A method of designing a variable performance load-acoustic metamaterial

Abstract

The application relates to a variable-performance load-acoustic metamaterial design method, which breaks the limitation of component period arrangement in a traditional load-acoustic metamaterial design process and can solve the problem that load-acoustic metamaterials designed by the same design method can only realize specific functions in specific places. The design method first needs to design limited basic components, then obtains more components by rotating the basic components, then determines the appearance probability of each type of component and the splicing rule between components, and finally constructs an irregular structure in a specified splicing area. In the process of constructing the irregular structure, each splicing needs to be expanded to the adjacent lattice with the smallest entropy. The load-acoustic metamaterial is generated based on the constructed irregular structure.

Description

Technical Field

[0001] This invention relates to the fields of acoustics and mechanics, and specifically to a method for designing load-bearing acoustic metamaterials with variable properties. Background Technology

[0002] Currently, most load-bearing acoustic metamaterials studied by researchers can only achieve specific functions in specific locations, making it difficult to use the same metamaterial in different engineering projects. This difficulty stems from the limitations of the microstructure and the shortcomings of the manufacturing methods. At present, most methods for constructing periodic load-bearing acoustic metamaterials rely on previous experience, repeatedly stacking microstructures to achieve the desired effect. Methods for constructing aperiodic load-bearing acoustic metamaterials mostly utilize jigsaw puzzle rules, piecing together multiple microstructures to exhibit structural heterogeneity, but this still involves the repeated stacking of microstructures. Existing methods cannot guarantee local aperiodicity, versatility, or flexibility in the construction process, and even less can they guarantee that the same metamaterial will exhibit different properties in different locations. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to propose a design method for load-bearing acoustic metamaterials with variable properties, breaking the current situation where the structure of load-bearing acoustic metamaterials is mostly a periodic array, and solving the defect that load-bearing acoustic metamaterials designed by the same design method can only achieve specific functions in specific places.

[0004] Technical solution: This invention provides a design method for load-bearing acoustic metamaterials with variable properties, comprising the following steps:

[0005] (1) Design basic components (1-4) and rotate them to form new components (5-12); establish splicing rules and give probability combinations; create a splicing area (16) to accommodate the final result.

[0006] (2) Assign a Boolean value “True” to each cell (15) in the splicing area (16). “True” indicates that the cell (15) has not yet been occupied by the component (13), and “False” indicates that the cell (15) has been occupied by the component (13).

[0007] (3) Randomly select a cell (15) in the splicing area (16), assign a specific component (13) to the cell (15) according to the probability combination, and update the boolean value of the cell (15) to "False". According to the splicing rules and probability combination, assign components (13) and update the boolean values ​​of the available neighboring cells of the cell (15) with a boolean value of "False". If there are multiple neighboring cells that can be assigned components, find the neighboring cell with the minimum entropy. If there are no neighboring cells that need to be assigned components, proceed to step (4).

[0008] (4) Determine whether the Boolean values ​​of all cells (15) in the splicing area (16) are all "False". If all are "False", it means that an irregular structure (18) has been generated, and further construct the load-bearing acoustic metamaterial (17). Otherwise, repeat steps (2), (3) and (4).

[0009] Furthermore, the method described in this invention includes four influencing factors: components (13), splicing rules, probability combinations, and splicing regions (16). There are four types of basic components (1-4) designed. By rotating these four types of basic components (1-4) clockwise by 90°, 180°, and 270°, eight new components (5-12) can be formed. In this invention, the new components (5-12) obtained by rotating based on the basic components (1-4) belong to the same category as the basic components (1-4). In this invention, the splicing rules restrict the connections between components (13), the probability combinations specify the probability of each type of component (13) appearing, and the splicing regions (16) restrict the total number of times components (13) appear.

[0010] Furthermore, Boolean update refers to updating the Boolean value of a cell from "True" to "False". All cells with a Boolean value of "False" (15) need to have their available neighboring cells assigned components (13) and Boolean values ​​updated. Available neighboring cells refer to neighboring cells with a Boolean value of "True".

[0011] Furthermore, the entropy is calculated as follows:

[0012]

[0013] Where i represents grid (15)i, T is the number of components (13) applicable to grid (15)i, Pj refers to the probability assigned to each of the T components (13), and w represents the sum of the probabilities of the T components (13).

[0014] Furthermore, the neighboring cell with the minimum entropy refers to the cell with the minimum entropy if the cell (15) with a Boolean value of “False” has multiple neighboring cells that satisfy the requirements of the allocation component (13).

[0015] Furthermore, after generating the irregular structure (18) according to the method of the present invention, the load-bearing-acoustic metamaterial (17) is designed with reference to the principle of micro-perforated plate.

[0016] Furthermore, the load-bearing acoustic metamaterial (17) consists of a perforated plate (19) and multiple chambers (20).

[0017] Furthermore, the types of holes on the perforated plate are divided into three categories (21-24). The second type of hole (lower) (22) and the second type of hole (rightward) (23) belong to the same category.

[0018] Furthermore, the number of chambers (20) supporting the acoustic metamaterial is related to the probability combination. The number of chambers (20) under the same probability combination is approximately the same, while the number of chambers (20) under different probability combinations differs significantly.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0020] This invention designs load-bearing acoustic metamaterials based on four influencing factors, breaking through the limitations of the periodic arrangement of components in the traditional load-bearing acoustic metamaterial design process. Furthermore, the load-bearing acoustic metamaterials generated by this invention exhibit a variety of acoustic and mechanical properties, demonstrating both consistency under the same probability combinations and diversity under different probability combinations. These properties provide inspiration for overcoming the limitation of current load-bearing acoustic metamaterials that can only achieve specific functions in specific locations. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention;

[0022] Figure 2 These are the basic components of the present invention and the new components resulting from their rotation;

[0023] Figure 3 These are the splicing rules defined in this invention;

[0024] Figure 4 This is an example of the probability combination and splicing region defined in this invention;

[0025] Figure 5 This invention is based on the process of forming irregular structures from components;

[0026] Figure 6 This invention describes the process of constructing a load-bearing acoustic metamaterial based on an irregular structure.

[0027] Figure 7 This is the classification form of the holes on the perforated plate of the present invention;

[0028] Figure 8 This is an irregular structure generated under the same probability combination in this invention;

[0029] Figure 9 These are irregular structures generated under different probability combinations in this invention;

[0030] Figure 10 This refers to the acoustic properties exhibited by the load-bearing acoustic metamaterial under the same probability combination in this invention.

[0031] Figure 11 The acoustic properties exhibited by the load-bearing acoustic metamaterial under different probability combinations in this invention;

[0032] Figure 12 This refers to the mechanical properties exhibited by the load-bearing acoustic metamaterial under the same probability combination in this invention.

[0033] Figure 13 These are the mechanical properties exhibited by the load-bearing acoustic metamaterial under different probability combinations in this invention;

[0034] Among them: 1-I-type basic component (I0), 2-Y-type basic component (Y0), 3-L-type basic component (L0), 4--type basic component (-0), 5-I1, 6-Y1, 7-Y2, 8-Y3, 9-L1, 10-L2, 11-L3, 12--1, 13-component, 14-port, 15-grid, 16-splitting area, 17-bearing-acoustic metamaterial, 18-irregular structure, 19-perforated plate, 20-chamber, 21-first type hole, 22-second type hole (lower), 23-second type hole (right), 24-third type hole, 25-irregular structure under the same probability combination, 26-irregular structure under different probability combinations. Detailed Implementation

[0035] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to examples. It should be understood that the following text is merely used to describe one or more specific embodiments of this invention and does not strictly limit the scope of protection specifically claimed by this invention.

[0036] Combination Figure 1 The design method for load-bearing acoustic metamaterials includes the following steps:

[0037] Step 1: Design the four influencing factors.

[0038] like Figure 2 This invention designs four basic components (1-4) and rotates them clockwise to obtain eight new components (5-12), which are collectively referred to as components (13). According to their shapes, the twelve components (13) can be divided into four categories: I-shaped components, Y-shaped components, L-shaped components, and --shaped components. Among them, the I-shaped components can be further subdivided into I0 (1) and I1 (5); the Y-shaped components are subdivided into Y0 (2), Y1 (6), Y2 (7), and Y3 (8); the L-shaped components are subdivided into L0 (3), L1 (9), L2 (10), and L3 (11); and the --shaped components are subdivided into -0 (4) and -1 (12).

[0039] like Figure 3The splicing rules given in this invention are that components (13) with corresponding ports (14) can be spliced. For example, the upper port (black rectangle) of I0 (1) can connect to 8 components (13) (red rectangles). They are I0 (1), I1 (5), -1 (12), L1 (9), L2 (10), Y0 (2), Y3 (8), and Y1 (6). Any one of these 8 components (13) can be connected to a component (13) with an upper port. For example, the upper port of -1 (12) can be connected to any one of these 8 components (13). The left port (black rectangle) of I0 (1) can connect to 8 components (13) (red rectangles). These are, I0(1), I1(5), -0(12), L0(3), L1(9), Y0(2), Y3(8), and Y2(7). Any one of these eight components (13) can be connected to any component (13) with a left port. The lower port (black rectangle) of I0(1) can connect to eight components (13) (red rectangles). These are, I0(1), I1(5), -1(12), L0(3), L3(11), Y1(6), Y3(8), and Y2(7). Any one of these eight components (13) can be connected to any component (13) with a lower port. The right port (black rectangle) of I0(1) can connect to eight components (13) (red rectangles). They are, respectively, I0(1), I1(5), -0(12), L3(11), L2(10), Y0(2), Y1(6) and Y2(7), any one of these 8 components (13) can be connected to the component (13) with the right port.

[0040] like Figure 4 The splicing area (16) given in this invention specifies the total number of components (13) that can appear. For example, given a 5×5 square splicing area (16), this area contains 25 grids (15), and each grid corresponds to one component (13). The probability combination given in this invention limits the probability of each type of component (13) appearing. For example, when the probability combination is (0.1, 0.7, 0.1, 0.1), it indicates that the probabilities of I-shaped components, Y-shaped components, L-shaped components, and --shaped components appearing are 0.1, 0.7, 0.1, and 0.1, respectively.

[0041] Step 2: Construct an irregular structure (18).

[0042] like Figure 5 The splicing area (16) given in this invention is a 20×20 square splicing area (16).

[0043] When constructing the irregular structure (18), this invention first sets the Boolean value of all cells (15) in the splicing area (16) to "True", then randomly selects a cell (15) in the splicing area (16) and assigns a component (13) to that cell (15) according to probability combinations. Once the cell (15) obtains the component (13), its Boolean value needs to be updated to "False".

[0044] The irregular structure (18) needs to continuously expand to adjacent cells (15) during its formation. If a cell (15) with a Boolean value of "False" has multiple available adjacent cells, the entropy values ​​of the adjacent cells need to be compared. The adjacent cell with the lowest entropy will be given priority in allocating components (13). For example, if adjacent cells i and j are both waiting for component (13) allocation, and the entropy of adjacent cell i is greater than that of adjacent cell j, then adjacent cell j will have priority in allocating components. Once an adjacent cell obtains a component (13), its Boolean value needs to be updated to "False". Component (13) allocation and Boolean value updates are performed on the available adjacent cells of all cells (15) with a Boolean value of "False" in the above manner. If the Boolean values ​​of all cells (15) within the splicing area (16) are all updated to "False", then the irregular structure (18) can be obtained.

[0045] Step 3: Construct a load-bearing acoustic metamaterial (17) based on the irregular structure (18).

[0046] like Figure 6 In this invention, an irregular structure (18) is constructed under the probability combination (0.7, 0.1, 0.1, 0.1), and the constructed irregular structure (18) is packaged to form a load-bearing acoustic metamaterial (17). The load-bearing acoustic metamaterial (17) consists of a perforated plate (19) and multiple chambers (20). In order to ensure that each chamber (20) contains at least one hole without appearing too crowded, this invention... Figure 7 The location of the holes is restricted. This invention divides the holes into three categories. Specifically, the first category of holes (21) are all located in the upper left of the grid (15) and arranged as a whole; the number of these holes in this invention is 400. The second category of holes (22, 23) are located in the lower left or upper right of the grid (15); the number of these holes is 40. The third category of holes (24) is located in the lower right of the grid (15) and there is only one. The area occupied by the third category of holes (24) is the lower right corner of the micro-perforated plate; the area occupied by the second category of holes (22, 23) is the bottom and rightmost part of the micro-perforated plate; the other areas are all occupied by the first category of holes (21).

[0047] Figure 8The figure shows four irregular structures (25) generated by the same probability combination (0.7, 0.1, 0.1, 0.1), and acoustic and mechanical calculations are performed on them to obtain Figure 10 The sound absorption coefficient curve and Figure 12 The stress-strain curves. The four irregular structures (25) under the same probability combination show structural differences, but the four sound absorption coefficient curves corresponding to them show a high degree of overlap, and the four stress-strain curves also show a high degree of overlap. The load-bearing-acoustic metamaterial designed using the present invention demonstrates structural diversity and performance consistency.

[0048] Figure 9 The four probability combinations given are (0.7, 0.1, 0.1, 0.1), (0.55, 0.2, 0.1, 0.14), (0.65, 0.1, 0.15, 0.1), and (0.3, 0.25, 0.3, 0.15). Based on these four probability combinations, four irregular structures under different probability combinations were generated (26), and acoustic and mechanical calculations were performed on them to obtain... Figure 11 The sound absorption coefficient curve and Figure 13 The stress-strain curves. The irregular structures (26) under four different probability combinations show significant differences in structure, and the four sound absorption coefficient curves corresponding to them also show significant differences, as do the four stress-strain curves. The load-bearing-acoustic metamaterial designed using this invention can exhibit a variety of properties.

[0049] The variable-performance load-bearing acoustic metamaterial design method provided by this invention addresses the diversity of the load-bearing acoustic metamaterial (17) structure due to the randomness of component selection and the limitations of splicing rules. In this invention, if the probability combination remains unchanged, the performance of the load-bearing acoustic metamaterial (17) exhibits consistency. If the probability combination changes, the performance of the load-bearing acoustic metamaterial (17) exhibits diversity. The combination of structural diversity and performance consistency enhances the system's resilience and better meets personalized design requirements. The combination of structural diversity and performance diversity ensures optimal system selection and improves fault tolerance. The combined use of structural diversity, performance consistency, and performance diversity provides the system with extremely strong robustness and flexibility. This design method effectively solves the technical problems existing in the background art.

[0050] Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, those skilled in the art should understand that the above embodiments are merely illustrative explanations of the implementation of the present invention and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute a limitation on the scope of the present invention. Any obvious changes, such as equivalent transformations or simple substitutions, based on the technical solutions of the present invention without departing from the spirit and scope of the present invention fall within the protection scope of the present invention.

Claims

1. A method for designing load-bearing-acoustic metamaterials with variable properties, characterized in that: Includes the following steps: (1) Design four basic components: I-shaped component, Y-shaped component, L-shaped component and --shaped component, and rotate them to form eight new components. Establish splicing rules and give probability combinations. Then create a splicing area (16) to accommodate the final result. (2) Assign a boolean value "True" to each cell (15) in the splicing area (16). "True" means that the cell (15) has not yet been occupied by the component (13), and "False" means that the cell (15) has been occupied by the component (13). The component (13) contains 4 basic components and 8 new components. (3) Randomly select a cell (15) in the splicing area (16), assign a component (13) to the cell (15) according to the probability combination, and update the Boolean value of the cell (15) to "False". According to the splicing rules and probability combination, assign components (13) and update the Boolean value of the available adjacent cells of the cell (15) with a Boolean value of "False". If there are multiple adjacent cells that can be assigned components (13), find the adjacent cell with the minimum entropy. The adjacent cell with the minimum entropy value is the adjacent cell with the minimum entropy. If there are no adjacent cells that need to be assigned components (13), then execute step (4). The entropy is calculated as follows: in i Represents a grid (15) i , T It is a grid (15) i Number of applicable components (13), P j It refers to T The probability assigned to each component (13) w represent T The sum of the probabilities of each component (13); (4) Determine whether the Boolean values ​​of all cells (15) in the splicing area (16) are "False". If all are "False", it means that an irregular structure (18) has been generated, and further construct the load-bearing acoustic metamaterial (17). Otherwise, repeat steps (2), (3) and (4).

2. The design method according to claim 1, characterized in that: The design method includes four influencing factors: components (13), splicing rules, probability combinations, and splicing regions (16). There are four types of basic components in the design. By rotating these four types of basic components clockwise by 90°, 180°, and 270°, eight new components can be formed. The new components obtained by rotating based on the basic components belong to the same type as the basic components. The splicing rules restrict the connection between components (13), the probability combinations specify the probability of each type of component (13) appearing, and the splicing regions (16) restrict the total number of times the components (13) appear.

3. The design method according to claim 1, characterized in that: Boolean update refers to updating the Boolean value of a cell from "True" to "False". All cells with a Boolean value of "False" (15) need to have their available neighboring cells assigned components (13) and Boolean values ​​updated. Available neighboring cells refer to neighboring cells with a Boolean value of "True".

4. The design method according to claim 1, characterized in that: After generating the irregular structure (18) using the method described above, the load-bearing-acoustic metamaterial (17) is designed with reference to the principle of micro-perforated plates.

5. The design method according to claim 4, characterized in that: The load-bearing acoustic metamaterial (17) consists of a perforated plate (19) and multiple chambers (20).

6. The design method according to claim 5, characterized in that: The number of chambers (20) supporting the acoustic metamaterial is related to the probability combination. The number of chambers (20) under the same probability combination is the same, while the number of chambers (20) under different probability combinations is significantly different.

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