CN111199722A - Multilayer composite sound absorption structure - Google Patents
Multilayer composite sound absorption structure Download PDFInfo
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- CN111199722A CN111199722A CN202010035658.1A CN202010035658A CN111199722A CN 111199722 A CN111199722 A CN 111199722A CN 202010035658 A CN202010035658 A CN 202010035658A CN 111199722 A CN111199722 A CN 111199722A
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- 238000010521 absorption reaction Methods 0.000 title claims abstract description 65
- 239000002131 composite material Substances 0.000 title claims abstract description 21
- 239000000463 material Substances 0.000 claims abstract description 43
- 239000011148 porous material Substances 0.000 claims description 10
- 239000006260 foam Substances 0.000 claims description 4
- 229920000877 Melamine resin Polymers 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 230000001788 irregular Effects 0.000 claims description 3
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 3
- 239000013590 bulk material Substances 0.000 claims description 2
- 230000001413 cellular effect Effects 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 14
- 230000009467 reduction Effects 0.000 abstract description 9
- 238000004364 calculation method Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000013016 damping Methods 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000010146 3D printing Methods 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004630 mental health Effects 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/162—Selection of materials
- G10K11/168—Plural layers of different materials, e.g. sandwiches
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Building Environments (AREA)
Abstract
The invention discloses a multilayer composite sound absorption structure, which belongs to the technical field of noise reduction and vibration reduction, and comprises a rigid wall, wherein a plurality of groups of brackets are arranged above the rigid wall, bracket bosses are arranged at the same positions of the side walls of the plurality of groups of brackets, and micron-sized porous loose materials are arranged above the bracket bosses; the top ends of the plurality of groups of supports are provided with millimeter-scale microperforated plates, namely micron-scale porous loose materials cover the millimeter-scale microperforated plates, and cavities are formed between the micron-scale porous loose materials and the millimeter-scale microperforated plates; according to the invention, the millimeter-scale micro-perforated plate is covered above the millimeter-scale micro-perforated plate, wherein the micron-scale porous loose material and the reserved cavity in the millimeter-scale micro-perforated plate are equivalent to a Helmholtz cavity, so that the sound absorption effect is further realized, and the sound absorption coefficient within the range that the sound wave frequency is lower than 1600Hz is larger than 0.8 according to a series of experimental data.
Description
Technical Field
The invention belongs to the technical field of noise reduction and vibration reduction, and particularly relates to a multilayer composite sound absorption structure.
Background
Vibration reduction and noise reduction are always hot problems which are closely concerned and addressed by the engineering industry. Mechanical vibration not only can reduce the life of machine equipment, reduces the processing or control precision of precision instruments, still can cause the sound pollution and then influence operating personnel's physical and mental health when serious. In military terms, various weaponry such as modern airplanes, naval vessels, armed armored vehicles and the like need to meet the challenges of various complex environments, and meanwhile, various randomly-carried precise instruments and equipment need to be ensured to be normally used. Therefore, the demand for vibration damping and noise reduction techniques is increasing. Therefore, it has become a hot spot in acoustic research to develop a structure having a good sound absorption performance in a wide frequency band. For many years, a great deal of research has been conducted by related scholars on foam porous materials, metal porous materials, micro-perforated plates, polymer sound-absorbing materials, and the like.
Bolton et al, based on Biot's theory, introduced the theory and method of measurement of acoustic transmission loss for elastic porous media bilayer composite structures. Liu et al have conducted computational studies on the acoustic transmission loss of the composite structure with three polyurethane core layers on the basis. W, Pannert, Tanghui Ping, xi Zheng and the like carry out intensive research on the metal porous material and obtain better effect, but the low-frequency sound absorption performance is poor and the like, so that the metal porous material is difficult to adopt in practical application.
The Micro-perforated panel sound absorption structure is valued by scholars at home and abroad after the Micro-perforated panel sound absorption structure theory is put forward for the first time by professor Ma Da 29495 in the 70 th of the 20 th century and an acoustic model of the Micro-perforated panel sound absorption structure is established to be accurately solved. On the basis, Ma great teaching 29495provides a sound absorption structure of double-layer series-connection micro-perforated plates, theoretically deduces a sound absorption coefficient calculation formula under the condition of vertical incidence, and obtains a result through numerical simulation calculation. The multilayer micro-perforated plate series structure can effectively widen the sound absorption frequency band and improve the possibility of the practical application of the multilayer micro-perforated plate in noise control. Liu etc. have made the microperforated panel through 3D printing to fill porous material in the back of the body chamber and form the structure of establishing ties microperforated, widened the sound absorption frequency band effectively. Subsequent researchers are inspired by the teaching of Ma university 29495.
At present, polymer sound absorption materials with more excellent comprehensive performance are widely applied. The good viscoelasticity and internal damping characteristics of the high polymer material are beneficial to fusing damping and other sound absorption mechanisms in the sound absorption material, so that the sound absorption performance of the sound absorption material is improved. It is still the focus of research to widen the noise reduction frequency band.
Disclosure of Invention
Aiming at the problems in the prior art, the invention discloses a multilayer composite sound absorption structure, which is a novel multilayer composite sound absorption structure formed by a micron-sized porous loose material and a millimeter-sized micro-perforated plate and can play a vibration reduction effect in a wider frequency domain range.
The invention is realized by the following steps:
a multilayer composite sound absorption structure comprises a rigid wall, wherein a plurality of groups of brackets are arranged above the rigid wall, bracket bosses are arranged at the same positions of the side walls of the plurality of groups of brackets, and micron-sized porous loose materials are arranged above the bracket bosses; a plurality of groups of supports, the top set up millimeter level microperforated panel, micron level porous loose material covers millimeter level microperforated panel top promptly, just micron level porous loose material, millimeter level microperforated panel between form the cavity.
In order to realize that sound waves or mechanical waves are attenuated in a required frequency range, only a support is required to be installed on the surface of a rigid wall (such as an engine room shell, a wall, a box body and the like), a millimeter-grade micro-perforated plate is installed on the support, and a micron-grade porous loose material is covered on the millimeter-grade micro-perforated plate to realize the sound absorption function. The thickness of the cavity, the perforation rate, the aperture and the thickness of the micro-perforated plate, and the material parameters and the thickness of the micron-sized porous loose material need to be determined according to the frequency range index of sound absorption. The simple device of the invention can achieve very good effect. In practical situations, the shapes of the surfaces of different objects are uncertain, the surfaces of the different objects are provided with planes and curved surfaces, and the micro-perforated plate and the micron-sized porous loose material can be cut into shapes which are in accordance with the shapes of the surfaces of the objects for installation.
Further, the micron-sized porous loose material comprises melamine porous foam; the millimeter-scale microperforated panel comprises a microperforated aluminum plate.
Further, the surface of the rigid wall is a plane, a curved surface or an irregular surface; the surfaces of the micron-scale porous loose material and the millimeter-scale micro-perforated plate are matched with the surface of the rigid wall.
Further, the thickness of the cavity is 1-20 cm; the thickness of the millimeter-grade micro-perforated plate is less than 3 mm; the thickness of the micron-sized porous loose material is 5-30 cm.
Furthermore, the sound absorption structure is installed in the order of rigidity, support, millimeter-scale microperforated panel, micron-scale porous loose material.
Further, the sound absorption coefficient of the sound absorption structure in the range of the sound wave frequency lower than 1600Hz is larger than 0.8. The beneficial effects of the invention and the prior art are as follows:
according to the invention, the micron-sized porous loose material is adopted, the micron-sized porous loose material can play a sound absorption effect, and the millimeter-sized micro-perforated plate covers the upper part of the millimeter-sized micro-perforated plate, wherein the reserved cavity in the micron-sized porous loose material and the millimeter-sized micro-perforated plate is equivalent to a Helmholtz cavity, so that the sound absorption effect is further played, and a certain series of experimental data show that the sound absorption coefficient is more than 0.8 when the sound wave frequency is lower than 1600 Hz. In addition, the multilayer composite sound absorption structure can be manufactured into a shape conforming to the shape of the rigid wall by cutting according to the shapes of different rigid walls in actual conditions, such as planes, curved surfaces or other irregular curved surfaces, so as to achieve better sound absorption effect.
Drawings
FIG. 1 is a schematic structural view of a compliant planar rigid wall in a multilayer composite sound absorbing structure according to the present invention;
FIG. 2 is a schematic view of the installation of a rigid wall bracket in a multilayer composite sound absorbing structure according to the present invention;
FIG. 3 is a schematic structural view of a curved compliant rigid wall in a multilayer composite sound absorbing structure according to the present invention;
FIG. 4 is a schematic view of an acoustic absorption coefficient impedance tube measurement system in an embodiment of the present invention;
FIG. 5 is a graph of sound absorption coefficient for a sound absorbing layer of a multilayer acoustic structure in an embodiment of the present invention;
FIG. 6 is a graph comparing sound absorption coefficient curves for different sound absorbing structures in an embodiment of the present invention;
wherein, 1-rigid wall, 2-bracket, 3-micron porous loose material and 4-millimeter-scale microperforated plate.
Detailed Description
In order to make the objects, technical solutions and effects of the present invention more clear, the present invention is further described in detail by the following examples. It should be noted that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1-2, the multilayer composite sound absorption structure of the present invention includes a rigid wall 1, the surface of the rigid wall 1 is a plane, four groups of supports 2 are disposed above the rigid wall 1, support bosses are disposed at the same positions of the side walls of the four groups of supports 2, and a micron-sized porous loose material 3 is disposed above the support bosses; the top ends of the plurality of groups of brackets 2 are provided with millimeter-scale microperforated plates 4, namely, micron-scale porous loose materials 3 cover the millimeter-scale microperforated plates 4, and cavities are formed between the micron-scale porous loose materials 3 and the millimeter-scale microperforated plates 4; the surfaces of the micron-scale porous loose material 3 and the millimeter-scale micro-perforated plate 4 are matched with the surface of the rigid wall 1. As shown in fig. 3, the surface of the rigid wall 1 is a curved surface, and similarly, the surfaces of the micron-sized porous bulk material 3 and the millimeter-sized micro-perforated plate 4 are matched with the curved surface of the rigid wall 1. The micron-sized porous loose material can adopt melamine porous foam and other similar materials; the millimeter-scale microperforated panel 4 may be a microperforated aluminum panel.
The multilayer acoustic sound absorption structure designed in the embodiment of the invention is placed in an impedance tube to measure the sound absorption coefficient, and the specific experimental device is a schematic diagram of a sound absorption coefficient impedance tube measuring system shown in fig. 4. In the experimental frequency range, the sound absorption coefficient change curve as shown in fig. 5 was obtained. From the observation, it was found that the sound absorption coefficient reached 0.8 at 400Hz, and gradually became larger as the frequency of the sound wave increased, and although a small decrease was experienced at a frequency after 920Hz, the sound absorption coefficient could be maintained above 0.9. Due to the excellent sound absorption effect of the porous material on the high-frequency sound waves, the high-frequency sound absorption effect of the novel multilayer sound absorption structure can be predicted to be still good by combining a simulation result, the sound absorption effect can be kept above 0.8, and the sound absorption structure has good sound absorption performance.
Due to the limitation of experimental equipment, only data within a 1600Hz range can be measured in the sound absorption test, but the fitting degree of the sound absorption test and a simulation result is high, and the sound absorption coefficient in a frequency range after 1600Hz can be predicted to still meet the technical index that the sound absorption coefficient is larger than 0.8.
The sound absorption coefficients of several materials measured by experiments are compared, and a comparison experiment result graph is shown in fig. 6, so that the multilayer acoustic sound absorption structure has a good sound absorption effect, particularly in a low-frequency range such as 400 Hz-1000 Hz, the sound absorption coefficients are all kept above 0.8, and the sound absorption coefficient reaches 0.97 even at 920 Hz. Compared with porous materials, the material has obvious low-frequency sound absorption advantages. This is the additive effect of the co-action of several materials in a multilayer material. After sound is absorbed by the porous material, the sound waves pass through the micro-perforated plate and generate excitation resonance with a plurality of Hemlholtz cavities formed by the cavities behind the plate, and finally the energy of the low-frequency sound waves can be consumed through further sound absorption and resonance of the parallel structure of the porous material and the Hemlholtz cavities. The impedance of the whole structure is close to that of air, so that a good sound absorption effect is generated in a frequency band of 400 Hz-1600 Hz.
The specific arrangement form of the multilayer composite sound absorption structure is 'micron-sized porous loose material + millimeter-sized micro-perforated plate + cavity + rigid wall'. According to the main frequency range of the required sound absorption, if the sound absorption coefficient is more than 0.8 within the range of 300-1500 HZ, calculation is carried out to select the material parameters of the micron-sized porous loose material, determine the thickness, porosity and other parameters of the micron-sized porous loose material and the millimeter-sized micro perforated plate, and the cavity thickness, namely the vertical distance from the millimeter-sized micro perforated plate to the rigid wall, can be obtained through calculation. The above parameters can also be obtained experimentally. The length and width of the plate are determined according to actual requirements. If the size is huge, wires can be arranged between the brackets for supporting. Then with metal snap-on at the rigid wall, install millimeter level microperforated panel in support boss department, can adopt modes such as welding, gluing according to actual need. The micron-sized porous loose material is clamped in the bracket and is stuck on the millimeter-sized micro-perforated plate, and then the micro-perforated plate can take effect.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the present invention, and these modifications should also be construed as the protection scope of the present invention.
Claims (6)
1. A multilayer composite sound absorption structure comprises a rigid wall (1), and is characterized in that a plurality of groups of brackets (2) are arranged above the rigid wall (1), bracket bosses are arranged at the same positions of the side walls of the groups of brackets (2), and micron-sized porous loose materials (3) are arranged above the bracket bosses; the top of a plurality of groups support (2) set up millimeter level microperforated panel (4), micron level porous loose material (3) cover in millimeter level microperforated panel (4) top promptly, just micron level porous loose material (3), millimeter level microperforated panel (4) between form the cavity.
2. A multilayer composite sound absorbing structure according to claim 1, characterized in that said micro-scale porous bulk material (3) comprises melamine cellular foam; the millimeter-scale microperforated panel (4) comprises a microperforated aluminum panel.
3. A multilayer composite sound absorbing structure according to claim 1, wherein the surface of said rigid wall (1) is a plane, curved or irregular surface; the surfaces of the micron-scale porous loose material (3) and the millimeter-scale micro-perforated plate (4) are matched with the surface of the rigid wall (1).
4. The multilayer composite sound absorbing structure according to claim 1, wherein the thickness of the cavity is 1 to 20 cm; the thickness of the millimeter-grade micro-perforated plate is less than 3 mm; the thickness of the micron-sized porous loose material is 5-30 cm.
5. A multilayer composite sound-absorbing structure according to claim 1, characterized in that the sound-absorbing structure is mounted in the order of a rigid wall (1), a support (2), a microperforated sheet (4) of millimeter scale, a porous material (3) of micron scale.
6. The multilayer composite sound absorbing structure according to claim 1 wherein the sound absorbing coefficient of the sound absorbing structure is greater than 0.8 at sonic frequencies below 1600 Hz.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010035658.1A CN111199722B (en) | 2020-01-14 | 2020-01-14 | Multilayer composite sound absorption structure |
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| CN202010035658.1A CN111199722B (en) | 2020-01-14 | 2020-01-14 | Multilayer composite sound absorption structure |
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| CN111199722A true CN111199722A (en) | 2020-05-26 |
| CN111199722B CN111199722B (en) | 2023-12-01 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102968985A (en) * | 2012-11-07 | 2013-03-13 | 江苏大学 | Thin broadband sound-absorbing structure of composite multi-layer mechanical impedance plates |
| CN203673822U (en) * | 2013-12-24 | 2014-06-25 | 江苏大学 | Wideband sound absorption structure realized through combining mechanical impedance of composite resonator with micropunch plate |
| AU2015252769A1 (en) * | 2014-05-02 | 2016-12-22 | Ashmere Holdings Pty Ltd | Acoustic absorption and methods of manufacture |
| CN206289549U (en) * | 2016-12-15 | 2017-06-30 | 厦门嘉达声学技术有限公司 | Outdoor composite sound absorbing module |
| CN108867904A (en) * | 2018-07-06 | 2018-11-23 | 长春理工大学 | There is the slim multilayer acoustic board of high acoustic absorption coefficient in low frequency band |
-
2020
- 2020-01-14 CN CN202010035658.1A patent/CN111199722B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102968985A (en) * | 2012-11-07 | 2013-03-13 | 江苏大学 | Thin broadband sound-absorbing structure of composite multi-layer mechanical impedance plates |
| CN203673822U (en) * | 2013-12-24 | 2014-06-25 | 江苏大学 | Wideband sound absorption structure realized through combining mechanical impedance of composite resonator with micropunch plate |
| AU2015252769A1 (en) * | 2014-05-02 | 2016-12-22 | Ashmere Holdings Pty Ltd | Acoustic absorption and methods of manufacture |
| CN206289549U (en) * | 2016-12-15 | 2017-06-30 | 厦门嘉达声学技术有限公司 | Outdoor composite sound absorbing module |
| CN108867904A (en) * | 2018-07-06 | 2018-11-23 | 长春理工大学 | There is the slim multilayer acoustic board of high acoustic absorption coefficient in low frequency band |
Non-Patent Citations (1)
| Title |
|---|
| 孙文娟等: "微穿孔板吸声体混合结构的声学性能研究" * |
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