3D printing cement-based multilayer perforated plate sound absorption structure and design method thereof

Abstract

The invention discloses a 3D printing cement-based multi-layer perforated plate sound absorption structure and a design method thereof.According to the 3D printing cement-based multi-layer perforated plate sound absorption structure, a large number of pore structures exist in a cement-based material, and the design of a top perforated plate is combined; sound waves enter the sound absorption structure of the 3D printing cement-based multi-layer perforated plate to generate resonance, friction, reflection and interference, and the internal cavity plays a role in adjusting a sound wave propagation path and enhancing a sound absorption effect; due to the design of the multi-layer structure, the sound absorption structure of the 3D printing cement-based multi-layer perforated plate can show good sound absorption performance in a wide frequency band range. Moreover, according to the design method for the sound absorption structure of the 3D printing cement-based multi-layer perforated plate, solid test piece measurement and simulation methods are combined, the structure parameters of the optimal sound absorption performance of the target external size can be obtained in advance, and the sound absorption performance of the target external size is improved by combining the 3D printing technology. The 3D printing cement-based multi-layer perforated plate sound absorption structure with the optimal sound absorption coefficient of the target external size can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of sound absorption and noise reduction, and specifically relates to a 3D printed cement-based multi-layer perforated plate sound absorption structure and a design method thereof. Background Art

[0002] With the rapid development of modern science and technology, a large amount of environmental pollution has also come along. Noise has gradually become one of the pollution sources that endanger human health. Traditional sound absorption methods include porous material sound absorption and resonant sound absorption. Although they can alleviate the noise problem to a certain extent, they still have limitations. Porous sound-absorbing materials generally refer to solids containing cavities, channels or pores. When sound waves propagate in them, they produce friction with the material matrix, thereby achieving the purpose of sound energy dissipation. Although porous sound-absorbing materials have excellent sound absorption effects in the case of high-frequency noise, they are difficult to absorb low-frequency sound waves. The noise encountered in the industrial manufacturing process has the characteristics of strong randomness and broadband, and porous sound-absorbing materials cannot meet this requirement; resonant sound-absorbing structures use resonance characteristics to consume energy. When the sound wave has the same natural frequency as the structure, the structure will resonate and absorb sound energy. Although this sound absorption method has a significant sound absorption effect at a specific frequency, its sound absorption frequency band is narrow, which limits its wide application.

[0003] As a resonant sound-absorbing structure, perforated plate has been widely studied by scholars due to its advantages such as simple structure, environmental protection and light weight. However, the disadvantage of perforated plate is its narrow sound absorption band, which is also the reason why it has been unable to replace porous materials in the field of sound absorption for a long time. Therefore, it is necessary to design a sound-absorbing structure with wide-band sound absorption ability.

[0004] A micro-perforated plate sound absorption structure provided by publication number CN115731912A is based on the folded cavity and incident cavity formed by the folded cavity and the micro-perforated plate coupled resonance sound absorption principle, and adopts a sub-wavelength sound absorption structure. The incident sound wave enters the folded cavity vertically through the micro-perforated plate in the positive direction. Since the wavelength of the low-frequency sound wave far exceeds the cross-sectional size of the channel, the sound wave propagates freely in the folded channel and works together with the perforated plate to produce a coupling effect to achieve sound absorption. However, due to the limitation of the resonance characteristics, its peak bandwidth is narrow and cannot meet the requirements of broadband sound absorption. Moreover, as the sound absorption frequency band widens, the overall thickness of the structure also thickens, and the purpose of saving space cannot be achieved. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a 3D printed cement-based multi-layer perforated plate sound absorption structure and a design method thereof, wherein the sound absorption structure has excellent sound absorption effect. The 3D printed cement-based multi-layer perforated plate sound absorption structure design method combines solid specimen measurement with simulation methods, and can obtain structural parameters of the best sound absorption performance of the target outer size in advance. Combined with 3D printing technology, the 3D printed cement-based multi-layer perforated plate sound absorption structure with the best sound absorption coefficient of the target outer size can be obtained, which has strong practical application value.

[0006] The technical solution adopted by the present invention to solve the technical problem is: designing a 3D printed cement-based multi-layer perforated plate sound absorption structure, characterized in that its external shape is a cylinder, and its internal structure specifically comprises a top perforated plate (100), an internal perforated plate (200), a side wall (4) and a bottom plate (5), the top perforated plate (100) is parallel to the bottom plate (5), and the top perforated plate (100), the side wall (4) and the bottom plate (5) are connected together from top to bottom to form a cylinder; at least one internal perforated plate (200) parallel to the top perforated plate (100) is arranged in a cavity (300) between the top perforated plate (100) and the bottom plate (5);

[0007] The cavity (300) on one side close to the top perforated plate (100) is the incident cavity (310), and the rest of the cavity is the internal cavity (320), and the cross-sectional area of ​​the incident cavity (310) and the internal cavity (320) is the same;

[0008] The through holes (110) on the top perforated plate (100) and the through holes (210) on the inner perforated plate (200) are of the same size and quantity and are located opposite to each other along the axial direction of the cylinder.

[0009] Furthermore, the present invention provides a 3D printed cement-based multi-layer perforated plate sound absorption structure design method, characterized in that the design method is applicable to the 3D printed cement-based multi-layer perforated plate sound absorption structure as described above, and the design method comprises the following steps:

[0010] S1: using a powder 3D printer to manufacture a solid cylindrical cement-based specimen of a target outer size, and then measuring the sound absorption coefficient of the obtained solid cylindrical cement-based specimen of the target outer size to obtain its sound absorption coefficient curve;

[0011] S2: The JCA model is used to describe the acoustic properties of the solid cylindrical cement-based specimen in S1. The sound absorption coefficient α is calculated as follows:

[0012]

[0013] Where: eq is the dynamic mass density, α ∞is the tortuosity factor, ρ0 is the air equilibrium density, j is the imaginary unit, and j 2 =-1, ω is the angular frequency, ∧ is the viscous characteristic length, ∧' is the thermal characteristic length, σ is the flow resistivity, γ is the air specific heat ratio, P r is the Planck coefficient, P0 is the air pressure, c0 is the speed of sound in the air, is the porosity of the porous material, η is the air dynamic viscosity; where ρ0, γ, P r , P0, c0, η are known quantities;

[0014] S3: The porosity of the solid cylindrical cement-based specimen in S1 was obtained by mercury intrusion testing Then select discrete frequency points from 0 Hz at fixed intervals in the sound wave frequency range of the sound absorption coefficient curve in S1, and set the frequency point f i The corresponding sound absorption coefficient is defined as A mea (f i ), which is the measured sound absorption coefficient value; at the frequency point f i The sound absorption coefficient calculated by the JCA model is defined as That is, the sound absorption coefficient value obtained by simulation, and the objective function is set as:

[0015]

[0016] In the formula, f i is the sound wave frequency value; is the flow resistance σ, the tortuosity factor α ∞ , arrays of viscous characteristic length ∧ and thermal characteristic length ∧', i.e., target parameter arrays; is the objective function, A mea (f i ) is the actual measured sound absorption coefficient value, is the sound absorption coefficient value obtained by simulation calculation; N is the number of selected discrete frequency points;

[0017] The porosity The value of the frequency point f i Substitute it into the JCA model and use the Nelder-Mead method to find the value of the target parameter array corresponding to the minimum value of the objective function through iterative search, that is, the optimal value of the target parameter array;

[0018] S4: according to the target outer dimensions of the solid cylindrical cement-based specimen in S1, the porosity obtained in S3 and the value of the optimal target parameter array, and in combination with the known quantities in S2, according to the structure of the 3D printed cement-based multi-layer perforated plate sound absorbing structure as described in any one of claims 1 to 7, the thickness of the side wall (4) and the thickness of the bottom plate (5) are set, geometric modeling is performed in comsol, and the sound absorption performance of the 3D printed cement-based multi-layer perforated plate sound absorbing structure with different internal detail dimensions under the target outer dimensions is simulated to obtain the internal detail dimension data of the simulated multi-layer perforated plate sound absorbing structure with the best sound absorption performance and the corresponding optimal frequency range; the internal detail dimensions include the perforation rate of the top perforated plate (100), the diameter of the through holes on the top perforated plate (100), the thickness of the top perforated plate (100), the thickness and number of the internal perforated plate (210), and the thickness of the incident cavity;

[0019] S5: Based on the target outer dimensions of the solid cylindrical cement-based specimen in S1, combined with the internal detail dimension data of the simulated multi-layer perforated plate structure with the best sound absorption performance obtained in S4, and the set thickness of the side wall (4) and the thickness of the bottom plate (5), a 3D model is established, and manufactured using a powder 3D printer to obtain the 3D printed cement-based multi-layer perforated plate sound absorption structure.

[0020] Compared with the prior art, the 3D printed cement-based multi-layer perforated plate sound-absorbing structure designed by the present invention has a large number of pore structures inside the cement-based material, which is a porous material with the ability to absorb sound energy; secondly, the existence of the top perforated plate allows the sound waves to resonate inside the 3D printed cement-based multi-layer perforated plate sound-absorbing structure, thereby achieving sound wave dissipation; the through holes on the internal perforated plate and the sound waves entering the 3D printed cement-based multi-layer perforated plate sound-absorbing structure generate friction energy consumption, thereby dissipating the sound waves; in addition, the multi-layer structure design of the 3D printed cement-based multi-layer perforated plate sound-absorbing structure requires multiple reflections and interferences during the propagation process. The incident cavity and the internal perforated plate can absorb and reflect the sound waves to a certain extent, while the internal cavity plays a role in adjusting the sound wave propagation path and enhancing the sound absorption effect. This multi-layer structure design enables the 3D printed cement-based multi-layer perforated plate sound-absorbing structure to exhibit good sound absorption performance in a wide frequency band. In addition, the 3D printed cement-based multi-layer perforated plate sound absorption structure design method of the present invention can obtain the structural parameters of the optimal sound absorption performance of the target outer size in advance by combining the solid specimen measurement and simulation methods. Combined with the 3D printing technology, the 3D printed cement-based multi-layer perforated plate sound absorption structure with the optimal sound absorption coefficient of the target outer size can be obtained, which has a strong practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the internal structure of an embodiment of a 3D printed cement-based multi-layer perforated plate sound-absorbing structure of the present invention (a cross-sectional view along the longitudinal plane).

[0022] Figure 2 This is a schematic diagram of the external structure of an embodiment of a 3D printed cement-based multi-layer perforated plate sound absorption structure of the present invention.

[0023] Figure 3 These are the measurement and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 1.

[0024] Figure 4 These are the measurement and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 2.

[0025] Figure 5 These are the measurement and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 3.

[0026] In the figure: 100—top perforated plate; 110—top perforation; 200—inner perforated plate; 210—inner perforation; 300—cavity; 310—incident cavity; 320—inner cavity; 4—side wall; 5—bottom plate. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0028] The present invention provides a 3D printed cement-based multi-layer perforated plate sound-absorbing structure, which is manufactured using 3D printing technology. The printing material used is a cement-based porous sound-absorbing material. Figure 1 to Figure 2 The 3D printed cement-based multi-layer perforated plate sound absorption structure is an integrated structure, and its external shape is a cylinder. Its internal structure specifically includes a top perforated plate (100), an internal perforated plate (200), a side wall (4) and a bottom plate (5). The top perforated plate (100) is parallel to the bottom plate (5), and the top perforated plate (100), the side wall (4) and the bottom plate (5) are connected together from top to bottom to form a cylinder; at least one internal perforated plate (200) parallel to the top perforated plate (100) is arranged in a cavity (300) between the top perforated plate (100) and the bottom plate (5).

[0029] The cavity (300) on one side close to the top perforated plate (100) is the incident cavity (310), and the rest of the cavity is the internal cavity (320). The cross-sectional areas of the incident cavity (310) and the internal cavity (320) are the same.

[0030] The through holes (110) on the top perforated plate (100) and the through holes (210) on the inner perforated plate (200) are of the same size and quantity and are located opposite to each other along the axial direction of the cylinder.

[0031] As an embodiment, the multi-layer perforated plate structure is a cylinder with a diameter of 30 mm and a thickness of 35 mm.

[0032] As an embodiment, the diameter of the through hole (110) on the top perforated plate (100) is 3 mm.

[0033] As an embodiment, the thickness of the side wall (4) is 1.5 mm, and the thickness of the bottom plate (5) is 5 mm.

[0034] Optionally, the perforation rate of the top perforated plate (100) is 6%, 9%, 12% or 16%, the thickness of the top perforated plate (100) is 3 mm to 12 mm, and the thickness of the internal perforated plate (200) is 3 mm to 12 mm.

[0035] Furthermore, the present invention provides a 3D printed cement-based multi-layer perforated plate sound absorption structure design method, the design method is applicable to the above-mentioned 3D printed cement-based multi-layer perforated plate sound absorption structure, the design method comprises the following steps:

[0036] S1: Using a powder 3D printer to manufacture a solid cylindrical cement-based specimen of target outer dimensions, as an embodiment, specifically a cylindrical cement-based specimen with a thickness of 35 mm and a diameter of 30 mm. Then, the sound absorption coefficient of the solid cylindrical cement-based specimen of the target outer dimensions is measured to obtain its sound absorption coefficient curve.

[0037] S2: The acoustic properties of the solid cylindrical cement-based specimen in S1 are described using the JCA (Johnson-Champoux-Allard) model. The JCA model is an important theoretical model for describing the propagation characteristics of sound waves in porous media. When solving acoustic problems, a set of macroscopic parameters of the material is required, including the porosity Flow resistance σ, tortuosity factor α ∞ , viscous characteristic length ∧ and thermal characteristic length ∧', the sound absorption coefficient α is calculated as follows:

[0038]

[0039]

[0040] Where: eq is the dynamic mass density, α ∞ is the tortuosity factor, ρ0 is the air equilibrium density, j is the imaginary unit, and j 2=-1, ω is the angular frequency, ∧ is the viscous characteristic length, ∧' is the thermal characteristic length, σ is the flow resistivity, γ is the air specific heat ratio, P r is the Planck coefficient, P0 is the air pressure, c0 is the speed of sound in the air, is the porosity of the porous material, η is the air dynamic viscosity; where ρ0, γ, P r , P0, c0, and η are known quantities.

[0041] S3: The porosity of the solid cylindrical cement-based specimen in S1 was obtained by mercury intrusion testing Then, the sound wave frequency range of the sound absorption coefficient curve in S1 is selected from 0 Hz at intervals of 100 Hz. In this embodiment, 50 discrete frequency points are selected. i The corresponding sound absorption coefficient is defined as A mea (f i ), which is the measured sound absorption coefficient value; at the frequency point f i The sound absorption coefficient calculated by the JCA model is defined as That is, the sound absorption coefficient value obtained by simulation, and the objective function is set as:

[0042]

[0043] In the formula, f i is the sound wave frequency value; is the flow resistance σ, the tortuosity factor α ∞ , arrays of viscous characteristic length ∧ and thermal characteristic length ∧', i.e., target parameter arrays; is the objective function, A mea (f i ) is the actual measured sound absorption coefficient value, is the sound absorption coefficient value obtained by simulation calculation. N is the number of selected discrete frequency points.

[0044] The porosity The value of the frequency point f i Substitute it into the JCA model and use the Nelder-Mead method to find the value of the target parameter array corresponding to the minimum value of the objective function through iterative search, that is, the optimal value of the target parameter array.

[0045] The above-mentioned Nelder-Mead method is a prior art. For its specific implementation process, please refer to the literature: Nelder JA, Mead R. A Simplex Method for Function Minimization [J]. The Computer Journal, 1964, 7 (4): 308-313.

[0046] Porosity The optimal non-acoustic parameters of the specimen are obtained by taking the optimal target parameter array as the optimal non-acoustic parameters of the specimen, and finally the optimal non-acoustic parameters of the solid cylindrical cement-based specimen in S1 are shown in Table 1:

[0047] Table 1 Optimal non-acoustic parameter values

[0048]

[0049] S4: According to the target outer dimensions of the solid cylindrical cement-based specimen in S1, the porosity obtained in S3 and the value of the optimal target parameter array, and in combination with the known quantities in S2, according to the structure of the above-mentioned 3D printed cement-based multi-layer perforated plate sound absorption structure, the thickness of the side wall (4) and the thickness of the bottom plate (5) are set, geometric modeling is performed in comsol, and the sound absorption performance of the 3D printed cement-based multi-layer perforated plate sound absorption structure with different internal detail dimensions under the target outer dimensions is simulated to obtain the internal detail dimension data of the simulated multi-layer perforated plate sound absorption structure with the best sound absorption performance and the corresponding optimal frequency range; the internal detail dimensions include the perforation rate of the top perforated plate (100), the diameter of the through holes on the top perforated plate (100), the thickness of the top perforated plate (100), the thickness and number of the internal perforated plate (210), and the thickness of the incident cavity.

[0050] S5: Based on the target outer dimensions of the solid cylindrical cement-based specimen in S1, combined with the internal detail dimension data of the simulated multi-layer perforated plate sound-absorbing structure with the best sound absorption performance obtained in S4, and the set thickness of the side wall (4) and the thickness of the bottom plate (5), a 3D model is established, and manufactured using a powder 3D printer to obtain the 3D printed cement-based multi-layer perforated plate sound-absorbing structure.

[0051] When the target outer dimensions are 30 mm in diameter and 35 mm in thickness, the thickness of the side wall (4) is set to 1.5 mm, the thickness of the bottom plate (5) is set to 5 mm, and the diameter of the through hole (110) on the top perforated plate (100) is set to 3 mm, and three groups of 3D printed cement-based multi-layer perforated plate sound absorption structures of embodiments are set to verify the effect of the design method of the present invention. Among them, other specific dimensional parameters of the 3D printed cement-based multi-layer perforated plate sound absorption structure in embodiment 1 are: the perforation rate is 16%, the thickness of the top perforated plate is 3 mm, and the thickness of the incident cavity is 7 mm; two internal perforated plates are set, the thickness of the first internal perforated plate is 3 mm, the thickness of the first internal cavity is 7 mm, the thickness of the second internal perforated plate is 7 mm, and the thickness of the second internal cavity is 3 mm. Figure 3 These are the measurement results (i.e., test results) and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 1.

[0052] The internal structural dimension parameters of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 2 are: the perforation rate is 16%, the top perforated plate thickness is 3 mm, the incident cavity thickness is 12 mm, the internal perforated plate thickness is 3 mm, and the internal cavity thickness is 12 mm. Figure 4 These are the measurement results (i.e., test results) and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 2.

[0053] The internal structural dimension parameters of the 3D printed cement-based multilayer perforated plate sound-absorbing structure in Example 3 are: a perforation rate of 6%, a top perforated plate thickness of 3 mm, an incident cavity thickness of 7 mm, two internal perforated plates are set, the first internal perforated plate thickness is 3 mm, the internal cavity thickness is 7 mm, and the second internal perforated plate thickness is 7 mm, and the internal cavity thickness is 3 mm. Figure 5 These are the measurement results (i.e., test results) and simulation results of the sound absorption coefficient of the 3D printed cement-based multi-layer perforated plate sound absorption structure in Example 1.

[0054] The results show that the 3D printed cement-based multi-layer perforated plate sound absorption structure in the embodiment has excellent sound absorption performance, and the sound absorption coefficient can reach up to 0.98. When the sound absorption coefficient is above 0.6, the sound absorption frequency band width is 3847Hz, 3223Hz, and 3285Hz, respectively, achieving broadband sound absorption. The sound absorption coefficient obtained by actual measurement is compared with the sound absorption coefficient obtained by simulation, which proves the feasibility of the design method of the present invention.

[0055] The working principle of the cement-based multi-layer perforated plate sound absorption structure of the present invention is as follows: The sound absorption capacity of the cement-based perforated plate depends on the design of the through holes on its surface. When sound waves are incident on the perforated plate, the resonance phenomenon can be used to achieve the purpose of sound absorption. The through hole design significantly increases the contact area between the cement-based material and the air, and during the propagation process, the sound waves are more likely to enter the material through these through holes. In addition to the through hole design increasing the contact area with the air, when the sound waves are incident on the perforated plate, due to the rough surface of the cement-based material itself, friction dissipation energy will also be generated, thereby enhancing the sound absorption effect.

[0056] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A 3D printed cement-based multi-layer perforated plate sound absorption structure, characterized in that: Its external shape is a cylinder, and its internal structure specifically comprises a top perforated plate (100), an internal perforated plate (200), a side wall (4) and a bottom plate (5); the top perforated plate (100) is parallel to the bottom plate (5); the top perforated plate (100), the side wall (4) and the bottom plate (5) are connected together from top to bottom to form a cylinder; at least one internal perforated plate (200) parallel to the top perforated plate (100) is arranged in the cavity (300) between the top perforated plate (100) and the bottom plate (5); The cavity (300) on one side close to the top perforated plate (100) is the incident cavity (310), and the rest of the cavity is the internal cavity (320), and the cross-sectional area of ​​the incident cavity (310) and the internal cavity (320) is the same; The through holes (110) on the top perforated plate (100) and the through holes (210) on the inner perforated plate (200) are of the same size and quantity and are located opposite to each other along the axial direction of the cylinder.

2. A 3D printed cement-based multi-layer perforated plate sound absorption structure according to claim 1, characterized in that: The 3D printed cement-based multi-layer perforated plate sound-absorbing structure is an integrated structure, manufactured using 3D printing technology, and the printing material used is a cement-based porous sound-absorbing material.

3. A 3D printed cement-based multi-layer perforated plate sound absorbing structure according to claim 1, characterized in that: The 3D printed cement-based multi-layer perforated plate sound absorption structure is a cylinder with a diameter of 30 mm and a thickness of 35 mm.

4. A 3D printed cement-based multi-layer perforated plate sound absorption structure according to claim 3, characterized in that: The diameter of the through holes (110) on the top perforated plate (100) is 3 mm.

5. The 3D printed cement-based multi-layer perforated plate sound absorbing structure according to claim 3, characterized in that: The thickness of the side wall (4) is 1.5 mm, and the thickness of the bottom plate (5) is 5 mm.

6. A 3D printed cement-based multi-layer perforated plate sound absorbing structure according to claim 1, characterized in that: The perforation rate of the top perforated plate (100) is 6%, 9%, 12% or 16%.

7. The 3D printed cement-based multi-layer perforated plate sound absorbing structure according to claim 3, characterized in that: The top perforated plate (100) has a thickness of 3 mm to 12 mm, and the inner perforated plate (200) has a thickness of 3 mm to 12 mm.

8. A 3D printed cement-based multi-layer perforated plate sound absorption structure design method, characterized in that: The design method is applicable to the 3D printed cement-based multi-layer perforated plate sound absorbing structure according to any one of claims 1 to 7, and the design method comprises the following steps: S1: using a powder 3D printer to manufacture a solid cylindrical cement-based specimen of a target outer size, and then measuring the sound absorption coefficient of the obtained solid cylindrical cement-based specimen of the target outer size to obtain its sound absorption coefficient curve; S2: The JCA model is used to describe the acoustic properties of the solid cylindrical cement-based specimen in S1. The sound absorption coefficient α is calculated as follows: Where: eq is the dynamic mass density, α ∞ is the tortuosity factor, ρ0 is the air equilibrium density, j is the imaginary unit, and j 2 =-1, ω is the angular frequency, ∧ is the viscous characteristic length, ∧' is the thermal characteristic length, σ is the flow resistivity, γ is the air specific heat ratio, P r is the Planck coefficient, P0 is the air pressure, c0 is the speed of sound in the air, is the porosity of the porous material, η is the air dynamic viscosity; Among them, ρ0, γ, P r , P0, c0, η are known quantities; S3: The porosity of the solid cylindrical cement-based specimen in S1 was obtained by mercury intrusion testing Then select discrete frequency points from 0 Hz at fixed intervals in the sound wave frequency range of the sound absorption coefficient curve in S1, and set the frequency point f i The corresponding sound absorption coefficient is defined as A mea (f i ), which is the measured sound absorption coefficient value; at the frequency point f i The sound absorption coefficient calculated by the JCA model is defined as That is, the sound absorption coefficient value obtained by simulation, and the objective function is set as: In the formula, f i is the sound wave frequency value; is the flow resistance σ, the tortuosity factor α ∞ , arrays of viscous characteristic length ∧ and thermal characteristic length ∧', i.e., target parameter arrays; is the objective function, A mea (f i ) is the actual measured sound absorption coefficient value, is the sound absorption coefficient value obtained by simulation calculation; N is the number of selected discrete frequency points; The porosity The value of the frequency point f i Substitute it into the JCA model and use the Nelder-Mead method to find the value of the target parameter array corresponding to the minimum value of the objective function through iterative search, that is, the optimal value of the target parameter array; S4: according to the target outer dimensions of the solid cylindrical cement-based specimen in S1, the porosity obtained in S3 and the value of the optimal target parameter array, and in combination with the known quantities in S2, according to the structure of the 3D printed cement-based multi-layer perforated plate sound absorbing structure as described in any one of claims 1 to 7, the thickness of the side wall (4) and the thickness of the bottom plate (5) are set, geometric modeling is performed in comsol, and the sound absorption performance of the 3D printed cement-based multi-layer perforated plate sound absorbing structure with different internal detail dimensions under the target outer dimensions is simulated to obtain the internal detail dimension data of the simulated multi-layer perforated plate sound absorbing structure with the best sound absorption performance and the corresponding optimal frequency range; the internal detail dimensions include the perforation rate of the top perforated plate (100), the diameter of the through holes on the top perforated plate (100), the thickness of the top perforated plate (100), the thickness and number of the internal perforated plate (210), and the thickness of the incident cavity; S5: Based on the target outer dimensions of the solid cylindrical cement-based specimen in S1, combined with the internal detail dimension data of the simulated multi-layer perforated plate sound-absorbing structure with the best sound absorption performance obtained in S4, and the set thickness of the side wall (4) and the thickness of the bottom plate (5), a 3D model is established, and manufactured using a powder 3D printer to obtain the 3D printed cement-based multi-layer perforated plate sound-absorbing structure.

9. A 3D printed cement-based multi-layer perforated plate sound absorption structure design method according to claim 8, characterized in that: In S3, the fixed interval is 100 Hz.

10. A 3D printed cement-based multi-layer perforated plate sound absorption structure design method according to claim 8, characterized in that: In S3, N is 50.

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