A multi-material composite superstructural unit with multi-state switching, a superstructure, and applications of the superstructure

Abstract

The present invention relates to the field of new material technologies, a multi-material composite superstructural unit capable of multi-state switching, a superstructure, and an application of the superstructure. The superstructural unit includes a soft matrix material unit and a hard matrix material unit. The hard matrix material unit is embedded inside the soft matrix material unit, and the difference in elastic modulus between the soft matrix material unit and the hard matrix material unit is more than two orders of magnitude. The superstructure is a periodic arrangement of two adjacent multi-material composite superstructural units. The beneficial effect of the present invention is that by combining flexible materials and rigid materials in a single structural unit, it becomes possible to achieve multi-stability and lightweight at a small scale.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and specifically to a multi-material composite superstructure capable of multi-state switching. Background Art

[0002] Under the background of the dual crises of resources and the environment, the fields of materials and structures are facing major challenges. It is necessary to achieve lightweight and reusable while maintaining high performance to meet the new requirements of low-carbon and green development. Once the geometric shape of a structure is determined, its performance and application scope are often limited, resulting in low utilization rate of the structure and lack of flexibility. Therefore, it is crucial to design intelligent materials and structures with multifunctionality or switchable functions.

[0003] Mechanical metamaterials or superstructures can achieve specific mechanical properties through artificially designed geometric structures rather than relying solely on the properties of the materials themselves. As an important branch of metamaterials, lattice structure materials can regulate various properties, including mechanical, acoustic, and optical properties, by utilizing their periodic microscopic geometric features. Different lattice structures exhibit different mechanical properties, such as high energy absorption efficiency, high load-bearing capacity, and excellent vibration damping performance. However, the current lattice structure design has limitations. Most of them can only maintain one stable state and lack the ability to respond to changes in the external environment, which restricts their applications under complex dynamic conditions. In addition, lattice structures are usually non-reconfigurable. Once designed and manufactured, it is difficult to adjust their geometric shapes and properties, and their functions are relatively fixed, unable to meet the requirements of multifunctional scenarios for adaptive adjustment. These limitations hinder the application of lattice structures in a wider range of fields.

[0004] In this context, the concept of multi-stable structures has received extensive attention. Multi-stable structures can switch between multiple stable equilibrium states under external stimuli or loading. Compared with traditional single-stable structures, they have multiple stable energy minima and can be switched between these states by controlling external conditions. This characteristic endows them with high adjustability and reconfigurability, enabling them to exhibit different mechanical or functional characteristics in different states and adapt to various application requirements. Such structures have broad application prospects in the design of multifunctional materials and can meet multiple performance requirements simultaneously.

[0005] Nevertheless, multi-stable structures still face challenges in practical applications. Designing and studying multi-stable structures at large scales is relatively easy, but the difficulty of achieving multi-stable behavior increases significantly at small scales. As the size decreases, the geometric and material properties of the structure make it difficult to stably achieve multi-stable behavior. In addition, in small-scale structures, the rigid part must be about five times thicker than the flexible part to avoid deformation and maintain the stability of the structure, which increases the overall mass and relative density of the structure, contrary to the requirement of lightweight. These limitations make the design of multi-stable structures at small scales complex, especially in application scenarios that emphasize lightweight. Therefore, a multi-stable superstructure combined with multi-material coupling design has become a potential solution, which can overcome these problems at small scales and achieve multifunctional performance. Summary of the Invention

[0006] To solve the deficiencies in the prior art, the present invention provides a multi-material composite superstructure with multi-state switching, which makes it possible to achieve multi-stability and lightweight at small scales by combining flexible materials and rigid materials within a single structural unit.

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] According to one aspect of the present invention, there is provided a multi-material composite superstructure unit with multi-state switching, including a soft matrix material unit and a hard matrix material unit, wherein the hard matrix material unit is embedded inside the soft matrix material unit, and the difference in elastic modulus between the soft matrix material unit and the hard matrix material unit is more than two orders of magnitude.

[0009] Further, the soft matrix material unit includes at least 2 arc-shaped strips with gentle ends and convex middle parts, and the adjacent two arc-shaped strips are connected end to end; the hard matrix material unit includes concave arc-shaped strips corresponding to the arc-shaped strips in the soft matrix material unit.

[0010] Further, a card slot is arranged on the inner side of the soft matrix material unit, and a card foot adapted to the card slot is arranged on the outer side of the hard matrix material unit.

[0011] A self-locking slot is arranged on the card slot, and a lock block adapted to the self-locking slot is arranged on the card foot.

[0012] Further, the card slot is located at the connection of two adjacent arc-shaped strips.

[0013] Further, the hard matrix material of the hard matrix material unit is a thin metal or high-ductility material plate on the upper and lower layers, and a composite material plate or a gradient multi-cell structure sandwich layer in the middle layer.

[0014] According to another aspect of the present invention, there is provided a multi-material composite superstructure capable of multi-state switching, including the above-mentioned multi-material composite superstructure unit capable of multi-state switching, and two adjacent multi-material composite superstructure units are arranged periodically.

[0015] Further, the angle between two adjacent multi-material composite superstructure units is 90 degrees, and the multi-material composite superstructure units are arranged alternately horizontally.

[0016] Further, the angle between the multi-material composite superstructure units on two adjacent layers is 90 degrees.

[0017] According to another aspect of the present invention, there is provided an application of the multi-material composite superstructure capable of multi-state switching in emergency rescue, construction, or transportation tools, especially in aerospace applications.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. By combining flexible materials and rigid materials within a single structural unit, the present invention makes it possible to achieve multi-stability and lightweight at a small scale.

[0020] 2. Utilizing the deformation ability of flexible materials and the constraint of rigid materials, the present invention constructs a structure that can switch between multiple stable states. Under each stable state, the structure exhibits different functions: in one stable state, the structure has sufficient flexibility to achieve vibration isolation and buffering functions; in another stable state, the structure exhibits high rigidity and can achieve load-bearing functions. In this way, the superstructure not only achieves multi-stability at a small scale but also provides the integration of multiple functions while ensuring lightweight.

[0021] 3. The structure designed in this solution has broad application prospects in the fields of emergency rescue, construction, and transportation, especially in aerospace, and can achieve a multi-functional integrated solution with high adaptability and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Attached Figure 1 is the front view of the soft matrix material unit of the present invention;

[0023] Attached Figure 2 is the perspective view of the soft matrix material unit of the present invention;

[0024] Attached Figure 3 is the front view of the hard matrix material unit of the present invention;

[0025] Attached Figure 4 is the perspective view of the hard matrix material unit of the present invention;

[0026] Attached Figure 5It is a schematic structural diagram of the combined state of the soft matrix material unit and the hard matrix material unit of the present invention;

[0027] Appendix Figure 6 It is a schematic diagram of various structures of the multi-material composite superstructure unit with multi-state switching of the present invention;

[0028] Appendix Figure 7 It is a schematic diagram of the embedded structure of the soft matrix material unit and the hard matrix material unit of the present invention Figure 1 ;

[0029] Appendix Figure 8 It is a schematic diagram of the embedded structure of the soft matrix material unit and the hard matrix material unit of the present invention Figure 2 ;

[0030] Appendix Figure 9 It is a schematic diagram of the soft base material structure of the soft matrix material unit of the present invention;

[0031] Appendix Figure 10 It is the transition process of the multi-material composite superstructure of the present invention in two states;

[0032] Appendix Figure 11 It is a schematic diagram of the multi-material composite superstructure with multi-state switching of the present invention Figure 1 Flexible state;

[0033] Appendix Figure 12 It is a schematic diagram of the multi-material composite superstructure with multi-state switching of the present invention Figure 1 Rigid state;

[0034] Appendix Figure 13 It is a schematic diagram of the multi-material composite superstructure with multi-state switching of the present invention Figure 2 Flexible state;

[0035] Appendix Figure 14 It is a schematic diagram of the multi-material composite superstructure with multi-state switching of the present invention Figure 2 Rigid state;

[0036] Reference numerals shown in the drawings: 1. Soft matrix material unit; 101. Arc bar; 2. Hard matrix material unit; 3. Card slot; 4. Card foot; 5. Multi-material composite superstructure unit. Detailed implementation manners

[0037] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by this application.

[0038] According to one aspect of the present invention, there is provided a multi-material composite superstructure unit with multi-state switching

[0039] As shown Figures 1-6 in the figure, a multi-material composite superstructure unit with multi-state switching is disclosed, which includes a soft matrix material unit 1 and a hard matrix material unit 2. The hard matrix material unit 2 is embedded inside the soft matrix material unit 1. The elastic moduli of the soft matrix material unit 1 and the hard matrix material unit 2 differ by more than two orders of magnitude. The soft matrix material unit 1 is used to generate deformation, and the hard matrix material unit 2 is used to constrain the soft matrix material unit to ensure stability. The soft matrix material and the hard matrix material are not limited to specific materials, but rather a relative naming method. As long as the elastic moduli of the two differ by more than two orders of magnitude, the rigid matrix material and the flexible matrix material can have the characteristics of multi-stability and lightweight at the same time under the same thickness configuration.

[0040] Specifically, the soft matrix material unit 1 includes at least two arc-shaped strips 101 with gentle ends and convex middle parts. The adjacent two arc-shaped strips 101 are connected end to end. The hard matrix material unit 2 includes concave arc-shaped strips corresponding to the arc-shaped strips 101 in the soft matrix material unit 1. As shown Figure 6 in the figure, the arc-shaped strips 101 can be 3, 4, 5, 6, etc., forming a triangle, a quadrilateral, a pentagon, a hexagon.

[0041] There are various ways to embed the hard matrix material unit 2 inside the soft matrix material unit 1. Among them, as shown Figure 7 in the figure, an adhesive is needed for assembly. As an optimization, as shown Figure 8 in the figure, a card slot 3 is arranged on the inner side of the soft matrix material unit 1, and a card foot 4 adapted to the card slot 3 is arranged on the outer side of the hard matrix material unit 2. The assembly is realized through the card slot 3 and the card foot 4.

[0042] Furthermore, a self-locking slot is arranged on the card slot, and a lock block adapted to the self-locking slot is arranged on the card foot, which can realize self-locking assembly after nesting.

[0043] As an optimization, the card slot 3 is located at the connection of two adjacent arc-shaped strips 101, further increasing stability.

[0044] In addition to the conventional single-material composition, in order to achieve extreme lightweight, a multi-material and multi-geometry configuration scheme is applied to the design of the hard matrix material unit. Figure 9The mesoscopic composition of the designed hard matrix material unit is given. According to the typical sandwich configuration, the upper and lower surface layers are thin plates of metal or highly ductile materials. In one solution, the interlayer is configured as a composite material plate, such as a fiber-reinforced composite material. Since the upper and lower panels are thin plates of metal or highly ductile materials, it is ensured that even if there is a small amount of damage in the fiber material, there will be no obvious decrease in the bearing capacity under the protection of the thin plates. Another solution is to configure an optimized gradient cellular structure interlayer. Cellular structures are widely used in lightweight design, and in order to further achieve lightweight, optimized design is applied. Cellular structures with different multi-level scales are used as candidate targets, and the number of cells in its local area changes with the magnitude of the required stress.

[0045] According to another aspect of the present invention, there is provided a multi-material composite superstructure capable of multi-state switching

[0046] A multi-material composite superstructure capable of multi-state switching includes the multi-material composite superstructure unit 5 capable of multi-state switching, and two adjacent multi-material composite superstructure units 5 are arranged periodically. The angle between two adjacent multi-material composite superstructure units differs by 90 degrees, and the multi-material composite superstructure units are arranged alternately horizontally. This design of alternating connection helps to enhance the difference in mechanical properties in different states. In the flexible state, two multi-material composite superstructure units are connected to each other through flexible units, with low stiffness and poor load-bearing capacity, and are suitable for applications such as vibration damping, shock absorption, and buffering. Press the two connected units against each other, that is Figure 10 transition from state (1) to state (2) in. After releasing the external load, the structure can still remain in state (2), that is, it enters another stable state. The two stable states can be freely switched and maintained through the external load. It can be found that in state (2), except for the connection part, the flexible matrix materials of the two units are in contact with each other. Furthermore, it can be considered that the convex rigid matrix materials and the concave rigid matrix materials are also indirectly in contact with each other, greatly improving the overall stiffness and strength of the structure. This state can be applied to fields such as load-bearing. Therefore, there are obvious differences in the performance and application scenarios in the two states.

[0047] Such as Figures 11-12As shown, one of the multi-material composite superstructures with multi-state switching is disclosed. The angle between adjacent two multi-material composite superstructure units is 90 degrees, and the multi-material composite superstructure units are arranged alternately horizontally. The light-colored part is the soft matrix material unit, and the dark-colored part is the hard matrix material unit. In the flexible mode, the connection between units only depends on the multi-stable structure. The structural characteristics in this mode are that it has relatively low rigidity and strength as a whole, but has excellent deformation ability. Only by applying a slight load at the mid-span position can significant flexural deformation be triggered. This characteristic enables the system to flexibly achieve flexible functions such as shock absorption and buffering according to the specific requirements of the working environment, especially suitable for protecting fragile items from impact. As the externally applied load gradually increases, the multi-stable structure will transition to a new stable form. At this time, the outer frame of the conversion module is in close contact with the load-bearing module, thus significantly improving the rigidity and strength of the entire structure. After entering the rigid mode, a greater load needs to be applied at the mid-span of the structure to produce significant deformation. This change enables it to be competent for the task of carrying and buffering heavy or hard objects.

[0048] In addition, the stable state can also be a clever configuration of partial flexibility and partial rigidity. It is convenient for separation, storage and carrying in the flexible state, and once it is converted to the rigid state, it can carry a large-span structure without support, showing extremely high practicality and adaptability. This innovative structure has great application potential and value in fields such as the rigid-flexible conversion operation of robotic arms, the rapid deployment of disaster emergency rescue, and the flexible construction of bridge engineering.

[0049] As Figures 13-14 shown, another multi-material composite superstructure with multi-state switching is disclosed. The angle between the multi-material composite superstructure units 5 on adjacent two layers is 90 degrees, and they are arranged alternately and crosswise with the soft matrix material units. The light-colored part is the soft matrix material unit, and the dark-colored part is the hard matrix material unit. As Figures 12-13 shown, it is similar in function to the horizontal arrangement, that is, it can both absorb shock and buffer in the flexible state and carry in the rigid state. The biggest difference is that the horizontally arranged multi-material composite superstructure units are in a single-row layout, suitable for occasions with limited space. For occasions with a larger allowable space, the array of obliquely (crosswise) arranged multi-material composite superstructure units can extend in multiple directions, showing the superiority of mechanical properties in multiple states.

Claims

1. A multi-material composite superstructure unit with multi-state switching, characterized in that: It includes a soft matrix material unit (1) and a hard matrix material unit (2), the hard matrix material unit (2) is embedded inside the soft matrix material unit (1), and the difference in elastic modulus between the soft matrix material unit (1) and the hard matrix material unit (2) is more than two orders of magnitude; The soft matrix material unit (1) includes at least two arc-shaped strips (101) with gentle ends and convex middle parts, and the adjacent two arc-shaped strips (101) are connected end to end; the hard matrix material unit (2) includes concave arc-shaped strips corresponding to the arc-shaped strips (101) in the soft matrix material unit (1).

2. The multi-material composite superstructure unit capable of multi-state switching according to claim 1, wherein: A clamping groove (3) is arranged on the inner side of the soft matrix material unit (1), and a clamping leg (4) adapted to the clamping groove (3) is arranged on the outer side of the hard matrix material unit (2).

3. The multi-material composite superstructure unit capable of multi-state switching according to claim 2, wherein: A self-locking groove is arranged on the clamping groove (3), and a locking block adapted to the self-locking groove is arranged on the clamping leg (4).

4. The multi-material composite superstructure unit capable of multi-state switching according to claim 1, wherein: The hard base material of the hard matrix material unit (2) is a thin metal or high-ductility material sheet on the upper and lower layers, and a composite material sheet or a gradient multi-cell structure sandwich layer in the middle layer.

5. A multi-material composite superstructure capable of multi-state switching, characterized in that: It includes the multi-material composite superstructure unit (5) capable of multi-state switching according to any one of claims 1-4, and the adjacent two multi-material composite superstructure units (5) are arranged periodically.

6. The multi-material composite superstructure capable of multi-state switching according to claim 5, wherein: The angle difference between the adjacent two multi-material composite superstructure units (5) is 90 degrees, and they are arranged alternately horizontally.

7. A multi-material composite superstructure capable of multi-state switching according to claim 5, characterized in that: The angle difference between the multi-material composite superstructure units (5) on the adjacent two layers is 90 degrees.

8. Application of the multi-material composite superstructure capable of multi-state switching according to any one of claims 5-7 in emergency rescue, construction or transportation tools.

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