Intelligent broadband sound absorption superstructure with acoustic black hole effect

Abstract

The invention discloses an intelligent broadband sound absorption superstructure with an acoustic black hole effect, which comprises a rubber-based bottom plate laid on a steel plate, a layer of piezoelectric composite material is arranged on the upper surface of the rubber-based bottom plate, the two sides of the piezoelectric composite material are externally connected with a shunt circuit, a cuboid array is arranged above the piezoelectric composite material, and the cuboid array is arranged above the piezoelectric composite material. And the top layer of the cuboid array covers the cuboid surface protection layer. The high-voltage-resistant broadband sound absorption device is high in voltage resistance, can realize resonance response at a specific frequency, and also has a stable broadband sound absorption effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater sound-absorbing composite structures, and in particular relates to an intelligent broadband sound-absorbing superstructure with an acoustic black hole effect. Background Art

[0002] Since the birth of the "Alberich" coating, various coating designs have effectively improved underwater sound absorption performance. However, with the continuous development of sonar technology, the importance of underwater anechoic design has become increasingly prominent.

[0003] The acoustic black hole (ABH) effect is achieved by introducing gradual changes in geometric parameters or material properties within thin-walled structures, gradually slowing down waves propagating through the structure. Ideally, the wave velocity eventually approaches zero, achieving non-reflective wave absorption. However, existing ABHs are primarily applied in air environments or single-material media, and there is a lack of mature solutions for integrating ABH properties into underwater multi-material composite structures.

[0004] Furthermore, connecting external shunt circuits on both sides of the piezoelectric composite material further modulates its electromechanical coupling properties. Adjusting the circuit parameters allows for effective absorption and dissipation of vibration energy, particularly by making the circuit purely resistive at specific frequencies, thereby creating circuit resonance. This significantly improves the structure's low-frequency sound absorption and frequency band control capabilities.

[0005] The present invention introduces an acoustic black hole structure with broadband sound absorption characteristics and a frequency-adjustable piezoelectric composite material into a conventional rubber material to construct a composite structure design that not only effectively broadens the sound absorption band, but also achieves a frequency-adjustable sound absorption peak, while extending the sound absorption performance to the low-frequency band. Summary of the Invention

[0006] The purpose of the present invention is to provide an intelligent broadband sound-absorbing superstructure with an acoustic black hole effect, which has strong pressure resistance, can achieve a resonant response at a specific frequency, and has a stable broadband sound-absorbing effect.

[0007] The technical solution adopted by the present invention is an intelligent broadband sound-absorbing superstructure with an acoustic black hole effect, including a rubber base plate laid on a steel plate, a layer of piezoelectric composite material is provided on the upper surface of the rubber base plate, shunt circuits are externally connected on both sides of the piezoelectric composite material, a rectangular array is provided above the piezoelectric composite material, and the top layer of the rectangular array is covered with a rectangular protective layer.

[0008] The present invention is also characterized in that: The rectangular array is a multi-layer rectangular structure layer stacked in sequence along the thickness direction. Each rectangular structure layer is composed of several rectangular units. Acoustic black hole cylinders are embedded inside the rectangular units. The radius of the acoustic black hole cylinder is distributed in a power law along the thickness direction.

[0009] All acoustic black hole cylinders are arranged along the z-axis, and the radius of the acoustic black hole cylinders satisfies the power law distribution relationship. ,in represents the coefficient of the power function, Indicates the position point on the z-axis, Represents the exponential term of the power function; the embedded acoustic black hole cylinder is flush with the surface of the cuboid, and the power function parameter of the acoustic black hole cylinder is The value is not greater than 1 / 8, The value cannot be greater than 2.

[0010] The number of rectangular array layers is not less than 10.

[0011] The rubber base plate, the piezoelectric composite material, the cuboid array and the cuboid protective surface layer are all connected by glue. The rubber base plate is made of rubber material, and the thickness of the rubber base plate is 10-30 mm.

[0012] The piezoelectric composite material is made of silicone rubber, piezoelectric material PZT-5H and epoxy resin, and the thickness of the piezoelectric composite material layer is 40-60 mm.

[0013] The rectangular array is a periodic structure with a single layer thickness of 4-6 mm. The rectangular array material is made of steel-rubber-steel periodically distributed from top to bottom.

[0014] The acoustic black hole cylinder is made of rubber material, and the thickness of a single layer of the acoustic black hole cylinder is 4-6 mm.

[0015] The rectangular protective surface layer is made of rubber material, and the thickness of the rectangular protective surface layer is 10-30 mm.

[0016] The cross section of the intelligent broadband sound absorbing superstructure with acoustic black hole effect of the present invention is square, the side lengths of the cross section are 110-130 mm, and the total height of the intelligent broadband sound absorbing superstructure with acoustic black hole effect is 100-180 mm.

[0017] The present invention provides an intelligent broadband sound-absorbing superstructure with an acoustic black hole effect. Based on the broadband sound absorption function of the acoustic black hole sound-absorbing structure, the adjustable resonant frequency of the piezoelectric composite material via an external shunt circuit, the good flexibility of rubber, and the strong pressure resistance of the non-cavity structure, a rubber base layer is applied to a steel plate, a layer of intelligent piezoelectric composite material is integrated on the surface of the rubber base, and external shunt circuits are connected on both sides of the piezoelectric composite material to form a frequency-adjustable sound absorption peak. A 10-layer three-dimensional rectangular array structure is arranged above the piezoelectric composite material. Each layer has several rectangular units evenly arranged, and a cylinder is embedded in the center of each rectangular unit, forming an acoustic black hole structure for stable broadband sound absorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The overall structure of the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; Figure 2 4 is a cross-sectional view of the intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to the present invention; Figure 3 This is a diagram of the acoustic black hole structure in the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; FIG4 (a) is a diagram showing the distribution of acoustic black hole materials in Example 1 of the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; FIG4( b ) is a diagram showing the distribution of acoustic black hole materials in Example 2 of the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; Figure 5 This is a structural diagram of the piezoelectric composite material in the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; Figure 6 This is a material distribution diagram of the piezoelectric composite material in Example 4 of the intelligent broadband sound-absorbing superstructure with acoustic black hole effect of the present invention; Figure 7 This is the sound absorption coefficient curve of Example 1 of the intelligent broadband sound absorption superstructure with acoustic black hole effect of the present invention; Figure 8 This is the sound absorption coefficient curve of Example 2 of the intelligent broadband sound absorption superstructure with acoustic black hole effect of the present invention; Figure 9 This is the sound absorption coefficient curve of Example 3 of the intelligent broadband sound absorption superstructure with acoustic black hole effect of the present invention; Figure 10 This is the sound absorption coefficient curve of Example 4 of the intelligent broadband sound absorption superstructure with acoustic black hole effect of the present invention.

[0019] In the figure, 1. Rubber base plate, 2. Piezoelectric composite material, 3. Rectangular array, 4. Acoustic black hole cylinder, 5. Rectangular protective layer. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The present invention has an intelligent broadband sound absorbing superstructure including acoustic black hole effect, the structure is as follows Figure 1 As shown, it includes a rubber base plate 1 laid on a steel plate, a layer of piezoelectric composite material 2 is provided on the upper surface of the rubber base plate 1, shunt circuits are externally connected on both sides of the piezoelectric composite material 2, a rectangular array 3 is provided above the piezoelectric composite material 2, and the top layer of the rectangular array 3 is covered with a rectangular protective layer 5.

[0022] The present invention introduces acoustic black hole structures and piezoelectric composite materials into the rubber material system. Through the coordinated design of multi-material composite design and geometric parameters, effective sound absorption is achieved in a wide frequency range, especially in the medium and low frequency bands. It can also achieve a sound absorption peak with adjustable frequency. At the same time, the rubber layer and non-cavity structure design have good flexibility and pressure resistance, and are suitable for application scenarios of underwater sound-absorbing covering layers.

[0023] The rectangular array 3 is a multi-layer rectangular structure layer, which is stacked in sequence along the thickness direction. Each rectangular structure layer is composed of several rectangular units. Acoustic black hole cylinders 4 are embedded inside the rectangular units to form an acoustic black hole structure for enhancing broadband sound absorption capability. The radius size of the acoustic black hole cylinder 4 is power-law distributed along the thickness direction.

[0024] All acoustic black hole cylinders 4 are arranged along the z-axis, and the radius of the acoustic black hole cylinder 4 satisfies the power law distribution relationship ,in represents the coefficient of the power function, Indicates the position point on the z-axis, Represents the exponential term of the power function; the embedded acoustic black hole cylinder 4 is flush with the surface of the cuboid, and the power function parameter of the acoustic black hole cylinder 4 is The value is not greater than 1 / 8, The value cannot be greater than 2.

[0025] In order to conform to the structure of an acoustic black hole, the number of layers of the rectangular array 3 is no less than 10.

[0026] See Figure 2 The rubber base plate 1, the piezoelectric composite material 2, the rectangular array 3, and the rectangular protective surface layer 5 are all connected by glue. The rubber base plate 1 is made of rubber material. In order to avoid reflection of sound waves from the rubber base plate laid on the steel plate, the rubber base plate 1 has a thickness of 10-30 mm.

[0027] The piezoelectric composite material 2 is made of silicone rubber, piezoelectric material PZT-5H and epoxy resin. In order to achieve resonance of the external shunt circuit, the layer thickness is 40-60 mm.

[0028] The rectangular array 3 is a periodic structure. In order to increase sound wave dissipation and achieve broadband sound absorption, the thickness of a single layer is 4-6 mm. The material of the rectangular array 3 is steel-rubber-steel distributed periodically from top to bottom.

[0029] The acoustic black hole cylinder 4 is made of rubber material. In order to conform to the acoustic black hole structure and be able to be embedded in the rectangular array structure, the single layer thickness of the acoustic black hole cylinder 4 is 4-6 mm.

[0030] The rectangular armour layer 5 is made of rubber, forming a gradient impedance transition interface to further enhance low-frequency sound absorption. To ensure good impedance transition and improved sound absorption at low frequencies, the armour layer 5 has a thickness of 10-30mm. The rubber layer and non-cavity structure also provide excellent flexibility and pressure resistance, maintaining overall structural integrity while enhancing underwater service reliability.

[0031] The cross section of the intelligent broadband sound absorbing superstructure with acoustic black hole effect of the present invention is square, the side lengths of the cross section are 110-130 mm, and the total height of the intelligent broadband sound absorbing superstructure with acoustic black hole effect is 100-180 mm.

[0032] By combining an acoustic black hole structure with multi-layered localized resonance units, piezoelectric composite materials, and a rubber armor layer, this invention significantly enhances underwater sound absorption, demonstrating exceptional broadband absorption performance and achieving a frequency-adjustable sound absorption peak. Furthermore, it boasts a robust structure, simple manufacturing, and flexible control, making it suitable for the design and manufacture of sound-absorbing covering structures for a variety of marine applications, including underwater vehicles and deep-sea exploration equipment.

[0033] The intelligent broadband sound-absorbing superstructure of the present invention has an acoustic black hole effect. Its structural composition includes a base layer, a piezoelectric layer, an acoustic black hole layer and a protective layer. Through the collaborative design of multi-material composite design and adjustable geometric parameters, it can achieve resonance in the target frequency band, significantly broaden the sound absorption frequency band range, and improve the sound absorption efficiency of the structure in the underwater low-frequency range. It has excellent sound absorption frequency control and broadband sound absorption capabilities. At the same time, compared with traditional structures, the present invention does not have a cavity, so it has excellent pressure resistance.

[0034] This invention utilizes a rubber base layer applied to a steel plate, with a piezoelectric composite material integrated on top. External shunt circuits are connected on both sides of the piezoelectric composite material to achieve a resonant response at the target frequency, significantly improving the sound absorption coefficient. Ten layers of a three-dimensional rectangular array are arranged on the surface of the piezoelectric material, with each layer evenly spaced with a single rectangular unit. A cylinder is embedded in the center of each rectangular unit, forming an acoustic black hole structure that enhances broadband sound absorption.

[0035] A rubber sheathing layer is laid atop the rectangular array, creating a gradient impedance transition interface to further enhance the absorption of low-frequency sound waves. The rubber layer and non-cavity structure also provide excellent flexibility and pressure resistance, maintaining overall structural integrity while enhancing underwater service reliability.

[0036] By combining an acoustic black hole structure with multi-layered localized resonance units, piezoelectric composite materials, and a rubber armor layer, this invention significantly enhances underwater sound absorption, demonstrating exceptional broadband absorption performance and achieving a frequency-adjustable sound absorption peak. Furthermore, it boasts a robust structure, simple manufacturing, and flexible control, making it suitable for the design and manufacture of sound-absorbing covering structures for a variety of marine applications, including underwater vehicles and deep-sea exploration equipment.

[0037] Example 1 Specific results reference Figure 7 Table 1 lists relevant material parameters for steel, rubber, epoxy resin, and silicone rubber, such as density, Young's modulus, Poisson's ratio, and damping loss factor. Also listed are parameters related to the superstructure designed in this invention, such as length, width, thickness, and the coefficients of the power function. In this example, varying the coefficients of the power function that constitutes the acoustic black hole allows for varying sound absorption coefficients. It can be seen that the addition of the acoustic black hole significantly improves the sound absorption coefficient, and as increases, the absorption coefficient gradually shifts toward lower frequencies.

[0038] Table 1 Related parameters of Example 1

[0039] Example 2 Specific results reference Figure 8 Table 2 shows the material parameters of steel, rubber, epoxy resin, and silicone rubber, such as density, Young's modulus, Poisson's ratio, and damping loss factor. It also shows the parameters of the superstructure designed by the present invention, such as length, width, thickness, and coefficients of the power function. In this example, by changing the shape of the acoustic black hole, the >0 to The effect obtained after <0 has a good sound absorption coefficient compared to traditional rubber, and it also verifies that in Example 1, As the frequency increases, the sound absorption coefficient gradually moves toward low frequencies.

[0040] Table 2 Related parameters of Example 2

[0041] Example 3 Specific results reference Figure 9 Table 3 shows the material parameters of steel, rubber, epoxy resin, and silicone rubber, such as density, Young's modulus, Poisson's ratio, and damping loss factor. It also shows the parameters of the superstructure designed by the present invention, such as length, width, thickness, and coefficients of the power function. In this example, by fixing other parameters, only the We find that The acoustic black hole structure with a value of >0 has better low-frequency sound absorption performance, so we choose The following examples are explored using acoustic black hole structures of shape >0.

[0042] Table 3 Related parameters of Example 3

[0043] Example 4 Specific results reference Figure 10 Table 4 shows the material parameters of steel, rubber, epoxy resin and silicone rubber, such as density, Young's modulus, Poisson's ratio, damping loss factor, etc. It also shows the parameters of the superstructure designed by the present invention, such as length, width, thickness, coefficient of power function, etc. >0 acoustic black hole superstructure, with an external RLC shunt circuit, to achieve circuit resonance and form a resonance peak.

[0044] Table 4 Related parameters of Example 4

[0045] Example 5 Table 5 lists relevant material parameters for steel, rubber, epoxy resin, and silicone rubber, such as density, Young's modulus, Poisson's ratio, and damping loss factor. It also lists relevant parameters of the superstructure designed in the present invention, such as length, width, thickness, and the coefficient of the power function. This example shows different values ​​of the power function.

[0046] Table 5 Related parameters of Example 5

[0047] Example 6 Table 6 lists relevant material parameters for steel, rubber, epoxy resin, and silicone rubber, such as density, Young's modulus, Poisson's ratio, and damping loss factor. It also lists relevant parameters of the superstructure designed in the present invention, such as length, width, thickness, and the coefficient of the power function. This example shows different values ​​of the power function.

[0048] Table 6 Parameters related to Example 6

[0049] By changing the structure of the acoustic black hole, the thickness of the rubber layer, the parameters of the acoustic black hole structure, the density of the rubber, the Young's modulus of the rubber, the damping loss factor of the rubber, the thickness and width of the piezoelectric composite material, the parameters of the external shunt circuit, and the total thickness of the sound-absorbing structure, the following technical effects are achieved: 1. Excellent broadband sound absorption performance By adjusting the geometry and material parameters of the acoustic black hole structure, the sound absorption band can be effectively broadened and the sound absorption coefficient can be improved, thereby achieving efficient absorption of medium and low frequency sound waves.

[0050] 2. The piezoelectric composite material with an external shunt circuit has a frequency control function The circuit parameters of the external shunt circuit and the thickness, length and width of the piezoelectric composite material layer have a significant impact on its inherent capacitance, thereby adjusting the resonant frequency with the external shunt circuit and significantly enhancing the sound absorption capacity of the structure in a specific frequency band.

[0051] 3. Mid- and low-frequency energy dissipation is significantly enhanced The periodic distribution of steel-rubber-steel materials in the three-dimensional array structure is used to enhance the multiple reflections and dissipation of medium and low frequency sound waves.

[0052] 4. Excellent structural flexibility and pressure resistance The surface rubber protective layer not only improves the flexibility of the structure, but the non-cavity structural design also has good pressure resistance, ensuring reliability in underwater service.

[0053] In summary, the present invention provides an intelligent broadband sound-absorbing metastructure with an acoustic black hole effect. By integrating an acoustic black hole structure, a multi-layer local resonance unit, a piezoelectric composite material, and a rubber damping layer, the device constructs an intelligent broadband sound-absorbing metamaterial device with a stable structure and excellent performance. Through the synergistic effect of local resonance and the impedance gradient mechanism, the energy dissipation capacity is effectively enhanced, and good sound absorption effects and a significant broadening of the sound absorption frequency band are achieved in the medium and low frequency bands. Circuit resonance is achieved by connecting an external shunt circuit, and the sound absorption frequency and peak value can be adjusted. At the same time, compared to traditional structures, the present invention does not have a cavity, so it has excellent pressure resistance. The overall design takes into account sound absorption efficiency, structural strength, and ease of manufacturing, and has good engineering practicality and control flexibility. It is suitable for marine acoustic application scenarios such as underwater vehicles and deep-sea detectors, providing an effective solution for underwater broadband sound absorption technology.

Claims

1. An intelligent broadband sound-absorbing superstructure having an acoustic black hole effect, characterized in that: The invention comprises a rubber base plate (1) laid on a steel plate, a layer of piezoelectric composite material (2) being provided on the upper surface of the rubber base plate (1), shunt circuits being externally connected to both sides of the piezoelectric composite material (2), a rectangular array (3) being provided above the piezoelectric composite material (2), and a rectangular protective layer (5) being covered on the top layer of the rectangular array (3).

2. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 1, characterized in that: The rectangular array (3) is a multi-layer rectangular structure layer, which is stacked in sequence along the thickness direction. Each rectangular structure layer is composed of a number of rectangular units. Acoustic black hole cylinders (4) are embedded in the rectangular units. The radius size of the acoustic black hole cylinders (4) is distributed in a power law along the thickness direction.

3. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 2, characterized in that: All of the acoustic black hole cylinders (4) are arranged along the z-axis direction, and the radius of the acoustic black hole cylinder (4) satisfies a power law distribution relationship. ,in represents the coefficient of the power function, Indicates the position point on the z-axis, Represents the exponential term of the power function; the embedded acoustic black hole cylinder (4) is flush with the surface of the cuboid, and the power function parameter of the acoustic black hole cylinder (4) The value is not greater than 1 / 8, The value cannot be greater than 2.

4. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 2, characterized in that: The number of layers of the rectangular parallelepiped array (3) is not less than 10.

5. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 3, characterized in that: The rubber base plate (1), the piezoelectric composite material (2), the cuboid array (3), and the cuboid protective surface layer (5) are all connected by glue.

6. The intelligent broadband sound-absorbing superstructure having an acoustic black hole effect according to any one of claims 1 to 5, characterized in that: The rubber base plate (1) is made of rubber material, and the thickness of the rubber base plate (1) is 10-30 mm.

7. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 1, characterized in that: The piezoelectric composite material (2) is made of silicone rubber, piezoelectric material PZT-5H and epoxy resin, and the thickness of the piezoelectric composite material (2) is 40-60 mm.

8. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 1, characterized in that: The rectangular parallelepiped array (3) is a periodic structure with a single layer thickness of 4-6 mm. The rectangular parallelepiped array (3) is made of materials that are periodically distributed in the order of steel-rubber-steel from top to bottom.

9. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 1, characterized in that: The acoustic black hole cylinder (4) is made of rubber material, and the single layer thickness of the acoustic black hole cylinder (4) is 4-6 mm.

10. The intelligent broadband sound-absorbing superstructure with acoustic black hole effect according to claim 1, characterized in that: The rectangular protective surface layer (5) is made of rubber material, and the thickness of the rectangular protective surface layer (5) is 10-30 mm.

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