CN114724536A - Underwater sound insulation metamaterial based on chiral structure - Google Patents

Underwater sound insulation metamaterial based on chiral structure Download PDF

Info

Publication number
CN114724536A
CN114724536A CN202210288730.0A CN202210288730A CN114724536A CN 114724536 A CN114724536 A CN 114724536A CN 202210288730 A CN202210288730 A CN 202210288730A CN 114724536 A CN114724536 A CN 114724536A
Authority
CN
China
Prior art keywords
sound insulation
arc surface
arc
unit
insulation unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210288730.0A
Other languages
Chinese (zh)
Inventor
赵宏刚
王超
王洋
杨海滨
肖勇
钟杰
尹剑飞
郁殿龙
温激鸿
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National University of Defense Technology
Original Assignee
National University of Defense Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National University of Defense Technology filed Critical National University of Defense Technology
Priority to CN202210288730.0A priority Critical patent/CN114724536A/en
Publication of CN114724536A publication Critical patent/CN114724536A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • G10K11/161—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general in systems with fluid flow
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T70/00—Maritime or waterways transport
    • Y02T70/10—Measures concerning design or construction of watercraft hulls

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Fluid Mechanics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

The invention discloses an underwater sound insulation metamaterial based on a chiral structure. The chiral structure is similar to the left and right hands of a human being, and does not coincide with the body after mirroring. In addition, compared to a symmetrical concave structure, the chiral structure can achieve a larger deformation. The extraordinary physical effect which is not possessed by the conventional material and the symmetrical structure can be obtained by utilizing the asymmetric characteristic and the deformation mechanism of the chiral structure. The invention starts from a quasi-static impedance mismatch mechanism, obtains the underwater sound insulation metamaterial by optimizing the geometric parameters of a sound insulation layer structure based on a chiral structure, can effectively improve the sound insulation performance of a low frequency band of 200-2000 Hz under the condition that the thickness of the metamaterial is not more than 35mm, has strong tunability in sound insulation peak, can be applied to noise control in underwater equipment and other fields, and has good engineering application prospect.

Description

Underwater sound insulation metamaterial based on chiral structure
Technical Field
The invention relates to the technical field of vibration and noise control of underwater equipment, in particular to an underwater sound insulation metamaterial based on a chiral structure.
Background
The sound stealth is one of important indexes for measuring the performance of the underwater equipment, and the sound insulation material laid on the surface of the underwater equipment can effectively block the path of the noise inside the equipment from spreading outwards, so that the radiation noise of the equipment is reduced. The underwater sound insulation technology is one of important means in vibration and noise control, and is used for blocking noise transmission on a noise transmission path. The sound insulation mechanism of the underwater sound insulation material is roughly divided into two aspects: firstly, the acoustic impedance of sound insulating material differs greatly with the acoustic impedance of water, causes serious impedance mismatch, forms the sound insulation through the sound wave reflection, secondly when the sound wave passes through sound insulating material, because the inside special acoustics structure of sound insulating material can be accompanied by a large amount of wave mode conversions, and the damping energy dissipation effect of material in addition, the sound wave energy dissipates in a large number. The combined action of the two mechanisms enables the sound wave transmission to be small, and the sound insulation effect is achieved.
Along with the development of sonar detection frequency gradually to low frequency, the demand of underwater equipment noise control on high-performance low-frequency sound insulation materials is urgent, and in the aspect of low-frequency sound insulation design, the sound insulation performance of 200-2000 Hz low-frequency bands of underwater sound materials needs to be further improved.
Disclosure of Invention
The invention provides an underwater sound insulation metamaterial based on a chiral structure, which is used for overcoming the defects of insufficient low-frequency acoustic performance and the like in the prior art.
In order to achieve the purpose, the invention provides an underwater sound insulation metamaterial based on a chiral structure, which comprises two cover plates and a sound insulation layer positioned between the two cover plates;
the two cover plates are parallel to each other, and the sound insulation layer consists of m multiplied by n sound insulation components which are arranged in an array period, wherein m is more than or equal to 1, and n is more than or equal to 1;
the sound insulation assembly comprises four sound insulation units with the same structure, wherein the four sound insulation units are respectively marked as a first sound insulation unit, a second sound insulation unit, a third sound insulation unit and a fourth sound insulation unit, and the transverse cross sections of the sound insulation units are in an arc shape;
the first sound insulation unit, the second sound insulation unit, the third sound insulation unit and the fourth sound insulation unit are connected with each other at the head ends and are rotationally and symmetrically distributed by taking the connection part as a central axis;
in the transverse direction of the array, the tail end of the second sound insulation unit is connected with the tail end of a fourth sound insulation unit of the adjacent sound insulation assembly;
and in the longitudinal direction of the array, the tail end of the third sound insulation unit is connected with the tail end of the first sound insulation unit of the adjacent sound insulation assembly.
Compared with the prior art, the invention has the beneficial effects that:
the underwater sound insulation metamaterial based on the chiral structure forms a sound insulation layer with the chiral structure through the design of sound insulation units and the array periodic arrangement of sound insulation components. The chiral structure is similar to the left and right hands of a human being, and does not coincide with the body after mirroring. In addition, compared to a symmetrical concave structure, the chiral structure can achieve a larger deformation. The extraordinary physical effect which is not possessed by the conventional material and the symmetrical structure can be obtained by utilizing the asymmetric characteristic and the deformation mechanism of the chiral structure. The invention starts from a quasi-static impedance mismatch mechanism, based on a chiral structure, and optimizes geometric parameters of a sound insulation layer structure to obtain the underwater sound insulation metamaterial, the metamaterial can obtain smaller equivalent acoustic impedance in the sound wave propagation direction, the 200-2000 Hz low-frequency sound insulation performance can be effectively improved under the conditions that the overall thickness is smaller than 35mm and the same areal density is achieved, the sound insulation peak frequency has good tunability, the metamaterial can be applied to noise control in underwater equipment and other fields, and the metamaterial has good engineering application prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a structural diagram of an underwater sound insulation metamaterial based on a chiral structure, provided by the invention;
FIG. 2 is a structural diagram of a sound insulation component in an underwater sound insulation metamaterial based on a chiral structure, provided by the invention;
FIG. 3 is a structural diagram of a sound insulation unit in the underwater sound insulation metamaterial based on a chiral structure, provided by the invention;
FIG. 4 is a partial structural cross section of the underwater acoustic sound insulation metamaterial based on a chiral structure in example 1;
FIG. 5 is a partial structural cross section of an underwater sound insulation metamaterial based on a chiral structure in example 2;
FIG. 6 is a partial structural cross section of an underwater sound insulation metamaterial based on a chiral structure in example 3;
FIG. 7 is a graph comparing the sound insulation coefficients of the underwater sound insulation metamaterial based on the chiral structure in examples 1 to 3 in the frequency range of 200 to 2000 Hz.
The reference numbers illustrate: 10: a cover plate; 20: a sound insulating layer; 201: a sound insulation assembly; 201-1: a first sound insulation unit; 201-2: a second sound insulation unit; 201-3: a third sound insulation unit; 201-4: a fourth sound insulation unit; 301: a first arc surface; 302: a second arc surface.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; the connection can be mechanical connection, electrical connection, physical connection or wireless communication connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
The drugs/reagents used are all commercially available without specific mention.
The invention provides a chiral structure-based underwater sound insulation metamaterial, which comprises two cover plates 10 and a sound insulation layer 20 positioned between the two cover plates 10, as shown in FIGS. 1 and 2;
the two cover plates 10 are parallel to each other, and the sound insulation layer 20 is composed of m × n sound insulation components 201 which are arrayed and periodically arranged, wherein m is more than or equal to 1, and n is more than or equal to 1;
the sound insulation assembly 201 comprises four sound insulation units with the same structure, which are respectively marked as a first sound insulation unit 201-1, a second sound insulation unit 201-2, a third sound insulation unit 201-3 and a fourth sound insulation unit 201-4, and the transverse sections of the sound insulation units are arc-shaped;
the head ends of the first sound insulation unit 201-1, the second sound insulation unit 201-2, the third sound insulation unit 201-3 and the fourth sound insulation unit 201-4 are connected, and are rotationally and symmetrically distributed by taking the connection part as a central axis;
in the transverse direction of the array, the tail end of the second sound insulation unit 201-2 is connected with the tail end of a fourth sound insulation unit of an adjacent sound insulation assembly;
in the longitudinal direction of the array, the tail end of the third sound-proof unit 201-3 is connected with the tail end of the first sound-proof unit of the adjacent sound-proof assembly.
Preferably, the inner wall of the sound insulation unit is defined as a first arc surface 301, and the outer wall of the sound insulation unit is defined as a second arc surface 302; the circular arc corresponding to the first circular arc surface is concentric with the circular arc corresponding to the second circular arc surface, as shown in fig. 3.
Preferably, the first arc surface 301 corresponds to an arc radius
Figure BDA0003560877380000051
The arc radius corresponding to the second arc surface
Figure BDA0003560877380000052
Wherein r is the radius of the center line plane arc between the first arc surface and the second arc surface, and t is the wall thickness of the sound insulation unit, as shown in fig. 3.
Preferably, the distance between the head end and the tail end of the central line plane arc between the first arc surface 301 and the second arc surface 302 is d, when
Figure BDA0003560877380000061
When the temperature of the water is higher than the set temperature,
Figure BDA0003560877380000062
when in use
Figure BDA0003560877380000063
When the temperature of the water is higher than the set temperature,
Figure BDA0003560877380000064
wherein the content of the first and second substances,
Figure BDA0003560877380000065
is the central angle of the central line surface arc between the first arc surface and the second arc surface.
Preferably, a distance b' is provided between the tail end of the center line surface arc between the first arc surface and the second arc surface in the first sound insulation unit 201-1 and the tail end of the center line surface arc between the first arc surface and the second arc surface in the third sound insulation unit 201-3;
the distance between the tail end of the central line surface arc between the first arc surface and the second arc surface in the second sound insulation unit 201-2 and the tail end of the central line surface arc between the first arc surface and the second arc surface in the fourth sound insulation unit 201-4 is a';
and d is the distance between the head end and the tail end of the central line plane arc between the first arc surface and the second arc surface.
Preferably, the cover plate 10 and the sound insulation layer 20 are made of metal or nonmetal materials, and the physical parameters of the metal or nonmetal materials are as follows:
the range of the elastic modulus E is more than or equal to 0.1GPa and less than or equal to E and less than or equal to 220GPa, the range of the Poisson ratio eta is more than or equal to 0.2 and less than or equal to 0.5, and the range of the density rho is more than or equal to 800kg/m3≤ρ≤12000kg/m3。
Preferably, the metal material is one of aluminum, steel, magnesium, and the like.
Preferably, the non-metallic material is one of resin, nylon, polylactic acid, and the like. .
Preferably, the thickness of the cover plate is more than or equal to 0.1mm and less than or equal to c and less than or equal to 4 mm.
Preferably, the wall thickness of the sound insulation unit is more than 0 and less than or equal to 2 mm.
The underwater sound insulation metamaterial based on the chiral structure can be integrally printed, manufactured and molded by adopting a 3D printing technology, and can also be manufactured and molded by machining modes such as wire cut electrical discharge machining and the like.
Example one
The present embodiment provides an underwater acoustic sound-insulating metamaterial based on a chiral structure, a cross-sectional view of a partial structure of the underwater acoustic sound-insulating metamaterial is shown in fig. 4, both the cover plate 10 and the sound-insulating layer 20 are made of aluminum, an elastic modulus E is 69GPa, a poisson ratio η is 0.33, and a density ρ is 2700kg/m3The overall thickness a of the underwater sound insulation metamaterial is 32.52 mm. The cover plate thickness c is 2 mm. The wall thickness of the sound insulation unit is that the arcs of the center surface of the sound insulation unit, the first arc surface 301 and the second arc surface 302 correspond to the same central angle
Figure BDA0003560877380000071
The corresponding arc radii are respectively: r is 2.69mm, and the thickness of the film is less than the thickness of the film,
Figure BDA0003560877380000072
Figure BDA0003560877380000073
the distance between the head end and the tail end of the central plane arc between the first arc surface 301 and the second arc surface 302
Figure BDA0003560877380000074
The distance a' between the tail end of the central line plane arc between the first arc surface and the second arc surface in the second sound insulation unit 201-2 in the sound insulation component 201 and the tail end of the central line plane arc between the first arc surface and the second arc surface in the fourth sound insulation unit 201-4 is 2d which is 2 × 5.36 which is 10.72 mm; the tail end of the center line plane arc between the first arc surface and the second arc surface in the first sound insulation unit 201-1 in the sound insulation component 201 and the tail end of the center line plane arc between the first arc surface and the second arc surface in the third sound insulation unit 201-3 have a distance b' of 2d of 10.72mm of 2 x 5.36.
In this embodiment, the cover plate 10 and the sound insulation layer 20 are integrally printed, manufactured and molded by a 3D printing technology.
Example two
The present embodiment provides an underwater acoustic sound insulation metamaterial based on a chiral structure, a cross section of a partial structure of the underwater acoustic sound insulation metamaterial is shown in fig. 5, both the cover plate 10 and the sound insulation layer 20 are made of aluminum, an elastic modulus E is 69GPa, a poisson ratio η is 0.33, and a density ρ is 2700kg/m3And the overall thickness a of the underwater sound insulation metamaterial is 32.52 mm. The cover plate thickness c is 2 mm. The wall thickness t of the sound insulation unit is 0.7mm, and the circular arcs of the center plane of the sound insulation unit, the first circular arc surface 301 and the second circular arc surface 302 correspond to the same central angle
Figure BDA0003560877380000084
The corresponding arc radii are respectively: r is 3.16mm, and the thickness of the film is less than the thickness of the film,
Figure BDA0003560877380000081
Figure BDA0003560877380000082
the distance between the head end and the tail end of the central plane arc between the first arc surface 301 and the second arc surface 302
Figure BDA0003560877380000083
The distance a' between the tail end of the central line plane arc between the first arc surface and the second arc surface in the second sound insulation unit 201-2 in the sound insulation component 201 and the tail end of the central line plane arc between the first arc surface and the second arc surface in the fourth sound insulation unit 201-4 is 2d which is 2 × 6.11 which is 12.22 mm; the tail end of center line face circular arc between first circular arc face and the second circular arc face in the first sound insulation unit 201-1 among the sound insulation subassembly 201, and the interval b' of the tail end of center line face circular arc between first circular arc face and the second circular arc face among the third sound insulation unit 201-3 2d 12.22mm 12.11 mm.
In this embodiment, the cover plate 10 and the sound insulation layer 20 are manufactured and molded by machining such as wire cut electrical discharge machining.
EXAMPLE III
The embodiment provides a chiral structure-basedThe partial structure cross section of the underwater sound insulation metamaterial is shown in fig. 6, the cover plate 10 and the sound insulation layer 20 are made of aluminum, the elastic modulus E is 69GPa, the Poisson ratio eta is 0.33, and the density is rho 2700kg/m3The overall thickness a of the underwater sound insulation metamaterial is 32.52 mm. The cover plate thickness c is 2 mm. The wall thickness t of the sound insulation unit is 0.7mm, and the circular arcs of the center plane of the sound insulation unit, the first circular arc surface 301 and the second circular arc surface 302 correspond to the same central angle
Figure BDA0003560877380000085
The corresponding arc radii are respectively: r is 3.93mm, and the thickness of the film is less than the thickness of the film,
Figure BDA0003560877380000091
Figure BDA0003560877380000092
the distance between the head end and the tail end of the central plane arc between the first arc surface 301 and the second arc surface 302
Figure BDA0003560877380000093
The distance a' between the tail end of the central line plane arc between the first arc surface and the second arc surface in the second sound insulation unit 201-2 in the sound insulation component 201 and the tail end of the central line plane arc between the first arc surface and the second arc surface in the fourth sound insulation unit 201-4 is 2d which is 2 × 7.13 which is 14.26 mm; the tail end of the center line plane arc between the first arc surface and the second arc surface in the first sound insulation unit 201-1 in the sound insulation component 201 and the tail end of the center line plane arc between the first arc surface and the second arc surface in the third sound insulation unit 201-3 have a distance b' of 2d of 14.26mm of 2 × 7.13.
In this embodiment, the cover plate 10 and the sound insulation layer 20 are integrally printed, manufactured and molded by using a 3D printing technology.
In the first to third examples, the filling ratios of the aluminum material were the same. The sound insulation performance structure of the three examples calculated by finite element software simulation is shown in fig. 7.
As can be seen from fig. 7, under the condition that the overall thickness is not more than 35mm and within the frequency range of 200-2000 Hz, the acoustic insulation metamaterial in the first to third examples has acoustic insulation peaks at 1385Hz, 1151Hz and 791Hz respectively, and under the condition of the same mass density, the acoustic insulation peak of the acoustic insulation metamaterial based on the chiral structure has a good tuning characteristic, and can be designed in a targeted manner according to the characteristic frequency of noise in engineering application. On the whole, the underwater sound insulation metamaterial in the three embodiments has good low-frequency sound insulation performance in a low-frequency band lower than the sound insulation peak frequency.
In conclusion, the underwater sound insulation metamaterial provided by the invention comprises the following components:
1. has better low-frequency sound insulation performance. The low-frequency band lower than the sound insulation peak frequency has good low-frequency sound insulation performance, and is beneficial to designing a low-frequency sound insulation material.
2. The low-frequency sound insulation performance has more adjustable parameters and design variables. Central angle corresponding to circular arc where central plane circular arc, first circular arc surface and second circular arc surface of sound insulation unit are located
Figure BDA0003560877380000101
And the radius of the arc r, r1、r2The distance d between the head end and the tail end of the central plane arc between the first arc surface and the second arc surface, the wall thickness t of the sound insulation unit and the like are all adjustable parameters, and the comparison of the first embodiment to the third embodiment shows that the central angle is increased under the condition of equal filling rate (average density)
Figure BDA0003560877380000102
The sound insulation effect of the low frequency band can be obviously improved, and meanwhile, the sound insulation peak frequency is tuned to move towards the low frequency. In addition, the central angle is ensured
Figure BDA0003560877380000103
Under certain conditions, the wall thickness t of the sound insulation unit is reduced in a reasonable range, and the sound insulation peak frequency can be tuned to move towards low frequency, so that the sound insulation effect of a low frequency band is improved. Therefore, the parameters or design variables can be optimally adjusted according to specific application scenarios, such as requirements on pressure resistance or noise spectrum characteristics.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. The underwater sound insulation metamaterial based on the chiral structure is characterized by comprising two cover plates and a sound insulation layer positioned between the two cover plates;
the two cover plates are parallel to each other, and the sound insulation layer consists of m multiplied by n sound insulation components which are arranged in an array period, wherein m is more than or equal to 1, and n is more than or equal to 1;
the sound insulation assembly comprises four sound insulation units with the same structure, wherein the four sound insulation units are respectively marked as a first sound insulation unit, a second sound insulation unit, a third sound insulation unit and a fourth sound insulation unit, and the transverse cross sections of the sound insulation units are in an arc shape;
the first sound insulation unit, the second sound insulation unit, the third sound insulation unit and the fourth sound insulation unit are connected at the head ends and are rotationally and symmetrically distributed by taking the connection part as a central shaft;
in the transverse direction of the array, the tail end of the second sound insulation unit is connected with the tail end of a fourth sound insulation unit of the adjacent sound insulation assembly;
and in the longitudinal direction of the array, the tail end of the third sound insulation unit is connected with the tail end of the first sound insulation unit of the adjacent sound insulation assembly.
2. The underwater acoustic sound insulation metamaterial according to claim 1, wherein an inner wall of the sound insulation unit is defined as a first circular arc surface, and an outer wall of the sound insulation unit is defined as a second circular arc surface; and the circular arc corresponding to the first circular arc surface and the circular arc corresponding to the second circular arc surface are concentric.
3. The underwater acoustic sound insulation metamaterial according to claim 2, wherein the first arc surface corresponds to an arc radius
Figure FDA0003560877370000011
The arc radius corresponding to the second arc surface
Figure FDA0003560877370000012
R is the radius of the central line surface arc between the first arc surface and the second arc surface, and t is the wall thickness of the sound insulation unit.
4. The underwater acoustic sound-insulating metamaterial according to claim 2, wherein the distance between the head end and the tail end of the central line plane arc between the first arc surface and the second arc surface is d when
Figure FDA0003560877370000013
When the temperature of the water is higher than the set temperature,
Figure FDA0003560877370000014
when in use
Figure FDA0003560877370000015
When the temperature of the water is higher than the set temperature,
Figure FDA0003560877370000021
wherein the content of the first and second substances,
Figure FDA0003560877370000022
is the central angle of the central line surface arc between the first arc surface and the second arc surface.
5. The underwater acoustic sound-insulating metamaterial according to claim 2, wherein a distance b' is provided between the tail end of the center line surface arc between the first arc surface and the second arc surface in the first sound-insulating unit and the tail end of the center line surface arc between the first arc surface and the second arc surface in the third sound-insulating unit;
the distance between the tail end of the central line surface arc between the first arc surface and the second arc surface in the second sound insulation unit and the tail end of the central line surface arc between the first arc surface and the second arc surface in the fourth sound insulation unit is a';
and d is the distance between the head end and the tail end of the central line plane arc between the first arc surface and the second arc surface.
6. The underwater acoustic sound insulation metamaterial according to claim 1, wherein the cover plate and the sound insulation layer are made of metal materials or nonmetal materials, and the physical parameters of the metal materials or the nonmetal materials are as follows:
the range of the elastic modulus E is more than or equal to 0.1GPa and less than or equal to E and less than or equal to 220GPa, the range of the Poisson ratio eta is more than or equal to 0.2 and less than or equal to 0.5, and the range of the density rho is more than or equal to 800kg/m3≤ρ≤12000kg/m3。
7. The underwater acoustic sound insulation metamaterial according to claim 6, wherein the metal material is one of aluminum, steel and magnesium.
8. The underwater acoustic sound insulation metamaterial according to claim 6, wherein the non-metallic material is one of resin, nylon and polylactic acid.
9. The underwater acoustic sound insulation metamaterial according to any one of claims 1 to 8, wherein the cover plate is 0.1mm or more and c or more and 4mm or less in thickness.
10. The underwater sound insulation metamaterial according to any one of claims 1 to 8, wherein the wall thickness of the sound insulation unit is more than 0 and less than or equal to 2 mm.
CN202210288730.0A 2022-03-23 2022-03-23 Underwater sound insulation metamaterial based on chiral structure Pending CN114724536A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210288730.0A CN114724536A (en) 2022-03-23 2022-03-23 Underwater sound insulation metamaterial based on chiral structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210288730.0A CN114724536A (en) 2022-03-23 2022-03-23 Underwater sound insulation metamaterial based on chiral structure

Publications (1)

Publication Number Publication Date
CN114724536A true CN114724536A (en) 2022-07-08

Family

ID=82240017

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210288730.0A Pending CN114724536A (en) 2022-03-23 2022-03-23 Underwater sound insulation metamaterial based on chiral structure

Country Status (1)

Country Link
CN (1) CN114724536A (en)

Similar Documents

Publication Publication Date Title
US7889601B2 (en) Lightweight acoustic array
EP0952571B1 (en) Sound absorbing arrangement using a porous material
CN110517659B (en) Multi-unit coupling type micro-perforated plate low-frequency broadband sound absorption structure and design method thereof
CN110097869B (en) Broadband acoustic metamaterial
US4559255A (en) Acoustical absorbing material
US20240046908A1 (en) Thin-layer low-frequency underwater sound insulation metamaterial
CN108909083B (en) Sound absorption and insulation sandwich plate containing labyrinth back cavity
CN111354330A (en) Broadband sparse sound absorber
JP5332495B2 (en) Sound absorption structure
SE465748B (en) LJUDOMVANDLARSYSTEM
CN108682411B (en) Broadband low-frequency acoustic silencer
CN112071296A (en) Sound insulation device
CN114724536A (en) Underwater sound insulation metamaterial based on chiral structure
JP4115032B2 (en) Silencer
JP6914004B2 (en) Noise reduction device
CN117316136A (en) Sound absorber based on microperforated film and Helmholtz multi-cavity coupling structure
Gaafer Perfect absorption for modulus-near-zero acoustic metamaterial in air or underwater at low-frequency
EP4001795A1 (en) Sound isolating wall assembly having at least one acoustic scatterer
CN113808563B (en) Low-frequency sound absorption covering layer containing cylindrical scatterer with gradient change parameters
KR102198952B1 (en) Radio Frequency Absorber
JP2010008997A5 (en)
RU2648726C1 (en) Noise absorbing panel
CN217506890U (en) Sound absorption structure
EP1226741B1 (en) Acoustic element
CN216562445U (en) Sound insulation assembly and electronic equipment

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination