Additional locally-slotted acoustic black hole plate

Abstract

The invention provides an additional locally slotted acoustic black hole board, which is mounted on a main board to be damped and comprises a black hole board main body and a damping layer, the black hole board main body is fixed on the main board to be damped and comprises a uniform thickness area and one or more acoustic black hole areas, one or more weight reduction grooves are formed in the uniform thickness area, and the damping layer is arranged on the damping layer. And a damping layer is arranged on the acoustic black hole area. According to the additional type locally-slotted acoustic black hole plate, by forming the weight reducing grooves in the non-key area of an original additional acoustic black hole plate structure, redundant materials are removed, the weight reduction of an 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 the acoustic black hole plate has the advantages of being simple in structure and convenient to use. Finally, broadband vibration control of the mainboard is achieved under the low additional mass, the overall structure meets the requirement for light weight, and the structure is particularly suitable for a plate-shaped system sensitive to the additional mass.

Description

Technical Field

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

[0002] Plate structures are widely used in mechanical equipment housings, aerospace skins, vehicle sound insulation panels, electronic equipment cavities, and other fields. Their inherent thin-walled characteristics make them prone to strong vibrations and structural sound radiation in the low and medium frequency range.

[0003] Traditional methods for vibration reduction of plates include coating damping layers, adding ribs for reinforcement, and adding local mass. However, these methods often have the following problems: large added mass, insufficient low-frequency control capability, complex processing or alteration of the original stress characteristics of the plate, making it difficult to meet the needs of modern equipment for lightweight and wide-frequency vibration suppression.

[0004] Acoustic Black Hole (ABH) technology has been proven in recent years to significantly improve the energy dissipation efficiency of damping materials by gradually slowing down and concentrating bending waves in the thinner region during plate propagation through power-law thinning or gradual material parameter variation mechanisms.

[0005] However, while various additional symmetrical and asymmetrical acoustic black hole panels, such as rectangular and circular designs, have been developed to avoid thinning the mainboard structure, they generally suffer from problems such as excessive structural mass, limited layout, and a lack of adjustable lightweight design. Therefore, there is an urgent need for a novel acoustic black hole panel structure that can achieve the acoustic black hole effect through an additional method without altering the integrity of the mainboard structure, and further achieve lightweight design, in order to solve the aforementioned problems. Summary of the Invention

[0006] Therefore, it is necessary to provide an additional locally slotted acoustic black hole board, which addresses the problems of existing additional symmetrical and asymmetrical acoustic black hole boards, which, although they can avoid thinning the mainboard structure, generally have large structural mass, limited layout, and lack of adjustable lightweight design.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an additional partially slotted acoustic black hole plate, mounted on the mainboard to be damped, comprising: A black hole plate body is fixed to the damped main plate. The black hole plate body includes a uniform thickness region and one or more acoustic black hole regions. One or more weight-reducing grooves are formed on the uniform thickness region. A damping layer is disposed on the acoustic black hole region.

[0008] In one embodiment, a portion of the uniform thickness region of the black hole plate body is connected to the damped main plate, and the connection method is adhesive or bolt connection.

[0009] In one embodiment, the damping layer is butyl rubber, asphalt-based damping membrane, polymer damping material, or constrained damping structure.

[0010] In one embodiment, an extension platform is provided at the end of the truncated region of the acoustic black hole region.

[0011] In one embodiment, the thickness variation of the cross-section of the acoustic black hole region is a function of the length of the acoustic black hole as follows: ; ; in, For the center of their respective acoustic black holes, For their respective acoustic black hole radii, For each uniform region thickness, The thickness is truncated at the end of each acoustic black hole. For acoustic black holes, the power-law order is given, and ≥2.

[0012] In one embodiment, the depth of the weight-reducing groove is less than the thickness of the uniform thickness region.

[0013] In one embodiment, the weight-reducing groove extends through the uniform thickness region, and the edge of the weight-reducing groove does not exceed the uniform thickness region.

[0014] In one embodiment, the black hole plate body is a rectangular or circular structure.

[0015] In one embodiment, the black hole plate body includes two sets of symmetrically arranged uniform thickness regions, each of which has one or more acoustic black hole regions arranged on it, and the weight reduction groove penetrates through 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] Compared with the prior art, the present invention has at least the following advantages: This additional locally slotted acoustic black hole panel removes excess material and achieves lightweighting of the additional structure by creating weight-reducing slots in non-critical areas of the original acoustic black hole panel structure. Simultaneously, it maintains the local resonance damping effect and the energy concentration capability of the acoustic black hole effect for bending waves. Ultimately, it achieves wide-frequency vibration control of the main board with a lower added mass, ensuring the overall structure meets lightweight requirements. This is particularly suitable for plate-like systems sensitive to added mass. Furthermore, the weight-reducing slot structure is simple to manufacture, achieving its design through conventional processes such as milling and cutting. The slot shape and layout are highly adjustable (including rectangular slots, circular slots, elliptical slots, multi-slot arrays, etc.), and the number and layout of slots are unlimited. Single slots, multi-slot arrays, equidistant or non-equidistant arrangements, multi-row slot combinations, combinations of annular and central slots, or slot structures optimized according to the plate's vibration mode distribution are all acceptable, as long as weight reduction is achieved and the energy concentration effect of the acoustic black hole region is maintained. This facilitates structural optimization according to different engineering needs. 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

[0018] 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.

[0019] Figure 1 A three-dimensional structural schematic diagram of an additional partially slotted acoustic black hole plate provided by the present invention; Figure 2 This is a top view of an additional partially slotted acoustic black hole plate according to the present invention; Figure 3 This is a front view of an additional partially slotted acoustic black hole plate according to the present invention; Figure 4 A schematic diagram of an additional partially slotted acoustic black hole plate with an extension platform; Figure 5 for Figure 4 The main view; Figure 6 This is a schematic diagram of the structure of the additional partially slotted acoustic black hole plate of the present invention, which is a circular additional multi-slotted array. Figure 7 This is a schematic diagram of the structure of an additional locally slotted acoustic black hole plate of the present invention, which is a circular symmetrical additional through-slot. Figure 8 This is a comparison chart of the damping loss factors of an additional locally slotted acoustic black hole plate of the present invention and a traditional acoustic black hole plate structure. Figure 9This is a comparison of the mean square velocity (MSV) of vibration after the additional partially slotted acoustic black hole plate of the present invention and the traditional acoustic black hole plate structure are applied to the damped main board.

[0020] Figure label: 1. The motherboard subjected to shock absorption; 2. Black hole panel main body; 21. Acoustic black hole region; 22. Uniform thickness region; 23. Weight reduction groove; 24. Expansion platform; 3. Damping layer. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Example 1: Please see Figures 1 to 3 This invention provides an additional locally slotted acoustic black hole plate, mounted on a damped main plate 1. It includes a black hole plate body 2 fixed to the damped main plate 1. The black hole plate body 2 includes a uniform thickness region 22 and one or more acoustic black hole regions 21. A damping layer 3 is disposed on the acoustic black hole region 21. The damping layer 3 is made of butyl rubber, asphalt-based damping membrane, polymer damping material, or constrained damping structure. The damping layer 3 is in direct contact with the energy accumulation region, which can significantly improve the dissipation efficiency of vibration energy. The thickness variation of the acoustic black hole region 21 is a function of the acoustic black hole length: ; ; in, For the center of their respective acoustic black holes, For their respective acoustic black hole radii, For each uniform region thickness, The thickness is truncated at the end of each acoustic black hole. For acoustic black holes, the power-law order is given, and ≥2.

[0025] The black hole plate body 2 allows bending waves within the plate to converge towards the center of the black hole and be absorbed by the damping layer 3. It is understood that, in some preferred embodiments, the black hole plate body 2 can be a rectangular structure and includes four acoustic black hole regions 21. To improve the vibration reduction effect of the acoustic black holes, an extension platform 24 can be extended into the truncated portion of the acoustic black holes. The overall shape and size of the additional acoustic black holes can be freely designed according to lightweighting and vibration reduction requirements, and are not limited to a rectangular, centrally symmetrical acoustic black hole plate.

[0026] Please refer to it again. Figures 1 to 3 In this embodiment, the uniform thickness region 22 of the black hole plate body 2 is connected to the damped main plate 1, and the connection method is adhesive or bolt connection, or it can be riveting, clamping, snap-fitting or a combination of connection methods. The overall shape and material of the black hole plate body 2 are not limited to a fixed form, and can be rectangular, circular, elliptical or other arbitrary contours; the material can be metal plate, composite material plate or polymer plate, etc., as long as the plate can provide non-critical areas with local slotting and areas that conform to the thinning law of acoustic black holes. The size of the uniform thickness region 22 is Luni*Duni*Huni. When the outer contour size of the acoustic black hole is fixed, its position and size can be determined by the respective radii of the acoustic black holes. Adjustments were made.

[0027] Please see Figure 2 , Figure 3 In this embodiment, one or more weight-reducing grooves 23 are formed on the uniform thickness region 22. It is understood that, in some preferred embodiments, the depth of the weight-reducing groove 23 is less than the thickness of the uniform thickness region 22. The weight-reducing groove 23 is not in a through state, so that the uniform thickness region 22 can be partially connected to the damped main board 1. In order to achieve lightweight design and reduce the mass of the additional structure, weight-reducing grooves 23 are locally formed on the upper surface of the acoustic black hole structure. The dimensions of the weight-reducing groove 23 are Ls*Ds*Hs, and its position is Lx away from the left side boundary of the acoustic black hole structure 2 and Ly away from the lower side boundary of the acoustic black hole structure 2. The specific dimensions can be adjusted according to the actual application requirements and lightweight goals.

[0028] The slotted area can be located in a region with uniform plate thickness or in a region where the thickness of the acoustic black hole varies. The shape and size of the slot can be freely designed according to the requirements of lightweighting, including rectangular slots, circular slots, elliptical slots, or arrays of multiple slots.

[0029] Example 2: Please see Figures 1 to 3 Taking the following dimensions as an example, the acoustic black hole region 21 is composed of four acoustic black hole structures. The lengths of the acoustic black holes in each direction are Labh_left=Labh_right=0.1m, Labh_up=Labh_down=0.08m, the thickness of the uniform region is Huni=0.006m, and the truncation thickness is H0=5E. -4 m (E-number is a simplified scientific notation used to represent extremely large or small values. The integer after E represents a power of 10. Its core form is aEb, which represents a × 10b. For example, 5E-4 represents 5 × 10^-4. This method optimizes the efficiency of numerical writing by unifying the exponent format and is mainly applied to digital data processing scenarios that require standardized representation).

[0030] The power law order of the acoustic black hole is m=2. To achieve a lightweight design and reduce the mass of the additional structure, a weight-reducing groove 23 is locally formed on the upper surface of the acoustic black hole structure. The specific dimensions of the weight-reducing groove 23 are Ls*Ds*Hs=0.04m*0.03m*0.004m. Its position is Lx=0.105m away from the left side boundary of the black hole plate body 2 and Ly=0.085m away from the lower side boundary of the black hole plate body 2. There is no filling material in this cavity. In order to dissipate the energy accumulated in the acoustic black hole region 21, a damping layer 3 with Dd*Hd=0.05m*0.0025m is installed on the upper surface of the acoustic black hole region 21.

[0031] Example 3: Please see Figures 4 to 5Taking the following dimensions as an example, the structure is a rectangular non-centrosymmetric acoustic black hole plate. The black hole lengths of the four acoustic black hole regions 21 are Labh_left=Labh_right=Labh_up=0.08m and Labh_down=0.02m, respectively. The thickness of the uniform region is Huni=0.006m, the truncated thickness is H0=5E-4m, and the power law order of the acoustic black hole is m=2. To achieve a lightweight design and reduce the mass of the additional structure, a weight-reducing groove 23 is locally opened on the upper surface of the acoustic black hole structure. The specific dimensions of the weight-reducing groove 23 are Ls (length) * Ds (width) * Hs (height) = 0.03m * 0.025m * 0.004m. Its position is Lx=0.11m away from the left side boundary of the black hole plate body 2 and Ly=0.1075m away from the lower side boundary of the black hole plate body 2. There is no filling material in this cavity. To enhance the vibration reduction effect of the acoustic black hole, an extended platform 24 is constructed in the truncated section of the acoustic black hole. The damping width is equal to the width of the extended platform 24, which has widths of Lt_left=Lt_right=0.03m, Lt_up=Lt_down=0.0275m, and thicknesses of both Ht=5E-4m. To dissipate the energy accumulated in the acoustic black hole region 21, a damping layer 3 with a uniform width and a thickness of Huni=0.0025m is installed on the upper surface of the extended platform 24.

[0032] Please see Figure 8 , Figure 9 Based on the above parameters, three-dimensional modeling and simulation were performed on the vibration reduction structure of the additional locally slotted acoustic black hole plate of the present invention and the traditional acoustic black hole plate to verify its vibration suppression effect. Figure 8 The damping loss factor comparison between the present invention and a conventional acoustic black hole plate is presented. It can be seen that the two structures have the same number of natural frequencies within the normal operating frequency range, and the frequency positions of each mode are almost identical. This indicates that the local slotting does not affect the traditional acoustic black hole plate's function as a local resonance damping device. Furthermore, the damping loss factor values ​​of the two structures are mostly the same, and in some cases even better than the traditional acoustic black hole plate, indicating that the invention improves the damping loss capability of the acoustic black hole plate. Figure 9 The comparison chart of the average square velocity (MSV) of the vibration-damped substrate is shown. It can be seen that both structures have similar excellent vibration suppression capabilities. This invention does not destroy the acoustic black hole effect of the original traditional acoustic black hole plate structure, nor does it have the local resonance vibration reduction capability of the additional structure. However, the mass of the additional structure of this invention is reduced by 10% to 15% compared with the traditional acoustic black hole plate structure, realizing the lightweight design of the additional structure.

[0033] Please see Figure 6 In some embodiments, the black hole plate body 2 can be a circular structure. Additionally, please refer to... Figure 7In this embodiment, the weight-reducing groove 23 penetrates the uniform thickness region 22, and the edge of the weight-reducing groove 23 does not exceed the uniform thickness region 22. The black hole plate body 2 includes two sets of symmetrically arranged uniform thickness regions 22, each of which has one or more acoustic black hole regions 21. The weight-reducing groove 23 penetrates both sets of uniform thickness regions 22. The damping layer 3 is arranged on one or both sides of the acoustic black hole region 21. The area around the weight-reducing groove 23 can be bolted or bonded to the damped main plate 1 to maximize the lightweight design.

[0034] Specific usage and beneficial effects of the present invention: This additional locally slotted acoustic black hole panel achieves lightweighting of the additional structure by removing excess material through weight-reduction slots 23 in non-critical areas of the original additional acoustic black hole panel structure. Simultaneously, it maintains the local resonance damping effect and the energy concentration capability of the acoustic black hole effect for bending waves. Ultimately, it achieves wide-frequency vibration control of the main board with a lower added mass, ensuring the overall structure meets lightweight requirements. This is particularly suitable for plate-shaped systems sensitive to added mass. Furthermore, the weight-reduction slots 23 are simple to manufacture, achievable through conventional processes such as milling and cutting. The slot shape and layout are highly adjustable (including rectangular slots, circular slots, elliptical slots, multi-slot arrays, etc.), and the number and layout of slots are unrestricted. Single slots, multi-slot arrays, equidistant or non-equidistant arrangements, multi-row slot combinations, combinations of annular and central slots, or slot structures optimized according to the plate's vibration mode distribution are all acceptable, as long as weight reduction is achieved and the energy concentration effect of the acoustic black hole region 21 is maintained. This facilitates structural optimization according to different engineering needs. 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.

[0035] 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 partially slotted acoustic black hole plate, installed on the main damping plate (1), characterized in that, Including: The black hole plate body (2) is fixed to the damped main plate (1). The black hole plate body (2) includes a uniform thickness region (22) and one or more acoustic black hole regions (21). One or more weight-reducing grooves (23) are formed on the uniform thickness region (22). A damping layer (3) is disposed on the acoustic black hole region (21).

2. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The uniform thickness region (22) of the black hole plate body (2) is connected to the damped main plate (1), and the connection method is adhesive or bolt connection.

3. The additional partially slotted acoustic black hole plate 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 plate according to claim 1, characterized in that: An extension platform (24) is provided at the truncated region at the end of the acoustic black hole region (21).

5. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The relationship between the cross-sectional thickness variation of the acoustic black hole region (21) and the length of the acoustic black hole is as follows: ； ； in, For the center of their respective acoustic black hole regions (22), For each acoustic black hole region (22), The thickness of each uniform thickness region (21) For the truncated thickness at the end of each acoustic black hole region (22), For acoustic black holes, the power-law order is given, and ≥2.

6. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The depth of the weight reduction groove (23) is less than the thickness of the uniform thickness region (22).

7. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The weight-reducing groove (23) penetrates the uniform thickness region (22), and the edge of the weight-reducing groove (23) does not exceed the uniform thickness region (22).

8. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The main body (2) of the black hole plate is a rectangular or circular structure.

9. The additional partially slotted acoustic black hole plate according to claim 1, characterized in that: The black hole plate body (2) includes two sets of symmetrically arranged uniform thickness regions (22), each of which has one or more acoustic black hole regions (21), and the weight reduction groove (23) penetrates the two sets of uniform thickness regions (22).

10. An additional partially slotted acoustic black hole plate according to claim 9, characterized in that: The damping layer (3) is arranged on one or both sides of the acoustic black hole region (21).

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