Damping and sound absorbing device with gradient modulus density
By introducing a vibration-absorbing and sound-absorbing device with gradient modulus density into the acoustic black hole structure, the problem of low absorption efficiency in the prior art is solved, and more efficient vibration noise control is achieved, which is suitable for different equipment and environmental conditions.
Patent Information
- Application Number
- CN202510439094.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-06-24
AI Technical Summary
The existing acoustic black hole structures are difficult to achieve theoretical smoothness in actual production, and processing and manufacturing errors lead to reduced absorption efficiency, which cannot effectively solve the demand for vibration noise control.
A vibration-absorbing and sound absorption device with gradient modulus density is adopted, which includes a damping sound absorption layer and a gradient modulus density layer. The gradient modulus density layer is covered outside the damping sound absorption layer in a spherical shell. The elastic modulus and density gradually decrease along the radius and are connected to the work surface of the equipment through bonding or vulcanization.
Through the design of the gradient modulus density layer, the phase velocity of the wave gradually decreases with the change of elastic modulus or density, the reflection coefficient is close to zero, the wave energy continues to gather inward and is transmitted to the damping sound absorption layer, forming a "energy absorption-energy consumption trap", effectively blocking the transmission of vibration and sound energy of the equipment, and achieving the purpose of vibration reduction and noise reduction.
Smart Images
Figure CN120199218A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of vibration and noise control, and particularly relates to a vibration damping and sound absorption device with a gradually changing modulus density. Background Art
[0002] During industrial production, mechanical equipment generates vibrations and noises during operation, which not only affect the work efficiency and physical health of workers, but may also cause a decline in equipment reliability, thereby affecting production safety and product quality. In daily life, equipment such as household appliances, generators, transformers, fans, and pumps that people often use also generate vibrations and noises during operation, affecting the surrounding environment and the lives of residents. Therefore, vibration damping and noise reduction technologies need to be adopted to reduce the impact of equipment vibrations and noises on the surrounding environment and the equipment itself, and improve the quality of the living environment of residents.
[0003] Vibration and noise control technologies are mainly divided into two categories: active control and passive control. Active control systems require the introduction of electronic devices such as sensors, controllers, and actuators. The system is complex, and the use and maintenance costs are high. In some cases, stability and reliability problems may occur. Passive control technologies use structural and material designs to block, absorb, and dissipate vibration and sound energy, which can directly suppress vibrations and noises and avoid the aforementioned problems. For example, the acoustic black hole vibration damping and noise reduction structure, as a new type of passive control technology with a simple structure and good attenuation ability for vibrations and noises in a wide frequency band, has been preliminarily applied to the field of vibration and noise control.
[0004] Existing acoustic black hole structure devices achieve the purpose of vibration damping and sound absorption based on geometric cross-section changes. However, in actual production and manufacturing, the processing requirements for the cross-section geometric contour curve are high, and it is difficult to achieve the theoretical smoothness. Processing and manufacturing errors will lead to a reduction in absorption efficiency. Summary of the Invention
[0005] The purpose of the present invention is to propose a vibration damping and sound absorption device with a gradually changing modulus density to make up for the deficiencies of existing acoustic black hole technologies, broaden the application scope of acoustic black hole theory, reasonably match the vibration damping and noise reduction requirements of equipment, and achieve the best vibration damping and noise reduction effect.
[0006] The present invention is specifically implemented through the following technical solutions. A vibration damping and sound absorption device with a gradient modulus density, proposed according to the present invention, has a spherical structure, including a damping sound absorption layer and a gradient modulus density layer. The gradient modulus density layer is in the shape of a spherical shell and covers the outside of the damping sound absorption layer, and the damping sound absorption layer is filled in the inner spherical cavity formed by the gradient modulus density layer. Define the outer diameter of the damping sound absorption layer as r1, and the outer diameter of the gradient modulus density layer as r2. Taking the origin of coordinates with a radius r centered on the center of the sphere, the elastic modulus of the gradient modulus density layer at r = r2 is E2, and the density is ρ2. The elastic modulus of the gradient modulus density layer at r = r1 is E1, and the density is ρ1, and it satisfies that the maximum value of E1 does not exceed 1 / 5 of E2, and the maximum value of ρ1 does not exceed 1 / 5 of ρ2. When r1 < r < r2, along the direction from the radius r2 towards the center of the sphere, the elastic modulus and density of the gradient modulus density layer gradually decrease.
[0007] For the aforementioned vibration damping and sound absorption device with a gradient modulus density, when r1 < r < r2, along the direction from the radius r2 towards the center of the sphere, the elastic modulus E of the gradient modulus density layer decreases according to the form of Function I with respect to the value of the radius r. Function I is: where n = 1 to 10; or, the density ρ of the gradient modulus density layer decreases according to the form of Function II with respect to the value of the radius r. Function II is: where n = 1 to 10.
[0008] For the aforementioned vibration damping and sound absorption device with a gradient modulus density, the damping sound absorption layer is a hollow structure or a solid structure.
[0009] Further, when the damping sound absorption layer is a hollow structure, it has a cavity inside. Define the radius of the cavity as r0, then r0, r1, and r2 satisfy (r1 - r0) / (r2 - r0) ≤ 1 / 10.
[0010] For the aforementioned vibration damping and sound absorption device with a gradient modulus density, the damping sound absorption material of the damping sound absorption layer includes rubber, polyurethane, and polymer resin; the material of the gradient modulus density layer includes stainless steel and aluminum alloy.
[0011] For the aforementioned vibration damping and sound absorption device with a gradient modulus density, the damping sound absorption layer and the gradient modulus density layer can be connected by bonding or vulcanization.
[0012] For the aforementioned vibration damping and sound absorption device with a gradient modulus density, it can also only include the gradient modulus density layer. The outer diameter of the gradient modulus density layer is r2. Taking the origin of coordinates with a radius r centered on the center of the sphere, the elastic modulus of the gradient modulus density layer at r = r2 is E2, and the density is ρ2. When 0 < r < r2, along the direction from the radius r2 towards the center of the sphere, the elastic modulus E of the gradient modulus density layer decreases according to the form of Function I with respect to the value of the radius r. Function I is: Among them, E1 = 0, r1 = 0, n = 1 to 10; alternatively, the density ρ of the gradient modulus density layer decreases in the form of Function II according to the value of the radius r, and Function II is: Among them, ρ1 = 0, r1 = 0, n = 1 to 10.
[0013] For the aforementioned vibration damping and sound absorption device with gradient modulus density, the gradient modulus density layer includes a plurality of spherical shell-shaped gradient modulus density structural layers stacked radially. Each gradient modulus density structural layer has a constant elastic modulus and density, and the change rates of the elastic modulus and density between the inner gradient modulus density structural layer and the outer gradient modulus density structural layer in two adjacent gradient modulus density structural layers are both less than 1 / 10.
[0014] Furthermore, the material of the gradient modulus density layer includes stainless steel and aluminum alloy.
[0015] For the aforementioned vibration damping and sound absorption device with gradient modulus density, it can be connected to the equipment workbench surface by bonding, welding or bolt connection, and the workbench surface needs to be a plane. When there are vibration and sound excitation in multiple directions on the equipment, waves will be transmitted to the gradient modulus density layer of the vibration damping and sound absorption device along the connection part between the equipment and the vibration damping and sound absorption device. During the continuous propagation into the interior of the vibration damping and sound absorption device, the phase velocity of the waves gradually decreases as the elastic modulus or density of the gradient modulus density layer changes, the reflection coefficient approaches zero, the wave energy continuously accumulates inward, and is transmitted to the damping and sound absorption layer connected to the gradient modulus density layer, and is dissipated by the damping and sound absorption material, forming an "energy absorption - energy dissipation trap", blocking the transmission of the equipment vibration and sound energy, and achieving the purpose of vibration reduction and noise reduction.
[0016] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solutions, the present invention can achieve quite high technological progressiveness and practicability, and has wide utilization value. It has at least the following advantages:
[0017] The vibration damping and sound absorption device of the present invention includes a damping and sound absorption layer located in the inner core and a gradient modulus density layer located in the outer shell. The elastic modulus or density of the gradient modulus density layer gradually decreases from the outside to the inside. The vibration damping and sound absorption device is connected to the plane of the equipment workbench by bonding, welding or bolt connection. When there is a vibration and sound excitation in the equipment, the wave will be transmitted to the gradient modulus density layer along the connection part between the vibration damping and sound absorption device and the equipment. During the process of the wave propagating inward along the gradient modulus density layer, the phase velocity of the wave gradually decreases with the change of the elastic modulus or density of the gradient modulus density layer, and the reflection coefficient approaches zero. The wave energy continuously accumulates inward and is transmitted to the damping and sound absorption layer connected to the gradient modulus density layer. It is dissipated by the damping and sound absorption material to form an "energy absorption - energy dissipation trap", blocking the transmission of the vibration and sound energy of the equipment and achieving the purpose of vibration reduction and noise reduction. At the same time, setting the "quasi - acoustic black hole structure" can greatly improve the absorption efficiency of vibration and noise energy, so that the damping and sound absorption layer can dissipate more vibration and sound energy, expand the application scenario of the acoustic black hole theory, and meet the actual application requirements of the acoustic black hole technology under different equipment and environmental conditions.
[0018] The vibration damping and sound absorption device of the present invention is expected to make up for the defects of the existing acoustic black hole technology, broaden the application scope of the acoustic black hole theory, reasonably match the requirements of equipment vibration reduction and noise reduction, and has the advantages of simple structure, convenient implementation, low cost and high reliability. Description of the Drawings
[0019] Figure 1 It is a cross - sectional view of the vibration damping and sound absorption device with gradient modulus density in Embodiment 1.
[0020] Figure 2 It is a cross - sectional view of the vibration damping and sound absorption device with gradient modulus density in Embodiment 2.
[0021] Figure 3 It is a cross - sectional view of the vibration damping and sound absorption device with gradient modulus density in Embodiment 4.
[0022] Figure 4 It is a cross - sectional view of the vibration damping and sound absorption device with gradient modulus density in Embodiment 5.
[0023] Figure 5 It is a cross - sectional view of the vibration damping and sound absorption device with gradient modulus density in Embodiment 7.
[0024] Figure 6 It is the amplitude diagram of the equipment under the excitation of an external harmonic load.
[0025] Figure 7 It is Figure 6 The amplitude diagram at the same position of the equipment after using the vibration damping and sound absorption device with gradient modulus density in Embodiment 1 under the excitation of the same external harmonic load. Detailed Embodiments
[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.
[0027] The vibration damping and sound absorption device with a gradient modulus density of the present invention has a spherical structure, which includes a damping and sound absorption layer 1 and a gradient modulus density layer 2. The gradient modulus density layer is in the shape of a spherical shell and covers the outside of the damping and sound absorption layer, and the damping and sound absorption layer is filled in the inner spherical cavity formed by the gradient modulus density layer. Alternatively, the vibration damping and sound absorption device only includes the gradient modulus density layer. The damping and sound absorption material of the damping and sound absorption layer can adopt known materials, such as rubber, polyurethane, polymer resin, etc. The material of the gradient modulus density layer can adopt stainless steel, aluminum alloy, etc. The 3D printing technology can be used to manufacture a stainless steel gradient modulus density layer or an aluminum alloy gradient modulus density layer with a gradient elastic modulus and a gradient density.
[0028] The following will be described in detail with specific embodiments:
[0029] Embodiment 1
[0030] The vibration damping and sound absorption device with a gradient modulus density is spherical, and its cross-sectional view is as Figure 1 shown, including a damping and sound absorption layer 1 and a gradient modulus density layer 2. The damping and sound absorption layer 1 has a spherical core inside the sphere, and the gradient modulus density layer 2 is a spherical shell covering the outside of the damping and sound absorption layer 1. The damping and sound absorption layer 1 is a hollow structure with a cavity 3 inside. The damping and sound absorption material of the damping and sound absorption layer 1 adopts a known material, such as one of rubber, polyurethane, and polymer resin. The material of the gradient modulus density layer 2 is stainless steel.
[0031] Define the radius of the cavity as r0, the outer diameter of the damping and sound absorption layer as r1, and the outer diameter of the gradient modulus density layer as r2. r0, r1, and r2 satisfy (r1 - r0) / (r2 - r0) ≤ 1 / 10. Along the direction from radius r2 to radius r1 (i.e., along the direction from radius r2 to the center of the sphere), the elastic modulus and density of the gradient modulus density layer gradually decrease, and specifically, the following conditions should be satisfied:
[0032] Taking the center of the sphere as the origin of the coordinate with radius r, at r = r2 (i.e., the coordinate of radius r is located at r2), the elastic modulus of the gradient modulus density layer is E2, and the density is ρ2 (the specific values of E2 and ρ2 are known numbers according to the material used for the gradient modulus density layer. In this embodiment, E2 = 2.5×10 11 Pa, ρ2 = 8000 kg / m 3);At the position where r = r1 (i.e., the coordinate of the radius r is at r1), the elastic modulus of the gradient modulus density layer is E1, the density is ρ1, and it satisfies that the maximum value of E1 does not exceed 1 / 5 of E2, and the maximum value of ρ1 does not exceed 1 / 5 of ρ2; when r1 < r < r2, along the direction from radius r2 to radius r1 (i.e., along the direction from radius r2 to the center of the sphere), the elastic modulus E of the gradient modulus density layer decreases according to the form of Function Ⅰ, and Function Ⅰ is: Where n = 1 to 10, preferably, n = 2 to 5. Or, the density ρ of the gradient modulus density layer decreases according to the form of Function Ⅱ, and Function Ⅱ is: Where n = 1 to 10, preferably, n = 2 to 5. In the same vibration damping and sound absorption device, when calculating the elastic modulus or density at different radii r of the gradient modulus density layer, the value of n is the same.
[0033] The damping sound absorption layer 1 and the gradient modulus density layer 2 are connected by bonding or vulcanization.
[0034] Example 2
[0035] As Figure 2 shown, the damping sound absorption layer is a solid structure, and the rest is the same as in Example 1.
[0036] Example 3
[0037] The material of the gradient modulus density layer 2 is aluminum alloy, E2 = 7.1×10 10 Pa, ρ2 = 2850 kg / m 3 , and the rest is the same as in Example 1.
[0038] Example 4
[0039] The vibration damping and sound absorption device with gradient modulus density is spherical, and its cross-sectional view is as Figure 3 shown, including a damping sound absorption layer 1 and a gradient modulus density layer 2. The damping sound absorption layer 1 has a spherical core inside the sphere, and the gradient modulus density layer 2 is a spherical shell covering the damping sound absorption layer 1. The damping sound absorption layer 1 is a hollow structure with a cavity 3 inside. The damping sound absorption material of the damping sound absorption layer 1 uses a known material, such as one of rubber, polyurethane, and polymer resin. The material of the gradient modulus density layer 2 is stainless steel.
[0040] In this embodiment, the gradient modulus density layer 2 is arranged in a multi-layer "onion-like" structure, that is, the gradient modulus density layer 2 includes a plurality of gradient modulus density structure layers 2.1 in the shape of spherical shells stacked along the radial direction. Each gradient modulus density structure layer has a constant elastic modulus and density, and the change rate of the elastic modulus and density between the inner gradient modulus density structure layer and the outer gradient modulus density structure layer in two adjacent gradient modulus density structure layers is less than 1 / 10. The materials of the plurality of gradient modulus density structure layers stacked along the radial direction can be the same or different. When the materials are the same, their densities are different, so different gradient modulus density structure layers have different elastic moduli and densities.
[0041] Define the radius of the cavity as r0, the outer diameter of the damping and sound-absorbing layer as r1, and the outer diameter of the gradient modulus density layer as r2. r0, r1, and r2 need to satisfy (r1 - r0) / (r2 - r0) ≤ 1 / 10. Along the direction from radius r2 to radius r1 (i.e., along the direction from radius r2 to the center of the sphere), the elastic modulus and density of the gradient modulus density layer gradually decrease, and specifically, the following conditions should be met:
[0042] Taking the origin of coordinates with the center of the sphere as the radius r, the elastic modulus of the gradient modulus density structure layer at r = r2 is E2, and the density is ρ2 (the specific values of E2 and ρ2 are known numbers according to the specific materials used in the gradient modulus density layer. In this embodiment, E2 = 2.5×10 11 Pa, ρ2 = 8000 kg / m 3 ); the elastic modulus of the gradient modulus density structure layer at r = r1 is E1, and the density is ρ1, and it satisfies that the maximum value of E1 does not exceed 1 / 5 of E2, and the maximum value of ρ1 does not exceed 1 / 5 of ρ2. At r1 < r < r2, along the direction from radius r2 to radius r1 (i.e., along the direction from radius r2 to the center of the sphere), the elastic modulus E of the gradient modulus density structure layer decreases according to the form of function Ⅰ with the value of the radius r. Function Ⅰ is: where n = 1 - 10, preferably, n = 2 - 5. Or the density ρ of the gradient modulus density structure layer decreases according to the form of function Ⅱ with the value of the radius r. Function Ⅱ is: where n = 1 - 10, preferably, n = 2 - 5.
[0043] The gradient modulus density layer of this embodiment includes a plurality of gradient modulus density structure layers stacked along the radial direction. What is calculated by the function Ⅰ and function Ⅱ is the elastic modulus and density of the gradient modulus density structure layer. In the formulas of function Ⅰ and function Ⅱ, the radius r = (r 内 + r 外 ) / 2, where r 内 , r 外are the inner radius and the outer radius of the corresponding gradient modulus density structure layer respectively. Each gradient modulus density structure layer has a constant elastic modulus and density. When calculating, the middle radius value of the gradient modulus density structure layer (i.e., r = (r 内 + r 外 ) / 2) is substituted into the corresponding formulas of Function Ⅰ and Function Ⅱ for calculation. At the same time, in the same vibration damping and sound absorption device, when calculating the elastic modulus or density at different radii r of the gradient modulus density layer, the value of n is the same.
[0044] The damping and sound absorption layer 1 and the gradient modulus density layer 2 are connected by bonding or vulcanization, and adjacent two gradient modulus density structure layers are connected by bonding or welding.
[0045] In this embodiment, the gradient modulus density layer is set as a multi-layer structure, which is convenient for actual processing and manufacturing.
[0046] Embodiment 5
[0047] As Figure 4 shown, the damping and sound absorption layer is a solid structure, and the rest is the same as in Embodiment 4.
[0048] Embodiment 6
[0049] The material of the gradient modulus density layer 2 is aluminum alloy, E2 = 7.1×10 10 Pa, ρ2 = 2850 kg / m 3 , and the rest is the same as in Embodiment 4.
[0050] Embodiment 7
[0051] The vibration damping and sound absorption device with gradient modulus density is spherical, and its cross-sectional view is as Figure 5 shown. It only includes the gradient modulus density layer, and the material of the gradient modulus density layer is stainless steel. Define the outer diameter of the gradient modulus density layer as r2, with the origin of coordinates at the center of the sphere with radius r. At r = r2 (i.e., the coordinate of radius r is located at r2), the elastic modulus of the gradient modulus density layer is E2, and the density is ρ2 (in this embodiment, E2 = 2.5×10 11 Pa, ρ2 = 8000 kg / m 3 ); at r = 0 (i.e., at the center of the sphere), the elastic modulus of the gradient modulus density layer is close to zero (for example, it can be 100 Pa); at 0 < r < r2, along the direction from radius r2 to the center of the sphere, the elastic modulus E of the gradient modulus density layer decreases according to the form of Function Ⅰ with the value of radius r. Function Ⅰ is: Wherein, E1 = 0, r1 = 0, n = 1 to 10, preferably, n = 2 to 5. Or, the density ρ of the gradient modulus density layer decreases according to the form of Function Ⅱ with the value of radius r. Function Ⅱ is: Among them, ρ1 = 0, r1 = 0, n = 1 to 10, preferably, n = 2 to 5. In the same vibration damping and sound absorption device, when calculating the elastic modulus or density at different radii r of the gradient modulus density layer, the value of n is the same.
[0052] In this embodiment, the vibration damping and sound absorption device only includes a gradient modulus density layer. Along the direction of the radius r2 towards the center of the sphere, the elastic modulus and density of the gradient modulus density layer gradually decrease until the elastic modulus at the center of the gradient modulus density layer approaches zero. In this case, the wave can be completely dissipated during the propagation towards the center of the sphere, and the damping sound absorption layer may not be provided.
[0053] Embodiment 8
[0054] This embodiment is the same as Embodiment 7, except that the gradient modulus density layer is set into a multi-layer "onion-like" structure, that is, the gradient modulus density layer includes a plurality of spherical shell-shaped gradient modulus density structure layers stacked along the radial direction. The innermost gradient modulus density structure layer is spherical. Each gradient modulus density structure layer has a constant elastic modulus and density, and the change rate of the elastic modulus and density between the inner gradient modulus density structure layer and the outer gradient modulus density structure layer in two adjacent gradient modulus density structure layers is less than 1 / 10. The materials of the plurality of gradient modulus density structure layers stacked along the radial direction can be the same or different. When the materials are the same, their densities are different, so different gradient modulus density structure layers have different elastic moduli and densities.
[0055] Define the outer diameter of the gradient modulus density layer as r2, with the origin of coordinates at the center of the sphere with radius r. The elastic modulus of the gradient modulus density structure layer at r = r2 is E2, and the density is ρ2 (in this embodiment, E2 = 2.5×10 11 Pa, ρ2 = 8000 kg / m 3 ); the elastic modulus of the innermost gradient modulus density structure layer approaches zero (for example, it can be 100 Pa); at 0 < r < r2, along the direction of the radius r2 towards the center of the sphere, the elastic modulus E of the gradient modulus density structure layer decreases according to the form of Function Ⅰ with the value of the radius r, and Function Ⅰ is: Among them, E1 = 0, r1 = 0, n = 1 to 10, preferably, n = 2 to 5. Or, the density ρ of the gradient modulus density structure layer decreases according to the form of Function Ⅱ with the value of the radius r, and Function Ⅱ is: Among them, ρ1 = 0, r1 = 0, n = 1 to 10, preferably, n = 2 to 5.
[0056] The gradient modulus density layer of this embodiment includes a plurality of gradient modulus density structure layers stacked along the radial direction. What is calculated through Function Ⅰ and Function Ⅱ is the elastic modulus and density of the gradient modulus density structure layer. The radius r in the formulas of Function Ⅰ and Function Ⅱ is r = (r 内 + r 外 ) / 2, where r内 and r 外 are the inner radius and the outer radius of the corresponding gradient modulus density structural layer respectively. Each gradient modulus density structural layer has a constant elastic modulus and density. When calculating, the intermediate radius value of the gradient modulus density structural layer (i.e., r = (r 内 + r 外 ) / 2) is substituted into the corresponding formulas of Function Ⅰ and Function Ⅱ for calculation. At the same time, in the same vibration damping and sound absorption device, when calculating the elastic modulus or density at different radii r of the gradient modulus density layer, the value of n is the same. The rest is the same as in Embodiment 7.
[0057] The working process of a vibration damping and sound absorption device with gradient modulus density according to the present invention will be described below to further clarify the technical solution of the present invention.
[0058] The vibration damping and sound absorption device with gradient modulus density is connected to the equipment workbench by bonding, welding or bolting. The workbench needs to be a flat surface. When there are multiple-direction vibration and sound excitations on the equipment, the wave will be transmitted to the gradient modulus density layer of the vibration damping and sound absorption device along the connection part between the equipment and the vibration damping and sound absorption device. During the process of continuing to propagate into the gradient modulus density layer, the phase velocity of the wave gradually decreases as the elastic modulus or density changes, the reflection coefficient approaches zero, and the wave energy continuously accumulates inward and is transmitted to the damping and sound absorption layer connected to the gradient modulus density layer. Ideally, the "acoustic black hole-like structure" inside the vibration damping and sound absorption device with gradient modulus density can capture the vibration and sound energy and completely dissipate it through the damping and sound absorption material, forming an "energy absorption - energy dissipation trap". In this way, the transmission of the equipment vibration and sound energy can be blocked, achieving the purpose of vibration reduction and noise reduction. In practice, due to the existence of the cut-off modulus and cut-off density in this "acoustic black hole-like structure", part of the vibration and sound energy still cannot be completely absorbed by the damping and sound absorption layer.
[0059] Figure 6 and Figure 7 show the simulation analysis results of the equipment flat plate structure before using the vibration damping and sound absorption device of Embodiment 1 of the present invention and after using the vibration damping and sound absorption device of Embodiment 1 under the same external excitation conditions. By comparing Figure 6 and Figure 7 's results, it can be seen that the vibration damping and sound absorption device with gradient modulus density of the present invention can effectively absorb the energy of vibration and sound waves in a wide frequency range.
[0060] The above are only embodiments of the present invention, and do not impose any form of limitation on the present invention. The present invention can also have other forms of embodiments based on the above structure and function, which will not be listed one by one. Therefore, any person skilled in the art, without departing from the scope of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A vibration-absorbing and sound-absorbing device with a gradient modulus density, characterized in that: The vibration damping and sound absorption device has a spherical structure, including a damping and sound absorption layer (1) and a gradient modulus density layer (2). The gradient modulus density layer is in the shape of a spherical shell and covers the outside of the damping and sound absorption layer. The damping and sound absorption layer is filled in the inner spherical cavity formed by the gradient modulus density layer. Define the outer diameter of the damping and sound absorption layer as r1 and the outer diameter of the gradient modulus density layer as r2. Taking the coordinate origin with a radius of r centered on the center of the sphere, the elastic modulus of the gradient modulus density layer at r = r2 is E2 and the density is ρ2, and the elastic modulus of the gradient modulus density layer at r = r1 is E1 and the density is ρ1, and it satisfies that the maximum value of E1 does not exceed 1 / 5 of E2, and the maximum value of ρ1 does not exceed 1 / 5 of ρ2. When r1 < r < r2, along the direction from r2 to the center of the sphere, the elastic modulus and density of the gradient modulus density layer gradually decrease.
2. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: When \(r_1 < r < r_2\), along the direction from radius \(r_2\) towards the center of the sphere, the elastic modulus \(E\) of the graded modulus density layer decreases according to the form of Function I with respect to the value of radius \(r\). Function I is: where \(n = 1 - 10\); alternatively, the density \(\rho\) of the graded modulus density layer decreases according to the form of Function II with respect to the value of radius \(r\). Function II is: where \(n = 1 - 10\).
3. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: The damping and sound absorption layer (1) is a hollow structure or a solid structure.
4. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 3, characterized in that: When the damping and sound absorption layer (1) is a hollow structure, it has a cavity (3) inside. Define the radius of the cavity as r0, then r0, r1, and r2 satisfy (r1 - r0) / (r2 - r0) ≤ 1 / 10.
5. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: The material of the damping and sound absorption layer includes rubber, polyurethane, and polymer resin; the material of the gradient modulus density layer includes stainless steel and aluminum alloy.
6. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: The damping and sound absorption layer and the gradient modulus density layer are connected by bonding or vulcanization.
7. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: It only includes a gradient modulus density layer. The outer diameter of the gradient modulus density layer is r2. Taking the origin of coordinates with a radius r centered at the center of the sphere, the elastic modulus of the gradient modulus density layer at r = r2 is E2, and the density is ρ2. When 0 < r < r2, along the direction from the radius r2 towards the center of the sphere, the elastic modulus E of the gradient modulus density layer decreases according to the form of Function Ⅰ. Function Ⅰ is: where E1 = 0, r1 = 0, n = 1 - 10; or the density ρ of the gradient modulus density layer decreases according to the form of Function Ⅱ according to the value of the radius r. Function Ⅱ is: where ρ1 = 0, r1 = 0, n = 1 - 10.
8. The vibration-damping and sound-absorbing device with a gradient modulus density according to claim 1 or 7, characterized in that: The gradient modulus density layer includes multiple spherical shell-shaped gradient modulus density structural layers stacked along the radial direction. Each gradient modulus density structural layer has a constant elastic modulus and density, and the change rate of the elastic modulus and density between the inner gradient modulus density structural layer and the outer gradient modulus density structural layer in two adjacent gradient modulus density structural layers is less than 1 / 10.
9. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 7, characterized in that: The material of the gradient modulus density layer includes stainless steel and aluminum alloy.
10. The vibration-damping and sound-absorbing device with a gradient modulus density as claimed in claim 1, characterized in that: It is set on the plane of the equipment workbench.