阅读说明：本技术 一种基于三重周期极小曲面的轻质隔声结构及其制备方法 (Light sound insulation structure based on triple-period extremely-small curved surface and preparation method thereof ) 是由 刘杰 林春贯 于 2020-12-31 设计创作，主要内容包括：本发明公开一种基于三重周期极小曲面的轻质隔声结构及其制备方法,包括上面板、上胶合层、夹芯、下胶合层和下面板,所述夹芯包括三重周期极小曲面,上面板与夹芯的上界面粘合,下面板与夹芯的下界面粘合。使用数学软件,根据定义三重周期极小曲面的数学公式和定义夹芯的整体形状划分区域的数学公式得出的布尔交集,建立三重周期极小曲面的模型,再导入逆向工程软件,将曲面沿法线方向两侧偏移指定的数值并连接起来,从而建立夹芯的三维实体模型,根据夹芯的三维实体模型制造夹芯；制造上面板和下面板,通过上胶合层使上面板与夹芯的上界面粘合,通过下胶合层使下面板与夹芯的下界面粘合。(The invention discloses a light sound insulation structure based on a triple-period extremely-small curved surface and a preparation method thereof. Establishing a model of the triple period minimum curved surface by using mathematical software according to Boolean intersection obtained by a mathematical formula for defining the triple period minimum curved surface and a mathematical formula for defining the whole shape dividing region of the sandwich, introducing reverse engineering software, deviating the curved surface from specified numerical values along the two sides of the normal direction and connecting the curved surfaces together so as to establish a three-dimensional entity model of the sandwich, and manufacturing the sandwich according to the three-dimensional entity model of the sandwich; the upper and lower face sheets are manufactured, the upper face sheet is bonded to the upper interface of the core by an upper adhesive layer, and the lower face sheet is bonded to the lower interface of the core by a lower adhesive layer.)

1. The light sound insulation structure based on the triple-period minimum curved surface is characterized by comprising an upper panel, an upper adhesive layer, a sandwich, a lower adhesive layer and a lower panel, wherein the sandwich comprises the triple-period minimum curved surface, the upper panel is adhered to an upper interface of the sandwich through the upper adhesive layer, the lower panel is adhered to a lower interface of the sandwich through the lower adhesive layer, and the structure of the sandwich is determined by a mathematical formula for defining the triple-period minimum curved surface, a mathematical formula for defining an integral shape dividing area of the sandwich and the thickness of the curved surface.

2. The light-weight sound insulation structure based on the triple-period minimum curved surface as claimed in claim 1 is characterized in that the mathematical formula for defining the triple-period minimum curved surface is as follows:

cos(aπx)cos(aπy)cos(aπz)-sin(aπx)sin(aπy)sin(aπz)＝C

the parameter a value is used for adjusting the size and the period of the triple-period minimum curved surface unit cell, the period is T2/a, the smaller the value a is, the larger the unit cell size is, and the larger the period is; the parameter C value is used for adjusting the degree of the triple period minimum curved surface deviating from the original minimum curved surface.

3. The light sound insulation structure based on the triple-period extremely-small curved surface as claimed in claim 2, wherein the mathematical formula for defining the overall shape dividing region of the sandwich core is as follows:

x²+y²＝D

wherein the value of parameter D is used to adjust the size of the cylindrical region.

4. The light sound insulation structure based on the triple-period minimum curved surface as claimed in claim 3, is characterized in that Boolean intersection operation is carried out on a mathematical formula for defining the triple-period minimum curved surface and a mathematical formula for defining the whole shape dividing region of the sandwich core, so as to establish a model of the triple-period minimum curved sandwich core.

5. The light sound insulation structure based on the triple-period extremely-small curved surface is characterized in that the extremely-small curved surface of the sandwich is formed by periodically arranging thin-wall structures, and the spatial geometric topological form of the extremely-small curved surface realizes a better sound insulation effect by increasing the transmission and dissipation ways of sound waves.

6. The method for preparing the light sound insulation structure based on the triple-period extremely-small curved surface according to any one of claims 1 to 5 is characterized by comprising the following steps:

establishing a model of the triple period minimum curved surface by using mathematical software according to Boolean intersection obtained by a mathematical formula for defining the triple period minimum curved surface and a mathematical formula for defining the whole shape dividing region of the sandwich, introducing reverse engineering software, deviating the curved surface from specified numerical values along the two sides of the normal direction and connecting the curved surfaces together so as to establish a three-dimensional entity model of the sandwich, and manufacturing the sandwich according to the three-dimensional entity model of the sandwich;

the upper and lower face sheets are manufactured, the upper face sheet is bonded to the upper interface of the core by an upper adhesive layer, and the lower face sheet is bonded to the lower interface of the core by a lower adhesive layer.

7. The method for preparing the light sound insulation structure based on the triple-period extremely-small curved surface according to claim 6, is characterized in that the mathematical formula for defining the triple-period extremely-small curved surface is as follows:

cos(aπx)cos(aπy)cos(aπz)-sin(aπx)sin(aπy)sin(aπz)＝C

the parameter a value is used for adjusting the size and the period of the triple-period minimum curved surface unit cell, the period is T2/a, the smaller the value a is, the larger the unit cell size is, and the larger the period is; the parameter C value is used for adjusting the degree of the triple period minimum curved surface deviating from the original minimum curved surface.

8. The method for preparing a light sound insulation structure based on a triple-period extremely-small curved surface according to claim 6, characterized in that the mathematical formula for defining the whole shape of the sandwich to divide the area is as follows:

x²+y²＝D

wherein the value of parameter D is used to adjust the size of the cylindrical region.

9. The method for preparing the light sound insulation structure based on the triple-period extremely-small curved surface according to claim 6 is characterized in that the sandwich is manufactured in a 3D printing mode according to a three-dimensional solid model of the sandwich.

Technical Field

The invention relates to the technical field of light sound insulation structures, in particular to a light sound insulation sandwich structure based on a triple-period extremely-small curved surface and a preparation method thereof.

Background

High-speed rails, airplanes and the like are difficult to avoid generating noise during running, great influence is caused on the physiological aspects, the psychological aspects and the like of passengers, and sound insulation can reduce the sound intensity of the noise in the transmission process and reduce noise pollution. The sandwich structure is widely applied to the field of sound insulation, and can balance light weight and rigidity and realize high specific stiffness while meeting the sound insulation requirement. However, some sandwich structures in the prior art have sound insulation valleys with larger frequency bands in some important frequency bands, so that the application range of the sandwich structures is limited. The extremely small curved surface is a unique topological configuration of a continuous smooth curved surface, so that the consumption mode and the propagation path of noise in the sandwich structure can be increased, the dissipation capacity of damping is improved, and better sound insulation performance is achieved. Therefore, the development of a novel light sound insulation structure which can simultaneously meet the requirements of high specific stiffness and excellent sound insulation performance of multiple frequency bands is of great significance.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a light sound insulation sandwich structure based on a triple-period extremely-small curved surface, and realizes high specific stiffness and strong sound insulation performance by utilizing the geometrical topological structure characteristic of a continuous smooth curved surface of the triple-period extremely-small curved surface.

The invention also aims to provide a preparation method of the light sound insulation sandwich structure based on the triple-period extremely-small curved surface.

The technical scheme of the invention is as follows: the light sound insulation structure based on the triple-period minimum curved surface comprises an upper panel, an upper adhesive layer, a sandwich core, a lower adhesive layer and a lower panel, wherein the sandwich core comprises the triple-period minimum curved surface, the upper panel is adhered to an upper interface of the sandwich core through the upper adhesive layer, the lower panel is adhered to a lower interface of the sandwich core through the lower adhesive layer, and the structure of the sandwich core is determined by a mathematical formula for defining the triple-period minimum curved surface, a mathematical formula for defining an integral shape dividing area of the sandwich core and the thickness of the curved surface.

The mathematical formula for defining the triple-period minimum curved surface is as follows:

cos(aπx)cos(aπy)cos(aπz)-sin(aπx)sin(aπy)sin(aπz)＝C

the parameter a value is used for adjusting the size and the period of the triple-period minimum curved surface unit cell, the period is T2/a, the smaller the value a is, the larger the unit cell size is, and the larger the period is; the parameter C value is used for adjusting the degree of the triple period minimum curved surface deviating from the original minimum curved surface.

The mathematical formula for defining the whole shape dividing area of the sandwich core is as follows:

x²+y²＝D

wherein the value of parameter D is used to adjust the size of the cylindrical region.

And performing Boolean intersection operation on the mathematical formula for defining the triple-period minimum curved surface and the mathematical formula for defining the whole shape division area of the sandwich core, and establishing a model of the triple-period minimum curved surface sandwich core.

The extremely-small curved surface sandwich is formed by periodically arranging thin-wall structures and has higher specific rigidity. The unique space geometric topological form of the extremely small curved surface can increase the transmission and dissipation ways of sound waves so as to realize better sound insulation effect.

A preparation method of a light sound insulation structure based on a triple-period extremely-small curved surface comprises the following steps:

establishing a model of the triple period minimum curved surface by using mathematical software according to Boolean intersection obtained by a mathematical formula for defining the triple period minimum curved surface and a mathematical formula for defining the whole shape dividing region of the sandwich, introducing reverse engineering software, deviating the curved surface from specified numerical values along the two sides of the normal direction and connecting the curved surfaces together so as to establish a three-dimensional entity model of the sandwich, and manufacturing the sandwich according to the three-dimensional entity model of the sandwich;

the upper and lower face sheets are manufactured, the upper face sheet is bonded to the upper interface of the core by an upper adhesive layer, and the lower face sheet is bonded to the lower interface of the core by a lower adhesive layer.

The mathematical formula for defining the triple-period minimum curved surface is as follows:

cos(aπx)cos(aπy)cos(aπz)-sin(aπx)sin(aπy)sin(aπz)＝C

the parameter a value is used for adjusting the size and the period of the triple-period minimum curved surface unit cell, the period is T2/a, the smaller the value a is, the larger the unit cell size is, and the larger the period is; the parameter C value is used for adjusting the degree of the triple period minimum curved surface deviating from the original minimum curved surface.

The mathematical formula for defining the whole shape dividing area of the sandwich core is as follows:

x²+y²＝D

wherein the value of parameter D is used to adjust the size of the cylindrical region.

And manufacturing the sandwich by adopting a 3D printing mode according to the three-dimensional solid model of the sandwich.

The principle of the light sound insulation structure based on the triple-period extremely-small curved surface is as follows: the sandwich structure based on the extremely small curved surface has a unique consumption mode for transmitted sound waves, when incident sound waves encounter the light sound insulation sandwich structure in the transmission process, one part of the sound waves can be reflected back, and the other part of the sound waves can excite the structure to vibrate; when the structure vibrates, sound waves are radiated outwards, so that the structure vibration caused by incident sound waves can radiate the sound waves to the air between the upper panel and the lower panel, the sandwich is a tiny curved surface entity with a complex configuration, the sound waves can be continuously reflected and excited between the air cavity and the sandwich to vibrate, and partial sound waves can be gradually consumed and converted into energy in other forms due to the damping of the structure and the air and the energy conversion efficiency of the structure and the air; finally, the sandwich structure transmits the vibration to the lower panel, so that a part of sound waves are radiated to the air at the other end from the lower panel, and the ratio of the part of sound waves to the incident sound waves is the sound isolated by the sandwich structure.

Compared with the prior art, the invention has the advantages of large specific rigidity, light weight and good multi-frequency band sound insulation effect:

the triple-period extremely-small curved surface sandwich has the advantages of large rigidity and uniform entity space distribution, the sound insulation performance of the rigidity control section in the sound insulation middle-low frequency range and the position of the frequency range in the resonance section are in direct proportion to the structural rigidity, the uniform space distribution mode can provide balanced mechanical properties in different directions, and the triple-period extremely-small curved surface entity sandwich can automatically adjust parameters such as intercepting position, period size and shape to adapt to different working environments. Therefore, the sandwich structure with the triple period and the extremely small curved surface can obtain better sound insulation performance and higher specific stiffness than the traditional sandwich structure.

The light sound insulation sandwich structure adopts a triple-period minimum curved surface solid structure as a sandwich, the geometric topological configuration of the sandwich is determined by a strict mathematical theory, the shape can be adjusted by adjusting and controlling the key geometric parameters of the minimum curved surface, and the sandwich of the sandwich under the condition of any shape is ensured to be a continuous and smooth minimum curved surface; the configuration of the extremely-small curved sandwich can increase the transmission and dissipation ways of sound waves in the process of exciting the structure to vibrate by the sound waves, thereby increasing the dissipation capability of damping, reducing the influence of sound insulation valleys and realizing better sound insulation of multiple frequency bands.

The structure is formed by periodically arranging thin-wall structures, has high specific stiffness, has better sound insulation performance in multiple frequency bands, and has good application prospect in the fields of aerospace, high-speed rail and the like.

Drawings

Fig. 1 is a structural schematic diagram of a light sound insulation structure based on a triple-period extremely-small curved surface.

FIG. 2 is a D-type minimum curved surface unit cell diagram adopted by the light sound insulation structure based on the triple period minimum curved surface.

FIG. 3 is a sound insulation simulation diagram of a light sound insulation structure based on a triple-period extremely-small curved surface.

In the figure, 1 is an upper panel, 2 is an upper gluing layer, 3 is a sandwich, 4 is a lower gluing layer, and 5 is a lower panel.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Examples

The light sound insulation structure based on the triple-period minimum curved surface comprises an upper panel 1, an upper adhesive layer 2, a sandwich 3, a lower adhesive layer 4 and a lower panel 5, wherein the sandwich comprises the triple-period minimum curved surface, the upper panel is adhered to the upper interface of the sandwich through the upper adhesive layer, the lower panel is adhered to the lower interface of the sandwich through the lower adhesive layer, and the structure of the sandwich is determined by a mathematical formula for defining the triple-period minimum curved surface, a mathematical formula for defining the whole shape dividing area of the sandwich and the thickness of the curved surface.

The mathematical formula for defining the triple-period minimum curved surface is as follows:

cos(aπx)cos(aπy)cos(aπz)·sin(aπx)sin(aπy)sin(aπz)＝C

the parameter a value is used for adjusting the size and the period of the triple-period minimum curved surface unit cell, the period is T2/a, the smaller the value a is, the larger the unit cell size is, and the larger the period is; the parameter C value is used for adjusting the degree of the triple period minimum curved surface deviating from the original minimum curved surface. In this example, the value of a is 0.1, and the size of one cycle is determined to be 20 mm.

An implicit function discretization area function is used in software to divide the curved surface of a certain area into meshes and then derive the meshes. The triple period minimum curved surface is repeated in an infinite period in the directions of three coordinate axes of x, y and z, but the sandwich structure is limited in size in actual use, so that a divided area needs to be controlled to intercept a curved surface with a proper shape to meet requirements, and the limited divided area can be determined according to actual conditions; this embodiment uses a very small curved surface having a unit cell period T of 20 mm. By controlling the value a and controlling the divided areas, the number of unit cells contained in the sandwich structure can be controlled. The mathematical formula for defining the whole shape dividing area of the sandwich core is as follows:

x²+y²＝D

wherein the value of parameter D is used to adjust the size of the cylindrical region.

And performing Boolean intersection operation on the mathematical formula for defining the triple-period minimum curved surface and the mathematical formula for defining the whole shape division area of the sandwich core, and establishing a model of the triple-period minimum curved surface sandwich core.

The materials of the upper panel, the lower panel and the core may be metals or polymers, and the embodiment is not limited.

A preparation method of a light sound insulation structure based on a triple-period extremely-small curved surface comprises the following steps:

using mathematical software, according to Boolean intersection obtained by a mathematical formula for defining a triple period minimum curved surface and a mathematical formula for defining an integral shape dividing region of the sandwich core, establishing a model of the triple period minimum curved surface, using an implicit function discretization region function in the software to divide the curved surface of a certain region into grids, then exporting the grids in an STL format, importing reverse engineering software to directly process an STL grid file, deviating the curved surface along the two sides of a normal direction by a specified numerical value and connecting the grids, wherein the thickened thickness is 1mm in the embodiment, thereby establishing a three-dimensional entity model of the sandwich core, exporting the sandwich core in the STL file format, and manufacturing the sandwich core by adopting a 3D printing mode according to the three-dimensional entity model of the sandwich core;

and manufacturing an upper panel and a lower panel, bonding the upper panel with the upper interface of the sandwich through the upper bonding layer, and bonding the lower panel with the lower interface of the sandwich through the lower bonding layer to manufacture the complete triple-period minimum curved surface light sound insulation sandwich structure.

The principle of the light sound insulation structure based on the triple-period extremely-small curved surface is as follows: the sandwich structure based on the extremely small curved surface has a unique consumption mode for transmitted sound waves, when incident sound waves encounter the light sound insulation sandwich structure in the transmission process, one part of the sound waves can be reflected back, and the other part of the sound waves can excite the structure to vibrate; when the structure vibrates, sound waves are radiated outwards, so that the structure vibration caused by incident sound waves can radiate the sound waves to the air between the upper panel and the lower panel, the sandwich is a tiny curved surface entity with a complex configuration, the sound waves can be continuously reflected and excited between the air cavity and the sandwich to vibrate, and partial sound waves can be gradually consumed and converted into energy in other forms due to the damping of the structure and the air and the energy conversion efficiency of the structure and the air; finally, the sandwich structure transmits the vibration to the lower panel, so that a part of sound waves are radiated to the air at the other end from the lower panel, and the ratio of the part of sound waves to the incident sound waves is the sound isolated by the sandwich structure.

The light sound insulation sandwich structure based on the triple-period minimum curved surface can realize better sound insulation performance in multiple frequency bands due to the unique configuration of the light sound insulation sandwich structure, and fig. 3 is a sound insulation simulation diagram of the light sound insulation sandwich structure based on the triple-period minimum curved surface when a D-shaped minimum curved surface is used, the structure is in a cylindrical shape, the edges of an upper panel and a lower panel are fixed, and sound insulation performance simulation is carried out in a sound vibration coupling mode; in the frequency band lower than 2000Hz, because the extremely small curved surface entity sandwich has larger rigidity, higher sound insulation quantity can be kept in the rigidity control interval; in a frequency band of a resonance interval of 3000Hz-7000Hz, the triple-period extremely-small curved sandwich has two sound insulation valleys at about 6000Hz due to resonance, but due to the unique configuration of the triple-period extremely-small curved sandwich, the damping consumption effect is enhanced when the structure and air coupling effect is in the resonance interval, the affected frequency band is very narrow, and the good sound insulation performance of about 40dB can be kept in a large frequency band at the resonance frequency band; in a high frequency band above 7000Hz, the sound insulation quantity is continuously stabilized at a higher value larger than 40dB, and the sound insulation quantity is gradually increased along with the increase of the frequency due to a quality law; within 10000Hz, 80 percent of the frequency range has better sound insulation quantity above 40dB, and the multi-band sound insulation effect is better.

As mentioned above, the present invention can be better realized, and the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; all equivalent changes and modifications made according to the present disclosure are intended to be covered by the scope of the claims of the present invention.