A broadband noise reduction composite sandwich panel with a core layer of a thin-film acoustic metamaterial

Abstract

The invention discloses a broadband noise reduction composite sandwich plate whose core layer is a thin-film acoustic metamaterial. The composite sandwich plate comprises an upper plate, a core plate and a lower plate. The core plate is arranged between the upper plate and the lower plate. The upper end surface of the core plate is fixedly connected to the lower end surface of the upper plate, and the lower end surface of the core plate is fixedly connected to the upper end surface of the lower plate. The core plate comprises a first frame, a second frame, a thin film, a plurality of first mass blocks and a plurality of second mass blocks. The thin film is fixedly connected between the first frame and the second frame. The first frame is provided with a plurality of first mounting holes in a matrix shape. The plurality of first mass blocks are arranged corresponding to the plurality of first mounting holes and the first mass blocks are fixedly connected to one side of the thin film. The second frame is provided with a plurality of second mounting holes in a matrix shape. The plurality of second mass blocks are arranged corresponding to the plurality of second mounting holes and the second mass blocks are fixedly connected to the other side of the thin film. The first mass blocks and the second mass blocks on both sides of the thin film are arranged correspondingly.

Description

Technical Field

[0001] The invention relates to the field of sound insulation, and in particular to a broadband noise reduction composite sandwich panel whose core layer is a film-type acoustic metamaterial. Background Art

[0002] The research and development and application of sound insulation materials are the key to noise control. However, for major equipment with lightweight requirements and space limitations (such as aircraft and high-speed railways), traditional sound insulation materials have little effect on the control of low-frequency noise. This is because the sound insulation of traditional materials follows the mass law. The larger the surface density and the higher the frequency, the better the sound insulation effect. To improve the sound insulation of the structure, especially the low-frequency sound insulation, it is necessary to make the sound insulation material very thick and bulky. Excessively increasing the mass and thickness of the sound insulation material is obviously inconsistent with the lightweight design principle of the equipment, and it is difficult to apply it in a limited space. Therefore, it is of great theoretical significance and application value to use new technologies and new methods to break through the limitations of the sound insulation mass law of traditional materials, and to design and prepare new thin and light materials with high-performance broadband sound insulation effects. Summary of the invention

[0003] The object of the present invention is to solve the above problems and provide a broadband noise reduction composite sandwich panel with a simple structure and better sound insulation effect and a core layer of a thin film acoustic metamaterial.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A broadband noise reduction composite sandwich panel whose core layer is a thin-film acoustic metamaterial, the composite sandwich panel comprising an upper panel, a core panel and a lower panel, the core panel being arranged between the upper panel and the lower panel, the upper end surface of the core panel being fixedly connected to the lower end surface of the upper panel, and the lower end surface of the core panel being fixedly connected to the upper end surface of the lower panel; the core panel comprising a first frame, a second frame, a thin film, a plurality of first mass blocks and a plurality of second mass blocks, the thin film being fixedly connected between the first frame and the second frame; the first frame being provided with a plurality of first mounting holes in a matrix shape, the plurality of first mass blocks being arranged corresponding to the plurality of first mounting holes, and the first mass blocks being fixedly connected to one side of the thin film; the second frame being provided with a plurality of second mounting holes in a matrix shape, the plurality of second mass blocks being arranged corresponding to the plurality of second mounting holes, and the second mass blocks being fixedly connected to the other side of the thin film; the first mass blocks and the second mass blocks on both sides of the thin film being arranged correspondingly.

[0006] Furthermore, the upper plate includes a first primary plate, a sound insulation felt, and a first bottom plate. The first primary plate, the sound insulation felt, and the first bottom plate are fixedly connected in sequence from top to bottom, and the first bottom plate is fixedly connected to a surface of the first frame on one side away from the film.

[0007] Furthermore, the lower plate includes a second primary plate, a damping plate, and a second bottom plate, which are fixedly connected in sequence from top to bottom, and the second primary plate is fixedly connected to a surface of the second frame on one side away from the film.

[0008] Furthermore, the thickness of the film is 0.1-0.5 mm.

[0009] Furthermore, among the first mass blocks and the second mass blocks on both sides of the film, the corresponding first mass blocks and the second mass blocks have the same shape; at the same time, the first mass blocks and the second mass blocks arranged vertically have the same shape but are made of different materials; and the first mass blocks and the second mass blocks arranged horizontally have different shapes.

[0010] Furthermore, the first mass block and the second mass block are both made of metal, and the first primary layer board, the first bottom layer board, the second primary layer board, and the second bottom layer board are all made of wood.

[0011] Furthermore, the film is made of polyamide and polyethylene, and the number of layers is 2 n , n is a positive integer and n≥1.

[0012] Compared with the prior art, the present invention has the following advantages and positive effects:

[0013] The present invention discloses a broadband noise reduction composite sandwich panel whose core layer is a thin-film acoustic metamaterial, which can achieve effective broadband sound insulation effect within a frequency band of 2000 Hz, and has an overall packaging structure, can be directly applied to actual projects, is not affected by installation conditions, has a stable noise reduction effect, can be widely used in noise isolation and protection of transportation vehicles such as rail vehicles, automobiles, ships, and airplanes, as well as units, equipment, buildings, and other objects, achieves a lightweight effect of sound insulation devices, and makes a certain contribution to the development of sound insulation and noise reduction technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0015] Figure 1 It is an assembly structure diagram of the present invention;

[0016] Figure 2 This is the assembly structure diagram of the core board;

[0017] Figure 3 This is a schematic diagram for comparing sound insulation effects. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0019] The present invention discloses a broadband noise reduction composite sandwich panel with a core layer of a thin film acoustic metamaterial, which is composed of an upper panel, a core panel 4, and a lower panel (such as Figure 1 As shown). Among them, the upper plate refers to the sandwich bonding structure of "first primary plate 1 + sound insulation felt 2 + first bottom plate 3", the core plate 4 is a new type of film-type acoustic metamaterial, and the lower plate is the sandwich bonding structure of "second primary plate 5 + damping sheet 6 + second bottom plate 7". The bottom surface of the upper plate is bonded to the upper surface of the core plate 4 using structural adhesive, and the top surface of the lower plate is bonded to the lower surface of the core plate 4 using structural adhesive.

[0020] The core plate 4, i.e., the novel film-type acoustic metamaterial, is composed of a first mass block 401, a first frame 402, a film 403, a second frame 404, and a second mass block 405 (eg, Figure 2 As shown). Among them, the first mass block 401 and the second mass block 405 are metal structures or other materials, which are respectively installed in the first mounting hole 4021 of the first frame 402 and the second mounting hole 4041 of the second frame 404. The number and shape of the mass blocks on both sides of the film 403 correspond. However, the shapes of the mass blocks on each side are not exactly the same, and the materials of the mass blocks of the same shape are different. The mass blocks are fixed to the center position of the film in the mounting hole area with an adhesive; the first frame 402 and the second frame 404 are metal structures or other materials, and the frames on both sides are correspondingly arranged to clamp the film 403 and fix it with an adhesive; the film 403 is a polymer material, which is made of two different polymer materials, polyamide and polyethylene, based on film blowing molding and micro-nano stacking co-extrusion technology. The total thickness of the film is 0.1-0.5 mm, and the number of layers is 2 n (n is a positive integer ≥ 1). When installing the core plate 4, the first frame 402, the second frame 404 and the film 403 are first fixed, a certain tension is applied to the film 403, and then the first mass block 401 and the second mass block 405 are fixed and bonded.

[0021] The preparation steps of the present invention are as follows:

[0022] Firstly, based on the traditional thin-film acoustic metamaterial, the polymer film is designed into a micro-nano layered structure, and the additional mass block is locally asymmetric modulated (different structures and materials are modulated alternately and periodically) to prepare the core board 4, thereby increasing the number and width of the low-frequency (below 500 Hz) band gaps of the thin-film acoustic metamaterial.

[0023] Next, an upper plate structure of "first primary plate 1 + sound insulation felt 2 + first bottom plate 3" is prepared to improve the high-frequency (1000-2000Hz) sound insulation of the structure.

[0024] Then, prepare the lower plate structure of "second primary plate 5 + damping sheet 6 + second bottom plate 7" to improve the sound insulation of the structure at medium frequency (500-1000Hz). The first primary plate, the first bottom plate, the second primary plate, and the second bottom plate are wooden boards or other materials, and their thicknesses may not be unique.

[0025] Finally, the lower surface of the upper plate, the upper surface of the first frame 402 in the core plate 4, the lower surface of the second frame 404 in the core plate 4, and the upper surface of the lower plate are bonded and assembled together.

[0026] Simulation Verification

[0027] For the composite sandwich panel in the present invention, a sample of 0.5m (length) × 0.5m (width) × 0.018m (thickness) was taken for sound insulation modeling and calculation analysis in COMSOL Multiphysics software. Among them, the thickness of each component of the composite sandwich panel is: 3mm wood board, 1mm sound insulation felt, 3mm wood board, 6mm film-type acoustic metamaterial, 2mm wood board, 1mm damping sheet, 2mm wood board. Using the reverberation field sound source as the excitation, the sound insulation prediction results of the model are as follows: Figure 3 As shown. Figure 3 It can be seen that compared with a 12 mm wooden board (without considering the thickness of the acoustic metamaterial), the sound insulation of the present invention is significantly higher than that of the wooden board in almost all frequency bands, and the average sound insulation is 7.7 dB higher than that of the wooden board; even compared with a wooden board of the same thickness (18 mm), the present invention still has an obvious sound insulation advantage in the frequency band of 315 to 2000 Hz, and the average sound insulation is 1.5 dB higher than that of the wooden board.

[0028] The present invention can achieve effective broadband sound insulation effect within the 2000Hz frequency band, and it has an overall packaging structure, can be directly applied to actual projects, is not affected by installation conditions, has a stable noise reduction effect, and can be widely used in noise isolation and protection of transportation vehicles such as rail vehicles, automobiles, ships, and airplanes, as well as units, equipment, buildings and other objects, achieving the lightweight effect of the sound insulation device, and making a certain contribution to the development of sound insulation and noise reduction technology.

Claims

1. A broadband noise reduction composite sandwich panel with a core layer of a thin-film acoustic metamaterial, characterized in that: The composite sandwich panel comprises an upper plate, a core plate and a lower plate, wherein the core plate is arranged between the upper plate and the lower plate, the upper end surface of the core plate is fixedly connected to the lower end surface of the upper plate, and the lower end surface of the core plate is fixedly connected to the upper end surface of the lower plate; the core plate comprises a first frame, a second frame, a film, a plurality of first mass blocks and a plurality of second mass blocks, and the film is fixedly connected between the first frame and the second frame; the first frame is provided with a plurality of first mounting holes in a matrix shape, a plurality of first mass blocks are arranged corresponding to the plurality of first mounting holes, and the first mass blocks are fixedly connected to one side of the film; the second frame is provided with a plurality of second mounting holes in a matrix shape, a plurality of second mass blocks are arranged corresponding to the plurality of second mounting holes, and the second mass blocks are fixedly connected to the other side of the film; the first mass blocks and the second mass blocks on both sides of the film are arranged correspondingly; The upper plate includes a first primary plate, a sound insulation felt, and a first bottom plate, which are fixedly connected in sequence from top to bottom, and the first bottom plate is fixedly connected to a surface of the first frame on one side away from the film; The lower plate includes a second primary plate, a damping plate, and a second bottom plate, which are fixedly connected in sequence from top to bottom, and the second primary plate is fixedly connected to the surface of the second frame on one side away from the film; among the first mass blocks and the second mass blocks on both sides of the film, the corresponding first mass blocks and the second mass blocks have the same shape; at the same time, the first mass blocks and the second mass blocks arranged longitudinally have the same shape but are made of different materials; the first mass blocks and the second mass blocks arranged transversely have different shapes; the first mass blocks and the second mass blocks are both made of metal, and the first primary plate, the first bottom plate, the second primary plate, and the second bottom plate are all made of wood; the film is made of polyamide and polyethylene stacked in layers, and the number of layers is 2 n , n is a positive integer and n≥1.

2. The broadband noise reduction composite sandwich panel with a core layer of a thin-film acoustic metamaterial as claimed in claim 1, characterized in that: The thickness of the film is 0.1-0.5 mm.

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