CN105882022B - A kind of low frequency vibration damping Meta Materials composite damping board - Google Patents

Abstract

The invention introduces a low-frequency vibration-reducing metamaterial composite damping plate, which includes a plate body, the plate body is composed of a first upper composite layer, a middle layer and a first lower composite layer, the first upper composite layer and the first lower composite layer The layers are all fiber composite material layers, the middle layer is a viscoelastic film damping layer, the first upper composite layer and the middle layer and the first lower composite layer and the middle layer are bonded by viscofluid damping rubber; A hole array is opened on the plate body, and a mass sheet is respectively installed in each hole, and the mass sheet is embedded on the viscoelastic film damping layer. The present invention has the functions of multi-layer damping and vibration reduction and acoustic metamaterial low-frequency vibration isolation, has outstanding advantages such as strong low-frequency attenuation ability, easy realization of frequency-selective attenuation, and good environmental protection performance; the structure can be used for vibration control within 1000 Hz, Compared with traditional materials, the vibration and noise reduction performance has been greatly improved, and it can be used for the reduction, isolation and control of low-frequency vibration and noise in automobiles, ships and other equipment.

Description

A low-frequency vibration-absorbing metamaterial composite damping plate

technical field

The invention belongs to the intersecting fields of vibration and noise control and functional composite materials, and in particular relates to a low-frequency vibration-reducing supermaterial composite damping plate structure.

Background technique

Low-frequency vibration and noise problems are ubiquitous in equipment such as automobiles, trains, aircraft, and ships. Due to the slow attenuation and strong penetration of low-frequency vibration and noise capabilities, it is difficult to obstruct and control them, which seriously restricts the performance of these equipment. The ride comfort even directly affects the equipment operation and the health and life safety of the passengers.

In actual engineering, sound insulation materials and damping materials are often used to reduce low-frequency vibration and noise. However, when traditional sound insulation materials are used to isolate sound waves and vibrations, the thickness of the sound insulation material components generally needs to match the wavelength of the sound waves. It is obviously unrealistic in equipment with compact internal spaces such as automobiles, trains, and airplanes; although damping materials can reduce low-frequency vibration and noise to a certain extent, with the continuous increase in lightweight and economical requirements, the damping The quality limit of materials is becoming more and more stringent, and traditional damping materials cannot meet the needs of low-frequency vibration and noise reduction; therefore, it is urgent to develop new low-frequency vibration and noise reduction materials.

In recent years, the US Naval Research Laboratory, the European Information Society Technology Research Council, and the National Natural Science Foundation of China have provided strong support for the theoretical and applied research on acoustic metamaterials. Acoustic metamaterials refer to artificial subwavelength structures with negative equivalent mass density or negative equivalent modulus. In 2000, Liu Zhengyou et al. reduced the band gap frequency of ordinary phononic crystals by two orders of magnitude, breaking through the limit of Bragg scattering. The purpose of small size to control large wavelength has been realized, which has opened up new paths and methods for low frequency research. They introduced a local resonance unit at low frequencies to achieve an equivalent negative mass density. At low frequencies, there will be motion detuning, and at the same time, a forbidden band will be generated at low frequencies because the vibrator motion can absorb the energy transmitted by the sound wave. Therefore, to isolate low-frequency vibration and noise, acoustic metamaterials are a very good choice.

To sum up, for the problem of low-frequency vibration isolation below 1000 Hz, especially within 200 Hz, the existing damping plate either fails to meet the requirements of low-frequency reduction and vibration isolation; or the structure is too bulky, space conditions or cost do not allow; It is effective for a single frequency or a narrow frequency band; therefore, a new type of damping plate with a wide frequency band and meeting the requirements of low frequency reduction and vibration isolation is urgently needed.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a low-frequency vibration-absorbing metamaterial composite damping plate structure.

The technical solution of the present invention: a low-frequency vibration-reducing metamaterial composite damping plate, characterized in that it includes a plate body, the plate body is composed of a first upper composite layer, an intermediate layer and a first lower composite layer, and the first Both the first upper composite layer and the first lower composite layer are fiber composite material layers, the middle layer is a viscoelastic film damping layer, between the first upper composite layer and the middle layer and between the first lower composite layer and the middle layer All of them are bonded by viscofluid damping glue; an array of holes is opened on the board body, and a mass sheet is respectively installed in each hole, and the mass sheet is embedded on the viscoelastic film damping layer .

Optimally, the viscoelastic film damping layer is made of nitrile rubber, silicon rubber or composite rubber material.

Optimally, the thickness of the fiber composite material layer is 0.1-2mm.

Optimally, the thickness of the viscoelastic film damping layer is 0.1-2mm.

Optimally, both the first upper composite layer and the first lower composite layer are made by overlapping at least two layers of fiber composite material.

Optimally, the mass sheet is made of high-density metal material.

Preferably, the mass sheet is circular, and the thickness of the mass sheet is smaller than that of the plate body.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention can form a wide acoustic band gap below 1000Hz or even within 200Hz to isolate low-frequency vibration and noise;

2. The present invention can design the central frequency band position and the forbidden band width of the acoustic forbidden band according to the engineering needs;

3. The present invention utilizes the interlayer damping between the fiber composite material layer and the fiber composite material layer and the viscoelastic film to form a multi-layer strong damping effect, which can effectively reduce vibration and noise;

4. The total thickness of the composite damping plate can be less than 5mm, which is relatively light and thin, and the plane size can be designed flexibly. The laying method is similar to traditional products, and it is easy to arrange in automobiles, trains, aircraft, ships and other equipment;

5. The design of the present invention is simple, and the basic materials used are all conventional materials, which are easy to process and produce in batches.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the low-frequency vibration-damping metamaterial composite damping plate of the present invention.

Fig. 2 is a schematic structural diagram of a unit cell (also known as a mass sheet unit) on a low-frequency vibration-reducing metamaterial composite damping plate of the present invention.

Fig. 3 is a half-cut perspective view of a unit cell (also known as a mass sheet unit) on a low-frequency vibration-reducing metamaterial composite damping plate of the present invention.

Fig. 4 is a half-sectional view of a unit cell (also known as a mass sheet unit) on a low-frequency vibration-reducing metamaterial composite damping plate of the present invention.

In the figure, 1—mass sheet, 2—the first lower composite layer, 3—the second lower composite layer, 4—the middle layer, 5—the first upper composite layer, 6—the second upper composite layer.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a kind of low-frequency vibration-absorbing metamaterial composite damping plate of the present invention includes a plate body, and the plate body is composed of the first upper composite layer 5, the middle layer 4 and The first lower composite layer 2 is composed, the first upper composite layer 5 and the first lower composite layer 2 are fiber composite material layers, the middle layer 4 is a viscoelastic film damping layer, and the first upper composite layer 5 Between the middle layer 4 and between the first lower composite layer 2 and the middle layer 4 are all bonded by viscous fluid damping glue; an array of holes is opened on the board body, and a A mass sheet 1, the mass sheet 1 is embedded on the viscoelastic film damping layer.

In the present invention, the viscoelastic film damping layer is made of nitrile rubber, silicon rubber or composite rubber material. The thickness of the fiber composite material layer is 0.1-2mm. The thickness of the viscoelastic film damping layer is 0.1-2 mm. Both the first upper composite layer 5 and the first lower composite layer 2 are made by overlapping at least two layers of fiber composite material. The mass sheet 1 is made of high-density metal material. The mass sheet 1 is circular, and the thickness of the mass sheet 1 is smaller than that of the plate body. Of course, the mass sheet 1 can also be made into a square or other shapes according to the needs, and the specific shape can be set according to the needs.

Embodiment, as shown in Figure 2, according to the mass sheet unit (also known as unit cell) designed according to the present invention, its unit cell is a square structure as a whole, and the side length of each unit cell is 40mm; the material distribution in the unit cell is shown in Figure 3 shown; the middle layer is made of acrylonitrile-butadiene rubber composite material to make viscoelastic film, the thickness of elastic film is 1mm, the second upper composite layer 6 is laid on the first upper composite layer 5, and the second upper composite layer 6 is laid below the first lower composite layer 2. The second lower composite layer 3, the first upper composite layer 5, the second upper composite layer 6, the first lower composite layer 2 and the second lower composite layer 3 are all fiber composite layers with a thickness of 1mm; The middle layer 4 has a circular hole with a diameter of 30 mm; a circular iron sheet is arranged in the circular hole. As for the viscoelastic film, the circular iron sheet has a diameter of 24.5 mm and a thickness of 1 mm. Arrange the above-mentioned unit cells according to the required arrangement to form a metamaterial composite damping plate as shown in Figure 1, then on this damping plate, the vibration transfer function is lower than 30dB within 100~150Hz, which can effectively isolate the vibration in this frequency band and noise, forming an acoustic band gap effect.

In practical applications, the geometric dimensions of the unit cells, the number of unit cells arranged, the bandgap frequency and bandwidth, vibration attenuation strength, etc. in the present invention can be designed according to engineering requirements, so as to achieve the purpose of on-demand production.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the technical solutions. Although the applicant has described the present invention in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that those who are not familiar with the technical solutions of the present invention The modification or equivalent replacement of the solution cannot deviate from the purpose and scope of the technical solution, and should be covered by the scope of the claims of the present invention.

Claims (2)

1. A low-frequency vibration-damping metamaterial composite damping plate, characterized in that it includes a plate body, and the plate body is composed of the first upper composite layer (5), the middle layer (4) and the first lower composite layer (2) The middle layer (4) is a viscoelastic film damping layer, between the first upper composite layer (5) and the middle layer (4) and between the first lower composite layer (2) and the middle layer (4) All of them are bonded by viscous fluid damping glue; an array of holes is opened on the board body, and a mass sheet (1) is installed in each hole, and the mass sheet (1) is embedded in the On the damping layer of the viscoelastic film; the middle layer (4) is made of a viscoelastic film made of nitrile rubber composite material, the thickness of the viscoelastic film is 1mm, and the second upper composite layer (5) is laid on the first upper composite layer ( 6), the second lower composite layer (3) is laid under the first lower composite layer (2), the first upper composite layer (5), the second upper composite layer (6), the first lower composite layer (2) and the second lower composite layer (3) are both fiber composite material layers with a thickness of 1mm; a round hole is opened on the middle layer (4), and the mass sheet (1) is a circular iron sheet with a circular The thickness of the shaped iron sheet is 1 mm. 2. A low-frequency vibration-damping metamaterial composite damping plate according to claim 1, characterized in that, both the first upper composite layer (5) and the first lower composite layer (2) are made of at least 2 layers of fiber Composite material layers are made overlapping.