Additional local slotting acoustic black hole beam

Abstract

The invention provides an additional local slotted acoustic black hole beam, which is mounted on a structure to be damped, and comprises a black hole beam main body and a damping layer, the black hole beam main body is fixedly arranged on the structure to be damped, the black hole beam main body comprises a uniform thickness area and an acoustic black hole area which are connected with each other, one or more groups of weight reduction grooves are formed in the uniform thickness area, and the damping layer is arranged in the acoustic black hole area. The damping layer is disposed on the acoustic black hole area. According to the structure, the weight reduction grooves are formed in the non-key area of an original additional acoustic black hole beam structure, redundant materials are removed, light weight of the additional structure is achieved, meanwhile, the local resonance vibration reduction effect and the energy gathering capacity of the acoustic black hole effect on bending waves are kept, and finally broadband vibration control over the main beam is achieved under the low additional mass. And the whole structure meets the requirement for light weight, and is particularly suitable for a beam-shaped system sensitive to additional mass, and particularly suitable for vibration reduction of beam-shaped structures such as beam-shaped components in an automobile body and frame beams of aerospace vehicles.

Description

Technical Field

[0001] This invention specifically relates to an additional locally slotted acoustic black hole beam. Background Technology

[0002] In recent years, acoustic black hole (ABH) technology has been widely used in the field of vibration reduction and noise reduction of thin-walled structures such as beams and plates because it can effectively concentrate and dissipate bending wave energy through power-law thickness or gradual changes in material parameters.

[0003] Acoustic black hole plates, with their two-dimensional wave focusing characteristics, are suitable for developing high-performance transducers and sensing devices. They can be used as radiating plates for longitudinal vibration transducers, utilizing the differences in sound radiation capabilities at different locations to construct multifunctional sound fields for applications such as particle screening.

[0004] Acoustic black hole beams focus on energy concentration in one dimension, making them suitable for sensing and monitoring linear structures. Embedding acoustic black hole beams in the beam-type load-bearing structures of bridges and buildings, along with sensor arrays, enables structural health monitoring. Their energy concentration function significantly improves sensor sensitivity, allowing for the timely detection of minute structural vibrations and the identification of potential safety hazards. They are particularly suitable for beam-type components in automobile bodies and frame beams in aerospace vehicles. However, traditional acoustic black hole beams are mostly made by directly thinning or embedding the original structure. These processing methods often damage the local stiffness and structural integrity of the original components, and are not suitable for engineering applications that require high strength and high reliability.

[0005] To avoid weakening the original components, various additional acoustic black hole beam vibration reduction structures have been proposed in recent years. These structures attach acoustic black holes as independent units to the surface of the original structure to achieve vibration reduction. However, existing additional acoustic black hole structures generally suffer from problems such as large added mass, large overall volume, and limited installation space. They are difficult to meet the actual needs of aerospace, precision equipment, and other fields for lightweight and compact layout, thus limiting their engineering applications.

[0006] Therefore, there is an urgent need for an improved additional acoustic black hole beam structure that can further reduce the self-weight of the additional structure while maintaining the acoustic black hole vibration reduction mechanism and the local resonance vibration reduction capability of the additional structure, and taking into account the installation reliability. Summary of the Invention

[0007] Therefore, it is necessary to provide an additional locally slotted acoustic black hole beam to address the problems of existing additional acoustic black hole structures, such as large added mass, large overall volume, and limited installation space, which make it difficult to meet the actual needs of aerospace, precision equipment and other fields for lightweight and compact layout, thus limiting their engineering applications.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an additional partially slotted acoustic black hole beam, installed on the structure to be vibration-damped, comprising: The black hole beam body is fixedly mounted on the vibration-damping structure. The black hole beam body includes a connected uniform thickness region and an acoustic black hole region. The uniform thickness region has one or more sets of weight-reducing grooves. A damping layer is disposed on the acoustic black hole region.

[0009] In one embodiment, the uniform thickness region of the black hole beam body is connected to the vibration-damping structure by means of adhesive bonding or bolt connection.

[0010] In one embodiment, the damping layer is butyl rubber, asphalt-based damping membrane, polymer damping material, or constrained damping structure.

[0011] In one embodiment, the relationship between the cross-sectional thickness variation of the acoustic black hole region and the length of the acoustic black hole is as follows: ; ; in, At the center of the acoustic black hole region, The length of the acoustic black hole region. The thickness of a uniform thickness region The thickness is the cutoff at the end of the acoustic black hole region. For acoustic black holes, the power-law order is given, and ≥2.

[0012] In one embodiment, the boundary of the weight-reducing groove is located inside the boundary of the uniform thickness region, and the height of the weight-reducing groove is less than the thickness of the uniform thickness region.

[0013] In one embodiment, the boundary of the weight-reducing groove coincides with the boundary of the uniform thickness region, and the height of the weight-reducing groove is less than the thickness of the uniform thickness region.

[0014] In one embodiment, the weight-reducing groove extends through the uniform thickness region in a direction perpendicular to the uniform thickness region.

[0015] In one embodiment, the black hole beam body includes two sets of symmetrically arranged uniform thickness regions, and the weight reduction grooves are formed on the opposite surfaces of the two sets of uniform thickness regions.

[0016] In one embodiment, the damping layer is disposed on one or both sides of the acoustic black hole region.

[0017] In one embodiment, the weight-reducing groove is located in the middle of the uniform thickness region and extends through one or more sides of the uniform thickness region in the horizontal direction.

[0018] Compared with the prior art, the present invention has at least the following advantages: This additional locally slotted acoustic black hole beam removes excess material by creating weight-reducing slots in non-critical areas of the original additional acoustic black hole beam structure, achieving lightweighting of the additional structure while maintaining local resonance vibration reduction effect and the energy concentration ability of the acoustic black hole effect on bending waves. Ultimately, it achieves broadband vibration control of the main beam with lower added mass, enabling the overall structure to meet the lightweight requirements. It is particularly suitable for beam-like systems that are sensitive to added mass, especially for beam-like components in automobile bodies, frame beams in aerospace vehicles, and other beam-like structures for vibration reduction.

[0019] The weight-reducing slot structure in this additional locally slotted acoustic black hole beam is simple to manufacture and can be achieved through conventional processes such as milling and cutting. Furthermore, the slot shape and layout are highly adjustable (including rectangular slots, circular slots, elliptical slots, multi-slot arrays, or borderless slots), and the number and layout of slots are unrestricted. Single slots, multi-slot arrays, equidistant or non-equidistant arrangements, combinations of multiple rows of slots, combinations of annular and central slots, or slot structures optimized according to the beam's vibration mode distribution—as long as weight reduction is achieved while maintaining the energy concentration effect of the acoustic black hole region—are readily adaptable to different engineering requirements.

[0020] The interior of the tank can be hollow, or it can be filled with porous materials, lightweight energy-absorbing materials, local mass blocks, local resonant structures, or multilayer functional materials according to application requirements, in order to achieve additional energy dissipation or tuning effects in specific frequency bands. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0022] Figure 1 A three-dimensional structural schematic diagram of an additional partially slotted acoustic black hole beam provided for this invention; Figure 2 This is a top view of an additional partially slotted acoustic black hole beam according to the present invention; Figure 3 This is a front view of an additional partially slotted acoustic black hole beam according to the present invention; Figure 4 This is a schematic diagram of the second embodiment of the additional locally slotted acoustic black hole beam weight reduction groove of the present invention; Figure 5This is a schematic diagram of the third embodiment of the additional locally slotted acoustic black hole beam weight reduction groove of the present invention; Figure 6 This is a schematic diagram of the fourth embodiment of the present invention, which is a weight reduction groove on an additional locally slotted acoustic black hole beam. Figure 7 This is a schematic diagram of the fifth embodiment of the present invention, which is a weight reduction groove on an additional locally slotted acoustic black hole beam. Figure 8 This is a comparison chart of the damping loss factors of an additional locally slotted acoustic black hole beam of the present invention and a traditional acoustic black hole beam. Figure 9 This is a comparison diagram of the mean square velocity (MSV) of the base beam of the vibration-damping structure after the addition of a partially slotted acoustic black hole beam of the present invention and the traditional acoustic black hole beam.

[0023] Figure label: 1. The structure being damped; 2. Main body of the black hole beam; 21. Uniform thickness region; 211. Weight reduction groove; 22. Acoustic black hole region; 3. Damping layer. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0027] Example 1: Please see Figures 1 to 3This invention provides an additional locally slotted acoustic black hole beam, installed on a vibration-damping structure 1. It includes a black hole beam body 2 fixedly mounted on the vibration-damping structure 1. The black hole beam body 2 includes a uniform thickness region 21 and an acoustic black hole region 22 connected together. The uniform thickness region 21 has one or more sets of weight-reducing grooves 211, and a damping layer 3 is disposed on the acoustic black hole region 22. The uniform thickness region 21 of the black hole beam body 2 is connected to the vibration-damped structure 1 by means of adhesion, bolting, riveting, clamping, snap-fitting, or a combination thereof. The damping layer 3 is made of butyl rubber, asphalt-based damping membrane, polymer damping material, constrained damping structure, or other damping structure. The damping layer 3 is in direct contact with the energy accumulation area, which can significantly improve the dissipation efficiency of vibration energy.

[0028] Please refer to it again. Figures 1 to 3 In this embodiment, the relationship between the thickness variation of the cross-section of the acoustic black hole region 22 and the length of the acoustic black hole is as follows: ; ; in, For the center of acoustic black hole region 22, The length of the acoustic black hole region is 22. The thickness of the uniform thickness region 21, The thickness is the truncated portion at the end of region 22 of the acoustic black hole. For acoustic black holes, the power-law order is given, and ≥2.

[0029] The thickness of the acoustic black hole region 22 gradually decreases along its length according to a power law until a certain truncated thickness is formed at the thinnest end. This region utilizes the characteristic that the propagation speed of flexural waves decreases with decreasing thickness to concentrate energy at the thinner end, providing a high energy density region for the energy dissipation of the damping layer 3. To improve the vibration reduction effect, the truncated thickness end can be extended into a platform.

[0030] Please see Figure 1 and Figure 3 The boundary of the weight-reducing groove 211 is located inside the boundary of the uniform thickness region 21, and the height of the weight-reducing groove 211 is less than the thickness of the uniform thickness region 21, so that the uniform thickness region 21 retains a region connected to the vibration-damping structure 1. The material of the black hole beam body 2 can be a metal plate, a composite material plate, or a polymer plate, as long as the plate can provide a non-critical area with local slotting and an area that conforms to the acoustic black hole thinning law. The dimensions of the uniform thickness region 21 are Luni*Duni*Huni. In addition, in some preferred embodiments, the weight-reducing groove 211 penetrates the uniform thickness region 21 along a direction perpendicular to the uniform thickness region 21 to improve the lightweight effect.

[0031] Example 2: Please see Figure 4 The boundary of the weight-reducing groove 211 coincides with the boundary of the uniform thickness region 21, and the height of the weight-reducing groove 211 is less than the thickness of the uniform thickness region 21. This ensures that the uniform thickness region 21 has a portion that can be connected to the vibration-damping structure 1, while also expanding the range of the weight-reducing groove 211 to further improve the lightweighting effect.

[0032] Example 3: Please see Figure 5 Multiple sets of weight-reducing grooves 211 are provided, and the multiple sets of weight-reducing grooves 211 are arranged in an array on the uniform thickness region 21. The arrangement of the weight-reducing grooves 211 can be either not penetrating the uniform thickness region 21 or penetrating the uniform thickness region 21, depending on the actual needs.

[0033] Example 4: Please see Figure 6 The main body 2 of the black hole beam includes two sets of symmetrically arranged uniform thickness regions 21. The opposite surfaces of the two sets of uniform thickness regions 21 are provided with weight reduction grooves 211, forming a symmetrical local weight reduction structure. The damping layer 3 is set on one or both sides of the acoustic black hole region 22 to further improve the vibration reduction effect and the lightweight effect.

[0034] Example 5: Please see Figure 7 The weight-reducing groove 211 is located in the middle of the uniform thickness region 21 and extends through one or more sides of the uniform thickness region 21 in the horizontal direction. The partial groove structure is arranged on the lateral surface of the beam, rather than the upper surface. This structure is suitable for certain installation scenarios where the upper surface mating surface is limited or needs to remain flat. Lateral grooves can also eliminate non-critical materials, achieving weight reduction.

[0035] Understandably, the weight-reducing groove 211 is used to reduce the mass of the additional acoustic black hole beam. Its location is not limited to the upper surface of the uniform thickness region 21; it can be placed on the upper surface of the acoustic black hole region 22, the side of the uniform thickness region 21, or other areas that do not affect the black hole thickness distribution and connection interface. The groove dimensions are Ls (length) * Ds (width) * Hs (height), which can be adjusted according to the lightweighting target. The weight-reducing groove 211 is Lx away from the left boundary of the uniform thickness region and Ly away from the lower boundary of the uniform thickness region. The weight-reducing groove 211 is used to remove some non-critical material, thereby reducing the overall mass of the additional acoustic black hole beam without affecting the connection interface with the vibration-damped structure 1. Simultaneously, this operation does not affect the local resonance capability of the additional structure. To achieve better lightweighting, a borderless groove can be designed, i.e., Lx = Ly = 0, which allows for maximum removal of excess material. The groove shape is not limited to rectangles; it can be circular, elliptical, multi-groove arrays, or borderless grooves, etc., to adapt to different processing conditions and performance requirements. The number of slots can be one or more.

[0036] Please refer to it again. Figures 1 to 3 In some embodiments, the uniform thickness region 21 has dimensions of Luni (length) * Duni (width) * Huni (height) = 0.25m * 0.08m * 0.04m, and is used for bonding or bolting to the damped structure 1, with its thickness remaining constant. A partially slotted cavity 221 with dimensions of Ls * Ds * Hs = 0.064m * 0.048m * 0.016m is formed on the upper surface of the uniform thickness region 21, at a distance of Lx = 0.032m from the left side boundary of the uniform thickness region and Ly = 0.02m from the lower side boundary of the uniform thickness region. The damping layer 3 has dimensions of Ld * Dd * Hd = 0.175m * 0.08m * 0.008m.

[0037] Please see Figure 8 , Figure 9 Based on the above parameters, three-dimensional modeling and simulation were performed on the additional locally slotted acoustic black hole beam vibration reduction structure of the present invention and the traditional acoustic black hole beam to verify its vibration suppression effect. Figure 8 To illustrate the comparison of damping loss factors between the present invention and a conventional acoustic black hole beam, it can be seen that the local slotting operation increases the modal number of the structure of the present invention, thereby expanding its local resonance range and enhancing vibration reduction energy at certain frequencies. Furthermore, the damping loss factors of the two structures are not significantly different in the high-frequency range, indicating that the high-damping effect of the acoustic black hole is not compromised. Figure 9A comparison of the mean square velocity (MSV) of the vibration-damped structural beam is shown. It can be seen that both structures exhibit excellent vibration suppression capabilities and similar damping effects. Within certain frequency ranges, the damping effect of this invention is superior to that of the traditional acoustic black hole beam. Furthermore, the added structure of this invention (14.01 kg) is 4.37 kg lighter than the traditional acoustic black hole beam structure (18.38 kg), achieving a lightweight design for the added structure.

[0038] Specific usage and beneficial effects of the present invention: This additional locally slotted acoustic black hole beam removes excess material by creating weight-reduction slots 211 in non-critical areas of the original additional acoustic black hole beam structure, achieving lightweighting of the additional structure while maintaining local resonance vibration reduction effect and the energy concentration ability of the acoustic black hole effect on bending waves. Ultimately, it achieves broadband vibration control of the main beam with lower added mass, enabling the overall structure to meet the lightweight requirements. It is particularly suitable for beam-like systems that are sensitive to added mass, especially for beam-like components in automobile bodies, frame beams in aerospace vehicles, and other beam-like structures for vibration reduction.

[0039] The weight-reducing groove 211 structure in this additional locally slotted acoustic black hole beam is simple to manufacture and can be achieved through conventional processes such as milling and cutting. Furthermore, the shape and layout of the grooves are highly adjustable (including rectangular grooves, circular grooves, elliptical grooves, multi-groove arrays, or borderless grooves), and the number and layout of the grooves are unrestricted. Single grooves, multi-groove arrays, equidistant or non-equidistant arrangements, combinations of multiple rows of grooves, combinations of annular grooves and central grooves, or groove structures optimized according to the beam's vibration mode distribution, are all acceptable as long as they achieve weight reduction and maintain the energy concentration effect of the acoustic black hole region 22. This allows for structural optimization based on different engineering requirements.

[0040] The interior of the tank can be hollow, or it can be filled with porous materials, lightweight energy-absorbing materials, local mass blocks, local resonant structures, or multilayer functional materials according to application requirements, in order to achieve additional energy dissipation or tuning effects in specific frequency bands.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. An additional locally slotted acoustic black hole beam, installed on the vibration-damping structure (1), characterized in that, Including: The black hole beam body (2) is fixedly mounted on the vibration-damping structure (1). The black hole beam body (2) includes a uniform thickness region (21) and an acoustic black hole region (22) connected to each other. The uniform thickness region (21) is provided with one or more sets of weight-reducing grooves (211). A damping layer (3) is disposed on the acoustic black hole region (22).

2. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The uniform thickness region (21) of the black hole beam body (2) is connected to the vibration-damped structure (1) by bonding or bolting.

3. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The damping layer (3) is butyl rubber, asphalt-based damping membrane, polymer damping material or constrained damping structure.

4. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that, The relationship between the thickness variation of the cross-section of the acoustic black hole region (22) and the length of the acoustic black hole is as follows: ； ； in, At the center of the acoustic black hole region (22), The length of the acoustic black hole region (22) The thickness of the uniform thickness region (21) The thickness is the cutoff at the end of the acoustic black hole region (22). For acoustic black holes, the power-law order is given, and ≥2.

5. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The boundary of the weight reduction groove (211) is located inside the boundary of the uniform thickness region (21), and the height of the weight reduction groove (211) is less than the thickness of the uniform thickness region (21).

6. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The boundary of the weight reduction groove (211) coincides with the boundary of the uniform thickness region (21), and the height of the weight reduction groove (211) is less than the thickness of the uniform thickness region (21).

7. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The weight reduction groove (211) penetrates the uniform thickness region (21) in a direction perpendicular to the uniform thickness region (21).

8. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The main body (2) of the black hole beam includes two sets of symmetrically arranged uniform thickness regions (21), and the weight reduction grooves (211) are opened on the opposite surfaces of the two sets of uniform thickness regions (21).

9. The additional partially slotted acoustic black hole beam according to claim 8, characterized in that: The damping layer (3) is disposed on one or both sides of the acoustic black hole region (22).

10. The additional partially slotted acoustic black hole beam according to claim 1, characterized in that: The weight reduction groove (211) is located in the middle of the uniform thickness region (21) and extends through the uniform thickness region (21) on one or more sides in the horizontal direction.

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