A multi-modal locally resonant acoustic metamaterial and device

Abstract

The utility model provides a kind of multi-modal local resonance acoustic metamaterial, including the substrate layer, coupling layer, resonant layer and sound-absorbing layer of laminated setting, resonant layer is provided with multiple resonant cavities;The two sides of coupling layer are connected with substrate layer and resonant layer respectively, the side of resonant layer away from coupling layer is in abutment with sound-absorbing layer.When sound wave is coupled to resonant layer by coupling layer, first, local resonance is generated to sound wave by resonant cavity, to attenuate sound wave.The two sides of coupling layer are connected with substrate layer and resonant layer respectively, resonant layer is in abutment between sound-absorbing layer, when sound wave is transmitted to sound-absorbing layer, part of sound wave will be reflected back to resonant layer, will be bound in resonant layer, realize the purpose of sound insulation, and another part of sound wave will be attenuated further by sound-absorbing layer, realize noise reduction.Resonant cavity multi-modal vibration mode and the abutment mode of sound-absorbing layer and resonant layer make that acoustic metamaterial provided by the utility model not only can realize sound insulation and noise reduction, and the frequency range is wide.

Description

Technical Field

[0001] This utility model relates to the field of acoustic functional materials technology, and in particular to a multimodal local resonant acoustic metamaterial and device. Background Technology

[0002] Acoustic metamaterials are a class of artificial composite materials with special acoustic properties. Their performance mainly comes from the artificially designed microstructure rather than the natural properties of the constituent materials themselves. They can manipulate sound waves in ways that natural materials cannot achieve, thereby reducing noise.

[0003] Existing acoustic metamaterials typically employ a single resonant structure for their local resonant units. Their operating frequency band is limited by the unit size and resonant mode, making it difficult to cover a wide range of subwavelengths. The dynamic equivalent mass density control range of traditional local resonant structures is limited, exhibiting only a weak negative response near specific frequency points, making it difficult to achieve active or passive control of multi-frequency sound waves. For example, thin-film acoustic metamaterials generally use a frame to separate individual units and arrange mass blocks on the film. Employing a local resonance mechanism, they possess an equivalent negative mass density at a specific frequency between two intrinsic frequencies, enabling them to control large-wavelength elastic waves with a small-size structure, achieving sound insulation far exceeding the mass law. However, once formed, thin-film acoustic metamaterials are difficult to adjust; their inherent frequencies are fixed, offering good noise reduction capabilities only within a very narrow frequency range near their inherent frequencies. In scenarios with highly variable sound fields, such acoustic metamaterials cannot automatically adjust frequencies according to the spectral characteristics of different sound sources, making it difficult to achieve sound insulation and noise reduction for different incident sound waves. Summary of the Invention

[0004] This invention provides a multimodal local resonant acoustic metamaterial and device to solve the technical problem that existing acoustic metamaterials with single resonant structures cannot cover a wide range of frequencies and multiple subwavelengths.

[0005] On the one hand, this utility model provides a multimodal local resonant acoustic metamaterial, comprising: basal layer; A coupling layer, wherein the coupling layer is stacked with the substrate layer; A resonant layer, at least one of the resonant layers is disposed on the side of the coupling layer away from the substrate layer, and a plurality of resonant cavities are disposed within the resonant layer; the coupling layer is used to couple acoustic wave vibrations to the resonant layer. A noise-absorbing layer, which is independent of the resonant layer and is stacked on the side of the resonant layer away from the coupling layer; The coupling layer is connected to the base layer and the resonant layer on both sides, respectively, so as to couple the acoustic vibration of the base layer to the resonant layer, and the side of the resonant layer away from the coupling layer abuts against the sound-absorbing layer.

[0006] In one embodiment of the present invention, the sound-absorbing layer is provided with a resonant layer, a coupling layer and a base layer on both sides of the sound-absorbing layer, and the resonant layer, the coupling layer and the base layer are arranged sequentially from the sound-absorbing layer outward along the thickness direction of the sound-absorbing layer.

[0007] In one embodiment of the present invention, a plurality of noise-absorbing layers and a plurality of resonant layers are disposed between the two coupling layers, and the noise-absorbing layers and the resonant layers are arranged alternately along the thickness direction of the noise-absorbing layers.

[0008] In one embodiment of the present invention, the number of the noise-absorbing layers is odd, the number of the resonant layers is even, and each noise-absorbing layer is sandwiched between two adjacent resonant layers along the thickness direction of the noise-absorbing layer.

[0009] In one embodiment of the present invention, a plurality of resonant structures are provided in the resonant layer, each of the resonant structures including a plurality of resonant cavities, and the resonant cavities in each resonant structure are arranged in an array.

[0010] In one embodiment of the present invention, the resonant cavity has an extending direction, and the extending direction of the resonant cavity intersects with the thickness direction of the sound-absorbing layer.

[0011] In one embodiment of this utility model, the thickness direction of the base layer, the resonant layer and the sound-absorbing layer is the X direction, the resonant cavity extends along the Y direction or along the Z direction, the Y direction and the Z direction are perpendicular to the X direction, and multiple resonant structures are stacked along the Z direction. The array shape of the resonant cavity in each resonant structure is polygonal or circular, and the array shapes of adjacent resonant structures arranged along the Z direction are different.

[0012] In one embodiment of the present invention, a plurality of grooves are provided on the side of the base layer near the coupling layer, and the opening of each groove faces the coupling layer. The grooves cooperate with the coupling layer to form a deformation cavity, and the extension direction of each deformation cavity intersects with the thickness direction of the sound-absorbing layer.

[0013] In one embodiment of the present invention, the resonant cavity is filled with a filler for forming an impedance mismatch with the substrate layer.

[0014] On the other hand, this utility model provides a multimodal local resonant acoustic metamaterial device, including the multimodal local resonant acoustic metamaterial described above.

[0015] The beneficial effects of this invention are as follows: This invention proposes a multimodal localized resonant acoustic metamaterial. Sound wave vibrations are coupled to a resonant layer via a coupling layer. The resonant layer contains multiple resonant cavities. When sound waves are coupled to the resonant layer through the coupling layer, they first undergo localized resonance through the resonant cavities. This localized resonance can occur radially, axially, or torsionally along the resonant cavities, thus attenuating the sound waves. The coupling layer is connected to the base layer and the resonant layer on both sides, respectively. The resonant layer and the sound-absorbing layer are abutted rather than rigidly connected. The vibrations of the sound-absorbing layer and the resonant layer are separate and have different frequencies. Therefore, when sound waves reach the sound-absorbing layer, some of the sound waves are reflected back to the resonant layer, confining them and achieving sound insulation. The remaining sound waves are further attenuated by the sound-absorbing layer, achieving noise reduction. The multimodal vibration modes of the resonant cavities and the abutting method between the sound-absorbing layer and the resonant layer enable this acoustic metamaterial to not only achieve sound insulation and noise reduction but also have a wide applicable frequency range. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 Structural schematic diagram of the multimodal local resonant acoustic metamaterial provided by this utility model Figure 1 ; Figure 2 Structural schematic diagram of the multimodal local resonant acoustic metamaterial provided by this utility model Figure 2 ; Figure 3 Structural schematic diagram of the multimodal local resonant acoustic metamaterial provided by this utility model Figure 3 ; Figure 4 This is a schematic diagram of the structure of the multimodal local resonant acoustic metamaterial provided by this utility model. Figure 4 .

[0018] The attached figures are labeled as follows: Base layer 1, groove 11, coupling layer 2, resonant layer 3, resonant cavity 31, noise-absorbing layer 4. Detailed Implementation

[0019] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0022] Please see Figures 1 to 4 As shown, this invention provides a multimodal localized resonant acoustic metamaterial, comprising a substrate layer 1, a coupling layer 2, a resonant layer 3, and a noise-absorbing layer 4. The coupling layer 2 is stacked on top of the substrate layer 1, and the resonant layer 3 is located on the side of the coupling layer 2 away from the substrate layer 1. The coupling layer 2 couples acoustic wave vibrations to the resonant layer 3. The noise-absorbing layer 4 is located on the side of the resonant layer 3 away from the coupling layer 2. That is, the substrate layer 1, coupling layer 2, resonant layer 3, and noise-absorbing layer 4 are stacked sequentially.

[0023] In this design, coupling layer 2 is connected to base layer 1 on one side and resonant layer 3 on the other, forming a continuous sound wave conduction and conversion channel. This ensures that sound wave vibrations can be transmitted with low loss, thereby efficiently exciting the local resonance effect of resonant layer 3. Resonant layer 3 and anechoic layer 4 are independent yet connected, meaning that coupling layer 2 is integrated with base layer 1 and resonant layer 3, while resonant layer 3 and anechoic layer 4 are in contact but independent of each other. This creates an impedance transition zone, allowing the resonant sound wave energy to be more effectively transferred to anechoic layer 4 for absorption and dissipation. This achieves optimized decoupling and synergy between the two core elements of vibration excitation and energy consumption.

[0024] The resonant layer 3 and the anechoic layer 4 are independent yet interconnected. Structurally, this interconnection means that while the two layers are in close contact, they are not rigidly bonded. A clear physical interface exists between them, allowing for slight relative displacement or strain differences under the influence of sound waves. This interconnection also provides the resonant layer 3 with the necessary mechanical freedom, enabling it to vibrate fully and efficiently scatter and localize sound wave energy. Simultaneously, the interconnection efficiently guides the resonant-modulated sound wave energy into the anechoic layer 4. The synergistic effect of the resonant layer 3 and the anechoic layer 4 expands the effective noise reduction frequency band, ensuring that vibrational energy is smoothly transferred to the dissipation stage.

[0025] Multiple resonant structures are arranged within the resonant layer 3, and each resonant structure contains multiple resonant cavities 31. The resonant cavities 31 can be cylindrical, prismatic, spherical, or polyhedral. The stacking direction of the base layer 1, resonant layer 3, and noise-absorbing layer 4 is the thickness direction of the noise-absorbing layer 4, and the extension direction of the resonant cavities 31 intersects with the stacking direction of the base layer 1, resonant layer 3, and noise-absorbing layer 4. Figure 1 As shown, the stacking direction of the base layer 1, coupling layer 2, resonant layer 3, and noise-absorbing layer 4 is in the X-direction, which is generally considered to be the direction of sound wave propagation. The extension direction of the resonant cavity 31 can be multi-directional. For example, the cylindrical resonant cavity 31 can extend along the Y-direction or along the Z-direction. Among them, the X-direction, Y-direction, and Z-direction are mutually perpendicular. Of course, the resonant cavity 31 can also extend laterally. If the extension direction of the resonant cavity 31 is parallel to the X-direction, the attenuation effect of the sound wave after entering the resonant cavity 31 will decrease. Therefore, in order not to affect the noise reduction effect, the extension direction of the resonant cavity 31 should be slightly deviated from the stacking direction, rather than parallel.

[0026] In some embodiments, the resonant cavities 31 within each resonant structure are arranged in an array, that is, the resonant cavities 31 are arranged in an array in the plane formed by the X and Y directions, and the multiple resonant structures are also arranged in an array in the Z direction.

[0027] The array arrangement of the resonant cavities 31 in the plane formed by the X and Y directions can be polygonal or circular. The polygonal shape can be rectangular, triangular, or hexagonal, etc. Each resonant structure can have multiple layers in the Z direction. For example, each resonant structure has multiple layers of resonant cavities 31, and the arrangement of each layer of resonant cavities 31 in each resonant structure is the same.

[0028] In some embodiments, multiple resonant structures are arranged along the Z direction, and the array shapes of adjacent resonant structures can be different, thereby making the resonant frequencies of the resonant cavities 31 of each resonant structure mismatched, which can extend the wide frequency modulation range.

[0029] In some embodiments, the plane formed by the X and Y directions can also be a combination of multiple resonant structures. The array arrangement of resonant structures at the same height along the Z direction can be the same or different. For example, along the stacking direction of the base layer 1, coupling layer 2, resonant layer 3 and sound-absorbing layer 4, the resonant cavities 31 of adjacent resonant structures can be arranged differently, which can adjust the refraction angle, reflection coefficient or absorption coefficient of the sound wave, and is suitable for active control in complex sound field environments.

[0030] In some embodiments, to further enhance sound attenuation performance, the metamaterial can employ a symmetrical composite structure centered on the sound-absorbing layer 4. Specifically, a resonant layer 3, a coupling layer 2, and a base layer 1 are sequentially disposed on both sides of the sound-absorbing layer 4, forming a mirror-symmetrical structure. The resonant layer 3, coupling layer 2, and base layer 1 on both sides of the sound-absorbing layer 4 correspond completely to each other in structure and thickness. This symmetrical arrangement facilitates symmetrical coupling and cancellation of sound wave energy within the structure, thereby achieving a more balanced and significant sound attenuation effect.

[0031] To achieve wider bandwidth or adjustable noise reduction, acoustic metamaterials can also employ an asymmetric design centered on the noise reduction layer 4. In this case, the resonant layer 3, coupling layer 2, and base layer 1 on both sides of the noise reduction layer 4 are not mirror images of each other in terms of structural parameters. For example, the geometry of the resonant layers 3 on both sides (such as the number and arrangement of resonant structures) can be different to target different frequency bands of sound waves. The thicknesses of the coupling layer 2 and base layer 1 on both sides can also be differentiated, such as the thickness of the layer closer to the sound source being greater than that of the layer farther from the sound source, to match different acoustic impedances. This asymmetric design, by introducing multiple local resonance peaks and impedance gradients, can effectively broaden the noise reduction bandwidth and improve transmission loss.

[0032] The base layer 1 serves as the carrier of sound wave input, while the coupling layer 2 efficiently transfers the broadband sound wave vibration energy from the base layer 1 to the entire resonant layer 3. Unlike individual excitation of each resonant cavity 31, the coupling layer 2, as a continuous elastic body, can synchronously excite the vibration of all resonant cavities 31 in the resonant layer 3. The resonant cavities 31 convert sound waves into vibrational energy through vibration, confining the sound waves within the resonant layer 3. When the resonant cavities 31 resonate, their vibrational energy radiates back to the base layer 1 through the coupling layer 2 and is also transferred to the anechoic layer 4. The anechoic layer 4 dissipates this concentrated vibrational energy through internal friction and other means.

[0033] A single resonant cavity 31 may have multiple vibration modes. A series of resonant cavities 31 of different sizes and shapes can be designed in the resonant layer 3. Each resonant cavity 31 has its own unique resonant frequency. The resonant frequencies of multiple resonant cavities 31 are close to each other or even partially overlap, which can connect multiple discrete attenuation peaks into a continuous and efficient attenuation band, thereby achieving wideband noise cancellation. Near the resonant frequency, the vibration of the resonant cavity 31 will cause the entire metamaterial to exhibit a negative equivalent mass or negative equivalent modulus. Sound waves cannot propagate normally in the acoustic metamaterial and are thus greatly reflected or absorbed. The resonant cavity 31 converts the propagating sound energy into localized mechanical vibration, which is then dissipated through damping or interference effects.

[0034] In some embodiments, to achieve multi-level, efficient attenuation of sound waves, the acoustic metamaterial may employ alternating layers of resonant layers 3 and anechoic layers 4 between two coupling layers 2. For example... Figure 3 and Figure 4 As shown, the resonant layer 3 and the anechoic layer 4 are arranged in a repeating periodic pattern along the stacking direction. Its core advantage lies in the fact that each resonant layer 3 can excite local resonance for sound waves in a specific frequency band, while the adjacent anechoic layer 4 is responsible for dissipating the modulated sound wave energy step by step. This cascading mechanism can significantly broaden the overall effective anechoic band and achieve higher transmission loss over a wider frequency range.

[0035] In some embodiments, such as Figure 4 As shown, to achieve optimal sound wave suppression, the acoustic metamaterial is arranged symmetrically in a layered configuration, with an odd number of anechoic layers 4 and an even number of resonant layers 3. The base layer 1, coupling layer 2, and resonant layer 3 are mirror-symmetrical, with the central anechoic layer 4 serving as the axis of symmetry. This design ensures a symmetrical transition of acoustic impedance from the center of symmetry to the two edges. When sound waves are introduced, the symmetrically arranged multiple resonant structures can be synchronously excited. The resulting reflected waves can be more effectively superimposed within the resonant structures, thereby enhancing the destructive interference effect on multi-frequency sound waves and achieving a more balanced and significant broadband noise reduction performance.

[0036] In some embodiments, the base layer 1 and the coupling layer 2 are rigidly connected. The rigid connection can be achieved through snap-fitting, welding, mechanical pressing, or adhesive bonding. In this embodiment, the coupling layer 2 and the base layer 1 are bonded together using adhesive. There is a significant difference in acoustic impedance between the base layer 1 and the coupling layer 2. If snap-fitting, welding, or mechanical pressing is used, air gaps may exist, causing strong sound wave reflection at the interface and reducing transmission efficiency. Adhesive can fill microscopic gaps, forming a continuous acoustic path. The adhesive layer between the base layer 1 and the coupling layer 2 has moderate elasticity and internal friction characteristics, allowing the vibrational energy of the base layer 1 to be transferred to the coupling layer 2 through shear deformation, rather than directly transmitting rigid vibration. This avoids local reflection of high-frequency vibrations and simultaneously excites the overall vibrational modes of the coupling layer 2, thereby more efficiently guiding energy to the resonant layer 3.

[0037] Meanwhile, the adhesive layer itself possesses certain viscoelastic damping properties, which can absorb some high-frequency vibration energy and suppress unnecessary resonance peaks. The flexibility of the adhesive can release the stress caused by thermal expansion or vibration between layers, improving the reliability of acoustic metamaterials under long-term vibration environments.

[0038] In some embodiments, a groove 11 is provided on the side of the base layer 1 near the coupling layer 2, with the opening of the groove 11 facing the coupling layer 2. The groove 11 forms a deformation cavity after being connected to the coupling layer 2. The extension direction of the deformation cavity intersects the stacking direction of the base layer 1, coupling layer 2, resonant layer 3, and noise-absorbing layer 4, i.e., the stacking direction of the base layer 1, coupling layer 2, resonant layer 3, and noise-absorbing layer 4 is the X-direction. Multiple grooves 11 are provided on the base layer 1 along the Z-direction, and each groove 11 extends along the Y-direction. The cross-section of the groove 11 is rectangular, trapezoidal, or arc-shaped.

[0039] Adhesives develop internal stresses due to temperature changes and vibration loads after curing and during use. Continuous adhesive layers can easily lead to stress concentration. Groove 11 can act as a stress buffer, absorbing and dispersing these stresses, preventing adhesive layer cracking or interface debonding, and significantly enhancing the reliability and durability of the structure under long-term vibration environments.

[0040] Meanwhile, during the application and pressing process, the groove 11 provides space for excess adhesive, i.e., overflow. This prevents the overflow from forming uncontrollable glue nodules in critical functional areas, thereby ensuring the uniformity and consistency of the adhesive layer thickness and bonding area between the coupling layer 2 and the base layer 1, and guaranteeing the stability and predictability of acoustic performance.

[0041] The groove 11 forms a mechanical interlocking effect with the cured adhesive, greatly enhancing the interface's resistance to shear stress, preventing relative slippage between the coupling layer 2 and the base layer 1, and ensuring the stability of the vibration energy transmission path. By relieving stress, accommodating excess adhesive, and enhancing mechanical interlocking, the groove 11 significantly improves the reliability of the interface connection between the base layer 1 and the coupling layer 2 and the long-term stability of the structure.

[0042] The presence of groove 11 reduces the local stiffness of its region, resulting in a periodic or non-uniform distribution of stiffness at the interface between the base layer 1 and the coupling layer 2. This stiffness gradient facilitates a more complex vibrational response under the influence of sound waves, thereby introducing additional sound wave scattering and energy localization effects. This breaks down a single broadband sound wave into more modes of vibration, allowing the subsequent resonant layer 3 and anechoic layer 4 to selectively absorb and dissipate components of different frequencies, effectively broadening the anechoic bandgap of the acoustic metamaterial.

[0043] In some embodiments, the groove 11 and the air inside it, or the damping material filling the groove 11, alter the effective acoustic impedance at the interface between the substrate layer 1 and the coupling layer 2. By designing the depth, width, and shape of the groove 11, the interface acoustic impedance can be fine-tuned to establish a smoother transition gradient between the high impedance of the substrate layer 1 and the relatively low impedance of the coupling layer 2, thereby reducing sound wave reflection at the interface and increasing the proportion of acoustic energy entering the coupling layer 2 and being effectively utilized.

[0044] In some embodiments, the substrate 1 is a transparent substrate, such as glass, polymethyl methacrylate (PMMA), or polycarbonate. PMMA material combines high stiffness, good acoustic transmittance, and excellent processability, providing stable mechanical support for multilayer structures. Polymethyl methacrylate is also known as acrylic or plexiglass. The transparent substrate 1 can be used in optical-acoustic co-window scenarios (such as the optical transparency of an invisibility cloak).

[0045] In some embodiments, the base layer 1 may also be made of metal, such as aluminum, aluminum alloy, copper, or titanium alloy. A metal base layer 1 can enhance the coupling efficiency between low-frequency sound waves and the coupling layer 2, making it suitable for high-frequency noise isolation or acoustic lenses.

[0046] In some embodiments, the resonant cavity 31 is filled with a filler for forming an impedance mismatch with the substrate layer 1, such as air, polystyrene foam, or silica aerogel; in some embodiments, the resonant cavity 31 may also be a vacuum, thereby creating a strong impedance mismatch between the resonant layer 3 and the substrate layer 1. Coating the inner wall of the resonant cavity 31 with a sound-absorbing coating (such as porous carbon particles) can achieve transparency and integrated sound absorption, or the resonant cavity 31 can be filled with a high-velocity gas to enhance low-frequency resonance through gas-solid coupling.

[0047] The coupling layer 2 can be made of polymer adhesives, such as epoxy resin, silicone rubber, polyurethane, acrylate adhesive, etc.; it can also be made of flexible polymer film, or metal foil, such as copper foil, aluminum foil, beryllium copper alloy, etc. The sound-absorbing layer 4 is usually a damping material or a porous material.

[0048] This invention constructs a functionally partitioned composite acoustic structure by sequentially stacking a base layer 1, a coupling layer 2, a resonant layer 3, and a sound-absorbing layer 4. The coupling layer 2 is firmly connected to both the base layer 1 and the resonant layer 3, ensuring efficient transmission of sound wave vibration energy to the resonant layer 3. The resonant layer 3 and the sound-absorbing layer 4 are connected by abutment, providing the necessary vibrational degrees of freedom for the resonant layer 3 and forming an effective sound energy transmission interface. Multiple resonant cavities 31 are arranged within the resonant layer 3. When sound waves enter through the base layer 1, they are first coupled to the resonant layer 3 via the coupling layer 2, exciting local resonance in each resonant cavity 31 and converting the sound wave energy into mechanical vibration energy. Part of this mechanical vibration energy is dissipated in a damped manner within the resonant structure, while the other part is transmitted to the sound-absorbing layer 4 for noise reduction. In addition, some sound waves are reflected back to the resonant layer 3 at the interface of the anechoic layer 4, and the contact structure between the resonant layer 3 and the anechoic layer 4 can effectively adjust the phase and amplitude of the reflected wave, so that it produces destructive interference with the incident wave, thereby further enhancing the sound energy dissipation efficiency of the overall structure.

[0049] This invention also provides a multimodal local resonant acoustic metamaterial device, comprising the aforementioned multimodal local resonant acoustic metamaterial.

[0050] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A multimodal localized resonant acoustic metamaterial, characterized in that, include: basal layer; A coupling layer, wherein the coupling layer is stacked with the substrate layer; A resonant layer, at least one of the resonant layers is disposed on the side of the coupling layer away from the substrate layer, and a plurality of resonant cavities are disposed within the resonant layer; A noise-absorbing layer, which is independent of the resonant layer and is stacked on the side of the resonant layer away from the coupling layer; The coupling layer is connected to the base layer and the resonant layer on both sides, respectively, so as to couple the acoustic vibration of the base layer to the resonant layer, and the side of the resonant layer away from the coupling layer abuts against the sound-absorbing layer.

2. The multimodal localized resonant acoustic metamaterial according to claim 1, characterized in that: The sound-absorbing layer has a resonant layer, a coupling layer and a base layer on both sides. The resonant layer, the coupling layer and the base layer are arranged sequentially from the sound-absorbing layer outward along the thickness direction of the sound-absorbing layer.

3. The multimodal localized resonant acoustic metamaterial according to claim 2, characterized in that: A plurality of noise-absorbing layers and a plurality of resonant layers are disposed between the two coupling layers, and the noise-absorbing layers and the resonant layers are arranged alternately along the thickness direction of the noise-absorbing layers.

4. The multimodal localized resonant acoustic metamaterial according to claim 3, characterized in that: The number of noise-absorbing layers is odd, the number of resonant layers is even, and each noise-absorbing layer is sandwiched between two adjacent resonant layers along the thickness direction of the noise-absorbing layer.

5. The multimodal localized resonant acoustic metamaterial according to any one of claims 1-4, characterized in that: The resonant layer contains multiple resonant structures, each of which includes multiple resonant cavities, and the resonant cavities within each resonant structure are arranged in an array.

6. The multimodal localized resonant acoustic metamaterial according to claim 5, characterized in that: The resonant cavity has an extending direction, which intersects with the thickness direction of the sound-absorbing layer.

7. The multimodal localized resonant acoustic metamaterial according to claim 5, characterized in that: The thickness direction of the sound-absorbing layer is X-axis, the resonant cavity extends along Y-axis or Z-axis, the Y-axis and Z-axis are perpendicular to the X-axis respectively, multiple resonant structures are stacked along Z-axis, the array shape of the resonant cavity in the resonant structure is polygonal or circular, and the array shape of adjacent resonant structures arranged along Z-axis is different.

8. The multimodal localized resonant acoustic metamaterial according to claim 1, characterized in that: The base layer has a plurality of grooves on the side near the coupling layer, and the opening of each groove faces the coupling layer. The grooves cooperate with the coupling layer to form a deformation cavity, and the extension direction of each deformation cavity intersects with the thickness direction of the sound-absorbing layer.

9. The multimodal localized resonant acoustic metamaterial according to claim 1, characterized in that: The resonant cavity is filled with a filler material that creates an impedance mismatch with the substrate layer.

10. A multimodal localized resonant acoustic metamaterial device, characterized in that: Including the multimodal local resonant acoustic metamaterial as described in any one of claims 1-9.

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