Acoustic cover body, sound absorption system, method for adjusting and compensating sound absorption performance

Abstract

The application provides an acoustic cover layer body, a sound absorption system and a sound absorption performance adjusting and compensating method. The acoustic cover layer body with a cavity is made of a soft base material, and the main feature is that a low-modulus soft material is selected as the base material. Compared with a traditional acoustic cover layer with a hard base material, nonlinear deformation is prone to occur under external load, especially in underwater application environment. By controlling the load or deformation of the acoustic cover layer body, the sound absorption effect can be adjusted according to the environmental characteristics and performance requirements. In addition, a sound absorption system is also provided, which is characterized by comprising an acoustic cover layer body and a control module, and the two work in coordination. The sound absorption system designed in this way has the following functions: wide-band high-performance sound absorption under specific working conditions, and performance adjustment according to the characteristics of underwater sound waves to maximize the sound absorption effect; the sound absorption performance is maintained at the same level under different working conditions, that is, it has high adaptability.

Description

Technical Field

[0001] This invention relates to an underwater high-efficiency broadband sound absorption structure, which mainly solves the problem of underwater sound absorption and belongs to the field of acoustic technology. Background Technology

[0002] Underwater acoustics is a primary means of underwater target location and communication. As a carrier of energy and information, it has a wide range of applications in engineering and daily life. However, underwater noise, such as marine environmental noise and underwater radiated noise, seriously affects the utilization of underwater acoustics. Effective absorption and shielding of underwater noise is fundamental to realizing a range of underwater acoustic applications. Therefore, a protective layer with a specific structure, which can be laid on the surface of underwater objects and effectively absorb underwater sound waves, has been proposed—an acoustic covering layer (or sound-absorbing surface, etc.).

[0003] A key technical challenge in the development of acoustic coverings is the absorption of low-frequency sound waves. Traditional solutions involve introducing special resonant structures within the acoustic covering. These internal structures resonate, converting the acoustic energy of low-frequency sound waves into structural kinetic energy. The viscosity of the acoustic covering matrix material then converts this kinetic energy into internal energy, thus dissipating the sound energy. Common resonant structures can be categorized into rigid resonator structures and cavity resonator structures. Rigid resonator structures incorporate rigid mass blocks within the matrix material as resonators, typically made of metal or high-density materials. While this type of acoustic covering possesses strong load-bearing capacity due to the rigid resonator, it also results in significant weight. Furthermore, once formed, its sound absorption capacity and frequency band are completely fixed, lacking any adjustability. With the increasing demand for lightweight and functional acoustic coverings, relatively lightweight cavity resonator acoustic coverings have gained attention. This type of acoustic covering layer is mainly made by setting cavities in the matrix material, which ensures both low-frequency sound absorption performance and light weight. In order to resist the interference of external loads on its performance, the matrix is ​​usually made of hard (i.e. high modulus) rubber material. Summary of the Invention

[0004] Based on the above background, to ensure the lightweight, wideband, and high-efficiency performance of the acoustic covering layer, this invention relaxes the design requirements for a high modulus of the covering layer matrix. A soft material with high acoustic loss and matching water impedance is selected as the matrix material, and combined with a control module and a backing, an acoustic covering layer with adjustable sound absorption performance is achieved. The backing serves to prevent sound transmission. The backing can be a separate component or formed from the mounting body of the acoustic covering layer (examples include walls, such as the shell of underwater equipment, etc.). Other components (such as the functional modules of the control module described below) can also be accommodated within the backing. This relates to the following aspects:

[0005] Aspect 1: An acoustic covering layer body made of a soft substrate material containing a cavity, characterized in that:

[0006] Low-modulus soft materials are selected as the matrix material: the Young's modulus of the material is no higher than 30 MPa. Compared with some traditionally used hard materials (modulus of about 200 MPa), the acoustic coating layer made from this material is more prone to nonlinear deformation in deep water environments (500m depth). Furthermore, the selected material satisfies underwater acoustic impedance matching characteristics and high acoustic loss characteristics: the impedance of a material describes the propagation characteristics of sound waves within it, and is the product of density and wave velocity. When the impedances of two materials are similar, it is called matching. Acoustic loss is the material loss factor, which is the ratio of the material's loss modulus to its storage modulus. The loss factor range for common solid materials is 0.001-1.60, and materials with a loss factor higher than 1.0 are considered high-loss materials. High sound wave transmittance is a prerequisite for the acoustic coating layer to function effectively, and good underwater acoustic impedance matching characteristics can improve the transmission capability of sound waves and reduce reflection intensity. Structural resonance of the acoustic coating layer is the main way to absorb sound energy, and the high acoustic loss characteristics of the soft material can effectively improve the effect of structural resonance in converting sound energy into internal energy. There are no restrictions on the types of soft materials. Common rubber materials such as tetrafluoroethylene rubber can be used. The molecular weight, degree of crosslinking, and additives of the selected materials can also be adjusted to prepare materials with suitable properties.

[0007] The acoustic covering layer adopts the existing acoustic covering layer structure, consisting of a matrix material and a resonant cavity. The main body can be a single-layer shell structure composed of unit cells of the same size and shape arranged periodically along the direction parallel to the incident sound wave face, or it can be a multi-layer structure along the direction parallel to the incident sound wave (thickness direction). The unit cells can be in the shape of regular square prisms, regular hexagonal prisms, etc.; the internal cavity is generally conical, with a larger radius at the backing end and a smaller radius at the water-near end (i.e., away from the backing end), achieving a uniform transition in the cavity cross-sectional area. This ensures both the porosity required for structural resonance and impedance matching. Furthermore, to avoid stress concentration leading to structural damage, the sharp corners of the cavity structure can be rounded.

[0008] The acoustic covering layer composed of the aforementioned matrix materials and structure is more prone to nonlinear deformation under external loads, especially in underwater applications, compared to acoustic covering layers made of traditional rigid matrix materials. This deformation alters the resonant cavity structure and the equivalent material properties of the matrix, thus affecting sound absorption performance. Utilizing this characteristic, the sound absorption can be adjusted according to environmental characteristics and performance requirements by controlling the load or deformation of the acoustic covering layer. Research has shown that this acoustic covering layer can achieve efficient absorption of low-frequency broadband sound waves at specific underwater locations (such as underwater fixed devices at specific depths).

[0009] Aspect 2. A sound absorption system, characterized in that it includes an acoustic covering layer body and a control module, which work together in coordination.

[0010] The main body of the acoustic covering layer (see aspect 1) is primarily responsible for sound absorption and has a certain high-efficiency sound absorption frequency band (such as the frequency band with a sound absorption coefficient higher than 0.7).

[0011] The control module is primarily responsible for environmental identification, scheme calculation, and performance adjustment. Specifically, it can include at least one of an environmental identification module, a calculation module, and an adjustment module. The environmental identification module identifies the sound waves, loads, and temperature information of the surrounding environment. It can be equipped with sound sensors, force sensors, and temperature sensors. The sound sensors capture the frequency band information of external sound waves, the force sensors identify the environmental load status, and the temperature sensors monitor the ambient temperature in real time. The calculation module calculates the target performance adjustment scheme for that environment based on the environmental information obtained from the input or environmental identification module, combined with the current system state and the sound absorption performance targets (frequency, peak value, bandwidth, sound absorption coefficient, etc.). The adjustment module applies a load to the acoustic covering layer, causing it to undergo nonlinear deformation. The specific load application method is not unique; for example, it can be achieved by laying pre-tightening wires on the sound wave incident end face of the acoustic covering layer to form a pre-tightening mesh, tensioning each pre-tightening wire to generate inward pressure perpendicular to the surface of the acoustic covering layer, or by vertically installing multiple bolts between the sound wave incident end face and the bottom backing of the acoustic covering layer, applying or releasing the load by rotating the bolts. If the material properties (such as loss factor, Young's modulus, etc.) are sensitive to temperature changes, the environmental identification module preferably includes a temperature sensor, and the adjustment module includes a temperature adjustment device (such as a heating coil). The temperature sensor is used to monitor the ambient temperature in real time; the temperature adjustment device provides temperature compensation to the matrix material of the acoustic covering layer based on the ambient temperature to ensure that the material performance does not change significantly with changes in ambient temperature and remains in optimal operating condition; or it can adjust the sound absorption performance of the acoustic covering layer through temperature compensation.

[0012] The sound absorption system designed in this way has the following functions:

[0013] (1) Wideband high-performance sound absorption under specific working conditions, and the performance can be adjusted according to the characteristics of underwater acoustic waves to maximize the sound absorption effect;

[0014] (2) The sound absorption performance remains at the same level under different working conditions, that is, it has high adaptability.

[0015] Aspect 3. A method for adjusting sound absorption performance, characterized in that: (1) a sound absorption system is provided, including an acoustic covering layer body and a control module (see Aspect 1 and Aspect 2 for details); (2) the sound absorption performance of the acoustic covering layer body is determined by its geometric structure and material properties, and the control module can simultaneously change the geometric structure and equivalent material properties of the acoustic covering layer body by applying a load, thereby changing the sound absorption performance accordingly. Therefore, by adjusting the load applied by the control module, the sound absorption performance of the acoustic covering layer can be adjusted.

[0016] Aspect 4. A method for compensating sound absorption performance, characterized in that: (1) a sound absorption system is provided, including an acoustic covering layer body and a control module (see Aspect 1 and Aspect 2 for details); (2) the sound absorption performance can be maintained unchanged under the compensation effect. The so-called compensation refers to avoiding the interference by certain internal adjustments when the performance is disturbed by external factors. The total load on the acoustic covering layer body is the superposition of the environmental load and the load provided by the active module (called the compensation load). When the environmental load changes, the total load is kept unchanged by adjusting the size of the compensation load, and the sound absorption performance remains unchanged. For example, when the water level where the acoustic covering layer body is located decreases, the decrease in water pressure will cause the sound absorption performance to be disturbed. At this time, the increase in the compensation load is equal to the decrease in water pressure, so that the total load on the acoustic covering layer body remains unchanged, and its sound absorption performance is not affected.

[0017] By utilizing the aforementioned acoustic covering layer and its control module, when the environment remains constant, the control module can adjust the load state on the acoustic covering layer to control frequency, peak value, bandwidth, and sound absorption coefficient. Furthermore, when the environment changes, the control module can maintain the load state on the acoustic covering layer, ensuring its sound absorption effect remains constant.

[0018] As an example, the sound absorption performance of the acoustic covering layer in a shallow water environment (water pressure of 0) can be adjusted by the control module.

[0019] As an example, the sound absorption performance of the acoustic covering layer under two different operating conditions (such as at different water levels—100m underwater and 400m underwater) can be maintained at the same level by adjustment.

[0020] Theoretically, the sound absorption effect achievable by the acoustic covering layer is influenced by factors such as the structure and materials of the main body of the acoustic covering layer. Structural factors include the thickness D of the main body of the acoustic covering layer, the shape of the cavities, the porosity σ, and the arrangement of the cavities. Comparatively, changes in sound absorption performance are more sensitive to changes in thickness D and porosity σ, and are also easier to adjust. Material factors include the material parameters of the matrix material, such as Young's modulus E, Poisson's ratio ν, density ρ, and loss factor η. Comparatively, changes in sound absorption performance are more sensitive to changes in Young's modulus E and loss factor η, and these parameters can also be adjusted to control sound absorption.

[0021] Preferably, the acoustic covering layer adopts a square prism unit cell shape (other structures that can achieve periodic arrangement, such as regular hexagonal prisms, can also be used), and the cavity shape adopts a generally conical structure (that is, meeting the design requirements of a large cross-sectional radius at the backing end and a small cross-sectional radius at the water-near end (i.e., the far backing end), or other cavity configurations that meet the requirements, such as a horn-shaped structure, can also be used); in terms of materials, it can be assembled from a single material or multiple materials in layers, and the softer the material, the stronger the controllability. On the one hand, in the production process, only the unit cells of the acoustic covering layer with the same size structure and material composition can be produced, and large-area assembly can be carried out according to needs, while ensuring the uniformity of porosity, which is convenient for industrial production and reduces processing costs; on the other hand, in the application process, regardless of the degree of control, the sound absorption performance of each area of ​​the acoustic covering layer can be guaranteed to be at the same level, simplifying the spatial complexity of the control module and achieving unified performance control. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 Schematic diagram of the main unit cell of the acoustic covering layer;

[0024] Figure 2 Schematic diagram of the main body of the acoustic covering layer;

[0025] Figure 3 Schematic diagram of the working logic of the sound absorption system;

[0026] Figure 4 Schematic diagram of a pre-tensioned mesh type load implementation device, in which Figure 4 (a) is a 3D diagram. Figure 4 (b) is a bottom view;

[0027] Figure 5 Sound absorption effect diagram of acoustic covering layer under different loads, where the horizontal axis f represents frequency (unit: kilohertz) and the vertical axis α represents sound absorption coefficient (unit: 1);

[0028] Figure 6 The sound absorption effect diagrams under different working conditions are shown, where the horizontal axis f represents the frequency (unit: kilohertz) and the vertical axis α represents the sound absorption coefficient (unit: 1). Detailed Implementation

[0029] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] The acoustic covering layer is composed of unit cells arranged periodically along a direction parallel to the incident sound wave face. Considering the lightweight design requirements of the acoustic covering layer, a smaller overall thickness is better; therefore, there is no periodic arrangement in the direction perpendicular to the face, resulting in a single-layer structure. The acoustic covering layer unit cell 1 is shown below. Figure 1 As shown, it is a regular square prism (but not limited to a regular square prism), composed of a matrix material 2 and a cavity 3. At this time, the main body of the acoustic covering layer is arranged as follows: Figure 2As shown, the material of cavity 3 is air, and the material of matrix material 2 is not specifically limited; conventional polymer materials in existing technologies, such as homopolymers, copolymers, and polymer mixtures, can be used. Considering the actual performance of the acoustic coating layer, the matrix material should, on the one hand, be selected as a material with acoustic impedance well matched to water, or additives with adjustable elasticity (such as carbon black) should be added during material preparation to adjust the elasticity of the material, thereby ensuring low reflectivity and high transmittance of sound waves on the surface of the acoustic coating layer, because sound waves can only be dissipated or absorbed if they penetrate into the interior of the acoustic coating layer. On the other hand, the matrix material should have a high acoustic loss factor (loss factor higher than 1.0), which enables more sound energy to be converted into internal energy, thereby improving the sound energy absorption effect. Additives with adjustable acoustic loss factor (such as glass microspheres) can be added during material preparation to adjust the acoustic loss factor of the material. Furthermore, according to the method for adjusting the sound absorption performance of the acoustic covering layer described in this invention, in order to make the main structure of the acoustic covering layer easily undergo nonlinear deformation under the applied load, it is necessary to use a material with a low modulus (preferably 5-30 MPa) as the matrix material. The softer the matrix material, the higher the sensitivity of performance adjustment and the greater the adjustment range. At the same time, the material cannot be too soft (below 5 MPa), otherwise the main structure of the covering layer is prone to distortion, which increases the control cost.

[0032] Materials that meet the above properties, such as tetrafluoroethylene rubber, not only have high material loss values, but also have a good match with the acoustic impedance of water, and are relatively soft, making them an exemplary matrix material.

[0033] The sound absorption system includes the aforementioned acoustic covering layer and control module.

[0034] The control module of the sound absorption system has three main functions, and its working logic is as follows: Figure 3As shown: Firstly, there is the environmental recognition function (environmental recognition module), which may include sound sensors, force sensors, temperature sensors, etc. The sound sensor can perform spectral analysis on the sound signal to obtain spectral characteristic information; the force sensor can provide feedback on the load conditions (such as water pressure) of the environment where the acoustic covering layer is located; and the temperature sensor can monitor the ambient temperature and the temperature of the acoustic covering layer substrate material. Secondly, there is the scheme calculation function (calculation module). The control module pre-stores information such as the target load and temperature corresponding to the optimal sound absorption coefficient at a specific sound wave frequency. Combined with the input or recognized environmental information, it calculates the performance compensation scheme for load, temperature, etc. Thirdly, there is the scheme implementation function (adjustment module). Based on the performance compensation scheme, it adjusts the load and temperature of the acoustic covering layer to achieve the state corresponding to the optimal performance, thereby maximizing the sound absorption performance. The load control method is not unique, but it should, as far as possible, not affect sound wave transmission, uniform loading, and high loading freedom standards. For example, pre-tightening wires (such as steel wire) can be evenly laid on the surface of the acoustic covering layer. Figure 4 As shown, the two ends of the pretension wire 30 pass through the acoustic covering layer body 10 and the backing 20 and are connected to the motor 40 set in the back cavity. Multiple pretension wires 30 are parallel or intersecting to form a pretension mesh. When the motor 40 is working, it tensions each pretension wire, which can form a vertical surface inward pressure on the surface of the acoustic covering layer body 10, thereby controlling the load on the acoustic covering layer body 10. Furthermore, by arranging the working degree of the motor 40, uniform and non-uniform loading on the surface of the acoustic covering layer body 10 can be achieved.

[0035] Under the control of the module, the acoustic covering layer will have a certain stress distribution state, which will affect the resonance effect of the overall structure. To characterize the influence of the stress distribution state on the sound absorption performance of the acoustic covering layer, this invention applies the incremental finite deformation wave propagation (Small-on-Large) theory, which equates the stress distribution state to the effective elastic tensor distribution state of the material. Combined with the wave equation, the acoustic performance of the acoustic covering layer can be described.

[0036] The matrix material of the acoustic coating layer can be considered as a hyperelastic material, undergoing finite deformation under the action of the control module. In this case, the effective elastic tensor D and equivalent density ρ of the matrix material can be expressed as:

[0037] D i′hk′l =J -1 F i′i F k′k C ijkl (1)

[0038] ρ=ρ0 / J, (2)

[0039] Where J is the Jacobian determinant, ρ0 is the density of the matrix material in the initial configuration, and F is the deformation gradient of the structure from the initial coordinate system (undeformed configuration) to the current coordinate system (deformed configuration):

[0040]

[0041] C ijkl Represents the elastic tensor of the matrix material under its initial configuration:

[0042]

[0043] Where W is the strain energy density function of the hyperelastic material, applicable to hyperelastic materials with arbitrary constitutive models.

[0044] The effective elastic tensor state of the acoustic covering layer matrix material after finite deformation can be obtained from equation (1). The structural state after deformation is easily obtained by the finite element method. Therefore, by combining the two, the sound absorption performance at this time can be evaluated.

[0045] If the properties of the matrix material 2 (such as loss factor, Young's modulus, etc.) are sensitive to temperature changes, the sound absorption system may also include a temperature sensor and a temperature control device (such as a heating coil). The temperature sensor is used to monitor the ambient temperature in real time. The temperature control device provides temperature compensation for the matrix material of the acoustic covering layer based on the ambient temperature to ensure that the material properties do not change significantly with changes in ambient temperature and are always maintained in optimal operating condition.

[0046] Example 1: As an embodiment of the present invention, the following describes in detail the effect of the control module on the sound absorption performance of the acoustic covering layer in a shallow water environment (corresponding to water pressure P=0). The acoustic covering layer body 10 adopts a regular square prism unit cell 1 with a base side length of l and a thickness of d; the specific cavity 3 shape is as follows... Figure 1 As shown, the overall structure is conical: it is composed of a frustum with an upper base radius r, a lower base radius R, and a height H, and a cylinder with a radius R and a height h. To avoid sharp corners that could lead to stress concentration, the upper base of the frustum and the lower base of the cylinder are rounded, with rounding radii of r and h, respectively. Detailed structural parameters of the unit cell described in this embodiment are shown in Table 1. The matrix material 2 is tetrafluoroethylene rubber, copolymerized from tetrafluoroethylene and propylene and doped with a certain mass fraction of carbon black. This material exhibits material nonlinearity, geometric nonlinearity, and boundary nonlinearity, and can withstand large deformations. Its mechanical behavior can be described using hyperelastic constitutive relations. Taking the neo-Hookean model as an example, the strain energy density function is:

[0047]

[0048] Where I1 is the first invariant of the elongation tensor, and λ and μ are Lamé's first and second constants, respectively:

[0049]

[0050] The specific values ​​of Young's modulus E, Poisson's ratio v, density ρ, and loss factor η of this material are shown in Table 2.

[0051] Table 1. Unit cell structural parameters of Example 1

[0052]

[0053] Table 2 Material parameters related to the matrix material in Example 1

[0054]

[0055] The specific load implementation method adopted by the control module is as follows: For a 10×10 single-layer acoustic covering layer body composed of 100 regular square prism unit cells, 20×20 pre-tightening wires can be evenly arranged in a cross shape on the sound incident end face. By giving each pre-tightening wire a tension T, an inward equivalent uniform pressure N can be applied to the surface of the acoustic covering layer body.

[0056] With N controlled at pressures of 0, 1 MPa, 2 MPa, 3 MPa, 4 MPa, and 5 MPa (T corresponding to 0, 2.25 kN, 4.5 kN, 6.75 kN, 9 kN, and 11.25 kN respectively), the sound absorption coefficient of the acoustic covering layer is as follows: Figure 5 As shown, with the increase of pressure N, the first absorption peak frequency of the sound absorption curve shifts from 0.2kHz to 0.9kHz, with an adjustable range of 350%, and the value of the first absorption peak increases from 0.9 to 0.95, with an adjustable range of 5.6%. The absorption trough frequency shifts from 1.4kHz to 3.5kHz, with an adjustable range of 150%, and the absorption trough value increases from 0.42 to 0.7, with an adjustable range of 67%. Therefore, this method provides an effective means to adjust the sound absorption performance of acoustic covering layers.

[0057] Example 2: As an embodiment of the present invention, the following describes how the acoustic covering layer can maintain its sound absorption performance at the same level under different load environments (such as different water levels) through adjustment of the control module. The structure, materials, and control module type of the acoustic covering layer are consistent with those described in Example 1. Taking two different water level conditions of the acoustic covering layer as examples: Condition 1 is a water level of 100m and an environmental load (i.e., water pressure) P1 = 1MPa. At this time, the control module adjusts the equivalent uniformly distributed load N1 = 4MPa applied to the sound incident end face of the main body of the acoustic covering layer; Condition 2 is a water level of 400m and an environmental load P2 = 4MPa. The control module adjusts the equivalent uniformly distributed load N2 = 1MPa applied; that is, ensuring that P1 + N1 = P2 + N2. At this time, the sound absorption coefficient of the acoustic covering layer under the two conditions is as follows: Figure 6 As shown, the two are consistent, meaning that the sound absorption performance of the acoustic covering layer can be maintained at the same level under different working conditions through the adjustment of the control module, thus achieving the same sound absorption effect. This provides an effective method for maintaining the performance of the acoustic covering layer and improving its environmental adaptability.

[0058] The above provides a detailed description of the acoustic covering layer body, sound absorption system, and method for adjusting and compensating sound absorption performance provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0060] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that elements inherent to a process, method, article, or apparatus that comprises a list of elements, or elements inherent to such processes, methods, articles, or apparatus, are also included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sound absorption system, characterized in that, Includes the acoustic overlay body and the control module; The acoustic covering layer consists of multiple single cells. The unit cell includes a cavity and a matrix material; The acoustic covering layer is primarily formed from a single material; The matrix material is a low-modulus soft material, and the Young's modulus of the matrix material is in the range of 5MPa-30MPa; the matrix material is a rubber material. The control module includes an adjustment module; The adjustment module applies a compensating load to the acoustic covering layer body, causing the acoustic covering layer body to undergo nonlinear deformation. Specifically, the adjustment module applies an equivalent uniformly distributed pressure perpendicular to the surface of the acoustic covering layer body to the surface of the acoustic covering layer body. The total load on the acoustic covering layer is the sum of the environmental load and the compensation load provided by the adjustment module. When the environmental load changes, the total load remains constant by adjusting the magnitude of the compensation load.

2. The sound absorption system as described in claim 1, characterized in that: The unit cell is a regular square prism or a regular hexagonal prism; and / or The cavity is generally conical in shape.

3. The sound absorption system as described in claim 2, characterized in that, The unit cells have rounded corners at their sharp points.

4. The sound absorption system as described in claim 1, characterized in that, The control module also includes at least one of an environment recognition module and a calculation module.

5. The sound absorption system as described in claim 4, characterized in that, The environmental recognition module includes at least one of an acoustic sensor, a force sensor, and a temperature sensor; and / or The calculation module calculates a target performance adjustment scheme based on environmental parameters, sound absorption target, and current system status; and / or The adjustment module can also adjust the temperature of the acoustic covering layer body through a temperature adjustment device.

6. The sound absorption system as described in claim 1, characterized in that, The loss factor and / or Young's modulus of the matrix material are sensitive to temperature changes. The control module includes an environment identification module and an adjustment module, wherein the environment identification module includes a temperature sensor and the adjustment module includes a temperature adjustment device.

7. A method for adjusting sound absorption performance, characterized in that... Includes the following steps: (1) To provide a sound-absorbing system as described in any one of claims 1-6; (2) The sound absorption performance of the acoustic covering layer body is adjusted by the control module.

8. The adjustment method according to claim 7, characterized in that: The sound absorption system operates under at least two conditions; Through the regulation of the control module, the sound absorption performance of the acoustic covering layer body is kept basically the same under at least two working conditions.

9. The method as described in claim 7 or 8, characterized in that, The control module regulates the compensating load applied to the acoustic covering layer body and / or provides temperature compensation.

10. The method as described in claim 7 or 8, characterized in that, The sound absorption performance includes at least one of the following: sound absorption frequency, peak value, bandwidth, and sound absorption coefficient.

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