A flat-plate low-frequency vibration-damping superstructure with multiple vibrators

Abstract

The present invention relates to the field of vibration-damping metamaterials, specifically a flat-plate, low-frequency vibration-damping metastructure containing multiple vibrators. The metastructure comprises a base plate with a square hole formed therein, within which a local resonance functional unit is disposed. The local resonance functional unit comprises an elastic mass block disposed within the square hole, and a curved beam connecting the elastic mass block and the base plate. One end of the curved beam is connected to the elastic mass block, while the other end forms two symmetrically distributed connecting arms through a bifurcated structure. The two connecting arms are respectively anchored to two mutually orthogonal inner walls of the base plate. This metastructure achieves low-frequency vibration and noise reduction within a limited space while exhibiting excellent mechanical properties.

Description

Technical Field

[0001] The present invention relates to the field of vibration-damping metamaterials, in particular to a flat-plate low-frequency vibration-damping superstructure containing multiple vibrators. Background Art

[0002] Low-frequency vibration and noise control is a common challenge in transportation, aerospace, and high-end equipment manufacturing. While significant efforts have been made to suppress low-frequency noise and vibration, traditional vibration suppression technologies suffer from narrow bandwidth, poor robustness, and are largely ineffective at low frequencies.

[0003] Mechanical metamaterials are a new class of materials that achieve mechanical properties unattainable by traditional materials through artificially designed microscopic or mesoscopic structures. These novel material systems with unconventional mechanical responses offer a new path to overcome the limitations of traditional materials in low-frequency wave manipulation. By manipulating the band gap range through Bragg scattering and localized resonance, elastic waves are suppressed within the band gap frequency range, achieving vibration and noise reduction.

[0004] However, for these lightweight structures, dealing with low-frequency noise below 200Hz remains challenging. Existing research shows that achieving a wide bandgap at low frequencies typically relies on a significant increase in the number and mass of resonant units, which is fundamentally inconsistent with the stringent requirements for lightweight and compact structures in practical applications. Particularly under the constraints of limited installation space, the typical external resonator layout of traditional metamaterials (such as panel surface attachment or truss external attachment) faces significant limitations, and the mechanical properties of the main load-bearing structure are also weakened. Therefore, the design of lightweight metamaterial structures for low-frequency vibrations remains an urgent problem that needs to be solved. Summary of the Invention

[0005] In order to solve the technical problems existing in the background technology, the present invention provides a flat-plate low-frequency vibration-damping superstructure containing multiple vibrators, which realizes vibration and noise reduction in the low-frequency domain within a limited space, and at the same time has good mechanical properties, which can effectively solve the problem of low-frequency vibration control of engineering structures.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A flat-plate low-frequency vibration-damping superstructure containing multiple vibrators, comprising:

[0008] A base plate, wherein a square hole is provided on the base plate, and a local resonance functional unit is provided in the square hole;

[0009] The local resonance functional unit includes:

[0010] an elastic mass block, disposed in the square hole;

[0011] a bending beam connecting the elastic mass block and the base plate;

[0012] One end of the bending beam is connected to the elastic mass block, and the other end forms two symmetrically distributed connecting arms through a bifurcated structure. The two connecting arms are respectively anchored to two inner walls on the base plate that are orthogonal to each other.

[0013] Furthermore, the curved beam is composed of four beam bodies connected in sequence, and its specific structure is as follows:

[0014] A first beam body, the first beam body being vertically fixed to the inner wall of the base plate;

[0015] A second beam body, the second beam body is bent vertically and extended from the end of the first beam body, and its extension direction is toward the geometric center axis of the square hole;

[0016] A third beam body, the third beam body is vertically bent and extended from the end of the second beam body, and its extension direction is toward the geometric center axis of the square hole;

[0017] The fourth beam body is bent and extended in the opposite direction from the end of the third beam body, and its extension direction is away from the geometric center of the square hole. The end of the fourth beam body is finally connected to the elastic mass block.

[0018] Furthermore, there are two first beams, two second beams and two third beams, which are symmetrically arranged on both sides of the fourth beam, and the fourth beam is arranged at the junction of the two third beams.

[0019] Furthermore, the length of the first beam is 1 / 20-1 / 10 of the side length of the base plate, and the distance between the first beam and the inner wall of the adjacent base plate is 1 / 20-1 / 5 of the side length of the base plate; the length of the second beam is 1 / 5-1 / 3 of the side length of the base plate; the width of the first beam, the second beam, the third beam and the fourth beam is 1 / 65-1 / 30 of the side length of the base plate.

[0020] Furthermore, there are four local resonance functional units, and the four local resonance functional units are distributed in the square hole in a centrosymmetric manner.

[0021] Furthermore, the elastic mass block is made of resin or steel, and the two elastic mass blocks located on the diagonal line of the square hole are made of the same material.

[0022] Furthermore, the diameter of the elastic mass block is greater than 1 / 10 of the side length of the base plate, and the diameter of the elastic mass block is less than 1 / 4 of the side length of the base plate.

[0023] Furthermore, the elastic mass block adopts a circular configuration.

[0024] Furthermore, the base plate is made of the same material as the elastic mass block.

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention utilizes the local resonance mechanism to achieve subwavelength-band low-frequency vibration suppression by constructing a local resonance unit comprising a mass block and a bifurcated curved beam. When the structure is subjected to external vibration excitation, the elastic deformation of the bifurcated curved beam and the inertial motion of the mass block couple to form an elastic wave band gap within a predetermined frequency band, causing the vibration energy transmitted to the structure to be strongly attenuated within this frequency band.

[0027] (2) The rational design of the structure and material parameters of the base plate, bending beam, and mass block in the present invention can change the frequency range of the band gap and achieve effective attenuation of vibrations within a specific frequency range.

[0028] (3) The flat-plate low-frequency vibration-damping superstructure of the present invention has excellent mechanical properties of light weight and high load-bearing capacity. At the same time, it can achieve wide-band vibration suppression through the synergistic effect of multiple vibrators, and has both structural strength and vibration-damping performance.

[0029] (4) The present invention provides an adjustable vibration reduction band gap design scheme by setting up multiple local resonant oscillators. Compared with traditional metamaterials containing single oscillators, the present invention can achieve multi-band vibration suppression by adjusting the mass, stiffness, and spatial arrangement of different oscillators. At the same time, the coupling between different oscillators can enhance the local resonance effect, further improving the low-frequency vibration reduction performance.

[0030] (5) The flat-plate low-frequency vibration-damping superstructure of the present invention is less than 5 mm thick and is relatively thin and light, making it easy to be arranged in vehicles, trains, airplanes, ships, and other equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] Figure 1 It is a schematic diagram of the cell structure of the present invention;

[0033] Figure 2 It is a structural schematic diagram of the curved beam of the present invention;

[0034] Figure 3 It is a schematic diagram of the overall structure of the present invention;

[0035] Figure 4 is a cellular band structure diagram of the present invention;

[0036] Figure 5 It is a test piece diagram used to test the frequency response function;

[0037] Figure 6 This is a comparison chart of the simulation and experimental results of the frequency response function test;

[0038] Figure 7Figure 3. Cells with elastic mass blocks of different materials and their corresponding energy band structures. (a) Cells with three typical material configurations: all-steel reference type, all-photosensitive polymer resin type, and steel / photosensitive resin hybrid type; (b) The corresponding energy band structures of the three cells.

[0039] In the picture:

[0040] 1. Base plate, 2. Bending beam, 3. Elastic mass block;

[0041] 21. The first beam, 22. The second beam, 23. The third beam, 24. The fourth beam. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings.

[0043] like Figure 1 As shown, a flat-plate, low-frequency vibration-damping superstructure with multiple oscillators comprises a base plate 1 with a square hole formed therein, within which a local resonance functional unit is disposed. The local resonance functional unit comprises an elastic mass 3 disposed within the square hole. A curved beam 2 connects the elastic mass 3 and the base plate 1. One end of the curved beam 2 is connected to the elastic mass 3, while the other end forms two symmetrically distributed connecting arms via a bifurcated structure. The two connecting arms are anchored to two mutually orthogonal inner walls of the base plate 1, forming a bidirectional anchoring connection. There are four local resonance functional units, distributed centrally and symmetrically within the square hole. The elastic mass 3 is circular in configuration, with a diameter greater than 1 / 10 and less than 1 / 4 of the side length of the base plate 1. The elastic mass 3 may also adopt a polygonal or other topological structure that meets low-frequency vibration requirements. The base plate 1 is made of the same material as the elastic mass 3, or other materials. In a specific embodiment, the elastic mass block 3 is made of resin or steel, and the two elastic mass blocks 3 located on the diagonal line of the square hole are made of the same material. Figure 3 As shown, a plurality of base plates 1 are periodically arranged in the X and Y directions and are combined to form a flat plate structure.

[0044] like Figure 2As shown, the curved beam 2 is composed of four beams connected in sequence. Its specific structure is as follows: the first beam 21 is vertically fixed to the inner wall of the base plate 1. The second beam 22 is vertically bent and extended from the end of the first beam 21, and its extension direction is toward the geometric center axis of the square hole. The third beam 23 is vertically bent and extended from the end of the second beam 22, and its extension direction is toward the geometric center axis of the square hole. The fourth beam 24 is bent and extended from the end of the third beam 23 in the opposite direction, and its extension direction is away from the geometric center of the square hole. The angle between the fourth beam 24 and the third beam 23 is 45°. The end of the fourth beam 24 is finally connected to the elastic mass block 3. There are two first beams 21, two second beams 22, and two third beams 23, which are symmetrically arranged on both sides of the fourth beam 24. The fourth beam 24 is arranged at the junction of the two third beams 23.

[0045] Dimensions and material parameters in the specific embodiment:

[0046] The materials of the base plate 1 and the bending beam 2 are both epoxy resin, with a Poisson's ratio of ν=0.41, an elastic modulus of E=2.65e9Pa, and a density of ρ=1110Κg / m 3 The material of the elastic mass block 3 is structural steel, with a Poisson's ratio of ν = 0.3, an elastic modulus of E = 200e9Pa, and a density of ρ = 7850Κg / m 3 .

[0047] The base plate 1 has a side length of 60 mm and a thickness of 4 mm. The first beam 21 has a length of 4.5 mm, a width of 1 mm, and a thickness of 4 mm. The spacing between the first beam 21 and the inner wall of the adjacent base plate 1 is 7 mm. The second beam 22 has a length of 18 mm, a width of 1 mm, and a thickness of 4 mm. Taking the left branch of the curved beam 2 in the upper right corner as an example, this branch extends downward 4.5 mm at a distance of 7 mm from the inner wall of the base plate 1, then turns inward 18 mm and turns downward again to merge with the right branch. After merging, the curved beam 2 continues to extend toward the center of the elastic mass block 3 until it connects with the elastic mass block 3. The radius of the elastic mass block 3 is 6.5 mm.

[0048] The band structure diagram of the flat superstructure with the above dimensions and material parameters is calculated below. Figure 4 As shown in the figure, the horizontal axis is the simplified wave vector, and the vertical axis is the frequency. The shaded area represents the band gap, that is, the vibration propagation in the structure within this frequency range is suppressed. The above superstructure has three band gaps: 61.4-75.7Hz, 142.3-213.1Hz, and 214.3-253.6Hz.

[0049] Next, a frequency response function test is performed on the flat superstructure with the above dimensions and material parameters. Figure 5The figure shows the specimen used for frequency response function test. The specimen is a metamaterial plate with a period of 6×2 cells. The frequency response function results obtained through simulation and experiment are shown in Figure 6 The results show that the elastic wave transmittance in the bandgap frequency range decreases significantly within the frequency range of 0Hz to 400Hz, indicating that vibrations are effectively attenuated within these frequency ranges. The above analysis shows that the flat metamaterial of the present invention has a very significant low-frequency vibration reduction effect.

[0050] like Figure 7 As shown in Figure 1, (a) shows three typical material configurations for the cells: an all-steel standard type, an all-photosensitive polymer resin type, and a steel / photosensitive resin hybrid type. Specifically, the four elastic masses in the cell structure on the left are all made of steel, the four elastic masses in the cell structure in the center are all made of photosensitive polymer resin, and the four elastic masses in the cell structure on the right are made of steel at the two diagonal positions, while the other two diagonal positions are made of photosensitive polymer resin.

[0051] The solution of this embodiment is further described below in conjunction with the closest existing technology:

[0052] The Chinese patent publication number CN112874066B discloses "a honeycomb structure plate integrating vibration suppression, lightness and high strength, and a preparation method thereof", the structure of which is closest to the technical solution of this embodiment.

[0053] It designed three types of multifunctional honeycomb Type A, Type B, and Type C. The band gap frequency bands obtained by the vibrator systems of the three structures are all around 1000Hz, and the relative bandwidth is maintained at around 15%. The band gap frequency band of the flat superstructure proposed in this embodiment is around 200Hz, with a relative bandwidth of 77%, a lower frequency attenuation frequency band, and a relative bandwidth increase of 413%, indicating that this embodiment has a significantly excellent broadband vibration reduction effect. In addition, the single vibrator system of the existing invention patent can only adjust the band gap by changing the geometry and material parameters of the vibrator, while the vibrator system of this embodiment has a total of four local resonance vibrators, which has a more flexible vibration reduction band gap adjustment scheme. Figure 7 As shown in the figure, the band structure diagram of the hybrid metamaterial, obtained by combining oscillators of two materials in a unit cell, retains the intrinsic mode characteristics of both base materials. Its band gap distribution range almost covers the combined band gap region of the two single material systems. The hybrid metamaterial has a wider band gap within the studied frequency range, and the oscillator weight is reduced by 42% compared to the all-steel configuration. This shows that this embodiment can achieve the synergistic optimization of band gap widening and structural lightweighting through the synergistic action of units with different band gap frequencies through the multi-material hybrid design in the oscillator.

[0054] The preparation method of the present invention is described in detail below, comprising the following steps:

[0055] Step 1: Use 3D printing technology to prepare the base plate 1 and the curved beam 2 connected thereto.

[0056] Step 2: Cut the elastic mass 3 using a laser.

[0057] Step 3: Use AB glue to bond the elastic mass block 3 to one end of the curved beam 2, keeping the height of the elastic mass block 3 level with the base plate 1 and the curved beam 2, to complete the design of the flat superstructure.

[0058] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A flat-plate low-frequency vibration-damping superstructure containing multiple vibrators, characterized in that: include: A base plate (1), wherein a square hole is provided on the base plate (1), and a local resonance functional unit is provided in the square hole; The local resonance functional unit includes: an elastic mass block (3), arranged in the square hole; A bending beam (2) connecting the elastic mass block (3) and the base plate (1); One end of the bending beam (2) is connected to the elastic mass block (3), and the other end forms two symmetrically distributed connecting arms through a bifurcated structure, and the two connecting arms are respectively anchored to two mutually orthogonal inner walls of the base plate (1); The curved beam (2) is composed of four beam bodies connected in sequence, and its specific structure is as follows: A first beam body (21), the first beam body (21) is vertically fixed to the inner wall of the base plate (1); A second beam body (22), the second beam body (22) is vertically bent and extended from the end of the first beam body (21), and its extension direction is toward the geometric center axis of the square hole; A third beam (23), the third beam (23) is vertically bent and extended from the end of the second beam (22), and its extension direction is toward the geometric center axis of the square hole; The fourth beam body (24) is bent and extended in the reverse direction from the end of the third beam body (23), and its extension direction is opposite to the geometric center of the square hole. The end of the fourth beam body (24) is finally connected to the elastic mass block (3).

2. A flat-plate low-frequency vibration-damping superstructure containing multiple vibrators according to claim 1, characterized in that: There are two of each of the first beam body (21), the second beam body (22) and the third beam body (23), which are symmetrically arranged on both sides of the fourth beam body (24). The fourth beam body (24) is arranged at the junction of the two third beam bodies (23).

3. The multi-vibrator flat-plate low-frequency vibration-damping superstructure according to claim 2, characterized in that: The length of the first beam (21) is 1 / 20-1 / 10 of the side length of the base plate (1); the distance between the first beam (21) and the inner wall of the adjacent base plate (1) is 1 / 20-1 / 5 of the side length of the base plate (1); the length of the second beam (22) is 1 / 5-1 / 3 of the side length of the base plate (1); and the widths of the first beam (21), the second beam (22), the third beam (23) and the fourth beam (24) are 1 / 65-1 / 30 of the side length of the base plate (1).

4. The multi-vibrator flat-plate low-frequency vibration-damping superstructure according to claim 1, characterized in that: There are four local resonance functional units, and the four local resonance functional units are distributed in the square hole in a centrally symmetrical manner.

5. The flat-plate low-frequency vibration-damping superstructure containing multiple vibrators according to claim 4, characterized in that: The elastic mass block (3) is made of resin or steel, and the two elastic mass blocks (3) located on the diagonal line of the square hole are made of the same material.

6. The multi-vibrator flat-plate low-frequency vibration-damping superstructure according to claim 1, characterized in that: The diameter of the elastic mass block (3) is greater than 1 / 10 of the side length of the base plate (1), and the diameter of the elastic mass block (3) is less than 1 / 4 of the side length of the base plate (1).

7. The flat-plate low-frequency vibration-damping superstructure containing multiple vibrators according to claim 1, characterized in that: The elastic mass block (3) is of circular configuration.

8. The flat-plate low-frequency vibration-damping superstructure containing multiple vibrators according to claim 1, characterized in that: The base plate (1) is made of the same material as the elastic mass block (3).

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