Adjustable collision acoustics black hole period vibration reduction and impact resistance device

Abstract

The invention discloses an adjustable collision acoustics black hole period vibration reduction and impact resistance device which comprises a plurality of same vibration reduction and impact resistance units periodically arranged on the surface of a structure subjected to vibration reduction. The vibration reduction and impact resistance unit comprises an n-shaped cavity wall and a mass block-acoustic black hole beam combined structure arranged in the n-shaped cavity wall. The adjustable collision acoustics black hole period vibration reduction and impact resistance device has periodicity in the n-shaped direction perpendicular to the n-shaped cavity wall. The n-shaped cavity wall comprises an upper cavity and a top vent hole formed in the top end of the upper cavity; the mass block-acoustic black hole beam combined structure comprises an acoustic black hole beam, a mass block and a containing cavity perpendicular to the structure to be damped. Damping layers are arranged at the tail ends of the acoustic black hole beams, and the mass block moves up and down in the containing cavity and collides with the acoustic black hole beams arranged below to transmit vibration energy which is absorbed and dissipated by the damping layers. By periodically arranging the vibration reduction and impact resistance units on the surface of the structure subjected to vibration reduction, the broadband vibration reduction effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of large-scale structure vibration reduction and impact resistance, in particular to an adjustable collision acoustic black hole period vibration reduction and impact resistance device. Background Art

[0002] With the development of modern equipment towards larger and lighter sizes, the low-frequency vibration problem it faces is becoming increasingly serious. In addition, the equipment will inevitably be subject to external shocks during use, and harmful vibrations and shocks will seriously affect the normal operation of the equipment and the physical and mental health of the staff.

[0003] Acoustic metamaterials are a new method of reducing vibration and noise proposed in recent years. They block the propagation of elastic waves in a specific frequency band by periodically arranging artificially designed unit structures. Compared with traditional passive control methods, acoustic metamaterials can achieve lightweight vibration reduction devices in terms of suppressing low-frequency broadband vibrations. However, the band gap frequency band of most acoustic metamaterials is fixed and cannot be adjusted according to changes in the vibration frequency of the environment.

[0004] The acoustic black hole effect is achieved by gradually reducing the propagation speed of bending waves in the acoustic black hole structure until it approaches zero by cutting the thickness of the structure according to a power law or setting the material parameters according to a power law, and by attaching a damping layer to the end of the structure, the vibration energy can be efficiently absorbed and dissipated. However, the traditional acoustic black hole structure is mainly effective in the medium and high frequency bands and is not suitable for low-frequency vibration reduction of large structures. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and to provide an adjustable collision acoustic black hole periodic vibration reduction and anti-impact device with a simple overall structure, easy processing, good theoretical and practical performance, aiming to achieve good low-frequency broadband vibration reduction and anti-impact effects, and can flexibly adapt to different working frequency bands through simple adjustment.

[0006] An adjustable collision acoustic black hole periodic vibration reduction and anti-impact device comprises a plurality of identical vibration reduction and anti-impact units periodically arranged on the surface of a structure to be damped; the vibration reduction and anti-impact unit comprises an "J"-shaped cavity wall and a mass block-acoustic black hole beam combination structure arranged therein; the adjustable collision acoustic black hole periodic vibration reduction and anti-impact device has periodicity in an "J"-shaped direction perpendicular to the "J"-shaped cavity wall; the "J"-shaped cavity wall comprises an upper cavity and an air vent at the top of the upper cavity; the mass block-acoustic black hole beam combination structure comprises an acoustic black hole beam, a mass block and a cavity perpendicular to the structure to be damped; a damping layer is arranged at the end of the acoustic black hole beam, and the mass block moves up and down in the cavity, transmits vibration energy by colliding with the acoustic black hole beam arranged below, and absorbs and dissipates it by the damping layer.

[0007] The “X”-shaped cavity wall comprises a metal base, and a bottom mounting hole is arranged on the metal base. The metal base of the “X”-shaped cavity wall is fixed to the vibration-damped structure through the bottom mounting hole.

[0008] The "X"-shaped cavity wall is a closed structure, and the thickness of the upper cavity is greater than the thickness of the base.

[0009] Wherein, the mass block is a spherical mass block.

[0010] Wherein, the cavity is a cylindrical cavity.

[0011] Wherein, the diameter of the cavity is slightly larger than the diameter of the mass block.

[0012] There is a predetermined gap between the bottom of the mass block and the acoustic black hole beam, and the mass block collides with the acoustic black hole beam during operation, transmitting vibration energy and absorbing and dissipating it through the damping layer.

[0013] The mass of the mass block, the parameters of the acoustic black hole beam, the thickness and material of the damping layer are flexibly designed according to the required frequency band to adapt to vibration reduction in different working frequency bands.

[0014] Wherein, the vibration-damped structure is a planar structure.

[0015] Among them, the mass blocks of different vibration-damping and anti-impact units have different mass sizes; by adjusting the mass blocks of different vibration-damping and anti-impact units, low-frequency and broadband vibration reduction of large structures can be achieved.

[0016] The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device provided by the present invention achieves a broadband vibration reduction effect by periodically arranging the vibration reduction and anti-shock units on the surface of the vibration-reduced structure. The contact collision is introduced into the design of the vibration reduction and anti-shock units to transmit low-frequency vibration energy, thereby improving the vibration reduction performance of the acoustic black hole in the low-frequency band.

[0017] The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device provided by the present invention can realize flexible adjustment of vibration reduction in different frequency bands by replacing the substructure in the unit. It is a new type of passive vibration reduction and anti-shock technology, which is suitable for vibration reduction and anti-shock of large structures. The whole device is easy to process and simple to assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the vibration reduction and impact resistance unit in the present invention;

[0020] Figure 3 It is a front view of the mass block-acoustic black hole beam combined structure of the vibration reduction and impact resistance unit in the present invention;

[0021] Figure 4 It is a front view of the acoustic black hole beam in the present invention;

[0022] Figure 5 It is a schematic diagram of the vibration reduction of the structure of the present invention;

[0023] Description of reference numerals:

[0024] 1-1, metal base; 1-2, upper chamber; 1-3, mounting hole; 1-4, vent; 2-1, acoustic black hole beam; 2-2, damping layer; 3-1, cavity; 3-2, mass block. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The adjustable collision acoustic black hole periodic vibration reduction and anti-impact device of the embodiment of the present invention improves the vibration reduction performance of the acoustic black hole in the low frequency band by introducing contact collision to transfer vibration energy; through periodic design, it achieves a wide-band vibration reduction effect on large structures; through simple adjustment, it can flexibly adapt to different vibration reduction working frequency bands.

[0027] The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device of the embodiment of the present invention has an overall structure composed of a number of identical vibration reduction and anti-shock units arranged periodically. Each vibration reduction and anti-shock unit uses the contact and collision between the mass block and the acoustic black hole beam to transmit vibration energy, which is absorbed and dissipated by the damping layer. By adjusting the mass blocks of different units, low-frequency broadband vibration reduction of large structures can be flexibly achieved.

[0028] like Figure 1 As shown, the present invention provides an adjustable collision acoustic black hole periodic vibration reduction and anti-impact device, which includes a plurality of identical vibration reduction and anti-impact units periodically arranged on the surface of the structure to be vibration-damped. When in use, the vibration reduction and anti-impact units can be simply adjusted to flexibly adapt to changes in environmental vibration frequencies, and have good low-frequency, broadband vibration reduction and anti-impact effects.

[0029] like Figure 2 As shown, the vibration reduction and anti-impact unit is composed of a "J"-shaped cavity wall and a mass block-acoustic black hole beam combination structure inside it; the "J"-shaped cavity wall is composed of a metal base 1-1 and an upper cavity 1-2, and a plurality of mounting holes 1-3 are symmetrically arranged on the metal base. The metal base of the "J"-shaped cavity wall is fixed to the vibration-damped structure through the bottom mounting holes and screws, wherein a plurality of ventilation holes 1-4 are symmetrically arranged on the top of the upper cavity. The mass block-acoustic black hole beam combination structure is composed of an acoustic black hole beam 2-1, a damping layer 2-2 arranged at the end of the acoustic black hole beam 2-1, a cavity 3-1 and a mass block 3-2.

[0030] The upper end of the cavity 3-1 is fixed to the inner top of the upper chamber of the "J"-shaped cavity wall, perpendicular to the base, the acoustic black hole beam 2-1 and the damping layer 2-2 are fixed in the upper chamber of the "J"-shaped cavity wall, the bottom is separated from the metal base 1-1 and does not contact it, and the equal thickness end is fixed to the side wall of the upper chamber of the "J"-shaped cavity wall.

[0031] In some embodiments, the "X"-shaped cavity wall is connected by a metal base 1-1 (which is a flat structure) and an upper chamber 1-2 to form a closed structure, and the thickness of the upper chamber is greater than the thickness of the base, so as to protect the inner top when the mass block collides with the inner top of the upper chamber.

[0032] Preferably, the mass block is a spherical mass block, and the cavity is a cylindrical cavity. The diameter of the cavity is slightly larger than the diameter of the mass block, that is, a gap is left between the inner wall of the cavity and the mass block, and the gap range is 1 / 150-1 / 100 of the radius of the mass block to facilitate the up and down movement of the mass block for vibration reduction.

[0033] Among them, a predetermined gap is left between the bottom of the mass block and the acoustic black hole beam, and the gap range is 1 / 5-1 / 2 of the radius of the mass block. This can prevent the mass block from falling out of the cavity and affecting the normal operation of the device. At the same time, by reserving a certain gap, the energy transfer efficiency during the collision process can be adjusted to avoid excessive increase in the stiffness of the system when a collision occurs, ensuring that the collision occurs at the right time.

[0034] The mass of the mass block, the parameters of the acoustic black hole beam, the thickness and material of the damping layer are flexibly designed according to the required frequency band to adapt to vibration reduction in different working frequency bands.

[0035] In some embodiments, the vibration-damped structure is a planar structure, which is fixed to the vibration-damping and anti-impact unit by screws.

[0036] In a preferred embodiment, the acoustic black hole beam is composed of a first part with a uniform cross-section thickness and a second part with a variable cross-section thickness, wherein the maximum thickness of the second part is consistent with the uniform thickness of the first part and is 15-20 times the minimum thickness of the second part. In this way, the wave velocity of the vibration energy gradually decreases during the transmission from the collision point to the end of the acoustic black hole beam, thereby concentrating near the minimum thickness.

[0037] Preferably, a damping layer of equal thickness is pasted on the end of the acoustic black hole beam, and the damping layer is pasted below the end of the acoustic black hole beam where the thickness changes. The right end face of the damping layer is aligned with the end face of the minimum thickness of the acoustic black hole beam, and the thickness of the damping layer is consistent with the minimum thickness of the acoustic black hole beam.

[0038] Preferably, the damping layer is made of a viscoelastic material, which can effectively dissipate the accumulated vibration energy and reduce reflection, thereby enhancing the vibration reduction effect.

[0039] like Figure 3 As shown, the mass block 3-2 can move up and down in the cylindrical cavity 3-1, and when working, it collides with the acoustic black hole beam 2-1 to transmit vibration energy and is absorbed and dissipated by the damping layer 2-2.

[0040] like Figure 4 As shown, the thickness h of the acoustic black hole structure 2-1 satisfies the following relationship:

[0041]

[0042] Among them, x is the distance from the left end of the acoustic black hole beam; x1 is the length of the uniform thickness part of the acoustic black hole beam; L is the total length of the acoustic black hole beam; h0 is the thickness of the uniform part of the acoustic black hole beam; h1 is the minimum thickness of the acoustic black hole beam; ε is the slope of the acoustic black hole profile, ε>0; m is the order of the acoustic black hole.

[0043] like Figure 5 As shown, the vibration-damping and anti-impact units are arranged periodically in a direction perpendicular to the plane of the plane. When working, they are fixed to the structure to be damped through the mounting holes 1-2 of the metal base. The mass block 3-2 contacts and collides with the acoustic black hole beam 2-1, transmitting vibration energy which is absorbed and dissipated by the damping layer 2-2.

[0044] The embodiments of the present invention improve the vibration reduction performance of the acoustic black hole in the low frequency band by introducing contact collision in the vibration reduction and anti-impact unit; realize wide-band vibration reduction of large structures by combining the concept of acoustic metamaterials (a structure obtained by periodically arranging the structure of a unit is called a metamaterial / acoustic metamaterial) for periodic design; and achieve flexible adjustment of the frequency band in which the overall structure performs its function according to changes in the ambient vibration frequency by simply adjusting the collision mass.

[0045] In the embodiment of the present invention, each vibration reduction and anti-shock unit utilizes the collision between the mass block and the acoustic black hole beam to transmit vibration energy, and then absorbs and dissipates it through the damping layer. The present invention combines the concept of metamaterials and arranges the vibration reduction and anti-shock units periodically to achieve a broadband vibration reduction effect. When the ambient vibration frequency changes, the mass block can be adjusted to meet the vibration reduction requirements of different working frequency bands.

[0046] The device of the embodiment of the present invention has a simple structure, is easy to process, has good vibration reduction and impact resistance performance, is easy to implement, and has good theoretical and practical performance.

[0047] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0048] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0049] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Adjustable collision acoustic black hole periodic vibration reduction and anti-shock device, characterized in that: It comprises a plurality of identical vibration-damping and anti-impact units periodically arranged on the surface of the structure to be damped; the vibration-damping and anti-impact unit comprises an "J"-shaped cavity wall and a mass block-acoustic black hole beam combination structure arranged therein; the adjustable collision acoustic black hole periodic vibration-damping and anti-impact device has periodicity in the "J"-shaped direction perpendicular to the "J"-shaped cavity wall; the "J"-shaped cavity wall comprises an upper cavity and an air vent at the top of the upper cavity; the mass block-acoustic black hole beam combination structure comprises an acoustic black hole beam, a mass block and a cavity perpendicular to the structure to be damped; a damping layer is arranged at the end of the acoustic black hole beam, and the mass block moves up and down in the cavity, and transmits vibration energy by colliding with the acoustic black hole beam arranged below, and the vibration energy is absorbed and dissipated by the damping layer.

2. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1 is characterized in that: The "X"-shaped cavity wall comprises a metal base, and a bottom mounting hole is arranged on the metal base. The metal base of the "X"-shaped cavity wall is fixed to the vibration-damped structure through the bottom mounting hole.

3. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1 is characterized in that: The "X"-shaped cavity wall is a closed structure, and the thickness of the upper cavity is greater than the thickness of the base.

4. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1 is characterized in that: The mass block is a spherical mass block.

5. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 4 is characterized in that: The containing cavity is a cylindrical cavity.

6. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 5 is characterized in that: The diameter of the cavity is slightly larger than the diameter of the mass block.

7. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1 is characterized in that: A predetermined gap is left between the bottom of the mass block and the acoustic black hole beam, and the mass block collides with the acoustic black hole beam during operation, transmitting vibration energy and absorbing and dissipating it through the damping layer.

8. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1 is characterized in that: The mass of the mass block, the parameters of the acoustic black hole beam, the thickness and material of the damping layer are flexibly designed according to the required frequency band to adapt to vibration reduction in different working frequency bands.

9. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1, characterized in that: The vibration-damped structure is a planar structure.

10. The adjustable collision acoustic black hole periodic vibration reduction and anti-shock device according to claim 1, characterized in that: The mass blocks of different vibration-damping and anti-shock units have different mass sizes; by adjusting the mass blocks of different vibration-damping and anti-shock units, low-frequency and broadband vibration reduction of large structures can be achieved.

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