Ultra-wideband noise reduction and bearing function integrated metamaterial structure sound barrier

Abstract

The invention discloses an ultra-wide-band noise reduction and bearing function integrated metamaterial structure sound barrier. The ultra-wide-band noise reduction and bearing function integrated metamaterial structure sound barrier comprises a multifunctional integrated screen body and a porous metamaterial sound absorber. The multifunctional integrated screen body comprises a composite non-uniform hollowed-out plate and a cavity, the composite non-uniform hollowed-out plate is arranged at the open end of the cavity, and partition plates are arranged in the cavity to divide the cavity into a plurality of sub-cavities; the porous super-structure sound absorber comprises a plurality of high-porosity sound absorption media arranged in the corresponding sub-cavities, and sound wave regulation and control channels are formed in the high-porosity sound absorption media. The metamaterial structure sound barrier is applied to the field of acoustic noise reduction, the metamaterial structure sound barrier can obtain low-frequency and ultra-wide-band efficient sound absorption performance, the overall rigidity of the sound barrier is improved, the longitudinal supporting area of the sound barrier is increased, the ultra-wide-band sound insulation performance of the sound barrier is greatly improved, meanwhile, the bearing capacity of a sound barrier body is greatly improved, and the noise reduction effect is good. The integration of the ultra-wideband efficient noise reduction performance and the high bearing function of the sound barrier with the metamaterial structure is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of acoustic noise reduction, and in particular to a metamaterial structure sound barrier integrating ultra-wideband noise reduction and load-bearing functions. Background Art

[0002] With the acceleration of urbanization, the intricate transportation network has greatly improved the quality of production and life, but the noise pollution problem brought about by it has become one of the important issues affecting people's growing needs for a better life. As a core noise reduction method, sound barriers achieve noise reduction by blocking direct sound and attenuating diffracted sound to form a "sound shadow zone". They are widely used in large noise reduction scenarios such as transportation (aircraft, high-speed rail, automobiles), industrial facilities (generators, compressors) and power equipment. Among them, the problem of transportation noise in cities is particularly prominent, greatly affecting human health and living comfort. However, the existing sound barrier schemes still have major problems in practical applications. First, transportation noise is mainly composed of low-frequency components (<500 Hz) such as wheel-rail noise and structure-borne noise. Traditional sound barriers are limited by the "mass law". The low-frequency sound insulation is directly related to the surface density of the material. Even if porous sound-absorbing materials are used, the low-frequency sound absorption performance is still insufficient. In addition, sound barriers are exposed to complex environments for a long time, which is prone to performance degradation and structural damage. The maintenance of traditional sound barrier solutions after performance degradation or barrier damage is difficult and costly, and it is difficult to maintain performance efficiently for a long time.

[0003] With the progress in acoustic physics and materials science, new metamaterials or superstructure technologies have brought breakthrough solutions to complex noise processing. This type of artificially synthesized special functional materials can exhibit unique properties that cannot be achieved in nature, such as negative equivalent mass density and negative equivalent elastic modulus. Compared with traditional sound-absorbing materials, sound-absorbing metamaterials, with their unique periodic structure design, can achieve efficient control of low-frequency sound waves in an extremely thin space. At the same time, by optimizing the internal structure, they can achieve low-frequency and ultra-wideband noise control requirements, showing broad application prospects in vibration noise control. This advantage just makes up for the shortcomings of traditional porous materials in low-frequency sound absorption in sound barriers. However, the existing sound insulation metamaterial design still has challenges in achieving low-frequency and broadband sound insulation under lightweight, and the sound insulation metamaterial needs to maintain the integrity of the structure. The complex environment in which the sound barrier is located is prone to fatigue damage to the screen or loosening due to vibration, and the durability is low. Therefore, the rapid development of sound-absorbing metamaterials or superstructure technology provides a new idea for low-frequency and ultra-wideband noise processing of sound barriers.

[0004] Traditional sound barriers mainly include types such as transparent plate type, metal plate type, and concrete monolithic casting type, etc. Plate-type sound barriers generally have the problem of poor sound absorption and insulation performance, resulting in limited noise reduction effect. In contrast, although concrete sound barriers perform outstandingly in terms of high-frequency sound absorption and sound insulation, they have obvious disadvantages in low-frequency noise control, and at the same time face technical problems of construction complexity and insufficient adaptability. In recent years, with the advent and development of new sound-absorbing materials, certain breakthroughs have been made in sound barrier technology. Among them, sound barriers using metal foam materials and porous ceramic materials perform well in medium-frequency noise control, with a sound absorption coefficient of up to more than 0.8 and excellent sound insulation performance. However, the noise reduction effect of such products in the low-frequency and high-frequency bands still needs to be improved, and at the same time, they face the problem of high production costs. On the other hand, sound barriers based on porous foam materials, with their excellent medium- and high-frequency sound absorption performance, lightweight characteristics, and ease of construction, show certain application potential in engineering practice. It should be noted that this type of sound barrier often requires a large structural thickness to achieve an ideal low-frequency sound absorption effect, which is restricted in application scenarios with limited space such as rail transit. To sum up, the existing sound barrier technology solutions still face significant technical bottlenecks in meeting the low-frequency and ultra-wideband noise reduction requirements, improving durability, and maintenance convenience. These limitations not only affect the actual noise reduction effect of the sound barrier but also bring many challenges to engineering applications. Summary of the Invention

[0005] Aiming at the deficiencies in the above-mentioned existing technologies, the present invention provides a metamaterial structure sound barrier integrating ultra-wideband noise reduction and load-bearing functions. Through ingenious design, the multi-functional integrated screen body can couple different low-frequency resonance modes or thermo-viscous dissipation forms while increasing the longitudinal support area of the sound barrier screen body, greatly improving the load-bearing capacity of the sound barrier screen body, and realizing the integration of ultra-wideband noise reduction and load-bearing functions of the metamaterial structure sound barrier. At the same time, the configuration of this metamaterial structure sound barrier is simple and easy to develop. The integrated design of noise reduction and load-bearing functions greatly reduces the processing and manufacturing costs and the overall weight, overcomes the deficiencies of traditional noise reduction sound barrier solutions such as excessive thickness, excessive weight, complex processing and installation, high cost, and poor reliability when achieving efficient sound absorption in the low-frequency and ultra-wideband ranges, and improves the maintainability of the sound barrier.

[0006] To achieve the above object, the present invention provides a metamaterial structure sound barrier integrating ultra-wideband noise reduction and load-bearing functions, including a multi-functional integrated screen body and a porous metamaterial sound absorber; The multi-functional integrated screen body includes a composite non-uniformly perforated plate and a cavity with one end open. The composite non-uniformly perforated plate is arranged at the open end of the cavity, and a partition is provided in the cavity to divide the space inside the cavity into several sub-cavities; The porous metamaterial sound absorber includes a number of high-porosity sound absorption media corresponding to the sub-cavities one by one. The high-porosity sound absorption media are arranged in the corresponding sub-cavities, and at least one acoustic wave control channel is provided on the high-porosity sound absorption media.

[0007] In one embodiment, the composite non-uniformly perforated plate has a perforated structure array with a variety of different configurations; The perforated structure array is one or a combination of two or more of a rectangular arrangement of perforated holes, a circumferential arrangement of perforated holes, a polygonal arrangement of perforated holes, and strip-shaped slots.

[0008] In one embodiment, the cross-sectional shape of the acoustic wave control channel is one or a combination of two or more of a circle, a rectangle, and a polygon.

[0009] In one embodiment, the porosity of the high-porosity sound absorption media is greater than or equal to 60%.

[0010] In one embodiment, the material of the high-porosity sound absorption media is one or a combination of two or more of foam-type porous materials, fiber-type porous materials, and metal-type porous materials.

[0011] In one embodiment, an acoustic wave high-transmission protective layer is further provided between the composite non-uniformly perforated plate and the open end of the cavity to block sand and rain from entering the porous metamaterial sound absorber, avoid the dispersion of the high-porosity sound absorption media, improve the service life of the high-porosity sound absorption media, and ensure the environmental protection of the metamaterial structure sound barrier.

[0012] In one embodiment, an acoustic wave high-transmission layer is provided on the outer surface of the composite non-uniformly perforated plate, so as to prevent the composite non-uniformly perforated plate from being directly exposed to the acoustic treatment environment and improve its service life in a harsh environment.

[0013] In one embodiment, the length and width of the composite non-uniformly perforated plate are less than or equal to the length and width of the open end of the cavity.

[0014] In one embodiment, the composite non-uniformly perforated plate, the cavity, and the partition are composed of at least one of a metal plate, a plastic plate, a gypsum board, a plywood board, a hard fiber board, tempered glass, and a composite material board.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: 1. By means of the ingenious combination of a multi-stage acoustic impedance modulation unit and a high-load-bearing cavity system, through the optimized design of multi-parameter coupling, a metamaterial-structured sound barrier integrating ultra-wideband noise reduction and load-bearing functions is constructed. On the one hand, through the multi-scale hollow design of the composite non-uniform hollow plate, an ultra-wideband acoustic wave scattering network is formed, and further combined with the high-porosity sound-absorbing medium in the cavity to produce a viscous-resonance coupling effect, realizing high-efficiency noise reduction performance in the low-frequency ultra-wideband under a thin layer. On the other hand, the composite support frame formed by the cavity partition based on mechanical topology optimization and the filling of high-porosity sound-absorbing medium enables the cavity structure to maintain lightweight characteristics while significantly improving the static load that can be borne, breaking through the limitation that traditional noise reduction schemes and load-bearing components need to be assembled separately, and overcoming the deficiencies such as excessive thickness, heavy mass, complex processing and installation, high cost, and poor reliability faced by traditional noise reduction barrier schemes when achieving efficient sound absorption in the low-frequency and ultra-wideband range, improving the maintainability of the sound barrier. 2. The metamaterial-structured sound barrier in the present invention has a unidirectional equal cross-section configuration in the thickness direction, and can be manufactured quickly and efficiently in large quantities at low cost with any required external dimensions through reliable integrated forming processes such as extrusion molding and casting according to the requirements of the actual acoustic treatment environment. At the same time, the design of integrating ultra-wideband noise reduction and load-bearing functions in the present invention simplifies the structural composition, further significantly reducing the structural manufacturing cost and being beneficial to realizing large-scale engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on the structures shown in these drawings without creative efforts.

[0017] Figure 1 It is an axonometric view of the metamaterial-structured sound barrier in the embodiment of the present invention; Figure 2 It is an exploded view of the metamaterial-structured sound barrier in the embodiment of the present invention; Figure 3 It is a structural schematic diagram of the composite non-uniform hollow plate in the embodiment of the present invention; Figure 4 It is a structural schematic diagram of the high-porosity sound-absorbing medium in the embodiment of the present invention, where: Figure 4 (a) is a high-porosity sound-absorbing medium using circular through-holes as acoustic wave regulation channels, Figure 4 (b) is a high-porosity sound-absorbing medium using square through-holes as acoustic wave regulation channels, Figure 4 (c) is a high-porosity sound-absorbing medium using diamond-shaped through-holes as acoustic wave regulation channels,Figure 4 (d) is a high-porosity sound-absorbing medium using triangular through-holes as acoustic wave regulation channels, Figure 4 (e) is a high-porosity sound-absorbing medium using rectangular grooves as acoustic wave regulation channels; Figure 5 This is a schematic diagram of the second implementation method of the metamaterial structure sound barrier in the embodiments of the present invention; Figure 6 This is a schematic diagram of the third implementation method of the metamaterial structure sound barrier in the embodiments of the present invention; Figure 7 This is a schematic diagram of the fourth implementation method of the metamaterial structure sound barrier in the embodiments of the present invention; Figure 8 This is a sound absorption coefficient curve graph of the metamaterial structure sound barrier in the embodiments of the present invention.

[0018] Reference numerals in the drawings: composite non-uniform hollow plate 1, high-porosity sound-absorbing medium 2, cavity 3, acoustic wave regulation channel 4, partition 5, acoustic wave high-transmission layer 6, acoustic wave high-transmission protection layer 7.

[0019] The realization, functional features, and advantages of the objectives of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] As Figure 1 , Figure 2 shown, this embodiment discloses a metamaterial structural sound barrier that integrates ultra-wideband noise reduction and load-bearing functions (hereinafter referred to as "metamaterial structural sound barrier"), which mainly includes a multi-functional integrated screen body and a porous metamaterial absorber. The multi-functional integrated screen body includes a composite non-uniformly perforated plate 1 and a cavity 3. The cavity 3 is a rectangular cavity structure surrounded by multiple enclosing walls, and one end of the cavity 3 has an opening. A number of vertically and horizontally intersecting partition plates 5 are arranged inside the cavity 3, so as to divide the internal space of the cavity 3 into several sub-cavities 3. The composite non-uniformly perforated plate 1 is arranged at the opening end of the cavity 3, and the composite non-uniformly perforated plate 1 covers some or all of the sub-cavities 3. The porous metamaterial absorber includes a number of high-porosity sound-absorbing media 2 corresponding one-to-one to the sub-cavities 3. The high-porosity sound-absorbing media 2 are arranged in the corresponding sub-cavities 3, and at least one acoustic wave control channel 4 is arranged on the high-porosity sound-absorbing media 2. Preferably, there can be a transition air layer with a certain thickness between the inner wall surface of the composite non-uniformly perforated plate 1 and the high-porosity sound-absorbing media 2, which can adjust the propagation path of acoustic waves and further optimize the acoustic impedance matching. Of course, in the specific application process, there may not be a transition air layer between the inner wall surface of the composite non-uniformly perforated plate 1 and the high-porosity sound-absorbing media 2, that is, the inner wall surface of the composite non-uniformly perforated plate 1 is in contact with the high-porosity sound-absorbing media 2.

[0025] In this embodiment, the porous metamaterial absorber, the single sub-cavity 3, and the area of the corresponding composite non-uniformly perforated plate 1 together form a metamaterial sound barrier unit. The metamaterial sound barrier unit can greatly modulate the acoustic impedance of the high-porosity sound-absorbing media 2 to achieve broadband air impedance matching. At the same time, each metamaterial sound barrier unit has different low-frequency resonance modes or thermo-viscous dissipation forms, and realizes the low-frequency and ultra-wideband high-efficiency sound absorption performance of the metamaterial structural sound barrier through coupling. When the metamaterial structural sound barrier is specifically applied, the composite non-uniformly perforated plate 1 can be oriented towards the direction where the noise source is located. The juxtaposed combination of metamaterial sound barrier units with different noise reduction modes constitutes a metamaterial structural sound barrier that integrates sound absorption, sound insulation, and load-bearing functions. It can be seen that the metamaterial structural sound barrier in this embodiment has a high degree of design flexibility. For different sound barrier noise reduction performance requirements, the geometric parameters of the metamaterial sound barrier unit can be optimized, and different acoustic superstructures can be combined to achieve the requirement of low-frequency and ultra-wideband high-efficiency sound absorption. At the same time, by introducing the porous metamaterial absorber, the balance between energy loss and leakage is achieved, and then it is matched with the air acoustic impedance, significantly improving the sound absorption performance of low-frequency acoustic waves.

[0026] In the specific implementation process, the partition 5 is hermetically connected to the cavity 3, that is, each sub-cavity 3 is not connected to each other. This not only enables the metamaterial structure sound barrier to obtain high-efficiency sound absorption performance with low frequency and ultra-wideband, but also improves the overall stiffness and longitudinal support area of the metamaterial structure sound barrier. While significantly enhancing the ultra-wideband sound insulation performance of the metamaterial structure sound barrier, it also greatly improves the bearing capacity of the panel of the metamaterial structure sound barrier, realizing the integration of the ultra-wideband high-efficiency noise reduction performance and high-bearing function of the metamaterial structure sound barrier.

[0027] Reference Figure 3 , the composite non-uniformly perforated plate 1 has a plurality of perforated structure arrays with different configurations. Among them, the perforated structure array is one or more combinations of a perforated hole array arranged in a rectangle, a perforated hole array arranged in a circle, a perforated hole array arranged in a polygon, and a strip groove. The shape of the perforated hole can be set as a circle, a rectangle, a polygon, etc.

[0028] Reference Figure 4 , the cross-sectional shape of the acoustic wave regulation channel 4 is one or more combinations of a circle, a rectangle, and a polygon. Among them, the acoustic wave regulation channel 4 can be a through hole or a through groove that penetrates the high-porosity sound absorption medium 2 along the thickness direction of the composite non-uniformly perforated plate 1, for example Figure 4 (a)~ Figure 4 (d) shown. The acoustic wave regulation channel 4 can also be set as a counterbore or a counter groove, for example Figure 4 (e) shown.

[0029] In this embodiment, the porosity of the high-porosity sound absorption medium 2 is greater than or equal to 60%. Specifically, the material of the high-porosity sound absorption medium 2 is one or more combinations of foam-type porous materials, fiber-type porous materials, and metal-type porous materials.

[0030] As a preferred implementation manner, an acoustic wave high-transmission protection layer 7 is further provided between the open end of the composite non-uniformly perforated plate 1 and the cavity 3, that is Figure 5 、 Figure 7 shown. The acoustic wave high-transmission protection layer 7 can be one or more combinations of a hydrophobic cloth, a highly breathable fiber cloth, a fiber felt, and a wire mesh, which is used to block sand and rain from entering the porous metamaterial absorber while preventing the escape of the high-porosity sound absorption medium 2, improving the service life of the high-porosity sound absorption medium 2 and ensuring the environmental protection of the metamaterial structure sound barrier.

[0031] As a preferred implementation manner, an acoustic wave high-transmission layer 6 is provided on the outer surface of the composite non-uniformly perforated plate 1, that is Figure 6 、 Figure 7As shown. The acoustic wave high-transmission layer 6 can be made of one or more combinations of high-permeability fiber cloth, fiber felt, polyester, cotton cloth, wire mesh, and perforated plate, so as to prevent the composite non-uniformly hollowed-out plate 1 from being directly exposed to the acoustic treatment environment and improve its service life in harsh environments.

[0032] In the specific implementation process, the length and width of the composite non-uniformly hollowed-out plate 1 are less than or equal to the length and width of the opening end of the cavity 3, that is, the composite non-uniformly hollowed-out plate 1 may not be provided above some sub-cavities 3, and they are directly communicated with the outside or the acoustic wave high-transmission layer 6 above.

[0033] In the specific implementation process, the composite non-uniformly hollowed-out plate 1, the cavity 3, and the partition 5 are composed of at least one of metal plate, plastic plate, gypsum board, plywood, hard fiber board, tempered glass, and composite material plate.

[0034] The following further illustrates the metamaterial structure sound barrier with integrated ultra-wideband noise reduction and load-bearing functions in this embodiment with specific examples.

[0035] Refer to Figure 8 which is the sound absorption coefficient curve of a configuration of the metamaterial structure sound barrier. It can be seen from Figure 8 that for this configuration of the metamaterial structure sound barrier in the low-frequency broadband range of 247 Hz to 4000 Hz, the sound absorption coefficient is above 0.9, and the average sound absorption coefficient reaches 0.96. This shows that the metamaterial structure sound barrier with integrated ultra-wideband noise reduction and load-bearing functions in this embodiment can achieve efficient sound absorption at low frequencies ( f ≤300 Hz) and with ultra-wideband.

[0036] The above are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the protection scope of the present invention.

Claims

1. A metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing functions, characterized in that: It includes a multifunctional integrated screen and a porous super-structure sound absorber; The multifunctional integrated screen body comprises a composite non-uniform hollow plate and a cavity with an opening at one end, wherein the composite non-uniform hollow plate is arranged on the opening end of the cavity, and a partition is arranged in the cavity to divide the space inside the cavity into a plurality of sub-cavities; The porous metastructure sound absorber includes a plurality of high-porosity sound absorbing media corresponding to the sub-cavities one by one, the high-porosity sound absorbing media are arranged in the corresponding sub-cavities, and at least one sound wave regulation channel is arranged on the high-porosity sound absorbing media.

2. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1 is characterized in that: The composite non-uniform hollow plate has a plurality of hollow structure arrays of different configurations; The hollow structure array is one or a combination of two or more of a rectangularly arranged hollow hole array, a circularly arranged hollow hole array, a polygonally arranged hollow hole array, and a strip-shaped notch.

3. The metamaterial structure sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1 is characterized in that: The cross-sectional shape of the sound wave control channel is one or a combination of two or more of a circle, a rectangle and a polygon.

4. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1, 2 or 3, characterized in that: The porosity of the high-porosity sound-absorbing medium is greater than or equal to 60%.

5. The metamaterial structure sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 4 is characterized in that: The high-porosity sound-absorbing medium is made of one or a combination of two or more of a foam-type porous material, a fiber-type porous material, and a metal-type porous material.

6. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1, 2 or 3, characterized in that: A high-sound-transmittance protective layer is also provided between the composite non-uniform hollow plate and the open end of the cavity to prevent wind, sand and rain from entering the porous meta-structure sound absorber while avoiding the escape of the high-porosity sound-absorbing medium, thereby increasing the service life of the high-porosity sound-absorbing medium and ensuring the environmental friendliness of the meta-material structure sound barrier.

7. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1, 2 or 3, characterized in that: The outer surface of the composite non-uniform hollow plate is provided with a high sound wave transmission layer, thereby preventing the composite non-uniform hollow plate from being directly exposed to the acoustic treatment environment, thereby increasing its service life in harsh environments.

8. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1, 2 or 3, characterized in that: The length and width of the composite non-uniform hollow plate are less than or equal to the length and width of the opening end of the cavity.

9. The metamaterial structural sound barrier with integrated ultra-wideband noise reduction and load-bearing function according to claim 1, 2 or 3, characterized in that: The composite non-uniform hollow plate, the cavity and the partition are composed of at least one of a metal plate, a plastic plate, a gypsum board, a plywood, a hard fiberboard, a tempered glass and a composite material plate.

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