Detachable vibration reduction metamaterial structure with adjustable frequency
By designing a detachable frequency-adjustable vibration-damping metamaterial structure and utilizing the local resonance system to absorb energy, the problem of fixed vibration-damping frequency in the aircraft cockpit is solved, achieving frequency adjustability and easy-to-maintain vibration-damping effects, which is suitable for aircraft vibration isolation devices.
Patent Information
- Application Number
- CN202423046602.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-12-10
AI Technical Summary
The passive noise reduction methods in existing aircraft cockpits have a simple structure and a fixed vibration reduction frequency, which cannot adapt to the complex and changing engineering environment. In addition, the structural size of traditional vibration reduction materials is too large at low target sound absorption frequencies and is not suitable for engineering applications.
A detachable, frequency-adjustable vibration-damping metamaterial structure is designed. The target frequency is changed by replacing the elastic structure and mass block, and the vibration reduction effect is achieved by absorbing energy through the local resonance system. The metamaterial structure includes a combination of periodically arranged cells, a frame, connecting blocks, sleeves and mass blocks.
The frequency adjustability with good vibration reduction effect and easy maintenance is achieved, which is suitable for aircraft vibration isolation devices. The target frequency range can be adjusted by replacing the local resonance part.
Smart Images
Figure CN223359764U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of aircraft structure design, and relates to a detachable frequency-adjustable vibration-damping metamaterial structure. Background Art
[0002] In the existing technology, a common noise reduction method in aircraft cockpits is to attach sound-insulating mineral wool to the wall panels, etc. Passive noise reduction and vibration reduction technical measures are adopted. This method has a simple structure and a fixed vibration reduction frequency, and is gradually unable to meet the complex and changing frequency environments in daily engineering environments.
[0003] Traditional vibration-damping materials or structures, such as porous materials and phononic crystals, have good sound absorption efficiency only when the working wavelength is comparable to the structure size. When the target sound absorption frequency is low, the structure size is large, which is not conducive to engineering applications.
[0004] Therefore, in order to solve the problems existing in the prior art, it is necessary to provide a vibration-damping metamaterial structure that can be attached to the aircraft wall panel and can easily change the target frequency by replacing the elastic structure and mass block. Utility Model Content
[0005] The purpose of the utility model is to provide a vibration-damping metamaterial structure that can be attached and applied on aircraft panels and can conveniently change the target frequency by replacing the elastic structure and the mass block.
[0006] The technical solution of this utility model:
[0007] A detachable frequency-adjustable vibration-damping metamaterial structure includes a plurality of periodically arranged cells. The cells include a frame, a mass block is arranged at the center of the frame, and the mass block is connected to the frame via an elastic structure. The elastic structure and the mass block form a local resonance system.
[0008] Furthermore, a plurality of connecting blocks are provided on the inner edge of the frame.
[0009] Furthermore, the mass block is arranged in the sleeve.
[0010] Furthermore, one end of the elastic structure is connected to the connecting block via a connecting piece, and the other end is connected to the outer surface of the sleeve.
[0011] Furthermore, the cross section of the frame is a hollow square, rectangle, regular hexagon or circle, and the connecting blocks are integrally formed with the frame.
[0012] Furthermore, the elastic structure is a beam structure sheet or a thin plate structure sheet.
[0013] Beneficial effects of the utility model
[0014] The present invention proposes a detachable, frequency-adjustable vibration-damping metamaterial structure composed of multiple cells. Each cell comprises an upper and lower support frame with an in-plane connecting block extending outward from the frame to connect the elastic structure, sleeve, and mass. The frame is connected to the local resonance portion via connectors (such as bolts), and a rigid mass is placed within the sleeve. The elastic structure and mass form a local resonance system. When excited by vibrations close to the natural frequency of the local resonance system, local resonance is stimulated, achieving a vibration reduction effect. The advantages of this structure are: 1. The local resonance portion, namely, the material, thickness, and shape of the elastic structure, the mass of the mass, and different spring and mass combinations, can be replaced or periodically changed; 2. This structural design allows for control of the frame preload range, allowing adjustment to the target frequency range as required. This metamaterial structure design offers excellent adjustability, ease of disassembly and replacement, and maintainability, resulting in excellent vibration reduction, making it suitable for use in aircraft vibration isolation devices. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the cellular structure of a detachable frequency-adjustable vibration-damping metamaterial structure;
[0016] Figure 2 This is a schematic diagram of the cell connection blocks of a detachable frequency-adjustable vibration-damping metamaterial structure;
[0017] Figure 3 It is a schematic diagram of the connection between the frame and the connecting blocks of the detachable frequency-adjustable vibration-damping metamaterial structure;
[0018] Figure 4 This is a schematic diagram of a periodic array of multicellular metamaterial structures;
[0019] In the figure: 1-frame, 2-connecting block, 3-elastic structure, 4-sleeve, 5-mass block. DETAILED DESCRIPTION
[0020] One embodiment of the present invention provides a detachable frequency-adjustable vibration-damping metamaterial structure, comprising a plurality of cells periodically arranged in a plane, wherein the frame of the cells has a connecting block with bolt holes extending outward from the frame and connected to the elastic structure through a connector, which facilitates the replacement of the elastic structure and the mass block to change the target frequency of the local resonance system.
[0021] Cells include:
[0022] A frame having a connecting block with bolt holes extending outward from the frame for installing and removing the local resonance part; the connecting block is connected to the elastic structure by a connecting member (such as a bolt); the elastic structure includes a sleeve, and a mass block is embedded in the sleeve. The elastic structure and the mass block form a local resonance system. When a vibration excitation close to the natural frequency of the local resonance system occurs, local resonance occurs, absorbing energy to achieve a vibration reduction effect; in addition, by periodically changing the properties (material, thickness or shape) of the elastic structure in each cell and the mass of the mass block, the frame is preloaded to varying degrees to change the stiffness of the elastic structure to achieve an extension of the target frequency of vibration reduction;
[0023] Preferably, the cross-section of the frame (excluding the protruding connection blocks) includes a hollow square, a rectangle, a regular hexagon, a circle, etc.;
[0024] Preferably, the positions and numbers of the outwardly extending connection blocks of the frame are the same or different, so as to meet the requirements for assembling various types of local resonance parts;
[0025] Preferably, the connection holes of the extended connection block of the frame include different positions to meet different installation requirements;
[0026] Preferably, the connection object of the extended connection block of the frame includes an elastic structure, a mass block, etc. of a local resonance system unit;
[0027] Preferably, the elastic structure of the local resonance system unit of the metamaterial includes structures such as beams and thin plates in different forms.
[0028] A second embodiment of the present invention provides a frequency-adjustable sound-absorbing metamaterial, comprising a plurality of cells periodically arranged in a plane. The frame of the cells has a connecting block with bolt holes extending outward from the frame, which is connected to an elastic structure through a connector. This facilitates changing the target frequency of the local resonance system by replacing the elastic structure and the mass block.
[0029] Cells include:
[0030] like Figure 1 As shown, the frame, the frame cross section includes hollow square, rectangle, regular hexagon and circle, etc. Figure 2 As shown, the frame has at least four connecting blocks with bolt holes extending from the frame. These blocks are connected to the elastic structure via bolts, forming an integral part of the frame. The elastic structure includes a sleeve and an embedded mass block. The elastic structure and the mass block form a local resonance system. When the incident vibration excitation frequency approaches the local resonance frequency, the system composed of the elastic structure and the mass block will undergo local resonance, absorbing energy and reducing the vibration transmission ratio. The geometric or material properties of the elastic structure and the mass block within each periodic cell may not be identical.
[0031] like Figure 3As shown, in this embodiment, the cellular frame has a hollow square cross-section, with a width of 90 mm and a thickness of 7 mm. The elastic structure has a rectangular cross-section, a total length of 29 mm, and a thickness of 1.5 mm. The mass is a metal cylinder with a diameter of 10 mm and a height of 20 mm. When the system undergoes local resonance, the transmission coefficient of the structure decays rapidly near the resonant frequency.
[0032] The designed periodic array of multicellular metamaterial structures such as Figure 4 When the frame is preloaded, the stiffness of the elastic structure changes, thereby changing the local resonance frequency of the system to achieve the expansion of the vibration reduction target frequency.
Claims
1. A detachable frequency-adjustable vibration-damping metamaterial structure, characterized in that: It includes a number of periodically arranged cells, wherein the cells include a frame, a mass block is arranged at the center of the frame, the mass block is connected to the frame through an elastic structure, and the elastic structure and the mass block form a local resonance system.
2. The detachable frequency-adjustable vibration-damping metamaterial structure according to claim 1, characterized in that: A plurality of connection blocks are arranged on the inner edge of the frame.
3. The detachable frequency-adjustable vibration-damping metamaterial structure according to claim 2, characterized in that: The mass block is arranged in the sleeve.
4. The detachable frequency-adjustable vibration-damping metamaterial structure according to claim 3, characterized in that: One end of the elastic structure is connected to the connecting block through a connecting piece, and the other end is connected to the outer surface of the sleeve.
5. The detachable frequency-adjustable vibration-damping metamaterial structure according to claim 1, characterized in that: The cross section of the frame is a hollow square, rectangle, regular hexagon or circle, and the connecting block and the frame are integrally formed.
6. The detachable frequency-adjustable vibration-damping metamaterial structure according to claim 1, characterized in that: The elastic structure is a beam structure sheet or a thin plate structure sheet.