CN112365871A

CN112365871A - Local resonance periodic structure with multi-stage vibrator

Info

Publication number: CN112365871A
Application number: CN202011182118.2A
Authority: CN
Inventors: 盛美萍; 方正; 何元安
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2021-02-12
Anticipated expiration: 2040-10-29
Also published as: CN112365871B

Abstract

The invention belongs to the technical field of vibration noise control, and particularly relates to a local resonance periodic structure with a multi-level vibrator, which comprises an elastic base, a frame, an elastic column and a mass block; the elastic base and the surface integral mass of the elastic base form a primary resonance structure, each elastic column and the mass block on the frame form a plurality of secondary sub-resonance structures, and the structures are periodically arranged on the surface of the structure to be subjected to vibration suppression treatment. Through the resonance of each order of vibrators, the vibration energy is converted into the kinetic energy of each order of vibrators, the vibration energy of the controlled structure is greatly dissipated, and therefore the multi-band vibration control is achieved. The aim is to better adapt to the vibration reduction requirement in engineering by utilizing the multi-mode and broadband design.

Description

Local resonance periodic structure with multi-stage vibrator

Technical Field

The invention belongs to the technical field of vibration noise control, and particularly relates to a local resonance periodic structure with a multi-stage vibrator.

Background

Vibration exists in various fields, and is harmful vibration mostly, and the vibration of instrument equipment not only affects the precision of precision equipment, but also damages the equipment, reduces the normal service life of the equipment, and even directly causes the equipment not to be normally used; vibration generated by large machinery is spread outwards along with the earth surface, and damages are caused to the house walls of factories and nearby residents; the driving of vehicles in cities, urban operation and daily life can generate a large amount of vibration, and citizens are exposed in the environment for a long time, so that the citizens feel bored, the physical fatigue is accelerated, the working efficiency is reduced, and even the health of the citizens is endangered in serious cases. At present, the methods for controlling vibration are widely applied as follows: dynamic vibration absorption, vibration isolation, damping vibration attenuation and the like, however, the control of low-frequency vibration is often difficult to realize due to the limitations of installation process, installation space and the like in the traditional vibration attenuation mode.

The local resonance periodic structure can generate a band gap with relatively low frequency, elastic waves in a band gap range cannot be transmitted, and compared with a traditional vibration reduction mode, the large-wavelength elastic waves can be really controlled by a small-size structure.

Disclosure of Invention

The invention aims to provide a local resonance periodic structure with a multi-order vibrator.

In order to achieve the purpose, the invention adopts the technical scheme that: a local resonance periodic structure with a multi-level vibrator comprises an elastic base, a frame, an elastic column and a mass block. The local resonance periodic structure cell element comprises a two-stage resonance structure, a through hole is formed in a mass block, the shape of the through hole is the same as that of the section of an elastic column, the two sizes of the through hole are the same, the elastic column penetrates through the mass block and is tightly attached to the mass block, a frame is integrally formed by a plurality of side frames, a center column and long frames at the top end and the bottom end, a through hole is formed in each side frame of the frame, a corresponding blind hole is formed in the side face of the frame center column opposite to each side frame, the sizes of the two holes are the same as that of the section of the elastic column, the depth of the blind hole is the same as that of the through hole, a corresponding pair of holes are formed in the same axis, two ends of the elastic column are inserted into one pair of holes to. The frame is fixedly connected to the upper surface of the elastic base to form a primary resonance structure. The elastic base and the elastic column are made of elastic damping materials, and the local resonance periodic structure is periodically arranged on the surface of the structure to be subjected to vibration suppression.

Preferably, the mass block is in the shape of a cylinder, a sphere, a cone and the like.

Preferably, the frame and the mass block are made of high-density, high-modulus and non-deformable materials.

Preferably, the frame may have a plurality of side frames, and a secondary sub-resonant structure may be provided between each side frame and the central column of the frame.

Preferably, the elastic base and each elastic column are made of materials with proper modulus according to the mode of the structure to be damped.

Preferably, the elastic base and each elastic column are made of materials with larger damping under the condition of meeting the modulus requirement.

Preferably, the cross section of the elastic base can be polygonal, circular and irregular.

Preferably, the local resonance periodic structure cells with the multi-level vibrators are arranged on the surface of the structure to be damped at equal intervals, and the arrangement form is not limited and can be simple square, simple hexagonal, simple oblique square and the like.

Based on the band gap theory of the local resonance periodic structure, the local resonance periodic structure can generate a low-frequency band gap, elastic waves cannot be transmitted in the band gap range of the infinite periodic structure, the elastic waves are greatly restrained in the band gap range of the finite periodic structure, the initial frequency of the band gap is related to the elastic parameters of the local resonance cell structure, the width of the band gap is related to the mass ratio and damping of the cell, and the damping has the function of widening the band gap.

The invention has the following beneficial effects: on one hand, in the structure of the local resonance periodic structure cell with the multi-stage vibrator, the elastic base and the frame form a primary resonance structure, and the elastic columns and the mass blocks in the frame form a plurality of secondary sub-resonance structures, so that the local resonance periodic structure cell has abundant vibration modes and can realize vibration suppression of a plurality of frequency bands; on the other hand, the resonance frequency of the secondary sub-resonance structures can be adjusted to be close, a plurality of narrow low-frequency vibration suppression band gaps are integrated into a wide-frequency band gap through the damping effect of the material of the elastic column, the low-frequency vibration suppression performance is effectively improved, the elastic base with high damping is attached to the surface of the structure to be controlled, and the damping effect on the medium-frequency and high-frequency vibration is very good. The invention has simple structure, convenient installation and batch production.

Drawings

FIG. 1 is a schematic diagram of a local resonant periodic structure cell with multiple secondary oscillators according to the present invention;

FIG. 2 is a schematic diagram of a primary resonance structure of a local resonance periodic structure according to the present invention;

FIG. 3 is a schematic diagram of a secondary sub-resonance structure of the local resonance periodic structure according to the present invention;

FIG. 4 is a schematic diagram of a homogeneous plate with attached local resonance periodic structure array of the present invention having a multi-order vibrator;

FIG. 5 is a schematic illustration of the vibration damping effect of the embodiment shown in FIG. 4;

in the figure: 1-elastic base, 2-frame, 21-short frame, 22-central column, 23-long frame, 24-through hole, 25-blind hole, 3-elastic column and 4-mass block

Detailed Description

The embodiments of the present invention will be further described with reference to the drawings in the following, and it should be understood that the described embodiments are only one embodiment of the present invention. Other embodiments, which can be obtained by other persons skilled in the art without any inventive work, based on the embodiments of the present invention, belong to the protection scope of the present invention.

As shown in fig. 1, which is a schematic view of a local resonance periodic structure cell with a multi-level oscillator of the present invention, a through hole is provided inside a mass block (4), the shape of the through hole is the same as the cross-sectional shape of an elastic column (3), and the sizes of the through hole and the elastic column are the same, the elastic column (3) penetrates through the mass block (4) and is tightly attached to the mass block (4), a frame (2) is integrally formed by a plurality of side frames (21), a central column (22) and long frames (23) at the top end and the bottom end, a through hole (24) is provided on each side frame of the frame, a corresponding blind hole (25) is provided on the side of the frame central column (22) opposite to each side frame (21), the sizes of the two holes are the same as the cross-sectional size of the elastic column (3), the depth of the blind hole (25) is the same as the through hole (24), a, transversely hung in the frame (2), and each elastic column (3) and the mass block (4) arranged on the elastic column form a secondary sub-resonance structure. The frame (2) is fixedly connected to the upper surface of the elastic base (1) to form a primary resonance structure. The elastic base (1) and the elastic column (3) are made of elastic damping materials, and the local resonance periodic structure is periodically arranged on the surface of the structure to be subjected to vibration suppression.

The frame (2) can be provided with a plurality of side frames (21), a secondary sub-resonance structure can be arranged between each side frame (21) and the frame central column (22), and the figure only illustrates the condition when the number of the side frames (21) is 4.

The section of the elastic base (1) can be polygonal, circular or irregular. The figure only shows the situation when the section of the elastic base (1) is quadrangular.

Preferably, the elastic base (1), the frame (2) and the elastic column (3) are of a symmetrical structure.

Preferably, the frame (2) and the mass block (4) are used as vibrators of the primary and secondary sub-resonance structures and made of high-density and high-modulus materials, and the shapes of cylinders, spheres and the like are selected to ensure the stability of the structure when the mass block (4) vibrates.

Preferably, the elastic base (1) and the elastic columns (3) at all levels provide rigidity, and are made of elastic damping materials, and rubber materials with larger damping are selected for obtaining a better damping effect.

The invention is composed of a plurality of resonance structures in series-parallel connection, as shown in fig. 2 and fig. 3, an elastic base (1) and a frame (2) form a primary resonance structure, an elastic column (3) and a mass block (4) in the frame (2) form a plurality of secondary sub-resonance structures, and the secondary sub-resonance structures have abundant vibration modes, and the vibration of a vibrator can dissipate the vibration energy of a controlled structure, so that a plurality of low-frequency band gaps can be generated.

When the controlled structure vibrates transversely, the elastic waves are transmitted to the local resonance structure from the controlled structure to cause the vibration of the frame (2) so as to drive the vibration of each secondary mass block (4), the frame (2) and the mass blocks (4) resonate at each order of natural frequency of the structure, so that the vibration energy is converted into the kinetic energy of the frame (2) and the mass blocks (4), the vibration energy of the controlled structure is greatly dissipated, the vibration is localized in the first cells, and the vibration response of the controlled structure is reduced.

FIG. 4 is a schematic diagram of the installation of the present invention in vibration suppression, wherein n structures of the present invention (only 9 structures are attached in the figure) are periodically attached to the uniform plate, the uniform plate is divided into n cells, each cell is attached with one structure of the present invention, appropriate parameters are set, and simulation analysis of vibration response is performed under the excitation of given specific force, as shown in FIG. 5, the vibration response comparison curves before and after the addition of the present invention are shown, and it can be seen from the graph that, in the frequency range of the band gap, the vibration response of the substrate plate is significantly reduced, and the starting frequency of the first band gap is as low as below 100 Hz.

Claims

1. A local resonance periodic structure with multiple-stage vibrators, characterized in that: a through hole is provided inside the mass block (4), and the shape of the through hole is the same as the cross-sectional shape of the elastic column (3), and the dimensions of the two are consistent, and the elastic column (3) penetrates through the mass block (4) and closely fits with the mass block (4), the frame (2) consists of a plurality of side frames (21), a central column (22) and long frames (22) at the top and bottom ends. 23) It is integrally formed, each side frame (21) of the frame (2) is provided with a through hole (24), and each side frame (21) is provided with a corresponding blind hole ( 25), the size of the two holes is consistent with the cross-sectional size of the elastic column (3), the depth of the blind hole (25) is consistent with the through hole (24), the corresponding pair of holes are on the same axis, and the two ends of the elastic column (3) Insert into a pair of holes to make both ends fixed, and hang horizontally in the frame (2), each elastic column (3) and the mass block (4) arranged on it form a secondary sub-resonant structure. The frame (2) is fixedly connected to the upper surface of the elastic base (1) to form a primary resonance structure. The elastic base (1) and the elastic column (3) are both elastic damping materials, and the local resonance periodic structure is periodically installed on the surface of the structure to be treated for vibration suppression.

2 . The local resonance periodic structure with multiple-stage oscillators according to claim 1 , wherein the mass block ( 4 ) is in the shape of a cylinder, a sphere, and a cone. 3 .

3 . The local resonance periodic structure with multi-stage oscillators according to claim 1 , wherein the frame ( 2 ) and the mass block ( 4 ) are made of materials with high density and high modulus that are not easily deformed. 4 .

4. The local resonance periodic structure with multi-stage vibrators according to claim 1, wherein the frame (2) can have a plurality of side frames (21), each side frame (21) and the frame A secondary sub-resonant structure can be arranged between the central columns (22).

5. The local resonance periodic structure with multi-stage vibrators according to claim 1, characterized in that: the elastic base (1) and each elastic column (3) select an appropriate modulus according to the mode of the structure to be damped s material.

6. The local resonance periodic structure with multiple-stage oscillators according to claim 1, characterized in that: the materials of the elastic base (1) and each elastic column (3) are selected to have relatively high elastic properties under the requirement of satisfying the modulus. High damping material.

7 . The local resonance periodic structure with multi-stage oscillators according to claim 1 , wherein the cross-section of the elastic base ( 1 ) can be polygonal, circular or irregular. 8 .

8. The local resonance periodic structure with multi-stage oscillators according to claim 1, wherein the local resonance periodic structure cells with multi-stage oscillators are arranged at equal intervals on the surface of the structure to be damped, The arrangement is not limited, and can be in the form of simple square, simple hexagon, simple rhombus, etc.