Soundproofing panel and its multi-stage Helmholtz acoustic metamaterial resonant structure and design method

Abstract

This invention discloses a sound insulation panel and its multi-tiered Helmholtz acoustic metamaterial resonant structure and design method, achieving broadband sound insulation, enriching the product's application scenarios, and optimizing the structural design to achieve easier processing and reduced costs. The multi-tiered Helmholtz acoustic metamaterial resonant structure includes at least two stages of thin-film-Helmholtz resonant structures arranged sequentially along the sound wave incident direction, and a homogeneous plate for fixing the last stage of the thin-film-Helmholtz resonant structure. Each stage of the thin-film-Helmholtz resonant structure includes a thin film and a plate arranged sequentially along the sound wave incident direction, with the opposite surfaces of the thin film and the plate sealed together. A first through-hole and a second through-hole are coaxially arranged sequentially along the sound wave incident direction on the plate. The second through-hole communicates with the first through-hole to form the resonant cavity of the thin-film-Helmholtz resonant structure, and the size of the second through-hole is larger than that of the first through-hole. The first and second through-holes of each stage of the thin-film-Helmholtz resonant structure have a stepped shape with gradually increasing opening size in the sound wave incident direction.

Description

Technical Field

[0001] This invention relates to the field of acoustic metamaterials technology, and in particular to a sound insulation panel and its multi-cascaded Helmholtz acoustic metamaterial resonant structure and design method. Background Technology

[0002] In modern society, low-frequency noise is widespread in many fields such as industry, aviation, and transportation, significantly impacting instruments and equipment and posing serious safety hazards. Simultaneously, low-frequency noise also affects people's work and daily lives. Traditional low-frequency noise control methods generally employ thick concrete walls or complex composite material structures, especially the latter, which suffers from drawbacks such as difficult fabrication and high cost. Due to the characteristics of low-frequency noise, such as long wavelength, long propagation distance, and weak attenuation, its effective control remains a very challenging issue in the field of noise control.

[0003] Acoustic metamaterials are composite materials composed of periodic subwavelength structures with negative equivalence properties, allowing for the control of large wavelengths through small dimensions. In recent years, researchers have proposed numerous Helmholtz cavity-type acoustic metamaterials, providing favorable structural models for low-frequency noise control. However, among these Helmholtz acoustic metamaterials, for a single resonant frequency sound-absorbing / insulating structure, there is only one good sound-absorbing / insulating peak value, and the narrow sound insulation bandwidth limits the practical application of the product, restricting its application scenarios. Conversely, products with a wider sound insulation bandwidth involve highly complex processing techniques and procedures, resulting in higher costs and longer manufacturing cycles. Summary of the Invention

[0004] The purpose of this invention is to provide a sound insulation panel and its multi-cascaded Helmholtz acoustic metamaterial resonant structure and design method, which can solve the problems existing in the prior art, achieve broadband sound insulation effect, enrich the application scenarios of the product, and optimize the structural design to achieve easy processing and reduced costs.

[0005] To achieve the above objectives, one solution of the present invention is:

[0006] A multi-tiered Helmholtz acoustic metamaterial resonant structure includes at least two stages of thin-film-Helmholtz resonant structures fixedly connected sequentially along the incident direction of sound waves, and a homogeneous plate for fixing the last stage of the thin-film-Helmholtz resonant structure. Each stage of the thin-film-Helmholtz resonant structure includes a thin film and a plate sequentially arranged along the incident direction of sound waves, with the opposite surfaces of the thin film and the plate sealed together. The plate has a first through-hole and a second through-hole arranged coaxially along the incident direction of sound waves. The second through-hole communicates with the first through-hole to form a resonant cavity of the thin-film-Helmholtz resonant structure, and the size of the second through-hole is larger than the size of the first through-hole. The first through-hole and the second through-hole of each stage of the thin-film-Helmholtz resonant structure have a stepped shape with gradually increasing opening size in the incident direction of sound waves.

[0007] The film and the plate, as well as the plate and the homogeneous plate, are bonded together by an adhesive.

[0008] Preferably, the adhesive is AB glue, UV glue, epoxy resin glue, or ABS-specific glue.

[0009] The plate is composed of a first frame and a second frame. Both the first frame and the second frame are perforated plates with holes, and are respectively formed with the first through hole and the second through hole.

[0010] The film is made of at least one of the following materials: PET, PVC, PV, silicone, TPU, PU, ​​PI, and PEI.

[0011] The film has a Young's modulus of 0.2~2000 MPa, a Poisson's ratio of 0.3~0.4, and a density of 900~1200 kg / m³. 3 The thickness is 0.01~0.5mm.

[0012] The material of the sheet is ABS, acrylic, polyurethane, fiberglass, aluminum, iron, calcium silicate, gypsum or cement fiber.

[0013] The second solution of the present invention is:

[0014] A sound insulation panel is provided, wherein a resonant unit is composed of the aforementioned multi-cascaded Helmholtz acoustic metamaterial resonant structure, and the sound insulation panel is formed by arranging several resonant units in a rectangular array.

[0015] The sound insulation panel is a multi-level composite structure consisting of a continuous layer of thin film and a whole sheet of board arranged sequentially along the direction of sound wave incidence, and a whole homogeneous board attached to the side of the last level of board. The board has a number of first through holes and second through holes arranged in a rectangular array according to the center spacing of the resonant units.

[0016] The third solution of the present invention is:

[0017] A design method for a sound insulation panel involves designing the resonant frequencies of the film and the sheet material of the sound insulation panel; the formula for calculating the resonant frequency of the film is as follows:

[0018]

[0019] Where n is the natural frequency order, taking positive integers greater than 0 such as 1, 2, 3, etc.; R is the radius of the circular film or the equivalent diameter of the polygonal film, in meters (m); T is the surface tension of the film, in N / m; and ρ is the density of the film, in cubic meters per second (m³). 3 / kg; σ is the film thickness, in meters; u n The inherent frequency factors are first-order u1=2.4048, u2=u3=3.8317, u4=u5=5.1356, u6=5.5201;

[0020] The formula for calculating the resonant frequency of the plate is:

[0021]

[0022] Where c is the speed of sound in air, taken as 340 m / s; S is the cross-sectional area of ​​the first through hole, in m². 2 ; l is the length of the first through hole, in meters; r is the radius of the circular first through hole or the equivalent diameter of the polygonal first through hole, in meters; V r The volume of the second through hole is in meters (m). 3 .

[0023] After adopting the above technical solution, the present invention has the following technical effects:

[0024] ① By coupling a thin film at the first through hole of the board, the equivalent mass of the board is changed from the air mass at the first through hole to the sum of the air mass at the first through hole and the mass of the film. The target frequency can be adjusted by adjusting the physical parameters of the film and the size of the first through hole, and the designability of the product is enhanced.

[0025] ② Due to the intrinsic modes of the thin film, when the incident sound wave resonates with the thin film, the elastic strain energy of the thin film can be used to increase the sound energy consumption of the acoustic resonance inside the plate. Moreover, the thin film itself will generate a certain acoustic band gap due to the principle of local resonance. Sound waves will be difficult to propagate within the band gap, thereby blocking noise through the structure of the present invention and realizing the sound insulation effect of the coupled resonance structure.

[0026] ③ By designing multi-level, interconnected thin-film-Helmholtz resonant structures in the direction of sound wave propagation, the coupling effect between each level of thin-film-Helmholtz resonant structure can improve the sound insulation performance of the previous level of thin-film-Helmholtz resonant structure. At the same time, multiple sound insulation frequency bands generated by different thin-film-Helmholtz resonant structures with different resonance frequencies are combined in a complementary manner to achieve a broadband sound insulation effect.

[0027] ④ Compared with the complex structure and processing technology of traditional composite materials, the present invention only requires processing the first and second through holes of the plate, and then processing the plate and bonding it with the film and homogeneous plate to obtain the formed sound insulation plate. This can optimize and simplify the process, thereby improving production efficiency and reducing production costs. Attached Figure Description

[0028] Figure 1 This is a perspective view of the first embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonance structure of the present invention;

[0029] Figure 2 This is an exploded view of the first embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonance structure of the present invention;

[0030] Figure 3 This is a cross-sectional view of the first embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonant structure of the present invention;

[0031] Figure 4 This is a front perspective view of the resonant frame of the second embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonant structure of the present invention;

[0032] Figure 5 This is a perspective view of the back of the resonant frame of the second embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonant structure of the present invention;

[0033] Figure 6 This is a perspective view of the sound insulation panel of the present invention;

[0034] Figure 7 This is a schematic diagram of the layer structure of the sound insulation panel of the present invention;

[0035] Figure 8 This is a simplified acoustic-solid coupling model established in COMSOL for this invention;

[0036] Figure 9 The sound insulation curves from 0 to 4000 Hz are for thin film structures and thin film-Helmholtz structures.

[0037] Figure 10 The stress contour plot of the thin film surface at the resonant frequency of the thin film-Helmholtz structure;

[0038] Figure 11 This is a surface stress cloud diagram of a thin film structure at its resonant frequency.

[0039] Figure 12 The sound insulation curves from 0 to 4000 Hz for Class 1, Class 2, and Class 1+2 resonant structures;

[0040] Figure 13 The surface stress cloud diagram of the thin film of the first-order + second-order resonant structure at the resonant frequency f1;

[0041] Explanation of icon numbers:

[0042] 1--Thin film-Helmholtz resonance structure; 11---Thin film; 12---Sheet material; 121--First frame; 1211--First through-hole; 122--Second frame; 1221--Second through-hole;

[0043] 2----Homogeneous plate;

[0044] a----Resonance unit;

[0045] b----Sound insulation panel. Detailed Implementation

[0046] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of protection of the invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of the embodiments of the present invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, or the orientation or positional relationship in which those skilled in the art are usually understood. It is only for the purpose of simplifying the description of the embodiments of the present invention, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0051] Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0055] Furthermore, this invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0056] refer to Figures 1 to 5 As shown, the present invention discloses a multi-stage Helmholtz acoustic metamaterial resonant structure, including at least two stages of thin-film-Helmholtz resonant structures 1 that are fixedly connected in sequence along the direction of sound wave incidence, and a homogeneous plate 2 for fixing the last stage of thin-film-Helmholtz resonant structure 1; each stage of thin-film-Helmholtz resonant structure 1 includes a thin film 11 and a plate 12 arranged in sequence along the direction of sound wave incidence, and the opposite surfaces of the thin film 11 and the plate 12 are sealed together.

[0057] The plate 12 has a first through hole 1211 and a second through hole 1221 arranged coaxially along the direction of sound wave incident. The second through hole 1221 communicates with the first through hole 1211 to form a resonant cavity of the thin film-Helmholtz resonant structure 1. The size of the second through hole 1221 is larger than the size of the first through hole 1211. The first through hole 1211 and the second through hole 1221 of each stage of the thin film-Helmholtz resonant structure 1 are in a stepped shape with gradually increasing opening size in the direction of sound wave incident.

[0058] In some embodiments of the present invention, the film 11 and the plate 12, and the plate 12 and the homogeneous plate 2 are bonded together by an adhesive to achieve a fixed connection and a seal.

[0059] Furthermore, when bonding the film 11 to the plate 12 and the plate 12 to the homogeneous plate 2, an adhesive that is resistant to high and low temperatures, acids and alkalis, high humidity and is stable under ultraviolet light is used, such as AB glue, UV glue, epoxy resin glue, ABS special glue, etc.

[0060] In some embodiments of the present invention, the number of first through holes 1211 in the same plate 12 can be set to one or more, and the shape of the first through hole 1211 can be a regular shape such as a circle, triangle, square, or hexagon. When there are multiple first through holes 1211 in the same plate 12, the shapes of each first through hole 1211 can be the same or different. In addition, when there are multiple first through holes 1211 in the same level thin film-Helmholtz resonance structure 1, they can be connected to the same second through hole 1221 at the same time (that is, they share a second through hole 1221), or they can be independently divided by a grid structure according to a certain optimization algorithm. That is, the plate 12 can also be provided with multiple second through holes 1221, and each second through hole 1221 corresponds to one or more first through holes 1211.

[0061] In some embodiments of the present invention, the aforementioned plate 12 may be composed of a first frame 121 and a second frame 122. Both the first frame 121 and the second frame 122 are plate-shaped with perforations, that is, respectively formed with the aforementioned first through hole 1211 and second through hole 1221. The first frame 121 and the second frame 122 may be an integral structure, or they may be formed separately and then bonded together with the aforementioned adhesive, or other similar methods to achieve a sealed connection to form a whole. Among them, the size design of the first frame 121 mainly affects the surface tension of the film 11, and the main design of the second frame 122 is the volume of the second through hole 1221.

[0062] In some embodiments of the present invention, the material of the aforementioned film 11 mainly includes PET (polyethylene terephthalate), PVC (polyvinyl chloride), PV (polyvinyl chloride resin), silicone, TPU (thermoplastic polyurethane), PU (polyurethane), PI (polyimide), PEI (polyethyleneimide), etc., with a Young's modulus generally ranging from 0.2 to 2000 MPa, a Poisson's ratio generally ranging from 0.3 to 0.4, and a density generally ranging from 900 to 1200 kg / m³. 3 The thickness is generally 0.01~0.5mm.

[0063] In some embodiments of the present invention, the above-mentioned plate 12 is made of metal and non-metal materials with high rigidity, such as ABS (acrylonitrile-butadiene-styrene copolymer), acrylic, polyurethane, fiberglass, and metal materials such as aluminum and iron. In construction applications, materials such as calcium silicate, gypsum, and cement fiber can be used.

[0064] In some embodiments of the present invention, the homogeneous plate 2 mentioned above needs to have a certain rigidity to provide a hard boundary pressure acoustic field condition for the Helmholtz resonant structure, and can also improve the mid-to-high frequency sound insulation performance of the entire structure. It is generally selected according to the application scenario, and needs to take into account high and low temperature resistance, acid and alkali resistance, fire resistance, humidity, impact resistance and decorative properties.

[0065] refer to Figures 1 to 3 The image shows the first embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonance structure of the present invention.

[0066] In the first embodiment, each plate 12 includes a first frame 121 and a second frame 122 formed separately, and the first through hole 1211 of the first frame 121 and the second through hole 1221 of the second frame 122 have a square cross-sectional shape, and only one first through hole 1211 is provided.

[0067] refer to Figure 4 and Figure 5As shown, this is the second embodiment of the multi-cascaded Helmholtz acoustic metamaterial resonance structure of the present invention. Figure 4 , Figure 5 The main feature is a schematic diagram of the shape of the board 12.

[0068] In the second embodiment, the plate 12 in the thin film-Helmholtz resonance structure 1 may include an integrally formed first frame 121 and second frame 122, that is, a first through hole 1211 and a second through hole 1221 are formed directly on both ends of the plate 12; and the first frame 121 has four first through holes 1211, the cross-sectional shapes of the four first through holes 1211 are circular, regular hexagonal, square and equilateral triangle respectively, and the cross-sectional shape of the second through hole 1221 is square.

[0069] refer to Figure 6 As shown, the present invention also discloses a sound insulation panel, wherein a resonant unit a is constituted by the above-mentioned multi-cascaded Helmholtz acoustic metamaterial resonant structure, and a sound insulation panel b is formed by arranging several resonant units a in a rectangular array. Figure 6 The middle section is a two-tiered Helmholtz acoustic metamaterial resonant structure. This sound insulation panel b can be used directly as a wall with sound insulation properties, or it can be attached to the walls of a building to improve its sound insulation performance.

[0070] Further, refer to Figure 7 As shown, the sound insulation panel b is a multi-level composite structure consisting of a continuous thin film 11' and a continuous plate 12' arranged sequentially along the direction of sound wave incidence, and a continuous homogeneous plate 2' attached to the side of the last plate 12'. The plate 12' has a number of first through holes 1211 and second through holes 1221 arranged in a rectangular array according to the center spacing of the resonant unit a.

[0071] Furthermore, the present invention also discloses a design method for the aforementioned sound insulation panel, which designs the resonant frequencies of the thin film 11 and the plate 12:

[0072] First, the formula for calculating the resonant frequency of thin film 11 is as follows:

[0073]

[0074] Where n is the natural frequency order, taking positive integers greater than 0 such as 1, 2, 3, etc.; R is the radius of the circular thin film 11 or the equivalent diameter of the polygonal thin film, in meters; T is the surface tension of the thin film 11, in N / m; and ρ is the density of the thin film 11, in cubic meters per second. 3 / kg; σ is the thickness of film 11, in meters; u nThe intrinsic frequency factors are: u1 = 2.4048, u2 = u3 = 3.8317, u4 = u5 = 5.1356, u6 = 5.5201. These values ​​are the zero solutions of the 0th and 1st order cylindrical Bessel functions, and can be determined according to... Figure 8 Obtain.

[0075] Secondly, the formula for calculating the resonant frequency of plate 12 is as follows:

[0076]

[0077] Where c is the speed of sound in air, typically taken as 340 m / s; S is the cross-sectional area of ​​the first through-hole 1211, in m². 2 ; l is the length of the first through hole 1211, in meters; r is the radius of the circular first through hole 1211 or the equivalent diameter of the polygonal first through hole, in meters; V r The volume of the second through hole 1221 is expressed in cubic meters (m³). 3 .

[0078] Using the above calculation formula (i.e., optimization algorithm), based on the target frequency, F can be... n Designed with F0: The material (physical parameters) and thickness of the film 11 of each stage of the thin-film-Helmholtz resonant structure 1 can be designed according to the target frequency; the physical parameters and dimensions of the film 11 of each stage of the thin-film-Helmholtz resonant structure 1 can be the same or different; the second through-hole 1221 of each stage of the thin-film-Helmholtz resonant structure 1 can be the same or different; the same sound absorption and insulation performance can be achieved by combining films 11 with different parameters and different plates 12; the number of stages of the thin-film-Helmholtz resonant structure 1 is determined by the sound insulation amount at the target frequency, and can be composed of 1 stage, 2 stages, 3 stages, etc.; in addition, the proportional relationship between the dimensions of the second through-hole 1221 and the first through-hole 1211 is determined by F. n The relationship between F0 and the resonant structure is determined, and the two make the sound absorption optimal and the sound insulation reach its peak.

[0079] refer to Figure 8 As shown, the working principle of this invention is as follows:

[0080] When a sound wave is incident, it first passes through the first-level resonant structure. The sound energy near the first-level resonant frequency will be consumed by the elastic strain of the thin film 11 and the second through-hole 1221 within the first-level resonant structure, with the greatest consumption at the resonant frequency. The sound wave near the first-level non-resonant frequency will continue to propagate into the second-level resonant structure. The sound energy near the second-level resonant frequency will be consumed by the elastic strain of the thin film and the resonant cavity (i.e., the first through-hole 1211 and the second through-hole 1221) within the second-level resonant structure. The sound wave near the second-level non-resonant frequency will continue to propagate into the third-level resonant structure. The sound energy near the third-level resonant frequency will be consumed by the elastic strain of the thin film and the resonant cavity within the third-level resonant structure. And so on. Through the multi-layer stacking of multi-level thin film-Helmholtz resonant structures 1, a broadband sound insulation effect is achieved. Furthermore, the series connection of the first-level and second-level resonant structures creates a coupling effect. That is, the addition of the second-level structure increases the volume of the resonant cavity of the first-level resonant structure, causing the thin film of the first-level resonant structure to produce greater strain and more sound energy to be consumed, thereby improving the sound insulation performance of the 1+2 series structure.

[0081] The following are the specific test data:

[0082] ①Silicone film was selected as film 11, with the following physical parameters: Young's modulus 200MPa, Poisson's ratio 0.38, thickness 0.1mm, and density 1020kg / m³. 3 The first through-hole 1211 of the first-stage thin-film-Helmholtz resonant structure 1 has dimensions of 20*20*5mm, and the second through-hole 1221 has dimensions of 30*30*20mm; the first through-hole 1211 of the second-stage thin-film-Helmholtz resonant structure 1 has dimensions of 30*30*5mm, and the second through-hole 1221 has dimensions of 40*40*20mm; ABS board is selected as the homogeneous board 2, with the following physical parameters: Young's modulus 2200MPa, Poisson's ratio 0.34, thickness 3mm, and density 1100kg / m³. 3 .

[0083] ② The acoustic-structure interaction model of this invention was established using the commercial software COMSOL multiphysics software. Inlet and outlet air domains were set at both ends, and the sound insulation of different structures was calculated. The results are as follows: Figures 9 to 13 As shown.

[0084] Figure 9 The sound insulation curves for thin-film and thin-film + Helmholtz structures are shown. It can be seen that compared to the thin-film structure, the peak sound insulation increases from 30dB to 53dB after adding the Helmholtz structure, and the average sound insulation after 1000Hz also shows a significant improvement. This is mainly because the thin film undergoes greater deformation, causing more sound energy to be converted into elastic strain energy and dissipated. Figure 10It can be seen that the stress at the center of the thin film with the Helmholtz structure reaches a maximum of 9 kPa, while Figure 11 The stress at the center of the thin film structure shown is about 5 kPa.

[0085] Figure 12 The sound insulation curves are for three types of resonant structures: Level 1, Level 2, and Level 1+2. The peak frequencies of sound insulation for Level 1 resonant structures are f1, f4, and f5, while those for Level 2 resonant structures are f2, f3, etc. The sound insulation curve of a multi-level structure formed by cascading Level 1 and Level 2 resonant structures exhibits the sound insulation performance characteristics of a single resonator. Furthermore, due to the coupling effect between the two resonators, the sound insulation at the peak frequencies is enhanced after cascading. Taking a Level 1 resonant structure as an example: Figure 10 The first-order resonant structure shown has a stress of approximately 9 kPa at the center of the thin film at the resonant frequency f1, while... Figure 13 In the multi-level resonant structure shown, the stress at the center of the film in the first-level resonant structure is 10 kPa at the resonant frequency f1. More stress means more sound energy is dissipated, which increases the sound insulation peak of f1 from 53 dB to 63 dB. f2~f5 are also improved to a certain extent due to this effect.

[0086] Through the above scheme, the present invention couples a thin film 11 at the first through hole 1211 of the plate 12, so that the equivalent mass of the plate 12 is changed from the air mass at the first through hole 1211 to the sum of the air mass at the first through hole 1211 and the mass of the thin film 11. By adjusting the physical parameters of the thin film 11 and the size of the first through hole 1211, the target frequency can be adjusted, and the designability of the product is enhanced. Secondly, due to the eigenmode of the thin film 11, when the incident sound wave resonates with the thin film 11, the elastic strain energy of the thin film 11 can be used to increase the sound energy consumption of the acoustic resonance inside the plate 12. Moreover, the thin film 11 itself will generate a certain acoustic band gap due to the principle of local resonance. Sound waves will be difficult to propagate within the band gap, thereby achieving noise blocking. Through the structure of the present invention, the sound insulation effect of the coupled resonance structure is achieved. Furthermore, by designing multi-level, interconnected thin-film-Helmholtz resonant structures 1 in the direction of sound wave propagation, the coupling effect between each level of thin-film-Helmholtz resonant structure 1 can improve the sound insulation performance of the previous level. At the same time, multiple sound insulation frequency bands generated by the different resonant frequencies of different thin-film-Helmholtz resonant structures 1 are combined in a complementary manner to achieve a broadband sound insulation effect. Compared with the complex structure and processing technology of traditional composite materials, this invention only requires processing the first through hole 1211 and the second through hole 1221 of the plate 12. After processing the plate 12, it is bonded to the thin film 11 and the homogeneous plate 2 to obtain the formed sound insulation plate b. This can optimize and simplify the process, thereby improving production efficiency and reducing production costs.

[0087] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A sound insulation panel, characterized in that: A resonant unit is composed of several cascaded Helmholtz acoustic metamaterial resonant structures; The multi-tiered Helmholtz acoustic metamaterial resonant structure includes at least two stages of thin-film-Helmholtz resonant structures that are fixedly connected in sequence along the direction of sound wave incidence, and a homogeneous plate for fixing the last stage of thin-film-Helmholtz resonant structure; each stage of thin-film-Helmholtz resonant structure includes a thin film and a plate that are arranged in sequence along the direction of sound wave incidence, and the opposite surfaces of the thin film and the plate are sealed together. The plate has a first through hole and a second through hole arranged coaxially along the direction of sound wave incidence. The second through hole communicates with the first through hole to form the resonant cavity of the thin-film-Helmholtz resonant structure. The size of the second through hole is larger than that of the first through hole. The first through holes and the second through holes of each level of the thin-film-Helmholtz resonant structure are in a stepped shape with gradually increasing opening size in the direction of sound wave incidence. After the thin-film-Helmholtz resonant structures are connected in series, the sound insulation of the peak frequency is improved due to the coupling effect. Multiple sound insulation frequency bands generated by the different resonant frequencies of different thin-film-Helmholtz resonant structures are combined in a complementary manner to achieve a broadband sound insulation effect. The sound insulation panel is formed by arranging a number of resonant units in a rectangular array. The sound insulation panel is a multi-level composite structure consisting of a continuous layer of thin film and a whole sheet of board arranged sequentially along the direction of sound wave incidence, and a whole homogeneous board attached to the side of the last level of board. The board has a number of first through holes and second through holes arranged in a rectangular array according to the center spacing of the resonant units.

2. The sound insulation panel as described in claim 1, characterized in that: The film and the plate, as well as the plate and the homogeneous plate, are bonded together by an adhesive.

3. The sound insulation panel as described in claim 2, characterized in that: The adhesive is AB glue, UV glue, epoxy resin glue, or ABS-specific glue.

4. The sound insulation panel as described in claim 1, characterized in that: The plate is composed of a first frame and a second frame. Both the first frame and the second frame are perforated plates with holes, and are respectively formed with the first through hole and the second through hole.

5. The sound insulation panel as described in claim 1, characterized in that: The film is made of at least one of the following materials: PET, PVC, PV, silicone, TPU, PU, ​​PI, and PEI.

6. The sound insulation panel as described in claim 1, characterized in that: The film has a Young's modulus of 0.2~2000 MPa, a Poisson's ratio of 0.3~0.4, and a density of 900~1200 kg / m³. 3 The thickness is 0.01~0.5mm.

7. The sound insulation panel as described in claim 1, characterized in that: The material of the sheet is ABS, acrylic, polyurethane, fiberglass, aluminum, iron, calcium silicate, gypsum or cement fiber.

8. A design method for a sound insulation panel, comprising designing the resonant frequencies of the film or sheet material of the sound insulation panel according to any one of claims 1 to 7, characterized in that: The formula for calculating the resonant frequency of the thin film is: ； in, The natural frequency order is a positive integer greater than 0. The radius of a circular thin film or the equivalent diameter of a polygonal thin film, in meters (m). The surface tension of the thin film is expressed in N / m. The density of the thin film, in meters. 3 / kg; The thickness of the film is expressed in meters (m). The natural frequency factor is a first-order factor. =2.4048, = =3.8317, = =5.1356, =5.5201; The formula for calculating the resonant frequency of the plate is: ； in, The speed of sound in air is taken as 340 m / s; The cross-sectional area of ​​the first through hole is in meters (m²). 2 ; The length of the first through hole, in meters; The radius of the first circular through hole or the equivalent diameter of the first polygonal through hole, in meters (m). The volume of the second through hole is expressed in cubic meters (m³). 3 .

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