Tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber, preparation method and regulation and control method

Abstract

The invention discloses a tunable ventilation and sound absorption structure unit cell based on electroactive polymer fibers, a preparation method and a regulation and control method, and belongs to the technical field of noise reduction and sound absorption. The Helmholtz resonator solves the technical problems that an existing Helmholtz resonator is narrow in effective attenuation frequency band range and has limitation in use. The upper layer Helmholtz resonant cavity is formed by an upper layer perforated plate, a sound absorption neck tube, a curved wall honeycomb structure side wall and a movable partition plate in a surrounding mode, and the lower layer Helmholtz resonant cavity is formed by a movable partition plate, a sound absorption neck tube, a curved wall honeycomb structure side wall and a lower layer perforated plate in a surrounding mode. The top surface of the electroactive polymer fiber sheet is fixedly connected with the bottom surface of the movable partition plate, the bottom surface of the electroactive polymer fiber sheet is fixedly connected with the top surface of the lower-layer perforated plate, the electroactive polymer fiber sheet is electrically connected with the adjustable direct-current power supply, and the adjustable direct-current power supply is used for driving the electroactive polymer fiber sheet to deform. The sound absorption frequency range of the Helmholtz resonator is widened. The invention is used for noise reduction and sound absorption.

Description

Technical Field

[0001] The invention relates to a tunable ventilation sound absorption structure unit cell based on electroactive polymer fibers, a preparation method and a control method, and belongs to the technical field of noise reduction and sound absorption. Background Art

[0002] The Helmholtz resonance principle refers to the phenomenon that when resonance occurs in a closed space, the sound or vibration in the space will be amplified. This phenomenon is called Helmholtz resonance. The Helmholtz resonance principle is based on the vibration theory of elastic bodies and is widely used in many fields, such as acoustics, physics, engineering, etc. The Helmholtz resonance principle is widely used in the field of engineering. For example, the Helmholtz resonance principle is used in the design of automobile exhaust pipes to reduce noise and increase exhaust rate. In industrial environments, it is used to reduce the noise of equipment to improve the working environment and improve production efficiency. At the same time, in offices, recording studios, audio-visual rooms and other places, it is used for indoor silencing and resonance effects to provide a more comfortable working and living environment, etc. In short, the basic principle of the Helmholtz resonance cavity is that the resonance frequency is related to the geometric size and material properties of the resonance cavity. However, for the time being, the sound absorption frequency band of Helmholtz is small, and it is impossible to effectively control the sound absorption. Therefore, further research is needed on its materials and structures. Traditional structural absorbing materials include absorbing honeycombs, absorbing foams, etc., which have stable performance and are suitable for large-scale industrial production and processing. At the same time, due to its low density, it is widely used in aircraft and ships. However, the mechanical properties of traditional composite wave-absorbing structures are poor and the absorption bandwidth is narrow, which cannot effectively absorb sound waves of different frequency bands.

[0003] Helmholtz resonators are widely used as silencing devices in piping systems because of their simple structure, good ventilation, and good noise attenuation capabilities within a specific frequency band. The application of Helmholtz resonators in the conventional sense has limitations, mainly because the frequency band range in which they can effectively attenuate is very narrow. When the noise frequency band is wide or the frequency changes, its attenuation performance is greatly affected.

[0004] The Helmholtz resonator is a simple and widely used sound-absorbing structure. The application of the traditional Helmholtz resonator has limitations, mainly in that the frequency band in which it can effectively attenuate is very narrow. When the noise band is wider or the frequency changes, its attenuation performance is greatly affected.

[0005] In summary, the existing Helmholtz resonator has the technical problem that the effective attenuation frequency band is narrow and has limitations in use. Summary of the invention

[0006] The present invention aims to solve the technical problems that the existing Helmholtz resonator has a narrow effective attenuation frequency band and is limited in use, and further provides a tunable ventilation sound absorption structure unit cell based on electroactive polymer fibers, a preparation method and a control method.

[0007] The technical solution of the present invention is a tunable ventilation sound-absorbing structural unit cell based on electroactive polymer fibers, which comprises an upper Helmholtz resonance cavity, a lower Helmholtz resonance cavity, an upper perforated plate, a lower perforated plate, a sound-absorbing neck tube, a curved honeycomb structure side wall, a movable partition, an electroactive polymer fiber sheet and an adjustable DC power supply;

[0008] The side wall of the curved honeycomb structure is a regular polygonal prism with two ends connected. The upper perforated plate is installed at the top of the side wall of the curved honeycomb structure, and the lower perforated plate is installed at the bottom of the side wall of the curved honeycomb structure. A sound-absorbing hole is opened in the middle of the upper perforated plate. The top of the sound-absorbing neck tube is installed on the upper perforated plate through the sound-absorbing hole. The movable partition is slidably sleeved on the lower part of the sound-absorbing neck tube in the vertical direction. The upper Helmholtz resonance cavity is surrounded by the upper perforated plate, the sound-absorbing neck tube, the side wall of the curved honeycomb structure and the movable partition. The lower Helmholtz resonance cavity is surrounded by the movable partition, the sound-absorbing neck tube, the side wall of the curved honeycomb structure and the lower perforated plate.

[0009] The electroactive polymer fiber sheet is laid along the inner circumferential direction of the side wall of the curved-wall honeycomb structure, the top surface of the electroactive polymer fiber sheet is fixedly connected to the bottom surface of the movable partition, the bottom surface of the electroactive polymer fiber sheet is fixedly connected to the top surface of the lower perforated plate, the electroactive polymer fiber sheet is electrically connected to an adjustable DC power supply, and the adjustable DC power supply is used to drive the electroactive polymer fiber sheet to deform.

[0010] As another improvement of the present invention, ventilation holes are provided on both the upper perforated plate and the lower perforated plate, and a plurality of ventilation holes are evenly distributed on the upper perforated plate and the lower perforated plate.

[0011] As another improvement of the present invention, the top surface height of the sound absorbing neck tube is the same as the upper surface height of the upper perforated plate.

[0012] As another improvement of the present invention, it also includes an electric wire, the electroactive polymer fiber sheet forms a closed loop along its laying direction, and an installation hole is opened at the lower part of the side wall of the curved wall honeycomb structure of the lower Helmholtz resonance cavity, and the electric wire passes through the installation hole, and the adjustable DC power supply is electrically connected to the electroactive polymer fiber sheet through the electric wire.

[0013] As another improvement of the present invention, the input voltage of the adjustable DC power supply is 220V, the output voltage value of the adjustable DC power supply ranges from 0-30V, and the output current value of the adjustable DC power supply ranges from 0-5A.

[0014] As another improvement of the present invention, the electroactive polymer fiber sheet is a polyacrylic rubber sheet.

[0015] As another improvement of the present invention, the upper perforated plate, the lower perforated plate, the sound-absorbing neck tube, the curved honeycomb structure side wall and the movable partition are all made of PC material.

[0016] The present invention also provides a preparation method, comprising the following steps:

[0017] S1. Use 3D printing technology to process and shape the upper perforated plate, the lower perforated plate, the sound-absorbing neck tube, the curved honeycomb structure side wall and the movable partition;

[0018] S2, gluing the sound absorbing neck tube to the upper perforated plate, gluing the bottom end of the curved honeycomb structure side wall to the lower perforated plate, gluing the electroactive polymer fiber sheet to one end of two wires, and respectively connecting the other ends of the two wires to the positive and negative electrodes of the adjustable DC power supply after passing through the mounting holes;

[0019] S3, the movable partition is slidably mounted on the sound-absorbing neck tube;

[0020] S4. The upper perforated plate is glued to the top of the side wall of the curved honeycomb structure.

[0021] The present invention also provides a control method, comprising the following steps:

[0022] S1, adjusting the output voltage of the adjustable DC power supply to drive the electroactive polymer fiber sheet to deform;

[0023] S2, the deformation of the electroactive polymer fiber sheet drives the movable partition to move, thereby changing the volume of the upper Helmholtz resonance cavity and the lower Helmholtz resonance cavity;

[0024] S3. By changing the volumes of the upper Helmholtz resonance cavity and the lower Helmholtz resonance cavity, the sound attenuation amount ΔL of the upper Helmholtz resonance cavity and the lower Helmholtz resonance cavity is changed to adapt to different sound absorption frequencies.

[0025] As another improvement of the present invention, the sound reduction amount ΔL satisfies the following formula:

[0026]

[0027] In the above formula, k is a dimensionless quantity, f is the sound absorption frequency, and f is the resonance frequency;

[0028]

[0029] In the above formula, G is the conductivity of the sound-absorbing neck tube, V is the cavity volume of the upper Helmholtz resonance cavity or the lower Helmholtz resonance cavity, S is the cavity cross-sectional area of ​​the upper Helmholtz resonance cavity or the lower Helmholtz resonance cavity, and C is the speed of sound;

[0030] V=SH,

[0031]

[0032] In the above formula, H is the height dimension of the upper Helmholtz resonance cavity or the lower Helmholtz resonance cavity, l is the length dimension of the sound absorbing neck tube, and d is the diameter dimension of the sound absorbing neck tube.

[0033] Beneficial effects of the present invention:

[0034] 1. The present invention modifies the structure of the Helmholtz resonator so that the size of some of its structures can be changed according to the continuous change of the noise frequency. The resonator is always in a resonant condition, thus ensuring better performance within a wider noise frequency band.

[0035] 2. The method of the present invention introduces the electroactive polymer fiber strain control technology to change the parameters of the resonant cavity height of the Helmholtz resonator and optimize the sound absorption performance of the Helmholtz resonator. Through this technology, the sound absorption frequency range of the Helmholtz resonator can be widened. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of a tunable ventilation and sound absorption structure unit cell based on electroactive polymer fibers of the present invention.

[0037] Figure 2 It is a schematic diagram of the upper perforated plate structure.

[0038] Figure 3 It is a schematic diagram of the lower layer perforated plate structure. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the examples of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. In the description of the present invention, it should be explained that the positional relationships indicated by the terms "upper", "lower", "first", "second", etc. are only based on the positional relationships of the orientations shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the referred components have specific orientations, are constructed and operated in specific orientations, and therefore cannot be understood as limitations on the present invention.

[0040] Specific implementation method 1: Combination Figures 1 to 3The present embodiment is described, and the present embodiment comprises an upper Helmholtz resonance cavity 1, a lower Helmholtz resonance cavity 2, an upper perforated plate 3 with a thickness of 2 mm, a lower perforated plate 4 with a thickness of 2 mm, a sound absorbing neck tube 5, a curved honeycomb structure side wall 6, a movable partition 7, an electroactive polymer fiber sheet 8 and an adjustable DC power supply;

[0041] The curved honeycomb structure side wall 6 is a regular polygonal prism with two ends through. The present embodiment adopts a regular hexagonal prism, and its cross section is a regular hexagon with a single-side inner diameter of 18 mm, an outer diameter of 20 mm, and a thickness of 2 mm. The upper perforated plate 3 is installed at the top of the curved honeycomb structure side wall 6, and the lower perforated plate 4 is installed at the bottom of the curved honeycomb structure side wall 6. A sound-absorbing hole is opened in the middle of the upper perforated plate 3, and the top of the sound-absorbing neck tube 5 is installed on the upper perforated plate 3 through the sound-absorbing hole. The movable partition plate 7 is slidably sleeved on the lower part of the sound-absorbing neck tube 5 in the vertical direction. The upper Helmholtz resonance cavity 1 is surrounded by the upper perforated plate 3, the sound-absorbing neck tube 5, the curved honeycomb structure side wall 6 and the movable partition plate 7, and the lower Helmholtz resonance cavity 2 is surrounded by the movable partition plate 7, the sound-absorbing neck tube 5, the curved honeycomb structure side wall 6 and the lower perforated plate 4.

[0042] The electroactive polymer fiber sheet 8 is laid along the inner circumferential direction of the side wall 6 of the curved honeycomb structure, the top surface of the electroactive polymer fiber sheet 8 is fixedly connected to the bottom surface of the movable partition 7, the bottom surface of the electroactive polymer fiber sheet 8 is fixedly connected to the top surface of the lower perforated plate 4, and the electroactive polymer fiber sheet 8 is electrically connected to an adjustable DC power supply, which is used to drive the electroactive polymer fiber sheet 8 to deform.

[0043] The inner diameter of the sound-absorbing neck tube 5 is 4 mm, the thickness is 1.5 mm, and the length is 35 mm; the height of the curved-wall honeycomb structure side wall 6 is 50 mm; the movable partition 7 of this embodiment adopts a regular hexagon with a thickness of 2 mm and a single side length of 18 mm; the electroactive polymer fiber sheet 8 is 108 mm long, 15 mm wide, and 1 mm thick; the adjustable DC power supply is DP30V5A type; the DP30V5A type adjustable DC power supply is used to provide an electric field to the electroactive polymer fiber sheet.

[0044] In this embodiment, the height of the Helmholtz resonator cavity changes after the polymer fiber sheet 8 is deformed. By changing the parameters of the Helmholtz resonator cavity height, the volume size of the Helmholtz resonator cavity is changed, and the sound absorption performance of the Helmholtz resonator is optimized. Through this technology, the sound absorption frequency range of the Helmholtz resonator can be widened.

[0045] Specific implementation method 2: Combination Figures 1 to 3This embodiment is described. The difference between this embodiment and the first embodiment is that ventilation holes 9 are provided on both the upper perforated plate 3 and the lower perforated plate 4. A plurality of ventilation holes 9 are evenly distributed on the upper perforated plate 3 and the lower perforated plate 4. The ventilation holes are provided for structural ventilation. Other components and connection methods are the same as those of the first embodiment.

[0046] Specific implementation method three: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that the top surface height of the sound absorbing neck tube 5 is the same as the top surface height of the upper perforated plate 3. The purpose of such design is that the sound absorbing neck tube is used to connect the lower Helmholtz resonance cavity 2 with the outside air at the top of the sound absorbing neck tube. The other components and connection methods are the same as those of the first or second embodiment.

[0047] Specific implementation method four: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that this embodiment also includes electric wires. The electroactive polymer fiber sheet 8 forms a closed loop along its laying direction. The lower part of the curved honeycomb structure side wall 6 of the lower Helmholtz resonance cavity 2 is provided with a mounting through hole. The electric wires pass through the mounting through hole. The adjustable DC power supply is electrically connected to the electroactive polymer fiber sheet 8 through the electric wires. The electric wires are 2 1.5 square millimeters long wires. The other components and connection methods are the same as any one of the specific embodiments 1 to 3.

[0048] Specific implementation method five: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that the input voltage of the adjustable DC power supply is 220V, the output voltage value range of the adjustable DC power supply is 0-30V, and the output current value range of the adjustable DC power supply is 0-5A. The adjustable DC power supply is digitally displayed, and the power supply parameters can be accurately adjusted. The other components and connection methods are the same as any one of the specific embodiments 1 to 4.

[0049] Specific implementation method six: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that the electroactive polymer fiber sheet 8 is a polyacrylic rubber sheet. The polyacrylic rubber sheet has a large deformation after being energized, and can be deformed by up to 380%, which is conducive to improving the control accuracy. The other components and connection methods are the same as any one of the first to fifth embodiments.

[0050] Specific implementation method seven: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that the upper perforated plate 3, the lower perforated plate 4, the sound absorbing neck tube 5, the curved honeycomb structure side wall 6 and the movable partition 7 are all made of PC material. The use of absolutely acoustically rigid materials is easy to process. The other components and connection methods are the same as any one of the specific embodiments 1 to 6.

[0051] Specific implementation method eight: Combination Figures 1 to 3 This embodiment is described. This embodiment provides a preparation method for preparing a tunable ventilation sound-absorbing structure unit cell based on electroactive polymer fibers according to a fourth embodiment, comprising the following steps:

[0052] S1. Use 3D printing technology to process and shape the upper perforated plate 3, the lower perforated plate 4, the sound-absorbing neck tube 5, the curved honeycomb structure side wall 6 and the movable partition 7;

[0053] S2, the sound absorbing neck tube 5 is glued to the upper perforated plate 3, the bottom end of the curved honeycomb structure side wall 6 is glued to the lower perforated plate 4, the electroactive polymer fiber sheet 8 is glued to one end of two wires, and the other ends of the two wires are passed through the mounting holes and connected to the positive and negative electrodes of the adjustable DC power supply respectively;

[0054] S3, the movable partition 7 is slidably mounted on the sound absorbing neck tube 5;

[0055] S4. The upper perforated plate 3 is glued to the top of the curved honeycomb structure side wall 6.

[0056] After all the printed materials are demolded; the sound-absorbing neck tube is glued to the upper perforated plate with polyurethane polymer glue; the side wall of the curved honeycomb structure is glued to the lower perforated plate with polyurethane polymer glue; the polyacrylic rubber is glued to the two wires with polyurethane polymer glue; the inner side of the curved honeycomb structure side wall is glued with polyacrylic rubber with polyurethane polymer glue, and the two wires are passed through the reserved installation hole; the sound-absorbing neck tube part of the structure after the upper perforated plate and the sound-absorbing neck tube are glued to the movable partition for sliding connection; the upper perforated plate and the sound-absorbing neck tube integrated structure after sliding connection with the movable partition are glued to the side wall of the curved honeycomb structure with polyurethane polymer glue. The two wires are connected to the positive and negative poles of the DP30V5A adjustable DC power supply respectively to complete the preparation. When the curved honeycomb structure side wall is glued to the lower perforated plate with polyurethane polymer glue, the lower surface of the polyacrylic rubber contacts the lower perforated plate, and the polyacrylic rubber contacts each other end to end, ensuring that the circuit is closed and the polyacrylic rubber can work normally under the action of current.

[0057] Specific implementation method nine: Combination Figures 1 to 3 This embodiment describes a control method for controlling a tunable ventilation sound-absorbing structure unit cell based on an electroactive polymer fiber, comprising the following steps:

[0058] S1, adjusting the output voltage of the adjustable DC power supply to drive the electroactive polymer fiber sheet 8 to deform;

[0059] S2, the electroactive polymer fiber sheet 8 is deformed to drive the movable partition 7 to move, thereby changing the volume of the upper Helmholtz resonance cavity 1 and the lower Helmholtz resonance cavity 2;

[0060] S3. By changing the volumes of the upper Helmholtz resonance cavity 1 and the lower Helmholtz resonance cavity 2, the sound attenuation amount ΔL of the upper Helmholtz resonance cavity 1 and the lower Helmholtz resonance cavity 2 is changed to adapt to different sound absorption frequencies.

[0061] The structure of the Helmholtz resonator is modified so that the size of some of its structures can be changed according to the continuous change of the noise frequency. The resonator is always in the condition of resonance, which ensures good performance within a wider noise frequency band. By introducing the electroactive polymer fiber strain control technology, the parameters of the resonant cavity height of the Helmholtz resonator are changed to optimize the sound absorption performance of the Helmholtz resonator. Through this technology, the sound absorption frequency range of the Helmholtz resonator can be widened.

[0062] Specific implementation method ten: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is different from the ninth embodiment in that the sound reduction amount ΔL satisfies the following formula:

[0063]

[0064] In the above formula, k is a dimensionless quantity, f is the sound absorption frequency, and f r is the resonant frequency;

[0065]

[0066] In the above formula, G is the conductivity of the sound absorbing neck tube 5, V is the cavity volume of the upper Helmholtz resonance cavity 1 or the lower Helmholtz resonance cavity 2, S is the cavity cross-sectional area of ​​the upper Helmholtz resonance cavity 1 or the lower Helmholtz resonance cavity 2, and C is the sound velocity;

[0067] V=SH,

[0068]

[0069] In the above formula, H is the height dimension of the upper Helmholtz resonance cavity 1 or the lower Helmholtz resonance cavity 2 , l is the length dimension of the sound absorbing neck tube 5 , and d is the diameter dimension of the sound absorbing neck tube 5 .

[0070] By changing the resonant frequency, the sound absorption can be moved toward the peak value. By introducing the electroactive polymer fiber strain control technology, the parameters of the resonant cavity height of the Helmholtz resonator are changed to optimize the sound absorption performance of the Helmholtz resonator. Through this technology, the sound absorption frequency range of the Helmholtz resonator can be widened.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tunable ventilation sound absorption structure unit cell based on electroactive polymer fiber, characterized in that It comprises an upper Helmholtz resonance cavity (1), a lower Helmholtz resonance cavity (2), an upper perforated plate (3), a lower perforated plate (4), a sound absorbing neck tube (5), a curved honeycomb structure side wall (6), a movable partition (7), an electroactive polymer fiber sheet (8) and an adjustable direct current power supply; The curved honeycomb structure side wall (6) is a regular polygonal prism with two ends connected. The upper perforated plate (3) is installed at the top end of the curved honeycomb structure side wall (6), and the lower perforated plate (4) is installed at the bottom end of the curved honeycomb structure side wall (6). A sound absorption hole is opened in the middle of the upper perforated plate (3). The top end of the sound absorption neck tube (5) is installed on the upper perforated plate (3) through the sound absorption hole. The movable partition plate (7) is slidably sleeved on the lower part of the sound absorption neck tube (5) in the vertical direction. The upper Helmholtz resonance cavity (1) is surrounded by the upper perforated plate (3), the sound absorption neck tube (5), the curved honeycomb structure side wall (6) and the movable partition plate (7). The lower Helmholtz resonance cavity (2) is surrounded by the movable partition plate (7), the sound absorption neck tube (5), the curved honeycomb structure side wall (6) and the lower perforated plate (4). The electroactive polymer fiber sheet (8) is laid along the inner circumferential direction of the side wall (6) of the curved honeycomb structure, the top surface of the electroactive polymer fiber sheet (8) is fixedly connected to the bottom surface of the movable partition (7), the bottom surface of the electroactive polymer fiber sheet (8) is fixedly connected to the top surface of the lower perforated plate (4), and the electroactive polymer fiber sheet (8) is electrically connected to an adjustable DC power supply, and the adjustable DC power supply is used to drive the electroactive polymer fiber sheet (8) to deform.

2. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that: The upper perforated plate (3) and the lower perforated plate (4) are both provided with ventilation holes (9), and a plurality of ventilation holes (9) are evenly distributed on the upper perforated plate (3) and the lower perforated plate (4).

3. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that: The top surface height of the sound absorbing neck tube (5) is the same as the top surface height of the upper perforated plate (3).

4. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that It also includes an electric wire. The electroactive polymer fiber sheet (8) forms a closed loop along its laying direction. A mounting through hole is provided at the lower part of the curved honeycomb structure side wall (6) of the lower Helmholtz resonance cavity (2). The electric wire passes through the mounting through hole. The adjustable DC power supply is electrically connected to the electroactive polymer fiber sheet (8) through the electric wire.

5. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that: The input voltage of the adjustable DC power supply is 220V, the output voltage value range of the adjustable DC power supply is 0-30V, and the output current value range of the adjustable DC power supply is 0-5A.

6. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that: The electroactive polymer fiber sheet (8) is a polyacrylic rubber sheet.

7. The tunable ventilation and sound absorption structure unit cell based on electroactive polymer fiber according to claim 1, characterized in that: The upper perforated plate (3), the lower perforated plate (4), the sound absorbing neck tube (5), the curved honeycomb structure side wall (6) and the movable partition plate (7) are all made of PC material.

8. A preparation method, characterized in that: The preparation method is used to prepare a tunable ventilation sound-absorbing structure unit cell based on electroactive polymer fibers as described in claim 4, comprising the following steps: S1. Using 3D printing technology, the upper perforated plate (3), the lower perforated plate (4), the sound-absorbing neck tube (5), the curved honeycomb structure side wall (6) and the movable partition (7) are processed and formed; S2, the sound absorbing neck tube (5) is glued to the upper perforated plate (3), the bottom end of the curved honeycomb structure side wall (6) is glued to the lower perforated plate (4), the electroactive polymer fiber sheet (8) is glued to one end of two wires, and the other ends of the two wires are passed through the mounting holes and connected to the positive and negative electrodes of the adjustable DC power supply respectively; S3, the movable partition (7) is slidably mounted on the sound absorbing neck tube (5); S4, the upper perforated plate (3) is glued to the top of the curved honeycomb structure side wall (6).

9. A control method, characterized in that: The control method is used to control the tunable ventilation and sound-absorbing structure unit cell based on electroactive polymer fibers as described in claim 4, comprising the following steps: S1, adjusting the output voltage of the adjustable DC power supply to drive the electroactive polymer fiber sheet (8) to deform; S2, the deformation of the electroactive polymer fiber sheet (8) drives the movable partition (7) to move, thereby changing the volume of the upper Helmholtz resonance cavity (1) and the lower Helmholtz resonance cavity (2); S3, by changing the volumes of the upper Helmholtz resonance cavity (1) and the lower Helmholtz resonance cavity (2), the sound attenuation amount ΔL of the upper Helmholtz resonance cavity (1) and the lower Helmholtz resonance cavity (2) is changed to adapt to different sound absorption frequencies.

10. A control method according to claim 9, characterized in that: The noise reduction ΔL satisfies the following formula: In the above formula, k is a dimensionless quantity, f is the sound absorption frequency, and f r is the resonant frequency; In the above formula, G is the conductivity of the sound absorbing neck tube (5), V is the cavity volume of the upper Helmholtz resonance cavity (1) or the lower Helmholtz resonance cavity (2), S is the cavity cross-sectional area of ​​the upper Helmholtz resonance cavity (1) or the lower Helmholtz resonance cavity (2), and C is the sound velocity; V=SH, In the above formula, H is the height dimension of the upper Helmholtz resonance cavity (1) or the lower Helmholtz resonance cavity (2), l is the length dimension of the sound absorbing neck tube (5), and d is the diameter dimension of the sound absorbing neck tube (5).

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