Dynamic vibration absorber based on acoustic black hole and particle damping coupling

Abstract

The invention relates to a dynamic vibration absorber based on acoustic black hole and particle damping coupling, which comprises an acoustic black hole structure and a cavity shell, the acoustic black hole structure comprises a thickness gradual change area and a uniform thickness area, and the thickness of the thickness gradual change area is gradually reduced from the maximum thickness end to the minimum thickness end; the minimum thickness end of the uniform thickness area and the minimum thickness end of the thickness gradual change area are connected into a whole, and a damping covering layer is arranged at the joint of the thickness gradual change area and the uniform thickness area. The cavity shell covers the acoustic black hole structure, a cavity is formed in the cavity shell, partition plates are arranged in the cavity at intervals, the adjacent partition plates divide the cavity into sub-cavities which are not communicated with one another, the sub-cavities are filled with free particles, and the height of the partition plates in the cavity is matched with the outer contour of the acoustic black hole structure in a coordinated mode. The gap between the top of each partition plate and the acoustic black hole structure is smaller than the diameter of a free particle. By means of the synergistic effect of acoustic black hole energy gathering and particle damping energy dissipation, the overall vibration reduction efficiency is improved, and the effective frequency band is widened.

Description

Technical Field

[0001] This invention relates to the field of vibration and noise control technology, specifically to a dynamic vibration absorber based on the coupling of acoustic black holes and particle damping. Background Technology

[0002] Traditional dynamic vibration absorbers typically employ a "mass-spring-damper" configuration, suppressing a specific order of vibration in the main structure by tuning the natural frequency of the added mass. These absorbers suffer from drawbacks such as a large mass proportion, narrow tuning bandwidth, and sensitivity to parameter deviations.

[0003] Acoustic black hole (ABH) vibration-absorbing structures achieve efficient local dissipation of structural vibration energy by thinning the structure to a minimum truncated thickness along a power-law function, causing bending waves to gradually decelerate and concentrate within the gradient region. Combined with high-loss damping material at the truncated end, this enables efficient local dissipation of structural vibration energy. However, acoustic black holes are highly sensitive to manufacturing precision, geometry, and the quality of the damping layer adhesion. Under high-frequency and strongly nonlinear conditions, the energy dissipation capacity of a single ABH structure still has room for improvement.

[0004] Particle dampers dissipate vibrational energy through collisions and friction between free particles and the cavity walls, as well as between particles themselves. They offer advantages such as simple structure and strong environmental adaptability. However, most existing particle dampers employ regular cavities, making it difficult to control the particle motion within the cavity. This can lead to problems such as particles "running around randomly," particles remaining essentially stationary at low frequencies, and particles becoming suspended and failing at high frequencies. Consequently, the damping effect becomes unstable, and the design relies on trial and error.

[0005] Therefore, it is necessary to propose a dynamic vibration absorber that effectively couples acoustic black hole structures with particle damping technology, so that the structural bending waves are guided and concentrated in the ABH region, while optimizing the cavity geometry to constrain particle motion, thereby achieving wide-bandwidth, high-efficiency and controllable vibration energy dissipation. Summary of the Invention

[0006] This invention discloses a dynamic vibration absorber based on the coupling of acoustic black holes and particle damping, which achieves efficient vibration reduction of the first and adjacent modes of the main structure while meeting spatial and mass constraints, and broadens the effective operating frequency band.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping includes an acoustic black hole structure and a cavity shell. The acoustic black hole structure includes a thickness gradient region and a uniform thickness region. The thickness gradient region has a maximum thickness and a minimum thickness. The thickness of the acoustic black hole structure gradually decreases from the maximum thickness end to the minimum thickness end. The uniform thickness region and the minimum thickness end of the thickness gradient region are connected as one unit. A damping covering layer is set at the transition connection between the thickness gradient region and the uniform thickness region. The cavity shell covers the acoustic black hole structure. The interior of the cavity shell forms a cavity. The cavity is divided into non-communicating sub-cavities by partitions. The sub-cavities are filled with free particles. The height of the partitions in the cavity is coordinated and matched with the external contour of the acoustic black hole structure, so that the gap between the top of each partition and the acoustic black hole structure is smaller than the diameter of the free particles.

[0008] Furthermore, the free particles are made of any one of metals, ceramics, and polymers, or a mixture of the above.

[0009] Furthermore, the spacing between adjacent partitions is equal, let the spacing between adjacent partitions be . d c Let the diameter of the free particle be... d p The relation 0.3 ≤ d p / d c ≤0.6.

[0010] Furthermore, the filling rate of the free particles filling the sub-cavity Φ Between 60% and 90%, of which Φ = V p / V c , V p The total volume of free particles within the subcavity. V c This is the effective volume of the sub-cavity.

[0011] Furthermore, the acoustic black hole structure is a one-dimensional acoustic black hole structure. It is formed by cutting the two opposite ends of a linear beam. The uncut part in the middle of the linear beam serves as the main beam body. One-dimensional acoustic black hole structures are formed on both sides of the main beam body. The thickest end of the one-dimensional acoustic black hole structure is integrated with the main beam body. The lower two sides of the main beam body extend outward to form beam protrusions. The cavity shell is an outer shell with flanges on its edges. Each one-dimensional acoustic black hole structure has an outer shell on each side to enclose the one-dimensional acoustic black hole structure. The flanges of the two outer shells on the same side of the main beam body are fitted together and fixedly connected. The flange facing the main beam body is fixed to the main beam body.

[0012] Furthermore, the thickness of the thickness-gradient region of the one-dimensional acoustic black hole structure satisfies a power-law function relationship along the x-axis, as follows:

[0013] Where ε is the initial thickness coefficient, its expression is:

[0014] In the above formula, L The length of the region where the thickness gradually changes. d The length of the uniform thickness region. m The power exponent. m ≥2, h max This represents the maximum thickness of the acoustic black hole structure. h cut This represents the minimum thickness of the acoustic black hole structure.

[0015] Furthermore, the acoustic black hole structure is a two-dimensional acoustic black hole structure. The bottom surface of the two-dimensional acoustic black hole structure is a plane, and the center of the top surface of the two-dimensional acoustic black hole structure is a central platform. The central platform is the end of the maximum thickness of the two-dimensional acoustic black hole structure. From the central platform, a thickness gradient region and a uniform thickness region are formed circumferentially. The cavity shell is a cavity cover plate, which includes a cover plate bottom plate and cover plate side plates located around the cover plate bottom plate. The cover plate bottom plate and the cover plate side plates enclose a cover plate cavity. The edges of the cover plate side plates extend outward to form cover plate flanges. Cover plate partitions are arranged at intervals to form a closed shape inside the cover plate cavity. An annular cavity is formed between adjacent cover plate partitions. The annular cavity is filled with free particles. A connecting boss is provided on the side of the cover plate bottom plate away from the cover plate cavity. The side of the cavity cover plate with the cover plate cavity faces the central platform. The cavity cover plate covers the two-dimensional acoustic black hole structure and the two are fixedly connected.

[0016] Furthermore, the thickness of the thickness-gradient region of the two-dimensional acoustic black hole structure satisfies a power-law relationship along the x-axis, as follows:

[0017] In the above formula, h max This represents the maximum thickness of the acoustic black hole structure. h cut The minimum thickness of an acoustic black hole structure, a i middle i =1,2,3,4 a i The length of the thickness gradient region projected onto the plane, starting from the central platform. m The power exponent. m ≥2.

[0018] Furthermore, the thickness of the partition is 1 mm, the thickness of the damping cover layer is 2 mm, and the diameter of the free particles is 2 mm.

[0019] Furthermore, the free particles are rubber balls or steel shot.

[0020] The present invention has the following beneficial effects: (1) Synergy of energy accumulation and particle energy consumption; The acoustic black hole geometry effectively guides the energy of bending waves to accumulate at the thickness cut-off end, keeping the particle damping region in the high mode response zone, significantly increasing the relative motion and collision frequency of particles. Compared with traditional uniform cavity particle dampers, it has more complete energy coupling and higher vibration reduction efficiency.

[0021] (2) Particle collision solves the problem of low energy consumption efficiency of acoustic black holes at low frequencies; Acoustic black holes have poor low-frequency characteristics. By utilizing the collision characteristics of particles with them, nonlinear effects are achieved, which transfer low-frequency energy in the acoustic black hole structure to high-frequency energy. The high-frequency energy concentration characteristics of acoustic black holes are used to efficiently dissipate energy and improve the low-frequency energy dissipation efficiency.

[0022] (3) Suppress the problem of "particles running around randomly"; By arranging the cavity in the ABH region and optimizing the power exponent, cavity thickness, and filling rate, the particle motion is confined within a space that matches the main mode shape, reducing the probability of random particle drift and high-frequency suspension, and improving the repeatability and stability of the damping behavior.

[0023] (4) Balancing wide bandwidth and lightweight design; The acoustic black hole structure itself has broadband vibration reduction characteristics, while the particle damper provides additional energy dissipation in the mid-to-high frequency range. After the two are coupled, a high loss factor is maintained in a wide frequency range. At the same time, the added mass mainly exists in the form of thin-walled gradient and a small number of particles, which can meet the strict mass and space constraints.

[0024] (5) Flexible structure and easy integration; This invention can design linear ABH, annular ABH, or locally grooved ABH according to different main structural forms such as beams, plates, and shells. The particle cavities can be arranged in single cavities, multiple cavities, or segments, making it suitable for integrated use in various occasions such as aerospace, vehicles, and mechanical equipment shells. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the assembly structure of the vibration absorber in Example 1; Figure 2 To be Figure 1 A schematic diagram showing the outer casing of the middle vibration absorber after its upper left corner has been removed; Figure 3 This is a schematic diagram of the one-dimensional acoustic black hole structure in Example 1; Figure 4 This is a schematic diagram of the internal structure of the outer shell in Embodiment 1; Figure 5 This is a schematic diagram of the external structure of the outer shell in Embodiment 1; Figure 6 This is a schematic diagram of the vibration absorber installed on the controlled flat plate structure in Embodiment 1; Figure 7 This is a schematic diagram of the cross-sectional dimensions of the one-dimensional acoustic black hole structure in Example 1; Figure 8 This is a cross-sectional view of the internal cavity of the outer shell in Embodiment 1; Figure 9 This is a schematic diagram of the linear beam after one side is cut to form a one-dimensional acoustic black hole structure in Example 1; Figure 10 In order to be in Figure 9 A schematic diagram of the one-dimensional acoustic black hole structure on the right after the outer shell has been installed. Figure 11 This is an exploded view of the vibration absorber in Example 2; Figure 12 This is a schematic diagram of the two-dimensional acoustic black hole structure in Example 2; Figure 13 This is a diagram showing the thickness region of the two-dimensional acoustic black hole structure in Example 2; Figure 14 This is a top-view dimensioned diagram of the two-dimensional acoustic black hole structure in Example 2; Figure 15 This is a schematic diagram of the internal structure of the cavity cover plate in Example 2; Figure 16 This is a schematic diagram of the external structure of the cavity cover plate in Example 2; Figure 17 This is a cross-sectional view of the internal cavity of the cavity cover plate in Embodiment 2.

[0026] Figure label: 1. Main beam section; 2. Beam protrusion; 3. Outer shell; 31. Base plate; 32. First side plate; 33. Second side plate; 34. Third side plate; 35. Partition plate; 36. Side plate flange; 37. Base plate flange; 38. Rectangular cavity; 4. One-dimensional acoustic black hole structure; 5. Damping cover layer; 6. Controlled flat plate structure; 7. Two-dimensional acoustic black hole structure; 71. Central platform; 72. Gradual thickness region; 73. Uniform thickness region; 8. Cavity cover plate; 81. Cover plate base plate; 82. Cover plate side plate; 83. Cover plate flange; 84. Cover plate partition plate; 85. Annular cavity; 86. Connecting boss. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] This embodiment overcomes the shortcomings of existing acoustic black hole vibration absorbers and particle dampers, and designs a dynamic vibration absorber based on the coupling of acoustic black holes and particle damping. Under the premise of meeting spatial and mass constraints, it achieves efficient vibration reduction of the first and adjacent modes of the main structure and broadens the effective operating frequency band. The dynamic vibration absorber in this embodiment is mainly assembled from an acoustic black hole structure and a cavity shell. The acoustic black hole structure has a thickness-gradient region along the main vibration transmission direction, with a maximum thickness end and a minimum thickness end. The thickness gradually decreases from the maximum thickness end to the minimum thickness end. At the minimum thickness end, there is a uniform thickness region with a consistent thickness, the same as the minimum thickness end. The uniform thickness end is integrated with the minimum thickness end of the thickness-gradient region. A damping covering layer is provided at the transition connection between the thickness-gradient region and the uniform thickness region to enhance the shear deformation and energy dissipation of the acoustic black hole structure region. The outer shell of the cavity is used to enclose the acoustic black hole structure. The interior of the outer shell forms a cavity, within which spaced partitions are installed. Adjacent partitions divide the cavity into non-communicating sub-cavities, which are filled with free particles. The cavity of the outer shell faces the acoustic black hole structure. In this embodiment, each sub-cavity has a different volume, meaning each partition has a different height. The height of the partitions within the cavity must be coordinated and matched according to the external contour of the acoustic black hole structure corresponding to each partition, ensuring that the gap between the top of each partition and the corresponding acoustic black hole structure is always less than the diameter of the free particles, thereby restricting the movement of the free particles.

[0029] Example 1: This example demonstrates an acoustic black hole particle vibration absorber on a linear beam. Figure 9 As shown, a bar of length along the x-direction is... L s Thickness is h s The two opposite ends of the aluminum alloy cantilever beam are cut to form a one-dimensional acoustic black hole structure. Figure 9 For simplicity, only one side of the cutting process is shown to form a one-dimensional acoustic black hole structure. The structure after cutting on both sides is as follows: Figure 3 As shown, the uncut portion in the middle forms the main beam 1, and the lower ends of the main beam 1 extend horizontally outward to form the beam protrusions 2. From Figure 3 As can be seen above, the one-dimensional acoustic black hole structure 4 on each side has a gradually changing thickness region near the main beam 1. Its maximum thickness end is fixedly connected to the main beam 1, while its minimum thickness end faces outwards. A damping covering layer 5 is used to cover the connection between the minimum thickness end and the uniform thickness region. In this embodiment, the thickness of the damping covering layer 5 is 2mm. Combined with... Figure 7 As shown, the thickness of the thickness-gradient region of the one-dimensional acoustic black hole structure 4 satisfies the following power-law function relationship along the x-axis:

[0030] Where ε is the initial thickness coefficient, its expression is:

[0031] In the above formula, L It is the length of the thickness gradient region (i.e., the length from the end of the maximum thickness to the end of the minimum thickness). d It is the length of the uniform thickness region (i.e., the length from the end of the minimum thickness to the end of the acoustic black hole structure). m The power exponent. m ≥2, h max This represents the maximum thickness of the acoustic black hole structure. h cut This represents the minimum thickness of the acoustic black hole structure. In this embodiment, m =3, h cut =0.2mm.

[0032] In this embodiment, the cavity shell used to enclose the one-dimensional acoustic black hole structure 4 adopts... Figure 4 and Figure 5 The outer casing 3 shown includes a base plate 31, a first side plate 32, a second side plate 33, and a third side plate 34. The first side plate 32, second side plate 33, and third side plate 34 are perpendicularly connected to the three edges of the base plate 31, thereby enclosing and forming the inner cavity of the outer casing 3. Partitions 35 are spaced apart within the inner cavity. The bottom of each partition 35 is fixed to the base plate 31, and the two ends of each partition 35 are fixed to the first side plate 32 and the third side plate 34, respectively, thus dividing the inner cavity into multiple non-communicating rectangular cavities 38. The edges of the first side plate 32 and the third side plate 34 extend outward perpendicularly to their respective ends to form side plate flanges 36, and the edges of the base plate 31 also extend outward perpendicularly to form bottom plate flanges 37. Figure 8 As shown, the height of each partition 35 in the inner cavity of the outer shell 3 is... h c The design needs to be coordinated with the external contour of the one-dimensional acoustic black hole structure 4 to ensure that the distance between each partition 35 and the surface of the one-dimensional acoustic black hole structure 4 is always less than the diameter of a free particle. The inner cavity length of the outer shell 3... L c = L + d Inner cavity width B c The height of the inner cavity is consistent with the width at the maximum thickness end of the one-dimensional acoustic black hole structure 4.H c = h max In this embodiment, the partitions 35 in the inner cavity are evenly spaced, and the distance between adjacent partitions 35 is... d c =4mm, the thickness of the partition 35 is 1mm. Each rectangular cavity 38 of the outer shell 3 is filled with free particles. The free particles can be any one of the following materials: metal, ceramic, or polymer, or a mixture of the above materials, such as rubber balls or steel shot. From Figure 8 As can be seen above, the effective volume of each rectangular cavity 38 is different, and the filling rate of each rectangular cavity 38 varies when filled with free particles. Φ Within the range of 60% to 90%, among which Φ = V p / V c , V p Let V be the total volume of free particles within the rectangular cavity 38 (i.e., the sub-cavity). V c The effective volume of the subcavity, and the diameter of the free particle. d p Spacing with adjacent partition 35 d c Satisfies the relation: 0.3≤ d p / d c ≤0.6, in this embodiment, the free particle is the diameter d p =2mm rubber ball.

[0033] When assembling the outer shell 3 of the above structure, with Figure 9 After the linear beam shown is cut on one side to form a one-dimensional acoustic black hole structure 4, an outer shell 3 is set on each of the upper and lower sides of the one-dimensional acoustic black hole structure 4 on that side, with the inner cavity of each outer shell 3 facing the one-dimensional acoustic black hole structure 4. The bottom plate flange 37 of the outer shell 3 is fixed to the main beam 1, and the side plate flanges 36 of the two outer shells 3 are correspondingly attached and fixedly connected. After assembly, a one-dimensional acoustic black hole structure 4 is formed. Figure 10 The structure shown. For the case where both sides of the beam are cut to form a one-dimensional acoustic black hole structure 4, it can be as follows: Figure 1 and Figure 2 As shown, two outer shells 3 are respectively set on both sides of the main beam 1, and the two outer shells 3 are used to cover the one-dimensional acoustic black hole structure 4 on the respective side.

[0034] To form Figure 1 Taking the dynamic vibration absorber shown as an example, when using this type of dynamic vibration absorber, it is installed on the controlled flat plate structure 6 (e.g., Figure 6 The region with a large peak displacement or strain energy density in the first-order bending mode on the acoustic black hole structure (as shown) is aligned with the direction of the main vibration in the thickness gradient region of the acoustic black hole structure. The ratio μ of the total additional mass of the dynamic vibration absorber after assembly to the mass of the controlled plate structure 6 satisfies: 0.02≤μ≤0.1. During installation, the beam protrusion 2 is fixed to the controlled plate structure 6. With the above arrangement, when external vibration excitation acts on the dynamic vibration absorber through the controlled plate structure 6, the bending wave of the main structure gradually decelerates and accumulates in the thickness gradient region of the acoustic black hole structure, increasing the vibration displacement and curvature in this region. At this time, the free particles in the subcavity generate significant relative motion and collision / friction under inertial drive, realizing the synergistic effect of energy concentration of the acoustic black hole structure and energy dissipation of particle damping, thereby improving the overall vibration reduction efficiency and widening the effective frequency band.

[0035] Example 2: This example designs an acoustic black hole particle vibration absorber for a plate structure. It is an additional two-dimensional flat plate acoustic black hole particle dynamic vibration absorber, and its structure is as follows. Figure 11 As shown, it is mainly assembled from a two-dimensional acoustic black hole structure 7 and a cavity cover plate 8. The two-dimensional acoustic black hole structure 7 is cut from a rectangular aluminum alloy sheet (it can also be a steel, titanium alloy, or composite material sandwich panel), as shown... Figures 12 to 14 As shown, the length of the aluminum alloy sheet is L Width is W The bottom surface of the aluminum alloy sheet is flat. By cutting the top surface of the aluminum alloy sheet, a two-dimensional acoustic black hole structure 7 is formed, creating an uncut square central platform 71. From the central platform 71, the thickness gradually decreases along the four sides, forming a thickness gradient region 72. The end of the thickness gradient region 72 is the minimum thickness end, and the central platform 71 is the maximum thickness end. The end of the thickness gradient region 72 extends horizontally to form a uniform thickness region 73. Figure 13 As shown, the thickness at point 71 of the central platform is h max The thickness of the uniform thickness region 73 is the same as the thickness of the minimum thickness end, and its thickness is... h cut The thickness of the gradually varying region 72 satisfies the following power-law relationship along the x-axis:

[0036] In the above formula, a i middle i =1,2,3,4 a i The length of the thickness gradient region 72 on the plane projection, starting from the central platform 71. Figure 13 In d Let be the length of the uniform thickness region 73 projected onto the plane. mThe power exponent. m ≥2. In this embodiment, a damping cover layer 5 is attached to the two-dimensional acoustic black hole structure 7 at the junction of the thickness gradient region 72 and the uniform thickness region 73.

[0037] In this embodiment, the cavity shell is made of, for example, Figures 15 to 17 The cavity cover plate 8 shown includes a rectangular cover plate base plate 81. The four sides of the cover plate base plate 81 are perpendicularly connected to cover plate side plates 82, and the cover plate base plate 81 and cover plate side plates 82 together enclose a cover plate cavity. The edge of each cover plate side plate 82 extends outward perpendicularly to form a cover plate flange 83. Cover plate partitions 84, arranged at intervals to form a closed shape, are provided within the cover plate cavity. An annular cavity 85 (i.e., a sub-cavity) is formed between adjacent cover plate partitions 84, and the annular cavity 85 is filled with free particles. A connecting boss 86 is also provided on the side of the cover plate base plate 81 away from the cover plate cavity. The height setting of the cover plate partitions 84 in this embodiment is the same as the partition 35 setting requirement in Embodiment 1. The height of the cover plate partitions 84 needs to be set according to the gap between the cover plate partitions 84 and the ABH surface and the diameter of the free particles. Figure 17 It is evident that the heights of the cover plates 84 on both sides of each annular cavity 85 are different, resulting in differences in the volume within each annular cavity 85. In this embodiment, the spacing between the cover plates 84, the thickness of the cover plates 84, and the requirements for the spacing between the cover plates 84 and the diameter of the free particles can all be designed with reference to the specifications given in Embodiment 1. The size of the cover plate cavity is set according to the size variation of ABH. The planar contour of the cover plate cavity can be annular, fan-shaped array, or rectangular cavity to match the shape of ABH. The requirements for the free particle material, diameter, and filling rate within the annular cavity 85 in this embodiment can all be designed with reference to the specifications given in Embodiment 1. When assembling the cavity cover plate 8 with the two-dimensional acoustic black hole structure 7, the side of the cavity cover plate 8 with the cover plate cavity faces the central platform 71. The cover plate flange 83 is fixedly connected to the cavity base formed by milling the outer ring of the two-dimensional acoustic black hole structure 7, so that the cavity cover plate 8 covers the two-dimensional acoustic black hole structure 7.

[0038] In this embodiment, during installation of the two-dimensional planar acoustic black hole particle dynamic vibration absorber, the connecting boss 86 on the two-dimensional ABH particle dynamic vibration absorber is fixed to the target position (e.g., near the peak value of the target modal displacement or curvature) of the controlled structure (e.g., equipment shell plate, raft panel, cabin wall panel, etc.) by screw connection or adhesive bonding, in order to reduce the structural vibration response in the target frequency band. When external excitation is applied to the controlled structure, the structural vibration energy is coupled into the absorber through the connecting interface: on the one hand, the two-dimensional ABH thickness gradient region 72 induces local wave deceleration and energy accumulation, increasing the energy density in the absorber; on the other hand, free particles undergo relative motion, collision and friction in the annular cavity 85, further dissipating the energy coupled into the absorber, thereby reducing the response of the controlled structure in the target frequency band and improving the overall equivalent damping level of the system.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping, characterized in that: It includes an acoustic black hole structure and a cavity shell. The acoustic black hole structure includes a thickness gradient region and a uniform thickness region. The thickness gradient region has a maximum thickness and a minimum thickness. The thickness of the acoustic black hole structure gradually decreases from the maximum thickness end to the minimum thickness end. The uniform thickness region and the minimum thickness end of the thickness gradient region are connected as one unit. A damping covering layer is set at the transition connection between the thickness gradient region and the uniform thickness region. The acoustic black hole structure is enclosed by a cavity shell, and the interior of the cavity shell forms a cavity. The cavity is divided into separate sub-cavities by partitions. The sub-cavities are filled with free particles. The height of the partitions in the cavity is coordinated and matched with the outer contour of the acoustic black hole structure, so that the gap between the top of each partition and the acoustic black hole structure is smaller than the diameter of the free particles.

2. The dynamic vibration absorber based on the coupling of acoustic black holes and particle damping according to claim 1, characterized in that: The free particles are made of any one of metals, ceramics, or polymers, or a mixture of the above.

3. The dynamic vibration absorber based on the coupling of acoustic black holes and particle damping according to claim 1, characterized in that: The spacing between adjacent partitions is equal, let the spacing between adjacent partitions be . d c Let the diameter of the free particle be... d p The relation 0.3 ≤ d p / d c ≤0.

6.

4. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping as described in claim 1, characterized in that: The filling rate of the free particles filling the sub-cavity Φ Between 60% and 90%, of which Φ = V p / V c , V p The total volume of free particles within the subcavity. V c This is the effective volume of the sub-cavity.

5. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping as described in claim 1, characterized in that: The acoustic black hole structure is a one-dimensional acoustic black hole structure. It is formed by cutting the two opposite ends of a linear beam. The uncut part in the middle of the linear beam serves as the main beam body. One-dimensional acoustic black hole structures are formed on both sides of the main beam body. The thickest end of the one-dimensional acoustic black hole structure is integrated with the main beam body. The lower two sides of the main beam body extend outward to form beam protrusions. The outer shell of the cavity is an outer shell with flanges on its edges. Each one-dimensional acoustic black hole structure has an outer shell on each side to enclose the one-dimensional acoustic black hole structure. The flanges of the two outer shells on the same side of the main beam body are fitted together and fixedly connected. The flange facing the main beam body is fixed to the main beam body.

6. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping as described in claim 5, characterized in that: The thickness of the thickness-gradient region of the one-dimensional acoustic black hole structure satisfies a power-law function relationship along the x-axis, as follows: Where ε is the initial thickness coefficient, its expression is: In the above formula, L The length of the region where the thickness gradually changes. d The length of the uniform thickness region. m The power exponent, m ≥2, h max This represents the maximum thickness of the acoustic black hole structure. h cut This represents the minimum thickness of the acoustic black hole structure.

7. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping as described in claim 1, characterized in that: The acoustic black hole structure is a two-dimensional acoustic black hole structure. The bottom surface of the two-dimensional acoustic black hole structure is a plane, and the center of the top surface of the two-dimensional acoustic black hole structure is a central platform. The central platform is the end of the maximum thickness of the two-dimensional acoustic black hole structure. From the central platform, a thickness gradient region and a uniform thickness region are formed circumferentially. The outer shell of the cavity is a cavity cover plate, which includes a cover plate bottom plate and cover plate side plates located around the cover plate bottom plate. The cover plate bottom plate and the cover plate side plates enclose a cover plate cavity. The edges of the cover plate side plates extend outward to form cover plate flanges. Cover plate partitions are arranged at intervals to form a closed shape inside the cover plate cavity. An annular cavity is formed between adjacent cover plate partitions. The annular cavity is filled with free particles. A connecting boss is provided on the side of the cover plate bottom plate away from the cover plate cavity. The side of the cavity cover plate with the cover plate cavity faces the central platform. The cavity cover plate covers the two-dimensional acoustic black hole structure and the two are fixedly connected.

8. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping as described in claim 7, characterized in that: The thickness of the thickness-gradient region of the two-dimensional acoustic black hole structure satisfies a power-law relationship along the x-axis, as follows: In the above formula, h max This represents the maximum thickness of the acoustic black hole structure. h cut The minimum thickness of an acoustic black hole structure, a i middle i =1,2,3,4 a i The length of the thickness gradient region projected onto the plane, starting from the central platform. m The power exponent, m ≥2.

9. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping according to claim 1, characterized in that: The thickness of the partition is 1 mm, the thickness of the damping cover layer is 2 mm, and the diameter of the free particles is 2 mm.

10. A dynamic vibration absorber based on the coupling of acoustic black holes and particle damping according to claim 1, characterized in that: The free particles are rubber balls or steel shot.

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