Tunable attached acoustic black hole vibration absorber coupled with PVC spring

Abstract

The invention discloses a tunable attached acoustic black hole vibration absorber coupled with a PVC spring, and relates to the technical field of vibration and noise reduction equipment. The interior of the frame is used for positioning and connecting the damping assembly, and the exterior of the frame is used for being connected with a controlled structure. The vibration reduction assembly comprises a PVC spring, a linear spring, a connecting column and vibration reduction beams on the two opposite faces of the periphery of the connecting column, the two ends of the PVC spring are fixedly connected with the frame and the connecting column, and the PVC spring can change the rigidity and damping under excitation of an electric field. The two ends of the linear spring are fixedly connected with the frame and the connecting column and provide pre-tightening force for the PVC spring, and the thickness of the longitudinal section of the vibration reduction beam is gradually decreased in an exponential mode from the side attached to the connecting column in the direction away from the connecting column. According to the tunable attached acoustic black hole vibration absorber coupled with the PVC spring, vibration can be absorbed within a broadband range, and line spectrum vibration with time-varying signals in the structure can be restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration and noise reduction equipment, and particularly to a tunable attached acoustic black hole absorber coupled with a PVC spring. Background Art

[0002] Vibration is a standing wave formed by multiple reflections at the boundaries in a structure, and noise is the wave energy radiated from the structural vibration into the air. Therefore, controlling the wave behavior in the structure is an effective means to achieve vibration and noise reduction. Currently, the common wave control methods include passive, semi-active, and active methods. The passive control method has a simple structure and remarkable effects, but once the structural parameters are determined, it is difficult to cope with the time-varying line spectrum vibration in the controlled structure. The active control method can solve the problem of time-varying line spectrum vibration of passive control by active adjustment, but it requires external energy and a complex system design, resulting in a high cost. In contrast, the semi-active method combines the advantages of passive and active control. The vibration reduction structure is relatively simple, and only a small amount of energy consumption is required to effectively suppress time-varying vibration. However, the existing semi-active control methods are usually only effective in some frequency bands and it is difficult to achieve wide-band vibration suppression.

[0003] The proposal of the Acoustic Black Hole (ABH) effect has opened a new chapter in controlling the propagation of flexural waves in elastic media and structures. As a new type of passive control method, the acoustic black hole controls the wave propagation by optimizing the structural shape, and has the advantages of light weight, high energy consumption, and wide operating frequency band. Initially, the acoustic black hole structure was used to reduce vibration and noise by trimming the controlled object, but this method would reduce the stiffness and strength of the structure, restricting its application. Subsequently, scholars at home and abroad have developed various attached acoustic black hole absorbers, which are applied to major equipment. By using the high damping and large modal density of the acoustic black hole, vibration can be effectively suppressed in a wide frequency range. Although the acoustic black hole has significantly suppressed vibration, as a passive control method, its suppression effect on the line spectrum vibration caused by external excitation, especially the time-varying excitation of non-natural frequencies, is still not ideal.

[0004] Polyvinyl chloride (PVC) gel is a new type of intelligent flexible material, which has the characteristics of simple driving method, fast response speed, and good stability. When a sandwich structure of cathode (plane electrode plate) - PVC gel - anode (metal mesh electrode) is adopted, the external electrical stimulation causes the negatively charged plasticizer molecules inside the PVC gel to migrate to the anode side. Under the action of the Maxwell electrostatic force, the gel creeps into the mesh holes, resulting in the shrinkage deformation of the entire driving structure in the thickness direction. After removing the electric field, the PVC gel quickly returns to its initial state due to its own elasticity. This unique deformation method can not only adjust the stiffness in the thickness direction, but also significantly enhance the friction between the PVC gel and the mesh holes when the gel matrix enters the metal mesh, changing the damping characteristics. Therefore, the PVC gel is expected to become an intelligent component with a wide range of variable stiffness-damping characteristics.

[0005] In order to suppress structural vibration in a wide frequency range and effectively cope with the time-varying line-spectrum vibration in the structure, it is necessary to design a new type of semi-active vibration damping structure by combining acoustic black holes and PVC gel springs. Summary of the Invention

[0006] Based on this, the object of the present invention is to provide a tunable attached acoustic black hole absorber coupled with a PVC spring, which gives full play to the advantages of acoustic black holes and PVC springs and improves the vibration damping effect.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a tunable attached acoustic black hole absorber coupled with a PVC spring, which includes a vibration damping component and a frame;

[0009] The frame is a hollow block structure with open ends on both sides. One end of the frame is used to connect to the controlled structure; the inside of the frame is used to position and connect the vibration damping component;

[0010] The vibration damping component includes a vibration damping beam, a PVC spring, a linear spring, and a connecting column; the linear spring, the connecting column, and the PVC spring are sequentially arranged inside the frame from the controlled structure to the other end of the frame; one vibration damping beam is arranged on each side of the connecting column;

[0011] The thickness of the longitudinal section of the vibration damping beam decreases exponentially along the direction away from the connecting column from the side attached to the connecting column.

[0012] Optionally, the frame includes an upper cover and a lower shell; the lower shell is in a U-shaped structure, and the upper cover is detachably arranged at the open end of the lower shell; the closed end of the lower shell is used to connect to the controlled structure; an upper cover groove is arranged on the side of the upper cover facing the lower shell, and a lower shell groove is arranged on the side of the lower shell facing the upper cover. The upper cover groove is used to position the PVC spring, and the lower shell groove is used to position the linear spring.

[0013] Optionally, the PVC spring includes a plurality of adjustment units arranged sequentially along the axial direction of the vibration damping component. Each adjustment unit includes a metal mesh electrode, a copper foil electrode, and PVC gel; a layer of PVC gel is arranged on each side of the metal mesh electrode, and the copper foil electrode is arranged outside the PVC gel; the copper foil electrode is electrically connected to the cathode of the power supply, and the PVC gel is electrically connected to the anode of the power supply.

[0014] Optionally, the PVC spring is adhesively connected to the frame, between the PVC spring and the connecting column, between the connecting column and the linear spring, and between the linear spring and the frame.

[0015] Optionally, an extension ring is provided at the edge of the damping beam, and the thickness of the extension ring is the same as the edge thickness of the damping beam.

[0016] Optionally, the damping assembly further includes a damping layer, and the damping layer is disposed on the upper end face and / or the lower end face of the extension ring; the outer edge of the damping layer is flush with the outer edge of the extension ring.

[0017] Optionally, the end face of the damping beam facing away from the controlled structure is a plane, and the perpendicular bisector of the plane is parallel to the center line of the connecting column and not collinear.

[0018] Optionally, the expression of the exponent is h(wi) = awi m , i = 1, 2, where h(wi) represents the thickness of the damping beam, wi, i = 1, 2 respectively represent the distance from any point on two edges on the end face of the connecting column facing away from the controlled structure to the corresponding parallel edges on the end face of the damping beam facing away from the controlled structure, a represents a coefficient, and m is greater than or equal to 2.

[0019] Optionally, the frame, the damping beam and the connecting column are made of aluminum, and the linear spring is made of stainless steel.

[0020] Optionally, the extension ring, the damping beam and the connecting column are of an integral structure.

[0021] The present invention has achieved the following technical effects compared with the prior art:

[0022] The tunable attached acoustic black hole absorber of the present invention that couples a PVC spring is mounted on a controlled structure through a frame. When the controlled structure is subjected to an external excitation of a specific frequency, the waves in the controlled structure first pass through the frame to the linear spring and the PVC spring, and then propagate to the damping beam. During this process, due to the dynamic vibration absorption characteristics of the PVC spring and the damping beam coupling system with multiple natural frequencies, as well as the high damping and acoustic black hole effect of the PVC spring itself, the system can effectively reduce vibration and noise in a wide frequency range. In addition, by adjusting the voltage at both ends of the PVC spring, changing the natural frequency and damping characteristics of the coupling system, the line spectrum vibration with time-varying characteristics in the controlled structure can be effectively suppressed, further improving the vibration and noise reduction performance. Description of the Drawings

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 Schematic structural diagram of a tunable attached acoustic black hole absorber with a coupled PVC spring for Embodiment 1;

[0025] Figure 2 Schematic side view of a tunable attached acoustic black hole absorber with a coupled PVC spring for Embodiment 1;

[0026] Figure 3 Schematic unit structure diagram of the PVC spring for Embodiment 1;

[0027] Figure 4 Schematic diagram of the propagation of elastic waves in the acoustic black hole beam provided in Embodiment 1;

[0028] Figure 5 Frequency-domain response diagram of the tunable attached acoustic black hole absorber with a coupled PVC spring under different voltages for Embodiment 1;

[0029] Figure 6 Time-domain response comparison diagram of the tunable attached acoustic black hole absorber with a coupled PVC spring for Embodiment 1;

[0030] Icons: 100, Tunable attached acoustic black hole absorber with a coupled PVC spring; 110, Vibration damping component; 111, Vibration damping beam; 112, PVC spring; 1121, Metal mesh electrode; 1122, Copper foil electrode; 1123, PVC gel; 113, Linear spring; 114, Connection column; 115, Damping layer; 116, Extension ring; 120, Frame; 121, Upper cover; 1211, Upper cover groove; 1212, Upper cover connection hole; 122, Lower shell; 1221, Lower shell groove; 1222, Lower shell connection hole; 200, Controlled structure. Detailed implementation manners

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0032] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] As Figures 1 to 4 shown, this embodiment provides a tunable attached acoustic black hole absorber coupling a PVC spring, specifically including a vibration damping component 110 and a frame 120; the inside of the frame 120 is used to position and connect the vibration damping component 110, and the outside of the frame 120 is used to connect with the controlled structure 200; the vibration damping component 110 includes a PVC spring 112, a linear spring 113, a connecting column 114, and vibration damping beams 111 on two opposite faces of the outer periphery of the connecting column 114. Both ends of the PVC spring 112 are fixedly connected to the frame 120 and the connecting column 114, and the PVC spring 112 can change its stiffness and damping under electric field excitation; both ends of the linear spring 113 are fixedly connected to the frame 120 and the connecting column 114, and provide a pre-tightening force for the PVC spring 112. The thickness of the longitudinal section of the vibration damping beam 111 decreases exponentially along the direction away from the connecting column starting from the side attached to the connecting column.

[0034] Among them, the vibration damping component 110 and the frame 120 are installed on the controlled structure 200. Waves of a certain frequency emitted by the controlled structure 200 pass through the frame 120, and then propagate through the PVC spring 112 and the linear spring 113 of the vibration damping component 110 to the connecting column 114, and finally propagate to the vibration damping beam 111. Since the thickness of the vibration damping beam 111 decreases exponentially, an acoustic black hole region is formed between the vibration damping beam 111 and the controlled structure 200. The propagation speed of the wave decreases as the thickness decreases, the wavelength decreases, and the amplitude of the wave increases, gathering towards the region with a smaller thickness. Please refer to Figure 4 ; By utilizing the dynamic vibration absorption characteristics of the coupling system of the PVC spring 112 and the vibration damping beam 111 having multiple natural frequencies, as well as the high damping and acoustic black hole effect of the PVC spring 112 itself, the system can achieve efficient vibration reduction and noise reduction in a wide frequency range; in addition, by changing the voltage at both ends of the PVC spring 112, and then changing the natural frequency and damping characteristics of the coupling system, it is possible to effectively suppress the line spectrum vibration with time-varying characteristics in the controlled structure 200, further improving the vibration reduction and noise reduction effect on the controlled structure 200.

[0035] In an alternative solution of this example, preferably, please refer to Figure 1 and Figure 2, the frame 120 includes an upper cover 121 and a lower shell 122 that can be detachably connected. The upper cover 121 and the lower shell 122 form the frame 120. One end of the lower shell 122 is fixedly attached to the controlled structure 200, and there is a small hole 1222 in the lower shell for fixedly connecting with the controlled structure 200. The upper cover groove 1211 and the lower shell groove 1221 are used for the positioning and fixed connection of the damping component 110. Specifically, the lower shell 122 is connected to the controlled structure 200 by fixed threads. The upper cover 121 is provided with a small hole 1212 in the upper cover. The open end of the lower shell 122 is provided with a threaded hole. The contact end of the upper cover 121 and the lower shell 122 is fixedly connected by bolts, which is convenient for installation and disassembly.

[0036] Further preferably, the damping component 110 is fixedly bonded inside the frame 120. Specifically, the PVC spring 112 is adhesively connected to the upper cover groove 1211 and the connecting column 114 respectively, and the linear spring 113 is adhesively connected to the lower shell groove 1221 and the connecting column 114 respectively. Since the damping component 110 is fixedly connected to the frame 120, the waves in the controlled structure 200 are first transmitted to the frame 120, and then transmitted to the connecting column 114 through the PVC spring 112 and the linear spring 113.

[0037] Further preferably, damping layers 115 are provided on the extension rings 116 at both ends of the damping beam 111 parallel to the upper end surface of the controlled structure 200, or damping layers 115 are provided on both the upper and lower end surfaces. And the outer edge of the damping layer 115 is flush with the outer edge of the extension ring 116, which can efficiently dissipate the energy of the system and improve the ability of vibration reduction and noise reduction. Specifically, the damping layer 115 can be made of butyl rubber material.

[0038] In the optional solution of this embodiment, more preferably, the perpendicular bisector passing through the center of the end surface of the damping beam 111 facing away from the controlled structure 200 and perpendicular to this end surface is parallel to the center line of the connecting column 114 and non-collinear, that is, the damping beams 111 on both sides are eccentrically arranged relative to the connecting column 114. Designing in an eccentric form compared with a symmetric structure enables the damping beam 111 to have more modes with different frequencies and can act in more frequency bands, giving full play to the advantages of the energy aggregation effect of the acoustic black hole.

[0039] Specifically, the connecting column 114, the damping beam 111 and the extension ring 116 can be integrally formed to ensure stability.

[0040] In the optional solution of this embodiment, more preferably, please refer to Figure 3, the PVC spring 112 includes a plurality of adjustment units arranged in sequence along the axial direction of the damping component. Each adjustment unit includes a metal mesh electrode 1121, a copper foil electrode 1122, and a PVC gel 1123. On both sides of the metal mesh electrode 1121, there is a layer of PVC gel 1123 respectively. On the outer side of the PVC gel 1123, there is a copper foil electrode 1122. The copper foil electrode 1122 is electrically connected to the cathode of the power supply, and the PVC gel 1123 is electrically connected to the anode of the power supply. After applying an electric field, the PVC gel 1123 undergoes creep deformation and retracts into the mesh holes of the metal mesh electrode 1121 to achieve changes in the overall stiffness and damping of the PVC spring 112. Therefore, changes in the modal frequency and damping of the damping component 110 are brought about, enabling the vibration absorber action frequency to be changed by adjusting the electric field for some line spectrum vibrations with time-varying characteristics in the controlled structure 200, thereby suppressing the line spectrum vibration in a timely manner and giving full play to the advantages of the tunable attached acoustic black hole absorber 100 with a coupled PVC spring.

[0041] Further preferably, the shapes of the contact surfaces of the copper foil electrode 1122, the polyvinyl chloride gel 1123, and the metal mesh electrode 1121 are consistent with the upper cover groove 1211, and the contour of the upper cover groove 1211 is slightly larger than the outer contour of the PVC spring 112. For example, if the PVC spring 112 is cylindrical with a circumferential diameter of 40 mm, the circumferential diameter of the upper cover groove 1211 can be set to 42 mm.

[0042] In an alternative solution of this example, more preferably, the frame 120, the damping beam 111, and the connecting column 114 are made of aluminum, which has low mass, good strength. The linear spring 113 is made of stainless steel, which is corrosion-resistant, has high strength, and a long service life.

[0043] In an alternative solution of this example, more preferably, see Figure 1 and Figure 2 , the cross-section of the damping beam 111 is rectangular, the connecting column 114 is a rectangular column, and the expression of the exponent of the thickness change of the damping beam 111 is h(wi) = awi m , i = 1, 2, where h(wi) represents the thickness of the damping beam 111, wi, i = 1, 2 respectively represent the distance from any point on one of the two edges on the end face of the connecting column 114 facing away from the controlled structure 200 to the corresponding parallel edge on the end face of the damping beam 111 facing away from the controlled structure 200, a represents a coefficient, and m is greater than or equal to 2.

[0044] The dimensions of each part of the tunable attached acoustic black hole absorber 100 with a coupled PVC spring provided in this embodiment are determined according to actual needs. The following provides a tunable attached acoustic black hole absorber 100 with a coupled PVC spring of specific dimensions, and a model is established in ABAQUS using the finite element method, and the frequency-domain response and time-domain response of the structure are calculated; please seeFigure 5 and Figure 6 The upper end surface of the connecting column 114 has two dimensions w in the directions perpendicular to the two edges of the upper end surface of the vibration damping beam 111 ABH1 = 80 mm, w ABH2 = 100 mm,; the cross-sectional dimension of the connecting column 114 is 50 mm * 50 mm; the upper end surface dimension of the vibration damping beam 111 is 180 mm * 50 mm, the maximum thickness is 3 mm, and the minimum thickness at the edge is 0.3 mm; the width of the extension ring 116 is 10 mm and the thickness is 0.3 mm; the size of the damping layer 115 is 10 mm * 50 mm and the thickness is 1 mm; butyl rubber material is selected for arrangement, and the material loss factor is set to 0.3; the initial stiffness of the PVC spring 112 is set to 200 N / m, and the initial damping coefficient is set to 0.1 N / (m / s). The stiffness and damping of the PVC spring 112 increase with the increase of voltage; the stiffness of the linear spring 113 is 10 N / m; a uniform plate with a length of 300 mm, a width of 240 mm, and a thickness of 2 mm is selected as the controlled structure 200. A coordinate system is established with the center point origin of the controlled structure 200, and the tunable attached acoustic black hole vibration absorber 100 with 1 coupled PVC spring is attached to the controlled structure 200 at (70, -100 mm); the controlled structure 200 with and without the attached vibration absorber is analyzed by sweeping the frequency in the frequency range of 5 - 1000 Hz. In order to illustrate the broadband vibration suppression and the suppression effect on the time-varying line spectrum vibration of the vibration absorber, the stiffness and damping corresponding to the PVC spring 112 at different voltages are brought into the finite element model to calculate the frequency domain response and the time domain response results under single-frequency excitation.

[0045] Analysis of calculation results

[0046] 1 Frequency domain response

[0047] As Figure 5 shown, in order to evaluate the vibration level of the system, the origin displacement response of the system is selected as the index for research. From Figure 5It can be found that after attaching the tunable attached acoustic black hole absorber 100 with the coupled PVC spring provided in this example, compared with the structure before being controlled, the vibration level can be reduced at the first-order resonance frequency of the controlled structure 100 under all voltages. This is because the tunable attached acoustic black hole absorber 100 with the coupled PVC spring provided in this example has a very high modal damping ratio due to the acoustic black hole effect and the dynamic vibration absorption effect, and can greatly exert its characteristics, absorb the wave energy on the controlled structure 200, and reduce the vibration level of the system. And because the damping beam 111 adopts an eccentric design, the structure has more natural frequencies, enabling the vibration absorber to better couple with the controlled object and better transfer the wave energy to the vibration absorber to be consumed, giving full play to the advantage of the energy focusing effect of the acoustic black hole; in addition, due to the adjustable stiffness and damping of the PVC spring 112, by controlling the stiffness and damping of the PVC spring 112 with voltage, the working frequency of the damping component can be adjusted in real time, which means that the tunable attached acoustic black hole absorber 100 with the coupled PVC spring has a wider operating frequency band and can suppress the time-varying line spectrum vibration in the structure.

[0048] 2 Time-domain response

[0049] To simulate the line spectrum vibration excitation, as Figure 6 shown, when the controlled structure 200 is subjected to a line spectrum vibration excitation of 23 Hz, although it does not cause the resonance state of the structure, if the energy of the excitation is too large, it will still cause a large-amplitude vibration. At this time, the stiffness and damping of the PVC spring 112 can be changed by adjusting the voltage, and the anti-resonance peak of the vibration absorber can be moved to the vicinity of the line spectrum frequency. Obviously, compared with the structure before being controlled, the overall displacement response has a significant reduction in the vibration level.

[0050] The tunable attached acoustic black hole absorber with the coupled PVC spring 112 cleverly combines the characteristics of the acoustic black hole and the PVC spring 112, avoiding the limitations of traditional passive acoustic black holes, and can achieve an efficient suppression effect on broadband and line spectrum vibrations by dynamically adjusting the natural frequency of the vibration absorber.

[0051] The present invention can be designed according to the frequency characteristics of the controlled object, etc., and can further improve the broadband characteristics.

[0052] The tunable attached acoustic black hole absorber 100 with the coupled PVC spring of the present invention has a small mass, is easy to meet engineering applications, and has the characteristics of high efficiency.

[0053] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0054] In this specification, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A tunable attached acoustic black hole vibration absorber coupled with a PVC spring, characterized in that: Includes vibration reduction assembly and frame; The frame is a hollow block structure with two open sides, one end of the frame is used to connect with the controlled structure; the interior of the frame is used to position and connect the vibration reduction assembly; The vibration reduction assembly includes a vibration reduction beam, a PVC spring, a linear spring and a connecting column; the linear spring, the connecting column and the PVC spring are sequentially arranged inside the frame from the controlled structure to the other end of the frame; and a vibration reduction beam is respectively arranged on both sides of the connecting column; The thickness of the longitudinal section of the vibration-damping beam decreases exponentially from the side attached to the connecting column in a direction away from the connecting column.

2. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The frame includes an upper cover and a lower shell; the lower shell is a U-shaped structure, and the upper cover is detachably arranged on the open end of the lower shell; the closed end of the lower shell is used to be connected with the controlled structure; an upper cover groove is provided on the side of the upper cover facing the lower shell, and a lower shell groove is provided on the side of the lower shell facing the upper cover, the upper cover groove is used to position the PVC spring, and the lower shell groove is used to position the linear spring.

3. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The PVC spring includes a plurality of adjustment units sequentially arranged along the axial direction of the vibration reduction assembly, each of the adjustment units includes a metal mesh electrode, a copper foil electrode and a PVC gel; a layer of the PVC gel is respectively arranged on both sides of the metal mesh electrode, and the copper foil electrode is arranged on the outer side of the PVC gel; the copper foil electrode is electrically connected to the cathode of the power supply, and the PVC gel is electrically connected to the anode of the power supply.

4. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The PVC spring and the frame, the PVC spring and the connecting column, the connecting column and the linear spring, and the linear spring and the frame are all connected by bonding.

5. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: An extension ring is provided at the edge of the vibration-damping beam, and the thickness of the extension ring is the same as the thickness of the edge of the vibration-damping beam.

6. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 5, characterized in that: The vibration reduction assembly further comprises a damping layer, and the damping layer is arranged on the upper end surface and / or the lower end surface of the extension ring; the outer edge of the damping layer is flush with the outer edge of the extension ring.

7. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The end surface of the vibration-damping beam facing away from the controlled structure is a plane, and the perpendicular bisector of the plane is parallel to and not colinear with the center line of the connecting column.

8. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The expression of the index is h(wi)=awi m , i=1,2, wherein, h(wi) represents the thickness of the vibration-damping beam, wi,i=1,2 respectively represent the distance from any point on the two edges on the end surface of the connecting column away from the controlled structure to the corresponding parallel edges on the end surface of the vibration-damping beam away from the controlled structure, a represents the coefficient, and m is greater than or equal to 2.

9. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The frame, the vibration-damping beam and the connecting column are made of aluminum, and the linear spring is made of stainless steel.

10. The tunable attached acoustic black hole vibration absorber coupled with a PVC spring according to claim 1, characterized in that: The extension ring, the vibration-damping beam and the connecting column are an integrated structure.

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