Multifunctional tunable bionic sound absorption and collision avoidance integrated superstructure and preparation method thereof

Abstract

The invention relates to the technical field of sound absorption, noise reduction and impact resistance, in particular to a multifunctional tunable bionic sound absorption and collision prevention integrated superstructure and a preparation method thereof.The multifunctional tunable bionic sound absorption and collision prevention integrated superstructure comprises a shell, an upper sound absorption layer, a lower sound absorption layer and a middle collision prevention layer, the sound absorption layer is provided with a plurality of curved-surface microwell plates which are connected end to end to form a cavity, and the embedded pipe is combined with the cavity to form a Helmholtz resonator; the anti-collision layer is composed of an energy absorption unit array. The preparation method comprises the steps that a three-dimensional model is firstly built, then a laser scanning mode and parameter printing are set, then heat treatment is conducted, then cutting and layer taking are conducted, and finally the superstructure is manufactured through glue joint. The sound absorption and noise reduction functions and the energy absorption and anti-collision functions are integrated, the sound absorption performance is improved through the bionic structure, energy is efficiently absorbed through the middle layer dot matrix, adjustable performance and lightweight design are achieved through parameterized design, the additive manufacturing process is simple, convenient and efficient, and large-scale production and application are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of sound absorption, noise reduction and impact resistance. Background Art

[0002] In modern engineering and science, acoustic control and structural protection are crucial. Efficient sound-absorbing materials are of great significance to reducing noise pollution and improving the quality of the acoustic environment. Reliable anti-collision structures are indispensable for protecting the safety of personnel and equipment. Researchers have long been committed to developing high-performance sound-absorbing and anti-collision materials and structures to meet the growing application needs.

[0003] Traditional sound-absorbing materials, such as porous fibers, foams, and resonant cavity structures, have played an important role in acoustic control. However, these traditional sound-absorbing technologies have exposed numerous limitations when applied to complex and demanding scenarios. First, they have a narrow sound absorption bandwidth. Most traditional sound-absorbing materials have a limited effective sound absorption bandwidth, particularly at low frequencies, where their sound absorption performance significantly decreases, making them unable to meet the demands of broadband noise environments. Second, they have poor environmental adaptability. Many traditional sound-absorbing materials are sensitive to environmental factors and are prone to moisture absorption, aging, and mildew. In harsh environments such as humidity, high temperatures, and corrosive environments, their sound absorption performance can be significantly reduced or even fail, resulting in a limited lifespan, limiting their application in complex environments. Third, they have a single structural design and poor adjustability. The relatively simple structural design of traditional sound-absorbing materials makes their sound absorption performance difficult to adjust after the materials are prepared, limiting their application in dynamic acoustic control scenarios. Traditional anti-collision materials and structures, such as metal, plastic, and rubber, are widely used in impact protection. However, with increasing demands for structural safety and lightweighting, existing anti-collision technologies face challenges. Traditional anti-collision structures usually only focus on impact protection and lack integration with other functions, making it difficult to meet the trend of multi-functional integration.

[0004] In existing technologies, sound absorption and anti-collision functions are usually designed and implemented independently, making it difficult to achieve coordinated optimization in the same structure and to meet the demands of modern engineering for lightweight, multifunctional, high-performance integrated structures. Summary of the Invention

[0005] In order to overcome the problem in the prior art that it is impossible to simultaneously meet the combination of high sound absorption and noise reduction performance and high energy absorption and anti-collision performance, the present invention provides a multifunctional tunable bionic sound absorption and anti-collision integrated superstructure, including a shell, an upper and lower sound absorption layer are provided inside the shell, an anti-collision layer is provided between the upper and lower sound absorption layers, the sound absorption layer is provided with a plurality of curved microporous plates, the plurality of curved microporous plates are interconnected end to end to form a cavity, a hole is provided on the shell, the hole is connected to the cavity through an embedded tube, the embedded tube and the cavity are combined to form a Helmholtz resonator, the anti-collision layer is composed of a plurality of energy absorption unit arrays, the energy absorption unit includes an octahedral structure formed by a plurality of short rods connected to each other, the eight vertices of the octahedron structure are respectively connected to the center of the octahedron through long rods, and the long rods extend axially to connect with the long rods of adjacent sound absorption units.

[0006] Preferably, the superstructure material is AlSi10Mg aluminum alloy.

[0007] Preferably, the shell thickness is 1 mm.

[0008] A method for preparing the multifunctional tunable bionic sound-absorbing and collision-avoiding integrated superstructure as described above comprises the following steps:

[0009] S1. Build a three-dimensional model of the superstructure;

[0010] S2. Set the laser scanning mode and process parameters, and print according to the corresponding parameters;

[0011] S3, heat treating the printed material;

[0012] S4. removing the sound absorbing layer with the shell and the anti-collision layer with the shell from the printed substrate through a cutting process;

[0013] S5. The cut sound-absorbing layer with a shell and the anti-collision layer with a shell are glued together to form a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure.

[0014] Preferably, step S1 includes:

[0015] S1-1. Construct and optimize the parameterized superstructure model:

[0016] The Helmholtz resonator aperture, embedded tube length, and aperture on the curved microporous plate were extracted as design variables, and the sound absorption coefficient was used as the evaluation index to optimize and establish the sound absorption layer. The lattice component ratio, short rod diameter, and long rod diameter were extracted as design variables, and the specific energy absorption was used as the evaluation index to optimize and establish the anti-collision layer.

[0017] Construct a parameterized superstructure outer layer model, the formula is: ;

[0018] in, are the length, width, and height of the superstructure outer model respectively. are the directions of the three axes in space;

[0019] Combine the sound absorption layer, anti-collision layer and outer layer to establish a parametric superstructure model;

[0020] S1-2. Establish a finite element model and conduct simulation analysis:

[0021] Based on the established structural outer layer model, the initial design domain is meshed into a sound-absorbing layer and an anti-collision layer. A background pressure field, a perfectly matched layer, a thermoviscous boundary impedance, and a hard acoustic field boundary impedance are applied to establish a finite element model of the sound-absorbing layer. External force loads are applied to establish a finite element model of the anti-collision layer.

[0022] S1-3. Calculate the sound absorption coefficient based on the Helmholtz resonator aperture, the embedded tube length, and the aperture of the curved microporous plate; calculate the specific energy absorption based on the lattice component ratio, the short rod diameter, and the long rod diameter; perform finite element analysis on the superstructure model to obtain the superstructure response information;

[0023] S1-3a, calculate the sound absorption coefficient of the sound absorption layer,

[0024] The surface acoustic impedance calculation formula is: ;

[0025] in, For the The surface acoustic impedance of each element, For the The microvia impedance of each component, For the The cavity impedance of each element;

[0026] Calculate micropore impedance : ;

[0027] in, is the imaginary unit, is the thickness of the curved microplate, is the hole diameter of the curved microplate, is the porosity of the curved microplate, is the angular frequency of the incident sound wave, , is the air density, is the dynamic viscosity, is the zero-order Bessel function, is a first-order Bessel function;

[0028] Calculating cavity impedance : ;

[0029] in, is the characteristic impedance of air, is the wave number, is the speed of sound in air;

[0030] Calculating the characteristic impedance of air : ;

[0031] Calculate the sound absorption coefficient under the action of incident sound waves : ;

[0032] in, is the total surface impedance, which is calculated as: ;

[0033] in, is the total number of absorbed components;

[0034] The formula for calculating viscous dissipation is: ;

[0035] S1-3b, calculate the specific energy absorption of the anti-collision layer,

[0036] Total energy dissipated when deformation occurs for: ;

[0037] in, is the instantaneous crushing force, is the crushing distance;

[0038] Energy absorbed per unit mass for: ;

[0039] in, is the mass of the superstructure;

[0040] Component ratio for: ;

[0041] in, is the volume of the long rod, is the volume of the short rod;

[0042] S1-3c. Based on the above calculation results, the superstructure response information is obtained.

[0043] Preferably, in step S2, a Stripes scanning method is adopted, the rotation angle of each layer is 67°, the printing layer thickness is 0.02-0.10 mm, the laser power is 80-500 W, the laser scanning speed is 500-2000 mm / s, and the scanning spacing is 0.17-0.23 mm.

[0044] Preferably, in step S3, under high vacuum conditions, the heat treatment temperature is 520° C.-530° C., the temperature is kept for 2 hours, and the argon gas is used for rapid cooling.

[0045] Preferably, in step S5, epoxy resin is used for bonding.

[0046] The beneficial effects of the present invention are as follows: the present invention integrates the two functions of sound absorption and noise reduction and energy absorption and collision prevention into an integrated superstructure, and can meet the dual needs at the same time without sacrificing a single performance; the present invention adopts a bionic Helmholtz resonator array and a bionic curved surface micro-perforated structure, which significantly improves the sound absorption performance of the superstructure. The average sound absorption coefficient in the frequency range of 750-1610Hz can reach above 0.9, which can effectively reduce noise pollution and improve the acoustic environment; the lattice structure of the middle layer of the present invention has excellent energy absorption characteristics, with a specific energy absorption of up to 17.6kJ / kg, which can effectively absorb impact energy, reduce impact damage, and improve the level of safety protection; through parametric design and optimization, the present invention realizes the tunability of the superstructure's sound absorption and anti-collision performance, and can flexibly adjust the performance parameters of the superstructure according to the needs of different application scenarios, with wider applicability; the present invention adopts lightweight alloy materials and porous structure design to achieve lightweight superstructure, with a weight reduction of more than 30% compared with traditional sound-absorbing and anti-collision structures, making it more suitable for weight-sensitive applications; the present invention adopts additive manufacturing technology to simplify the preparation process of complex structures, shorten the production cycle, reduce manufacturing costs, and create conditions for large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 2. It is a schematic diagram of a method for preparing a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to an embodiment of the present invention;

[0048] Figure 2 This is a cross-sectional view of a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to an embodiment of the present invention;

[0049] Figure 3 This is an exploded view of the air domain of the sound absorbing layer according to an embodiment of the present invention;

[0050] Figure 4 is a three-dimensional schematic diagram of an anti-collision layer according to an embodiment of the present invention;

[0051] Figure 5 1. This is a graph showing the sound absorption coefficient-frequency curve of the sound absorption layer of the multifunctional tunable bionic sound absorption and anti-collision integrated superstructure according to an embodiment of the present invention;

[0052] Figure 6 2. The load-displacement curve of the sound-absorbing layer of the multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to an embodiment of the present invention;

[0053] Figure 7 1 is a load-displacement curve of the anti-collision layer of the multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to an embodiment of the present invention;

[0054] Figure 8 is a load-displacement curve diagram of a multifunctional tunable bionic sound-absorbing and collision-avoiding integrated superstructure according to an embodiment of the present invention;

[0055] Figure 9 Schematic diagram of the energy absorption unit of the multifunctional tunable bionic sound absorption and anti-collision integrated superstructure according to an embodiment of the present invention.

[0056] In the figure: 1. Helmholtz resonator; 2. Sound absorption layer; 3. Anti-collision layer; 4. Shell; 5. Hole; 6. Short rod; 7. Long rod; 8. Embedded tube; 9. Curved microporous plate; 10. BCC-Octet lattice structure. DETAILED DESCRIPTION

[0057] The present invention draws inspiration from the armor of glyptodonts and tortoise shells in nature, integrates sound absorption and collision avoidance functions into an integrated superstructure, and realizes performance decoupling and regulation. Specifically, the embodiments of the present invention provide a multifunctional tunable bionic sound absorption and collision avoidance integrated superstructure, such as Figure 2 As shown, it includes a shell 4, wherein two layers of sound absorbing layers 2 are provided inside the shell 4, and an anti-collision layer 3 is provided between the two layers of sound absorbing layers 2. Figure 3 As shown, the sound absorbing layer 2 is provided with a plurality of curved microporous plates 9, which are connected end to end to form a cavity. The shell 4 is provided with a hole 5, which is connected to the cavity through an embedded tube 8. The embedded tube 8 and the cavity are combined to form a Helmholtz resonator 1. The anti-collision layer 3 is composed of a plurality of energy absorbing unit arrays, as shown in FIG. Figure 4 、 9 As shown, the energy absorbing unit includes an octahedral structure formed by interconnecting multiple short rods 6. The eight vertices of the octahedral structure are respectively connected to the center of the octahedron through long rods 7. The long rods 7 extend axially to connect with the long rods 7 of the adjacent sound absorbing unit. The energy absorbing unit is a BCC-Octet lattice structure 10.

[0058] The superstructure material is a lightweight aluminum alloy material with good mechanical properties and machinability. In this embodiment, AlSi10Mg aluminum alloy is used. The thickness of the shell 4, the thickness of the sound-absorbing layer 2, and the thickness of the anti-collision layer 3 can be adjusted according to actual needs. In this embodiment, the thickness of the shell 4 is 1 mm, and the thickness of the sound-absorbing layer 2 and the anti-collision layer 3 are the same.

[0059] The embodiment of the present invention also provides a method for preparing a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure, such as Figure 1 As shown, the following steps are included:

[0060] S1. Build a three-dimensional model of the superstructure;

[0061] S1-1. Construct and optimize the parameterized superstructure model:

[0062] Drawing on the cross-sectional structures of glyptodon armor and tortoise shells, a parametric superstructure outer layer model was constructed. The aperture of the Helmholtz resonator 1, the length of the embedded tube 8, and the aperture of the curved microporous plate 9 were extracted as design variables. The sound absorption coefficient was used as an evaluation metric to optimize and establish the sound absorption layer 2, achieving efficient sound wave absorption. The lattice component ratio, the diameter of the short rod 6, and the diameter of the long rod 7 were extracted as design variables. The specific energy absorption was used as an evaluation metric to optimize and establish the anti-collision layer 3, achieving efficient impact energy absorption.

[0063] Construct a parameterized superstructure outer layer model, the formula is: ;

[0064] in, are the length, width, and height of the superstructure outer model respectively. are the directions of the three axes in space;

[0065] A parameterized superstructure model is established by combining the sound absorption layer 2, the anti-collision layer 3 and the outer layer;

[0066] S1-2. Establish a finite element model and conduct simulation analysis:

[0067] Based on the established structural outer layer model, the initial design domain was meshed into the sound-absorbing layer 2 and the anti-collision layer 3. A background pressure field, a perfectly matched layer, a thermoviscous boundary impedance, and a hard acoustic boundary impedance were applied to establish a finite element model of the sound-absorbing layer 2 for sound absorption performance analysis. External force loads were applied to establish a finite element model of the anti-collision layer 3 for anti-collision performance analysis.

[0068] S1-3. Calculate the sound absorption coefficient based on the aperture of the Helmholtz resonator 1, the length of the embedded tube 8, and the aperture of the curved microporous plate 9; calculate the specific energy absorption based on the lattice component ratio, the diameter of the short rod 6, and the diameter of the long rod 7; perform finite element analysis on the superstructure model to obtain superstructure response information;

[0069] S1-3a, calculate the sound absorption coefficient of the sound absorbing layer 2,

[0070] The surface acoustic impedance calculation formula is: ;

[0071] in, For the The surface acoustic impedance of each element, For the The microvia impedance of each component, For the The cavity impedance of each element;

[0072] Calculate micropore impedance : ;

[0073] in, is the imaginary unit, is the thickness of the curved microporous plate 9, is the hole diameter of the curved microplate 9, is the porosity of the curved microporous plate 9, is the angular frequency of the incident sound wave, , is the air density, is the dynamic viscosity, is the zero-order Bessel function, is a first-order Bessel function;

[0074] Calculating cavity impedance : ;

[0075] in, is the characteristic impedance of air, is the wave number, is the speed of sound in air;

[0076] Calculating the characteristic impedance of air : ;

[0077] Calculate the sound absorption coefficient under the action of incident sound waves : ;

[0078] in, is the total surface impedance, which is calculated as: ;

[0079] in, is the total number of absorbed components;

[0080] The formula for calculating viscous dissipation is: ;

[0081] S1-3b, calculate the specific energy absorption of the anti-collision layer 3,

[0082] Total energy dissipated when deformation occurs for: ;

[0083] in, is the instantaneous crushing force, is the crushing distance;

[0084] Energy absorbed per unit mass for: ;

[0085] in, is the mass of the superstructure;

[0086] Component ratio for: ;

[0087] in, is the volume of the long rod 7, The volume is 6 for the short rod;

[0088] S1-3c, based on the above calculation results, the superstructure response information is obtained, and the relevant performance curve is as follows Figure 5-8 shown.

[0089] S2. Set the laser scanning mode and process parameters, and print according to the corresponding parameters; use the Stripes scanning mode, with a rotation angle of 67° per layer, a printing layer thickness of 0.02-0.10 mm, a laser power of 80-500 W, a laser scanning speed of 500-2000 mm / s, and a scanning interval of 0.17-0.23 mm.

[0090] S3. The printed material is heat treated at a temperature of 520°C-530°C under high vacuum conditions for 2 hours, followed by rapid cooling using argon gas.

[0091] S4, removing the sound absorbing layer 2 with the shell 4 and the anti-collision layer 3 with the shell 4 from the printed substrate by wire cutting process;

[0092] S5. Use epoxy resin to glue the cut sound-absorbing layer 2 with the shell 4 and the anti-collision layer 3 with the shell 4 together to form a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure.

[0093] The present invention is described by way of example, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be within the scope of the present invention.

Claims

1. A multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure, characterized in that: The shell (4) is provided with an upper and lower sound absorbing layer (2), an anti-collision layer (3) is provided between the upper and lower sound absorbing layers (2), the sound absorbing layer (2) is provided with a plurality of curved microporous plates (9), the plurality of curved microporous plates (9) are connected to each other end to form a cavity, the shell (4) is provided with a hole (5), the hole (5) is connected to the cavity through an embedded tube (8), the embedded tube (8) and the cavity are combined to form a Helmholtz resonator (1), the anti-collision layer (3) is composed of a plurality of energy absorbing unit arrays, the energy absorbing unit includes an octahedral structure formed by interconnecting a plurality of short rods (6), the eight vertices of the octahedral structure are respectively connected to the center of the octahedron through long rods (7), and the long rods (7) are extended axially to be connected to the long rods (7) of the adjacent sound absorbing units.

2. The multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to claim 1 is characterized in that: The superstructure material is AlSi10Mg aluminum alloy.

3. The multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to claim 1 is characterized in that: The shell (4) has a thickness of 1 mm.

4. A method for preparing a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Build a three-dimensional model of the superstructure; S2. Set the laser scanning mode and process parameters, and print according to the corresponding parameters; S3, heat treating the printed material; S4, removing the sound absorbing layer (2) with the shell (4) and the anti-collision layer (3) with the shell (4) from the printed substrate through a cutting process; S5. The cut sound-absorbing layer (2) with the shell (4) and the anti-collision layer (3) with the shell (4) are glued together to form a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure.

5. The method for preparing a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to claim 4, characterized in that: The step S1 comprises: S1-1. Construct and optimize the parameterized superstructure model: The aperture of the Helmholtz resonator (1), the length of the embedded tube (8), and the aperture of the curved microporous plate (9) are extracted as design variable parameters, and the sound absorption coefficient is used as an evaluation index to optimize and establish the sound absorption layer (2); the lattice component ratio, the diameter of the short rod (6), and the diameter of the long rod (7) are extracted as design variable parameters, and the specific energy absorption is used as an evaluation index to optimize and establish the anti-collision layer (3); Construct a parameterized superstructure outer layer model, the formula is: ； in, are the length, width, and height of the superstructure outer model respectively. are the directions of the three axes in space; A parameterized superstructure model is established by combining the sound absorption layer (2), the anti-collision layer (3) and the outer layer; S1-2. Establish a finite element model and conduct simulation analysis: Based on the established structural outer layer model, the initial design domain is meshed and divided into a sound absorption layer (2) and an anti-collision layer (3). A background pressure field, a perfect matching layer, a thermoviscous boundary impedance, and a hard acoustic field boundary impedance are applied to establish a finite element model of the sound absorption layer (2). An external force load is applied to establish a finite element model of the anti-collision layer (3). S1-3, calculating the sound absorption coefficient based on the aperture of the Helmholtz resonator (1), the length of the embedded tube (8), and the aperture of the curved microporous plate (9), calculating the specific energy absorption based on the lattice component ratio, the diameter of the short rod (6), and the diameter of the long rod (7), performing finite element analysis on the superstructure model to obtain the superstructure response information; S1-3a. Calculate the sound absorption coefficient of the sound absorbing layer (2). The surface acoustic impedance calculation formula is: ； in, For the The surface acoustic impedance of each element, For the The microvia impedance of each component, For the The cavity impedance of each element; Calculate micropore impedance : ； in, is the imaginary unit, is the thickness of the curved microporous plate (9), is the hole diameter of the curved microplate (9), is the porosity of the curved microporous plate (9), is the angular frequency of the incident sound wave, , is the air density, is the dynamic viscosity, is the zero-order Bessel function, is a first-order Bessel function; Calculating cavity impedance : ； in, is the characteristic impedance of air, is the wave number, is the speed of sound in air; Calculating the characteristic impedance of air : ； Calculate the sound absorption coefficient under the action of incident sound waves : ； in, is the total surface impedance, which is calculated as: ； in, is the total number of absorbed components; The formula for calculating viscous dissipation is: ； S1-3b, calculate the specific energy absorption of the anti-collision layer (3), Total energy dissipated when deformation occurs for: ； in, is the instantaneous crushing force, is the crushing distance; Energy absorbed per unit mass for: ； in, is the mass of the superstructure; Component ratio for: ； in, is the volume of the long rod (7), is the volume of the short rod (6); S1-3c. Based on the above calculation results, the superstructure response information is obtained.

6. The method for preparing a multifunctional tunable bionic sound-absorbing and collision-avoiding integrated superstructure according to claim 4, characterized in that: In step S2, a Stripes scanning method is used, the rotation angle of each layer is 67°, the printing layer thickness is 0.02-0.10 mm, the laser power is 80-500 W, the laser scanning speed is 500-2000 mm / s, and the scanning interval is 0.17-0.23 mm.

7. The method for preparing a multifunctional tunable bionic sound-absorbing and collision-avoiding integrated superstructure according to claim 4, characterized in that: In step S3, the heat treatment temperature is 520° C.-530° C. under high vacuum conditions, and the temperature is kept for 2 hours, followed by rapid cooling with argon.

8. The method for preparing a multifunctional tunable bionic sound-absorbing and anti-collision integrated superstructure according to claim 4, characterized in that: In the step S5, epoxy resin is used for gluing.

Images