiral Helical Rigid Rod Assembly; 301. First Chiral Helical Rigid Rod; 302. Second Chiral Helical Rigid Rod; 303. Third Chiral Helical Rigid Rod; 4. Stiffness Adjustment Knob Assembly; 401. First Adjustment Knob; 402. Second Adjustment Knob; 403. Third Adjustment Knob; 5. Central Elastic Component; 501. First Elastic Cable; 502. Second Elastic Cable; 503. Third Elastic Cable; 511. First Embedded Anchorage Frame; 512. Second Embedded Anchorage Frame; 513. Third Embedded Anchorage Frame; 521. First Embedded Anchorage End; 522. Second Embedded Anchorage End; 523. Third Embedded Anchorage End; 531. First Rigid-Flexible Coupling Node; 532. Second Rigid-Flexible Coupling Node; 533. Third Rigid-Flexible Coupling Node; 534. Fourth Rigid-Flexible Coupling Node Coupled nodes; 535, Fifth rigid-flexible coupling node; 536, Sixth rigid-flexible coupling node; 541, First embedded rigid reinforcement; 542, Second embedded rigid reinforcement; 543, Third embedded rigid reinforcement; 544, Fourth embedded rigid reinforcement; 545, Fifth embedded rigid reinforcement; 546, Sixth embedded rigid reinforcement; 547, Seventh embedded rigid reinforcement; 548, Eighth embedded rigid reinforcement; 549, Ninth embedded rigid reinforcement; 6, Stiffness adjustment limiting node group; 601, First adjusting limiting block; 602, Second adjusting limiting block; 603, Third adjusting limiting block; 604, Fourth adjusting limiting block; 605, Fifth adjusting limiting block; 606, Sixth adjusting limiting block; 607, Seventh adjusting limiting block; 608, Eighth adjusting limiting block; 609, Ninth adjusting limiting block. Detailed Implementation

[0024] To clearly illustrate the embodiments of the present invention, a detailed description will be provided below in conjunction with the accompanying drawings. The same or similar reference numerals in the drawings represent the same or similar components or components having the same or similar functions. It should be understood that the following description in conjunction with the accompanying drawings is merely exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] It should be noted that the same reference numerals or numbers may be used repeatedly in different embodiments or figures. This repetition is only for simplifying the text description and figure indication, and does not in itself indicate that there is necessarily a specific relationship between the various embodiments or structures.

[0026] In the description of this invention, the terms "upper," "symmetrical," "inner," "top," "bottom," and "axial," etc., refer to orientations or positional relationships, all defined based on the orientations or positions shown in the accompanying drawings. These definitions are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the components referred to must have a specific orientation, nor should they constitute a limitation on the invention. Furthermore, the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as limiting the number of technical features described. Based on this description, a feature specified as "X" may explicitly or implicitly include one or more of that feature.

[0027] The following description illustrates different structures of the present invention through specific embodiments and accompanying drawings, with particular examples focusing on the components and their arrangement. It should be understood that these examples are merely illustrative and should not be construed as limiting the invention.

[0028] Please see Figures 1 to 3 as well as Figure 6 This invention provides a variable stiffness compressive-torsional chiral metamaterial cell based on integrated molding, which mainly includes a top rigid end cap 1, a bottom rigid end cap 2, a chiral helical rigid rod assembly 3, a stiffness adjustment knob assembly 4, a central elastic component 5, and a stiffness adjustment limiting node assembly 6. The top rigid end cap 1 and the bottom rigid end cap 2 are both triangular and symmetrically arranged. The chiral helical rigid rod assembly 3 is positioned between them, allowing the structure to generate a preset torsional angle when an external force is applied to the metamaterial cell, thereby achieving compressive-torsional coupled motion characteristics. Specifically, the chiral helical rigid rod assembly 3 includes a first chiral helical rigid rod 301, a second chiral helical rigid rod 302, and a third chiral helical rigid rod 303. The inclined configuration of these three components allows the top rigid end cap 1 to generate a preset torsional angle relative to the bottom rigid end cap 2 when the cell is subjected to axial pressure, thus achieving compressive-torsional coupled motion characteristics and giving the overall structure good mechanical response characteristics during deformation.

[0029] See Figures 1 to 3 The stiffness adjustment knob group 4 includes a first adjustment knob 401, a second adjustment knob 402 and a third adjustment knob 403 that are evenly distributed and fixed on the upper surface of the top rigid end cap 1. By rotating the knob, the effective working length and pre-tightening state of the central elastic component 5 can be adjusted, thereby realizing the control of the overall stiffness of the metamaterial cell.

[0030] See Figures 1 to 5 as well as Figure 7The central elastic component 5 is formed from a highly resilient superelastic material through an integrated casting and curing process. It includes a first elastic cable 501, a second elastic cable 502, a third elastic cable 503, a first embedded anchor frame 511, a second embedded anchor frame 512, a third embedded anchor frame 513, a first embedded anchor end 521, a second embedded anchor end 522, a third embedded anchor end 523, a first rigid-flexible coupling node 531, a second rigid-flexible coupling node 532, a third rigid-flexible coupling node 533, a fourth rigid-flexible coupling node 534, a fifth rigid-flexible coupling node 535, a sixth rigid-flexible coupling node 536, a first embedded rigid reinforcement 541, a second embedded rigid reinforcement 542, a third embedded rigid reinforcement 543, a fourth embedded rigid reinforcement 544, a fifth embedded rigid reinforcement 545, a sixth embedded rigid reinforcement 546, a seventh embedded rigid reinforcement 547, an eighth embedded rigid reinforcement 548, and a ninth embedded rigid reinforcement 549. The central elastic component 5 can undergo effective tensile and compressive deformation under external axial (i.e., along direction A) pressure, converting mechanical energy into elastic potential energy. When the external load is removed, the component uses the stored elastic potential energy to generate a self-restoring force, driving the entire metamaterial cell structure to automatically return to its initial equilibrium position.

[0031] It should be noted that the upper ends of the first elastic cable 501, the second elastic cable 502, and the third elastic cable 503 are respectively fixed to the corresponding first embedded anchor end 521, second embedded anchor end 522, and third embedded anchor end 523 by molding process. When the overall structure is subjected to an axial (i.e., along direction A) external load, the top rigid end cap 1 moves towards the bottom rigid end cap 2, and the chiral helical rigid rod assembly 3 tilts accordingly, causing the overall structure to deform. The first elastic cable 501, the second elastic cable 502, and the third elastic cable 503 in the central elastic component 5 convert mechanical energy into elastic potential energy for storage. After the external load is removed, the stored elastic potential energy is transferred to the top rigid end cap 1 and the bottom rigid end cap 2 through the first rigid-flexible coupling node 531, the second rigid-flexible coupling node 532, the third rigid-flexible coupling node 533, the fourth rigid-flexible coupling node 534, the fifth rigid-flexible coupling node 535, and the sixth rigid-flexible coupling node 536, so that the entire structure returns to its initial equilibrium state.

[0032] It should be noted that the first embedded anchor frame 511, the second embedded anchor frame 512, and the third embedded anchor frame 513 provide additional support and rigidity for the overall structure. Together with the first elastic cable 501, the second elastic cable 502, and the third elastic cable 503, they constitute the first rigid-flexible coupling node 531, the second rigid-flexible coupling node 532, the third rigid-flexible coupling node 533, the fourth rigid-flexible coupling node 534, the fifth rigid-flexible coupling node 535, and the sixth rigid-flexible coupling node 536. Furthermore, the first embedded anchor frame 511, the second embedded anchor frame 512, and the third embedded anchor frame 513 are disposed inside the first chiral helical rigid rod 301, the second chiral helical rigid rod 302, and the third chiral helical rigid rod 303, further enhancing the structural stability and motion capability of the metamaterial cell.

[0033] Please see Figures 1 to 6 The stiffness adjustment limiting node group 6 includes a first adjusting limiting block 601, a second adjusting limiting block 602, a third adjusting limiting block 603, a fourth adjusting limiting block 604, a fifth adjusting limiting block 605, a sixth adjusting limiting block 606, a seventh adjusting limiting block 607, an eighth adjusting limiting block 608, and a ninth adjusting limiting block 609. The first adjusting limiting block 601, the second adjusting limiting block 602, the third adjusting limiting block 603, the fourth adjusting limiting block 604, the fifth adjusting limiting block 605, the sixth adjusting limiting block 606, the seventh adjusting limiting block 607, the eighth adjusting limiting block 608, and the ninth adjusting limiting block 609 can be selectively fixed in preset slots or countersunk holes on the surface of the top rigid end cap 1 to achieve stiffness adjustment at different height positions. During the application of external force, by locking the adjustment limit blocks at different positions, the effective elastic segment length participating in free deformation in the central elastic component 5 can be changed, thereby realizing the graded adjustment of the equivalent elastic modulus of the metamaterial cell under compressive torsional load and further regulating its overall stiffness response. Simultaneously, the first embedded rigid reinforcement 541, the second embedded rigid reinforcement 542, the third embedded rigid reinforcement 543, the fourth embedded rigid reinforcement 544, the fifth embedded rigid reinforcement 545, the sixth embedded rigid reinforcement 546, the seventh embedded rigid reinforcement 547, the eighth embedded rigid reinforcement 548, and the ninth embedded rigid reinforcement 549 are disposed inside the first adjustment limit block 601, the second adjustment limit block 602, the third adjustment limit block 603, the fourth adjustment limit block 604, the fifth adjustment limit block 605, the sixth adjustment limit block 606, the seventh adjustment limit block 607, the eighth adjustment limit block 608, and the ninth adjustment limit block 609, increasing the overall structural connection stability and preventing slippage of the components under load.

[0034] It should be noted that by replacing the first elastic cable 501, the second elastic cable 502, and the third elastic cable 503 with different elastic moduli or stiffness coefficients, the load-bearing capacity, shape recovery capacity, and energy absorption capacity of the cell can be adjusted to a certain extent in a proportional manner.

[0035] In summary, although the present invention has been described in detail above with reference to specific embodiments, the scope of protection of the present invention is not limited to the specific embodiments described. Those skilled in the art can modify, alter, or adapt these embodiments without departing from the principles of the present invention. All such changes or substitutions based on the inventive concept should be covered within the scope of protection of the present invention.

Claims

1. A variable stiffness compressive-torsional chiral metamaterial cell based on integral molding, characterized in that, include: The system comprises a top rigid end cap (1), a bottom rigid end cap (2), a chiral helical rigid rod assembly (3), a stiffness adjustment knob assembly (4), a central elastic component (5), and a stiffness adjustment limiting node assembly (6); wherein the chiral helical rigid rod assembly (3) includes a first chiral helical rigid rod (301), a second chiral helical rigid rod (302), and a third chiral helical rigid rod (303); the stiffness adjustment knob assembly (4) includes a first adjustment knob (401), a second adjustment knob (402), and a third chiral helical rigid rod (303). The third adjustment knob (403); the central elastic component (5) includes a first elastic cable (501), a second elastic cable (502), a third elastic cable (503), a first embedded anchor frame (511), a second embedded anchor frame (512), a third embedded anchor frame (513), a first embedded anchor end (521), a second embedded anchor end (522), a third embedded anchor end (523), a first rigid-flexible coupling node (531), and a second rigid-flexible coupling node (5423). 32) Third rigid-flexible coupling node (533), fourth rigid-flexible coupling node (534), fifth rigid-flexible coupling node (535), sixth rigid-flexible coupling node (536), first embedded rigid reinforcement (541), second embedded rigid reinforcement (542), third embedded rigid reinforcement (543), fourth embedded rigid reinforcement (544), fifth embedded rigid reinforcement (545), sixth embedded rigid reinforcement (546), seventh embedded rigid reinforcement (547), eighth embedded rigid reinforcement (548), and ninth embedded rigid reinforcement (549); the stiffness adjustment limiting node group (6) includes a first adjusting limiting block (601), a second adjusting limiting block (602), a third adjusting limiting block (603), a fourth adjusting limiting block (604), a fifth adjusting limiting block (605), a sixth adjusting limiting block (606), a seventh adjusting limiting block (607), an eighth adjusting limiting block (608), and a ninth adjusting limiting block (609).

2. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The top rigid end cap (1) and the bottom rigid end cap (2) are both triangular and symmetrically arranged; the chiral helical rigid rod group (3) is disposed between the top rigid end cap (1) and the bottom rigid end cap (2).

3. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The inclined configuration of the first chiral helical rigid rod (301), the second chiral helical rigid rod (302) and the third chiral helical rigid rod (303) enables the top rigid end cap (1) to generate a preset torsion angle relative to the bottom rigid end cap (2) when the cell is subjected to axial pressure, thereby realizing the pressure-torsion coupling motion characteristics.

4. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The first adjustment knob (401), the second adjustment knob (402) and the third adjustment knob (403) are evenly distributed on the upper surface of the top rigid end cap (1). By rotating the knob, the effective working length and pre-tightening state of the central elastic component (5) can be adjusted, thereby controlling the overall stiffness of the metamaterial cell.

5. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The central elastic component (5) is integrally cast and cured from a super-elastic material with high resilience, and its two ends are respectively connected to the top rigid end cap (1) and the bottom rigid end cap (2).

6. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The upper ends of the first elastic cable (501), the second elastic cable (502) and the third elastic cable (503) are respectively fixed to the corresponding first embedded anchor end (521), the second embedded anchor end (522) and the third embedded anchor end (523) by molding process.

7. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: When the overall structure is subjected to an axial external load, the top rigid end cap (1) moves toward the bottom rigid end cap (2), the chiral helical rigid rod group (3) tilts and causes the overall structure to deform, and the first elastic cable (501), the second elastic cable (502) and the third elastic cable (503) in the central elastic component (5) convert mechanical energy into elastic potential energy for storage; after the external load is removed, the stored elastic potential energy is transmitted to the top rigid end cap (1) and the bottom rigid end cap (2) through the first rigid-flexible coupling node (531), the second rigid-flexible coupling node (532), the third rigid-flexible coupling node (533), the fourth rigid-flexible coupling node (534), the fifth rigid-flexible coupling node (535) and the sixth rigid-flexible coupling node (536), so that the entire structure returns to the initial equilibrium state.

8. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The first embedded anchor frame (511), the second embedded anchor frame (512), and the third embedded anchor frame (513) provide support and rigidity for the overall structure. The first embedded anchor frame (511), the second embedded anchor frame (512), and the third embedded anchor frame (513), together with the first elastic cable (501), the second elastic cable (502), and the third elastic cable (503), constitute the first rigid-flexible coupling node (531), the second rigid-flexible coupling node (532), the third rigid-flexible coupling node (533), the fourth rigid-flexible coupling node (534), the fifth rigid-flexible coupling node (535), and the sixth rigid-flexible coupling node (536).

9. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The first embedded anchor frame (511), the second embedded anchor frame (512) and the third embedded anchor frame (513) are disposed inside the first chiral helical rigid rod (301), the second chiral helical rigid rod (302) and the third chiral helical rigid rod (303).

10. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The first adjustment limit block (601), the second adjustment limit block (602), the third adjustment limit block (603), the fourth adjustment limit block (604), the fifth adjustment limit block (605), the sixth adjustment limit block (606), the seventh adjustment limit block (607), the eighth adjustment limit block (608), and the ninth adjustment limit block (609) can be selectively fixed in the slots or countersunk holes preset on the surface of the top rigid end cap (1) to achieve stiffness adjustment at different height positions.

11. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: During the application of external force, by locking the first adjustment limit block (601), the second adjustment limit block (602), the third adjustment limit block (603), the fourth adjustment limit block (604), the fifth adjustment limit block (605), the sixth adjustment limit block (606), the seventh adjustment limit block (607), the eighth adjustment limit block (608) and the ninth adjustment limit block (609) at different positions, the effective elastic segment length participating in free deformation in the central elastic component (5) can be changed, thereby realizing the graded adjustment of the equivalent elastic modulus of the metamaterial cell under compressive torsional load, and further controlling its overall stiffness response.

12. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: The first embedded rigid reinforcement (541), the second embedded rigid reinforcement (542), the third embedded rigid reinforcement (543), the fourth embedded rigid reinforcement (544), the fifth embedded rigid reinforcement (545), the sixth embedded rigid reinforcement (546), the seventh embedded rigid reinforcement (547), the eighth embedded rigid reinforcement (548), and the ninth embedded rigid reinforcement (549) are disposed inside the first adjusting limit block (601), the second adjusting limit block (602), the third adjusting limit block (603), the fourth adjusting limit block (604), the fifth adjusting limit block (605), the sixth adjusting limit block (606), the seventh adjusting limit block (607), the eighth adjusting limit block (608), and the ninth adjusting limit block (609), to increase the overall structural connection stability and prevent the components from slipping when under load.

13. The integrally molded variable stiffness compressive-torsional chiral metamaterial cell according to claim 1, characterized in that: By replacing the first elastic cable (501), the second elastic cable (502), and the third elastic cable (503) with different elastic moduli or stiffness coefficients, the load-bearing capacity, shape recovery capacity, and energy absorption capacity of the cell can be adjusted proportionally.

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