阅读说明：本技术 一种圆形通道-橡胶复合水下吸声结构 (Circular channel-rubber composite underwater sound absorption structure ) 是由 辛锋先 卢天健 于晨磊 段明宇 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种圆形通道-橡胶复合水下吸声结构,包括复合材料层,复合材料层设置在底板上,复合材料层的上表面设置有橡胶层,复合材料层内间隔设置有多个圆形通道,圆形通道的一端与橡胶层连接,另一端与底板连接,圆形通道内填充有粘弹性材料,粘弹性材料与底板之间设置有空气隔层。本发明结构简单,易于制造,大幅度提升吸声性能。(The invention discloses a circular channel-rubber composite underwater sound absorption structure which comprises a composite material layer, wherein the composite material layer is arranged on a bottom plate, a rubber layer is arranged on the upper surface of the composite material layer, a plurality of circular channels are arranged at intervals in the composite material layer, one end of each circular channel is connected with the rubber layer, the other end of each circular channel is connected with the bottom plate, viscoelastic materials are filled in the circular channels, and an air isolation layer is arranged between each viscoelastic material and the bottom plate. The invention has simple structure and easy manufacture, and greatly improves the sound absorption performance.)

1. The utility model provides a circular passageway-rubber composite sound absorption structure under water which characterized in that, includes the combined material layer, the combined material layer sets up on the bottom plate, and the upper surface of combined material layer is provided with rubber layer (1), and the internal interval of combined material is provided with a plurality of circular passageways (2), and the one end and the rubber layer (1) of circular passageway (2) are connected, and the other end is connected with the bottom plate, and circular passageway (2) intussuseption is filled with viscoelastic material, is provided with air interlayer (3) between viscoelastic material and the bottom plate.

2. The circular channel-rubber composite underwater sound absorbing structure as claimed in claim 1, wherein the centers of the circular channels (2) are arranged in a triangle or a quadrangle on the bottom plate.

3. The circular channel-rubber composite underwater sound absorption structure as claimed in claim 2, wherein the arrangement period of the circular channel (2) on the bottom plate is 10-36 mm.

4. The circular channel-rubber composite underwater sound absorption structure as claimed in claim 1, wherein the radius r of the circular channel (2) is 9 to 35mm, and the width a of the cell formed by each circular channel (2) is 10 to 36 mm.

5. The circular channel-rubber composite underwater sound absorption structure as claimed in claim 1, wherein the height of the circular channel (2) is 21 to 51 mm.

6. The circular channel-rubber composite underwater sound absorbing structure as claimed in claim 1, wherein the filling thickness of the viscoelastic material is 20 to 50 mm.

7. The circular channel-rubber composite underwater sound absorbing structure as claimed in claim 1, wherein the viscoelastic material has a density of 800 to 1400kg/m³(ii) a The transverse wave sound velocity of the viscoelastic material is 500-2000 m/s, and the transverse wave loss factor of the viscoelastic material is 0.01-0.3; the longitudinal wave sound velocity of the viscoelastic material is 30-300 m/s, and the longitudinal wave loss factor of the viscoelastic material is larger than 0.5.

8. The circular channel-rubber composite underwater sound absorption structure as claimed in claim 1, wherein the thickness of the rubber layer (1) is 1 to 10 mm.

9. The circular channel-rubber composite underwater sound absorption structure as claimed in claim 1, wherein the thickness of the air barrier (3) is 1 to 10 mm.

10. The circular channel-rubber composite underwater sound absorbing structure as claimed in claim 1, wherein the composite material layer is made of a metal material or a carbon fiber/glass fiber composite material.

Technical Field

The invention belongs to the technical field of underwater sound absorption composite structures, and particularly relates to a circular channel-rubber composite underwater sound absorption structure.

Background

The underwater sound attenuation layer technology is an important way for absorbing underwater sound wave energy and inhibiting underwater sound wave reflection. It is a comprehensive technology, covering a wide range of subdivision technologies, including material synthesis and structural design, etc. in many directions. Viscoelastic materials are often used as the basis for sound absorbing layers, such as rubber and polyurethane, due to their acoustic impedance matching water and sufficient damping loss. The polymer chains in the viscoelastic material are excited to vibrate by incident sound waves, and the relative motion between the molecular chains generates heat through friction, so that mechanical energy can be used for storing sound energy, and the sound absorption effect is achieved.

However, the absorption of low frequency sound remains a great challenge due to the inherently poor dissipation of viscoelastic materials in the low frequency domain. In addition, the wavelength of low-frequency sound wave in water is longer, previous researches show that broadband sound absorption is difficult to realize only by the characteristics of internal materials, and the only method is to increase the thickness of the materials, which is mutually contradictory to actual requirements.

Therefore, structural design concepts based on resonance absorption mechanisms have been incorporated into the manufacture of sound absorbing layers, the most common being the cavity resonance structural sound absorbing layers, i.e. cavities of various shapes embedded inside. When the frequency of the incident sound wave approaches the natural frequency of the cavity, the vibration of the polymer chain is intensified, the internal friction is intensified, and the sound absorption performance is improved. However, the resonance muffling structure has the characteristics of narrow sound absorption frequency band, and the cavity is sensitive to water pressure, so that the actual requirements of deep sea conditions cannot be met.

Challenges still exist in the design of underwater broadband sound absorbing structures and water pressure resistant sound absorbing structures.

Disclosure of Invention

The invention aims to solve the technical problem of providing a circular channel-rubber composite underwater sound absorption structure aiming at the defects in the prior art, improving the underwater sound absorption performance of sound absorption rubber through reasonable design of the structure, and solving the problem of poor broadband sound absorption performance of a viscoelastic material.

The invention adopts the following technical scheme:

the circular channel-rubber composite underwater sound absorption structure comprises a composite material layer, wherein the composite material layer is arranged on a bottom plate, a rubber layer is arranged on the upper surface of the composite material layer, a plurality of circular channels are arranged at intervals in the composite material layer, one ends of the circular channels are connected with the rubber layer, the other ends of the circular channels are connected with the bottom plate, viscoelastic materials are filled in the circular channels, and an air interlayer is arranged between the viscoelastic materials and the bottom plate.

Specifically, the centers of the circular channels are arranged on the bottom plate in a triangular or quadrangular manner.

Furthermore, the arrangement period of the circular channels on the bottom plate is 10-36 mm.

Specifically, the radius r of the circular channel is 9-35 mm, and the width a of a cell formed by each circular channel is 10-36 mm.

Specifically, the height of the circular channel is 21-51 mm.

Specifically, the filling thickness of the viscoelastic material is 20-50 mm.

Specifically, the density of the viscoelastic material is 800-1400 kg/m³(ii) a The transverse wave sound velocity of the viscoelastic material is 500-2000 m/s, and the transverse wave loss factor of the viscoelastic material is 0.01-0.3; the longitudinal wave sound velocity of the viscoelastic material is 30-300 m/s, and the longitudinal wave loss factor of the viscoelastic material is larger than 0.5.

Specifically, the thickness of the rubber layer is 1-10 mm.

Specifically, the thickness of the air interlayer is 1-10 mm.

Specifically, the composite material layer is prepared from a metal material or a carbon fiber/glass fiber composite material.

Compared with the prior art, the invention has at least the following beneficial effects:

the circular channel-rubber composite underwater sound absorption structure is characterized in that viscoelastic materials are filled in the circular channel, the wall surface of the circular channel is connected with a bottom plate and has higher rigidity, so that the wall surface of the channel cannot vibrate due to the disturbance of sound waves, the viscoelastic materials vibrate under the excitation of the sound waves, due to the existence of the wall surface of the circular channel, the vibration of the viscoelastic materials close to the wall surface is restrained, and the vibration of the viscoelastic materials far away from the wall surface is relatively violent, so that a strong shearing effect is generated in the viscoelastic materials; the shear loss of the viscoelastic material is far greater than the compression loss, so that the sound wave loss capability of the viscoelastic material can be greatly improved; on the other hand, an air layer is arranged between the viscoelastic material and the bottom plate, and the air layer releases bottom restraint, so that the vibration of the viscoelastic material is enhanced, and the sound wave loss capacity of the viscoelastic material is further improved; on the other hand, the circular channel wall surface is connected with the bottom plate, and pressure is transmitted to the bottom surface through the channel wall surface, so that the structure has certain bearing capacity, and the water pressure resistance of the structure is further improved.

Furthermore, in order to ensure the volume content of the viscoelastic material in the periodic structure, the circular channels are arranged on the bottom plate in a quadrilateral or triangular arrangement.

Furthermore, the arrangement period of the circular channel on the bottom plate is 10-36 mm, so that proper viscous resistance in the rubber re-circular channel is ensured.

Furthermore, 1-5 mm of allowance is reserved between the size of the cellular unit and the circular channel, the rigidity of the partition plate can be ensured, the wall surface of the channel does not vibrate along with the viscoelastic material, the width of the cellular unit is selected to be related to the parameters of the viscoelastic material, and the cellular unit and the viscoelastic material are matched with each other to achieve good sound absorption performance.

Furthermore, the height of the circular channel is 21-51 mm, so that the sound wave can be ensured to have enough propagation distance in the structure, and the sound absorption performance at a low-frequency stage is effectively guaranteed.

Furthermore, the filling thickness of the viscoelastic material is 20-50 mm, and the thickness of the viscoelastic material is slightly smaller than that of the circular channel, so that the arrangement of a bottom air layer is ensured.

Furthermore, the density of the viscoelastic material is 800-1400 kg/m³The sound absorption material has the main sound absorption function in the structure, and the transverse wave loss factor of the viscoelastic material is 0.5 or more, so that the sufficient viscous action between the viscoelastic material and the wall surface is ensured, and the sufficient loss capacity is provided for the sound wave energy.

Furthermore, the thickness of the upper rubber covering layer is 1-10 mm, and the main function is to protect the metal framework from being corroded by seawater.

Further, in order to improve the vibration of rubber in the circular channel-rubber composite underwater sound absorption structure, an air interlayer is embedded between the viscoelastic material and the bottom plate, and the thickness of the air interlayer is 1-10 mm.

Furthermore, in order to ensure acoustic impedance mismatch between the circular pipe and the viscoelastic material and have certain bearing capacity, the pipe wall can be made of metal such as steel and aluminum or composite materials such as carbon fiber and glass fiber.

In conclusion, the sound absorption performance of the viscoelastic material can be improved to a great extent, more adjustable parameters including structural parameters and material parameters are provided in the aspect of design, the sound absorption performance can be adjusted correspondingly according to the requirements of actual working conditions, and the sound absorption device is simple in structure and easy to manufacture.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic view of an underwater sound absorbing structure of the present invention;

FIG. 2 is a top and side view of a circular channel, wherein (a) is a top view of a quadrilateral arrangement, (b) is a top view of a triangular arrangement, (b) is a front view;

fig. 3 is a schematic diagram of sound absorption coefficients of three embodiments of the underwater sound absorption structure of the present invention.

Wherein: 1. a rubber layer; 2. a circular channel; 3. an air barrier.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. 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.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

The invention provides a circular channel-rubber composite underwater sound absorption structure, which is characterized in that a circular channel is formed in a metal or carbon fiber/glass fiber composite material, and a viscous elastic material such as polyurethane or rubber is filled in the channel and is solidified. An air interlayer is arranged at the bottom of the viscoelastic material to promote the vibration of the viscoelastic material, and a pure rubber layer covers the upper surface of the viscoelastic material to protect the circular channel wall from being eroded by seawater; compared with the viscoelastic material with the same thickness, the finally formed structure has greatly improved sound absorption performance, and the sound absorption coefficient is larger than 0.8 in a wide frequency band range. And the formed structure has the property of difficult deformation under hydrostatic pressure, thereby realizing the underwater sound absorption structure which can resist hydrostatic pressure and has broadband sound absorption effect.

Referring to fig. 1 and 2, the circular channel-rubber composite underwater sound absorption structure of the present invention includes a circular channel 2, a rubber layer 1 and an air interlayer 3, the circular channel 2 is disposed on a bottom plate, the upper surface of the circular channel 2 is covered with the rubber layer 1, and the rubber layer 1 plays a role in protecting the circular channel from seawater erosion; the circular channel 2 is formed by opening a hole on the metal or carbon fiber/glass fiber composite material; the circular channel 2 is filled with viscoelastic materials, the viscoelastic materials are used as sound absorption materials for absorbing sound wave energy, an air interlayer 3 is arranged between the bottom of the viscoelastic materials and the bottom plate, the air interlayer 3 is used for improving the sound absorption performance, the thickness h of the circular channel-rubber composite underwater sound absorption structure is 22-70 mm, the sound absorption coefficient of the circular channel-rubber composite underwater sound absorption structure is larger than 0.8 at 800-10000 Hz, and the average sound absorption coefficient is larger than 0.9.

Thickness h of the rubber layer 1₃1 to 10mm, as shown in FIG. 2 (c).

The circular channels 2 are arranged on the bottom plate in a quadrilateral or triangular mode, the arrangement period is 10-36 mm, as shown in fig. 2(a) and (b), the circle centers of the circular channels are quadrilateral or triangular, and the side length of the quadrilateral or the triangular is the arrangement period.

Referring to fig. 2, the height of the circular channel (2) is 21-51 mm, the radius r is 9-35 mm, so as to ensure certain requirements of bearing capacity and weight, and the like, to improve the sound absorption performance of rubber and to transmit loads such as water pressure, and the width a of the cell formed by each circular channel (2) is 10-36 mm.

The wall surface of the circular channel 2 is made of metal material or carbon fiber/glass fiber composite material to ensure enough rigidity and acoustic impedance difference with rubber.

Thickness h of viscoelastic material filled in circular channel 2₂20 to 50mm, the viscoelastic material has a density of 800 to 1400kg/m³(ii) a The transverse wave sound velocity is 500-2000 m/s, and the transverse wave loss factor is 0.01-0.3; the longitudinal wave sound velocity is 30-300 m/s, and the longitudinal wave loss factor is larger than 0.5.

Thickness h of air barrier 3 arranged between viscoelastic material and base plate₁1 to 10mm, as shown in FIG. 2 (c).

The circular channel-rubber composite underwater sound absorption structure can achieve a good sound absorption effect between 800 Hz and 10000Hz, and compared with a viscoelastic material with the same thickness, the sound absorption performance is greatly improved. The reason is that steel has a modulus much greater than rubber, and steel plates can be considered as stiff relative to rubber. The sound waves cause the rubber to vibrate, and because the vibration at the connection position with the circular channel wall is limited, a strong shearing action is generated near the wall surface, so that the sound wave energy is lost. The bottom air interlayer releases the constraint of the bottom on the rubber vibration and increases the crossed vibration, thereby effectively improving the sound absorption performance of the low-frequency stage structure. In addition, the structure also meets the requirement that the sound absorption performance is not easy to decline when the sound absorption performance is maintained under high hydrostatic pressure; simple structure, maneuverability are strong.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. 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.

Example 1

Metal steel: it is characterized by a density of 7850kg/m3, a Young's modulus of 2.05GPa and a Poisson's ratio of 0.28.

Viscoelastic material: it is characterized by a density of 1000kg/m³The longitudinal wave velocity is 1000m/s, the longitudinal wave loss factor is 0.3, the transverse wave velocity is 100m/s, and the transverse wave loss factor is 0.9.

Water: it is characterized by a density of 1000kg/m³The speed of sound is 1500 m/s.

Air: it is characterized by a density of 1.29kg/m³The speed of sound is 340 m/s.

Example structure dimensions:

cell size: a is 23 mm. Radius: r is 11 mm. Thickness of air interlayer: h is₁1 mm. Thickness of mixed layer filled with rubber in the circular channel: h is₂45 mm. Thickness of the upper rubber layer: h is₃＝4mm。

Example 2

Materials for examples:

metal steel: it is characterized by a density of 7850kg/m3, a Young's modulus of 2.05GPa and a Poisson's ratio of 0.28.

Viscoelastic material: it is characterized by a density of 1000kg/m³The longitudinal wave velocity is 1200m/s, the longitudinal wave loss factor is 0.2, the transverse wave velocity is 100m/s, and the transverse wave loss factor is 0.9.

Water: it is characterized by a density of 1000kg/m³The speed of sound is 1500 m/s.

Air: it is characterized by a density of 1.29kg/m³The speed of sound is 340 m/s.

Example structure dimensions:

cell size: a is 19 mm. Radius: r is 9 mm. Thickness of air interlayer: h is₁2 mm. Thickness of mixed layer filled with rubber in the circular channel: h is₂40 mm. Thickness of the upper rubber layer: h is₃＝5mm。

Example 3

Materials for examples:

metal steel: it is characterized by a density of 7850kg/m3, a Young's modulus of 2.05GPa and a Poisson's ratio of 0.28.

Viscoelastic material: it is characterized by a density of 900kg/m³The longitudinal wave velocity is 900m/s, the longitudinal wave loss factor is 0.25, the transverse wave velocity is 80m/s, and the transverse wave loss factor is 0.8.

Water: it is characterized by a density of 1000kg/m³The speed of sound is 1500 m/s.

Air: it is characterized by a density of 1.29kg/m³The speed of sound is 340 m/s.

Example structure dimensions:

cell size: a is 15 mm. Radius: r is 6.5 mm. Thickness of air interlayer: h is₁2 mm. Thickness of mixed layer filled with rubber in the circular channel: h is_2＝50 mm. Thickness of upper rubber layer: h is₃＝1mm。

Comparative example 1 is a uniform rubber material of the same thickness as the examples, and comparative example 2 is a circular channel-rubber hybrid structure without air barriers inside, and the total thickness is kept consistent. To ensure the objectivity of the control, the material parameters were kept consistent with the examples.

Theoretical calculation and numerical simulation are carried out by adopting the materials and the structural dimensions, and the comparison of the sound absorption coefficients of the examples and the comparative examples is given as follows:

and calculating the sound absorption coefficients of the two structures between 0 and 10000Hz and the uniform comparison group.

Referring to fig. 3(a-c), the dotted line represents the sound absorption coefficient of the uniform viscoelastic material with the same thickness, the dotted line represents the sound absorption coefficient of the square-arranged circular channel-rubber composite underwater sound absorption structure, and the solid line represents the sound absorption coefficient of the hexagonal close-packed circular channel-rubber composite underwater sound absorption structure. As can be seen from FIG. 3, compared with the viscoelastic material with the same thickness, the sound absorption structure provided by the invention is greatly improved within 0-10000 Hz.

The concrete expression is as follows:

in the embodiment 1, the sound absorption coefficients of the quadrilateral arrangement structures are all more than 0.8 when 800-10000 Hz is adopted, and the sound absorption coefficients of the triangular arrangement structures are more than 0.8 when 820-10000 Hz is adopted. The average sound absorption coefficient is above 0.85.

In the embodiment 2, the sound absorption coefficient of the quadrilateral arrangement structure reaches more than 0.8 at 1200-4000 Hz, and the sound absorption coefficient of the triangular arrangement structure reaches more than 0.8 at 1000-10000 Hz. The average sound absorption coefficient is above 0.8.

In embodiment 3, the sound absorption coefficients of the quadrilateral arrangement structures are all more than 0.8 at 1400-10000 Hz, and the sound absorption coefficients of the triangular arrangement structures are more than 0.8 at 1200-10000 Hz. The average sound absorption coefficient is above 0.85.

The result shows that the sound absorption performance in a wide frequency range can be greatly improved by controlling the size and the thickness of the circular channel and selecting rubber materials with different physical parameters in a parameter value range. Among them, the sound absorption bandwidth of example 1 is the widest, and the average sound absorption coefficient is the best.

According to the data, the technical effects achieved by the invention are as follows:

1. the sound absorption coefficients of the simulation calculation results of the invention are all above 0.8 at 800-10000 Hz, the average sound absorption coefficient is above 0.85, and the requirements of effective sound absorption in a wide frequency band are met;

2. the circular pipeline has simple structure, simple mixing process with rubber and convenient processing;

3. the mechanical property of the whole structure can be changed by changing the structural parameters and the material parameters of the circular channel, so that the requirements of different occasions are met.

4. The rubber layer effectively protects the circular channel structure from being corroded by seawater, keeps the surface smooth and effectively reduces the surface resistance.

In conclusion, the circular channel-rubber composite underwater sound absorption structure can be used for manufacturing an underwater sound absorption covering layer, the sound energy loss capability of a viscoelastic material is improved through the structural design, the underwater sound absorption structure with the pressure bearing capability is realized, and the underwater sound absorption structure has a wide engineering application prospect.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.