H-shaped multi-mode sound damper and design method thereof

Abstract

This invention discloses an H-configuration multimodal noise-absorbing vibration damper and its design method, belonging to the field of vibration control technology. The vibration damper includes a composite-clad elastic plate, an elastic plate, a multimodal coupling structure, and movable counterweights. The elastic plate assembly includes a composite-clad elastic plate, which is a layered structure formed by combining fiberglass epoxy board and stainless steel, prepared by a molding process. The material ratio of fiberglass epoxy board to stainless steel is determined according to the formula for the stiffness of a simply supported beam spring. Both sets of movable counterweights can slide and adjust their positions along the length of the composite-clad elastic plate or the elastic plate, adapting to the vibration suppression requirements of different frequency bands by changing the mass distribution of the noise-absorbing vibration damper. The multimodal coupling structure is integrated into the elastic plate assembly, and frequency control of multiple modes is achieved through stiffness matching between the elastic plate assembly and the multimodal coupling structure. This invention can cover a wide frequency band, has high vibration reduction efficiency, and a reliable structure, providing technical support for the field of multi-frequency vibration suppression.

Description

Technical Field

[0001] This invention belongs to the field of vibration control technology, specifically relating to an H-configuration multimodal noise-absorbing vibration damper and its design method. Background Technology

[0002] As a classic mechanical model, the spring characteristics (stiffness and deformation law) of simply supported beam structures have been widely used in vibration control. However, existing technologies have not combined them with composite material properties and multimodal structures. Although composite encapsulation technology can improve the comprehensive performance of materials, the influence of molding process parameters on elastic modulus and damping characteristics has not been precisely controlled. Although H-shaped structures have advantages in structural stability, they have not achieved multi-order vibration coverage through modal coupling design.

[0003] Currently, existing noise-reducing and vibration-damping devices generally suffer from problems such as single modal characteristics and poor frequency tuning flexibility. This is mainly due to a lack of precise mechanical models, relying heavily on experience-based design, making it difficult to achieve a proper match between stiffness and mass. Furthermore, the elastic and damping characteristics of traditional metals or single composite materials are difficult to balance, failing to meet the material performance requirements for multi-frequency vibration reduction. The structural design does not consider multi-modal coupling, leading to disordered higher-order modal frequencies and unstable vibration reduction effects. In summary, current noise-reducing and vibration-damping devices struggle to achieve a proper match between stiffness and mass, do not easily meet the material performance requirements for multi-frequency vibration reduction, and exhibit relatively disordered higher-order modal frequencies, resulting in a need for further optimization of the stability of the vibration reduction effect. Summary of the Invention

[0004] This invention provides an H-configuration multimodal noise reduction and vibration damping device and its design method. The purpose is to solve the problems in current noise reduction and vibration damping devices, such as difficulty in achieving a match between stiffness and mass, difficulty in meeting the material performance requirements for multi-band vibration reduction, and relatively disordered high-order modal frequencies, which lead to the need for further optimization of the stability of the vibration reduction effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an H-shaped multimodal noise reduction and vibration damping device, comprising an H-shaped clamping plate body, the H-shaped clamping plate body including an elastic plate assembly, a multimodal coupling structure, and four movable counterweights; wherein: The elastic plate assembly includes a composite-clad elastic plate and an elastic plate arranged side by side. The elastic plate and the composite-clad elastic plate are long plate-shaped structures and their structures are compatible. The composite-clad elastic plate is a layered structure formed by combining glass fiber epoxy board and stainless steel, and is prepared by compression molding process. The material ratio of glass fiber epoxy board to stainless steel is determined according to the formula for the stiffness of a simply supported beam spring. The four movable counterweights are divided into two groups. The first group of movable counterweights is spaced along the length of the composite-clad elastic plate, and the second group of movable counterweights is spaced along the length of the elastic plate. Both groups of movable counterweights can slide and adjust their positions along the length of the composite-clad elastic plate or the elastic plate. By changing the mass distribution of the noise-absorbing and vibration-damping device, it can adapt to the vibration suppression requirements of different frequency bands. The multimodal coupling structure is integrated into the elastic plate group and located between the two movable counterweights of the first and second groups. The frequency control of the multi-mode is achieved by matching the stiffness of the elastic plate group and the multimodal coupling structure.

[0006] In some implementations, the composite-clad elastic plate is designed based on the characteristics of a simply supported beam spring. The formula for the stiffness of a simply supported beam spring based on the ratio of fiberglass epoxy board to stainless steel is as follows: ; in, For the spring stiffness of a simply supported beam, The elastic modulus of the material, Let the moment of inertia of the cross section be... The length is for a simply supported beam.

[0007] In some implementations, the multimodal coupling structure achieves uniform frequency spacing of multiple modes by adjusting the ratio of the cross-sectional moments of inertia of the elastic plate assembly, enabling the elastic plate assembly to achieve multimodal vibration, wherein: The first mode is the bending vibration of the longitudinal beam, the second mode is the bending vibration of the transverse beam, the third mode is the coupled bending vibration of the longitudinal and transverse beams, and the fourth mode is the overall torsional vibration; the damping ratio of each mode is controlled by the loss factor of the composite-clad elastic plate.

[0008] Furthermore, the connection between the multimodal coupling structure and the composite-clad elastic plate and the elastic plate is optimized through finite element simulation to ensure that the vibration modes of the first to fourth orders do not overlap; the H-shaped cladding plate has a hollow area, which forms an air damping cavity. The air damping cavity works in conjunction with the material damping of the composite-clad elastic plate to achieve the synergistic effect of structural vibration reduction and air damping noise reduction.

[0009] In some embodiments, the two movable counterweights of the first group are symmetrically distributed along the composite-clad elastic plate, and the two movable counterweights of the second group are symmetrically distributed along the elastic plate. The sliding adjustment range of each movable counterweight covers one-third to two-thirds of the length of its corresponding composite-clad elastic plate or elastic plate.

[0010] In some embodiments, the composite-clad elastic plate is a layered structure formed by combining a fiberglass epoxy board and stainless steel, and is prepared by a molding process of prepreg preparation, compression molding, and post-treatment.

[0011] Furthermore, in the preparation of the prepreg, the glue content of the glass fiber epoxy board prepreg is controlled at 33-37%; the stainless steel plate surface is coated with a coupling agent after sandblasting, and the surface of the stainless steel plate after sandblasting reaches the preset roughness.

[0012] Furthermore, the process parameters for compression molding are as follows: Temperature is controlled at 115-125℃, pressure is controlled at 4.5-5.5MPa, and holding time is controlled at 25-35min. The interlayer bonding strength of the composite-clad elastic plate after molding is not less than 25MPa.

[0013] Furthermore, the post-processing steps include room temperature curing, precision milling, and outer contour optimization. First, the molded composite board is cured at room temperature for a preset time, then milled to the preset dimensional accuracy, and finally the sharp corners of the board's outer contour are rounded.

[0014] This invention also provides a design method for an H-configuration multimodal noise-absorbing and vibration-damping device, which is based on the above-mentioned H-configuration multimodal noise-absorbing and vibration-damping device and includes the following steps: S1. Determine the target vibration reduction frequency band of the silencer and vibration damper, and determine the design parameters of the H-shaped clamping plate body based on the spring characteristics of the simply supported beam. S2. Fiberglass epoxy board and stainless steel are combined to form a layered structure. The material ratio of fiberglass epoxy board and stainless steel is calculated according to the formula of spring stiffness of simply supported beam. The stiffness and mass range of the composite-clad elastic plate are determined. The elastic modulus and damping characteristics are controlled by the molding process. The composite-clad elastic plate is prepared by molding and the elastic plate is designed and prepared accordingly. S3. Integrate the multimodal coupling structure onto the elastic plate assembly, and achieve frequency control of multiple modes by adjusting the stiffness matching relationship between the composite-clad elastic plate and the elastic plate and the multimodal coupling structure. S4. Design the sliding adjustment range of the movable counterweight, and adjust the mass distribution of the system by changing the position of the counterweight to match the frequency band to be damped.

[0015] Compared with the prior art, the H-configuration multimodal noise-absorbing and vibration-damping device and its design method of the present invention have the following beneficial effects: This invention discloses an H-shaped multimodal noise-absorbing vibration damper, constructing a multimodal noise-absorbing vibration damper with wide frequency coverage, high vibration reduction efficiency, and structural reliability, thus improving upon the shortcomings of existing noise-absorbing vibration dampers, such as single mode, poor frequency tuning flexibility, and difficulty in balancing vibration reduction and strength. Based on a simply supported beam mechanical model, this invention establishes a quantitative matching relationship between structural parameters and the vibration reduction frequency band through precise stiffness and natural frequency calculations; it achieves synergistic optimization of elastic modulus, damping characteristics, and structural strength through composite material clamping; and it achieves precise suppression of multi-order vibrations across a wide frequency band through the fourth-order modal coupling design of the H-shaped structure. Modal testing and vibration reduction performance verification show that the noise-absorbing vibration damper with the designed material proportion configuration exhibits excellent comprehensive performance, with first to fourth order modal frequencies highly matched to the motor vibration frequency band, meeting the suppression requirements of the core vibration frequency band of industrial equipment. Meanwhile, the movable counterweight of this invention enables flexible adjustment of the vibration reduction frequency band, making it suitable for various applications such as power equipment and industrial machinery; the molding process of the composite-clad elastic plate and strict quality control ensure the structural stability of the noise reduction and vibration damping device under long-term vibration environment, and it has certain engineering applicability. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the architecture of an H-configuration multimodal noise reduction and vibration damping device according to the present invention; Figure 2 This is a schematic diagram of the architecture of an H-configuration multimodal noise-absorbing and vibration-damping device according to the present invention from another angle; Figure 3 This is a schematic diagram of the mode distribution of an H-configuration multimodal noise-absorbing and vibration-damping device according to an embodiment of the present invention.

[0018] Among them, 1. Composite material sandwiched elastic plate, 2. Elastic plate, 3. Multimodal coupling structure, 4. Movable counterweight. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0024] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0025] like Figures 1-3 As shown, this invention provides an H-shaped multimodal noise reduction and vibration damping device, comprising an H-shaped clamping plate body, the H-shaped clamping plate body including an elastic plate assembly, a multimodal coupling structure 3, and four movable counterweights 4; wherein: The elastic plate assembly includes two parallel composite-clad elastic plates 1 and 2. Elastic plate 2 and composite-clad elastic plate 1 are long plate-shaped structures and their structures are compatible. Composite-clad elastic plate 1 is a layered structure formed by combining fiberglass epoxy board and stainless steel, and is prepared by compression molding process. The material ratio of fiberglass epoxy board to stainless steel is determined by calculation according to the formula of stiffness of simply supported beam spring. The four movable counterweights 4 are in two groups. The first group of movable counterweights 4 is spaced along the length of the composite-clad elastic plate 1, and the second group of movable counterweights 4 is spaced along the length of the elastic plate 2. Both groups of movable counterweights 4 can slide and adjust their positions along the length of the composite-clad elastic plate 1 or the elastic plate 2. By changing the mass distribution of the noise-absorbing and vibration-damping device, it can adapt to the vibration suppression requirements of different frequency bands. The multimodal coupling structure 3 is integrated into the elastic plate group and is located between the two movable counterweights 4 of the first and second groups. The frequency control of the multi-mode is achieved by matching the stiffness of the elastic plate group and the multimodal coupling structure 3.

[0026] Specifically, the present invention discloses an H-configuration multimodal noise-absorbing and vibration-damping device, which is designed and manufactured in the following manner.

[0027] The elastic plate assembly, with its composite sandwiched material encasing elastic plate 1 and elastic plate 2, is considered a simply supported beam (longitudinal beam). The theoretical basis for the spring characteristics of the simply supported beam structure in this invention is the spring stiffness formula for a simply supported beam under uniformly distributed load: ; The formula for natural frequency is: ; in, For the spring stiffness of a simply supported beam, The elastic modulus of the material, Let the moment of inertia of the cross section be... For the length of a simply supported beam, The mass of the simply supported beam.

[0028] This characteristic determines the matching relationship between the stiffness and natural frequency of the noise-absorbing and vibration-damping device.

[0029] Based on the target first-order modal frequency (128.74Hz), the cross-sectional dimensions and material ratio of the elastic plate assembly are calculated using a formula. For example, when the target is the first-order frequency, substitute... E (The composite elastic modulus is calculated by weighting the material ratios; when the ratio is 1.5:7:1.5) ), m (The mass of a simply supported beam, approximately 0.66 kg, with dimensions of 260×50×10 mm) L (260mm), calculated backwards The corresponding elastic plate assembly has a cross-sectional size of 50×10mm to ensure that the stiffness meets the requirements.

[0030] In some embodiments, a bottom fixing seat can be used. The ground fixing seat adopts a simple support constraint, and the spacing between the constraint points is set to 1 / 4 (65mm) of the length of the elastic plate assembly. This allows the elastic plate assembly to exhibit a simply supported beam bending deformation during vibration, avoiding structural damage caused by stress concentration at the fixed end, while ensuring that vibration energy is transmitted and dissipated along a preset path.

[0031] Based on the relationship between the natural frequency and mass of a simply supported beam: ; The natural frequency can be adjusted by changing the mass distribution of the longitudinal beam (simply supported beam) using the movable counterweight 4. For example, when the movable counterweight 4 is moved from 1 / 3 of the elastic plate assembly (close to the boundary) to 2 / 3 (far from the boundary), the equivalent mass of the elastic plate assembly is reduced by 15%, and the natural frequency is increased by about 8%, thus widening the frequency band.

[0032] The composite-clad elastic plate 1 of the present invention is composed of a glass fiber epoxy board (low modulus, high damping) and 201 stainless steel (high modulus, high strength), and its equivalent elastic modulus is:

[0033] in: E 1. E 2 represents the elastic modulus of the two materials; A 1. A 2 represents the cross-sectional area.

[0034] Damping characteristics are determined by the loss factor of the glass fiber epoxy board ( The process is dominated by the proportion of materials and the molding process.

[0035] The molding process of the composite-clad elastic plate 1 is as follows: Prepreg preparation: The prepreg for the fiberglass epoxy board uses unidirectional fiberglass cloth with a resin content of 35±2%, ensuring a fiber volume fraction of ≥60%; the surface of the 201 stainless steel plate (thickness 1-2mm) is sandblasted (Sa2.5 grade), and after removing the oxide layer, it is coated with KH-550 coupling agent to enhance the bonding force with the resin.

[0036] Compression molding: The autoclave molding process is adopted, with a heating rate of 5℃ / min to 120℃, holding for 30min, and a pressure of 5MPa, so that the resin can flow fully and impregnate the fiber; the cooling rate is 3℃ / min to room temperature to avoid interlayer stress cracking.

[0037] Post-processing: Dimensional accuracy (±0.1mm) is ensured by CNC milling, and the surface is coated with F5281 structural adhesive (50μm thickness) to improve corrosion resistance and damping characteristics. The interlayer bond strength test is ≥25MPa.

[0038] Furthermore, this invention optimizes the material ratio by adjusting the ratio of glass fiber epoxy board to 201 stainless steel (1.5:7:1.5) to control the equivalent modulus of elasticity. At a ratio of 1.5:7:1.5... It is suitable for mid-to-high frequency bands, achieving multi-band stiffness matching. Utilizing the high damping characteristics of fiberglass epoxy board, the loss factor of the composite-clad elastic plate is no less than 0.03, which is 30 times higher than that of pure metal plate (tanδ≈0.001), enhancing the dissipation of vibration energy in all modes, especially in the high-frequency band (400-580Hz), where the damping and vibration reduction effect is improved by 25%. The high tensile strength of 201 stainless steel (≥520MPa) solves the problem of insufficient strength of pure fiberglass epoxy board (tensile strength ≤300MPa). The bending strength of the composite-clad structure is ≥400MPa, meeting the structural reliability requirements of industrial equipment under long-term vibration.

[0039] like Figure 3 As shown, the H-shaped clamping plate of the present invention consists of longitudinal beams formed by composite-clad elastic plates 1 and 2, and transverse beams formed by a multimodal coupling structure. The stiffness ratio of the longitudinal and transverse beams is adjusted (…). This results in four independent modes in the structure: first (longitudinal beam bending), second (crossbeam bending), third (longitudinal beam-crossbeam coupled bending), and fourth (overall torsion). The frequency intervals of each mode are uniform, covering the 60-600Hz frequency band.

[0040] Furthermore, the first mode (128.74Hz) corresponds to the vertical bending of the elastic plate assembly, which is used to suppress low-frequency vibrations; the second mode (201.2Hz) corresponds to the horizontal bending of the crossbeam, which covers the mid-frequency range; the third mode (292.45Hz) is the coupled bending of the elastic plate assembly and the multi-mode coupling structure 3, which fills the gap in the mid-to-high frequency range; and the fourth mode (402.61Hz) is the overall torsion, which suppresses high-frequency vibrations.

[0041] This invention optimizes the connection position between the elastic plate assembly and the multimodal coupling structure 3 using finite element simulation (ANSYS software), ensuring that the mode shapes of each order do not overlap, thus avoiding frequency shifts caused by modal coupling. For example, the first-order mode shape is concentrated at both ends of the elastic plate assembly, the second-order mode shape is concentrated at both ends of the multimodal coupling structure 3, the third-order mode shape is the coordinated bending of the elastic plate assembly and the multimodal coupling structure 3, and the fourth-order mode shape is the overall torsion around the central axis. The hollow region of the H-shaped structure can form an air damping cavity, which, combined with the material damping of the composite-clad elastic plate, achieves a synergistic effect of structural vibration reduction and air damping noise reduction. In the 400Hz frequency band, the sound pressure level reduction is 15dB higher than that of traditional structures.

[0042] This invention relates to an H-configuration multimodal noise and vibration damper. Through its multimodal design, it can simultaneously suppress vibrations in four frequency bands, such as 80Hz (mechanical vibration), 200Hz (aerodynamic vibration), 300Hz (structural resonance), and 400Hz (high-frequency noise) of transformer ventilation fans, solving the problem of traditional noise and vibration dampers requiring multiple units to be stacked. This invention achieves precise control of the stiffness ratio between the elastic plate assembly and the multimodal coupling structure, ensuring that the frequency deviation of each modal is ≤5%, and that the modal frequency change rate is no greater than 2% after testing, guaranteeing long-term stability. The dimensions of the elastic plate assembly and the multimodal coupling structure 3 of this invention match the existing equipment installation space, allowing for direct installation via a simply supported base without equipment modification, thus improving installation efficiency by 40%.

[0043] This invention also provides a design method for an H-configuration multimodal noise-absorbing and vibration-damping device, comprising the following steps: S1. Determine the target vibration reduction frequency band of the silencer and vibration damper, and determine the design parameters of the H-shaped clamping plate body based on the spring characteristics of the simply supported beam. S2. A layered structure is formed by combining fiberglass epoxy board and stainless steel. The material ratio of fiberglass epoxy board and stainless steel is calculated according to the formula of spring stiffness of simply supported beam. The stiffness and mass range of composite-clad elastic plate 1 are determined. The elastic modulus and damping characteristics are controlled by molding process. Composite-clad elastic plate 1 is prepared by molding, and elastic plate 2 is designed and prepared accordingly. S3. Integrate the multimodal coupling structure 3 onto the elastic plate assembly, and achieve frequency control of the multimodal modes by adjusting the stiffness matching relationship between the composite-clad elastic plate 1 and elastic plate 2 and the multimodal coupling structure 3. S4. Design the sliding adjustment range of the movable counterweight, and adjust the mass distribution of the system by changing the position of the counterweight to match the frequency band to be damped.

[0044] The present invention further experimentally demonstrated the H-configuration multimodal noise reduction and vibration damping device and its design method through performance testing.

[0045] Modal testing: First-order 128.74Hz, second-order 201.2Hz, third-order 292.45Hz, and fourth-order 402.61Hz, meeting the requirements for mid-to-high frequency vibration reduction; Vibration reduction testing: Installed on a motor (vibration frequency 200-500Hz), the acceleration level was reduced by 40.2dB in the 200Hz band and by 35.5dB in the 500Hz band, with stable performance.

[0046] In summary, this invention presents an H-configuration multimodal noise-absorbing vibration damper and its design method. Through a four-order modal coupling design, it achieves precise suppression of multi-order vibrations within a wide frequency band of 64.708-581.96Hz. Modal testing and vibration reduction performance verification demonstrate that the noise-absorbing vibration damper exhibits excellent overall performance. The first to fourth order modal frequencies are highly matched with the 200-500Hz vibration frequency band of the motor, reducing the acceleration level by 40.2dB at 200Hz and by 35.5dB at 500Hz. Simultaneously, the movable counterweight has a maximum outer contour of 260×130×86mm, controllable weight (±5%), and convenient installation, making it suitable for various applications such as power equipment and industrial machinery. This ensures the structural stability of the noise-absorbing vibration damper under long-term vibration environments. After testing, the modal frequency change rate is ≤2%, demonstrating its engineering mass production and long-term service capability. It provides technical support for the field of multi-band vibration suppression and has engineering applicability.

[0047] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Anyone skilled in the art can readily implement the present invention according to the description and above. Any modifications, alterations, or equivalent variations made using the technical content disclosed above are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An H-configuration multimodal noise-absorbing and vibration-damping device, characterized in that, The system includes an H-shaped clamping plate body, which comprises an elastic plate assembly, a multimodal coupling structure (3), and four movable counterweights (4); wherein: The elastic plate assembly includes a composite-clad elastic plate (1) and an elastic plate (2) arranged side by side. The elastic plate (2) and the composite-clad elastic plate (1) are long plate-shaped structures and their structures are compatible. The composite-clad elastic plate (1) is a layered structure formed by combining a fiberglass epoxy board and stainless steel, and is prepared by a molding process. The material ratio of the fiberglass epoxy board to the stainless steel is determined according to the formula for the stiffness of a simply supported beam spring. The four movable counterweights (4) are in two groups. The first group of movable counterweights (4) is spaced along the length direction on the composite-clad elastic plate (1), and the second group of movable counterweights (4) is spaced along the length direction on the elastic plate (2). Both groups of movable counterweights (4) can slide and adjust their positions along the length direction of the composite-clad elastic plate (1) or the elastic plate (2). By changing the mass distribution of the noise-absorbing and vibration-damping device, the vibration suppression requirements of different frequency bands can be adapted. The multimodal coupling structure (3) is integrated into the elastic plate group and is located between the two movable counterweights (4) of the first and second groups. The frequency regulation of the multimodal modes is achieved by matching the stiffness of the elastic plate group with that of the multimodal coupling structure (3).

2. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 1, characterized in that, The composite-clad elastic plate (1) is designed based on the characteristics of a simply supported beam spring. The formula for the stiffness of the simply supported beam spring based on the ratio of the fiberglass epoxy board to stainless steel is as follows: ， in, For the spring stiffness of a simply supported beam, The elastic modulus of the material, Let the moment of inertia of the cross section be... The length is for a simply supported beam.

3. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 1, characterized in that, The multimodal coupling structure (3) achieves uniform frequency spacing of multiple modes by adjusting the ratio of the cross-sectional moments of inertia of the elastic plate group. The elastic plate group can realize multimodal vibration, wherein: The first mode is the bending vibration of the longitudinal beam, the second mode is the bending vibration of the transverse beam, the third mode is the bending vibration of the coupled longitudinal and transverse beams, and the fourth mode is the overall torsional vibration. The damping ratio of each mode is controlled by the loss factor of the composite-clad elastic plate (1).

4. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 3, characterized in that, The connection between the multimodal coupling structure (3) and the composite-clad elastic plate (1) and elastic plate (2) is optimized through finite element simulation so that the vibration modes of the first to fourth order do not overlap; the main body of the H-shaped cladding plate has a hollow area, which forms an air damping cavity. The air damping cavity is combined with the material damping of the composite-clad elastic plate (1) to achieve the synergistic effect of structural vibration reduction and air damping noise reduction.

5. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 1, characterized in that, The two movable counterweights (4) in the first group are symmetrically distributed along the composite-clad elastic plate (1), and the two movable counterweights (4) in the second group are symmetrically distributed along the elastic plate (2). The sliding adjustment range of each movable counterweight (4) covers one-third to two-thirds of the length of its corresponding composite-clad elastic plate (1) or elastic plate (2).

6. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 1, characterized in that, The composite-clad elastic plate (1) is a layered structure formed by combining glass fiber epoxy board and stainless steel, and is prepared by a molding process of prepreg preparation, molding and post-treatment.

7. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 6, characterized in that, In the preparation of prepreg, the glue content of the glass fiber epoxy board prepreg is controlled at 33-37%; after the stainless steel plate surface is sandblasted, a coupling agent is coated, and the surface of the sandblasted stainless steel plate reaches the preset roughness.

8. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 6, characterized in that, The process parameters for compression molding are as follows: The temperature is controlled at 115-125℃, the pressure is controlled at 4.5-5.5MPa, and the holding time is controlled at 25-35min. The interlayer bonding strength of the composite-clad elastic plate (1) after molding is not less than 25MPa.

9. The H-configuration multimodal noise-absorbing and vibration-damping device according to claim 6, characterized in that, The post-processing steps include room temperature curing, precision milling, and outer contour optimization. First, the molded composite board is cured at room temperature for a preset time, then milled to a preset dimensional accuracy, and finally the sharp corners of the board's outer contour are rounded.

10. The design method of the H-configuration multimodal noise-absorbing and vibration-damping device according to claim 1, characterized in that, The process is based on the H-configuration multimodal noise-absorbing and vibration-damping device according to any one of claims 1-9, and includes the following steps: S1. Determine the target vibration reduction frequency band of the silencer and vibration damper, and determine the design parameters of the H-shaped clamping plate body based on the spring characteristics of the simply supported beam. S2. Fiberglass epoxy board and stainless steel are combined to form a layered structure. The material ratio of fiberglass epoxy board and stainless steel is calculated according to the formula of spring stiffness of simply supported beam. The stiffness and mass range of the composite-clad elastic plate (1) are determined. The elastic modulus and damping characteristics are controlled by the molding process. The composite-clad elastic plate (1) is prepared by molding. The elastic plate (2) is designed and prepared accordingly. S3. Integrate the multimodal coupling structure (3) onto the elastic plate group, and realize the frequency control of the multimodal modes by adjusting the stiffness matching relationship between the composite-clad elastic plate (1) and the elastic plate (2) and the multimodal coupling structure (3). S4. Design the sliding adjustment range of the movable counterweight, and adjust the mass distribution of the system by changing the position of the counterweight to match the frequency band to be damped.

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