An underwater lightweight pressure-resistant sound-absorbing grid array structure

Abstract

The present invention belongs to the technical field of underwater lightweight pressure-resistant sound-absorbing structures, and in particular relates to an underwater lightweight pressure-resistant sound-absorbing grid array structure. The structure comprises an array frame and a sound-absorbing unit array; the array frame is composed of a surface panel and an array frame; the surface panel comprises an upper panel and a lower panel arranged in parallel and facing each other, as well as side panels on all sides; the array frame comprises a plurality of vertically arranged grid plates; the grid plates divide the inner cavity of the surface panel into a plurality of mounting cavities; the sound-absorbing unit array comprises sound-absorbing units sequentially arranged in each mounting cavity 21; the sound-absorbing units comprise a cladding layer, a sound-absorbing core layer, and a mass distribution structure arranged in the sound-absorbing core layer; the structure of the present invention is simple in structure and has good mechanical and acoustic properties; the grid array structure of the present application has a small overall thickness, is lightweight and pressure-resistant, is easy to use, and has good underwater pressure-bearing capacity and acoustic stealth capability.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater lightweight pressure-resistant sound-absorbing structures, and in particular relates to an underwater lightweight pressure-resistant sound-absorbing grid array structure. Background Art

[0002] Composite materials and structures based on fiber-reinforced resin materials have advantages such as high specific strength, high specific stiffness, strong specific energy absorption, and good designability, and have attracted increasing attention in the field of structural engineering. However, the use of some underwater navigation equipment and wading structures requires not only excellent mechanical bearing properties, but also good adaptability to the water environment and stealth properties such as high sound absorption and low reflection. Currently, structures based on this functional requirement mainly rely on the sound absorption properties of sound-absorbing core materials, but they have shortcomings such as a single absorption band, low controllability of sound absorption performance, and large overall thickness and size. Summary of the Invention

[0003] The purpose of the present invention is to provide a lightweight, pressure-resistant, sound-absorbing grid array structure for use in underwater environments. While having high mechanical bearing performance, it also has outstanding low-frequency bandwidth sound absorption performance, good adaptability and flexibility, and has broad application prospects in underwater stealth equipment or stealth shell structures.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions.

[0005] An underwater lightweight, pressure-resistant, sound-absorbing grid array structure, comprising an array frame and a sound-absorbing unit array;

[0006] The array frame is composed of a surface panel 1 and an array frame 2;

[0007] The surface panel includes an upper panel 10 and a lower panel 11 arranged parallel to each other and side panels 12 around them; the array frame 2 includes a plurality of vertically arranged grid plates 20; the grid plates 20 divide the inner cavity of the surface panel into a plurality of installation cavities 21;

[0008] The sound absorbing unit array includes sound absorbing units sequentially arranged in each installation cavity 21;

[0009] The sound absorbing unit includes a cladding layer, a sound absorbing core layer 4 and a mass distribution structure arranged in the sound absorbing core layer 4;

[0010] The sound-absorbing core layer 4 fills the installation cavity 21, and the cladding layer is arranged between the sound-absorbing core layer 4 and the inner wall of the installation cavity 21. A plurality of tower-shaped sound-absorbing cavities are evenly arranged in the sound-absorbing core layer 4. The tower-shaped sound-absorbing cavities are composed of three combined cavities arranged coaxially along the vertical axis. The combined cavity is composed of a cylindrical cavity 40 at the top and a frustum cavity 41 at the bottom.

[0011] The diameter of the cylindrical cavity 40 is consistent with the diameter of the cone top of the frustum cavity 41; adjacent combined cavities are connected by the cylindrical cavity 40; the thickness of the coating layer on the top of the cylindrical cavity 40 is not less than 2 mm; the cone bottom of the frustum cavity 41 at the bottom of the combined cavity passes through the bottom of the sound-absorbing core layer 4 to form a sound-transmitting opening 41a;

[0012] The mass distribution structure is composed of an inner ring 30, an outer ring 31, and a free ring 32;

[0013] The inner ring 30 and the outer ring 31 are arranged between two adjacent combined cavities; the inner diameter of the inner ring 30 is consistent with the diameter of the cylindrical cavity 40 adjacent to its lower side and is arranged opposite to it; the outer diameter of the inner ring 30 is smaller than the cone bottom diameter of the frustum cavity 41 adjacent to its upper side; the inner diameter of the outer ring 31 is consistent with the cone bottom diameter of the frustum cavity 41 adjacent to its upper side and is arranged opposite to it; the free rings 32 are evenly arranged between each outer ring 31.

[0014] As a further improvement or preferred embodiment of the aforementioned underwater lightweight pressure-resistant sound-absorbing grid array structure, the grid plates 20 are perpendicular to each other and divide the inner cavity of the surface panel into a number of cubic installation cavities of uniform size.

[0015] As a further improvement or preferred embodiment of the aforementioned underwater lightweight, pressure-resistant, sound-absorbing grid array structure, the thickness of the grid plate 20 is much greater than the thickness of the upper panel 10 and the lower panel 11; the coating layer is evenly coated on the surface of the sound-absorbing core layer 4, and the thickness of the coating layer is much smaller than the size of the sound-absorbing core layer 4.

[0016] As a further improvement or preferred embodiment of the aforementioned underwater lightweight pressure-resistant sound-absorbing grid array structure, the thickness H1 of the cylindrical cavity 40: the thickness H2 of the frustum cavity 41: the thickness H3 of the mass distribution structure is 1~1.5:1.5~2:1~1.5.

[0017] As a further improvement or preferred embodiment of the aforementioned underwater lightweight, pressure-resistant, and sound-absorbing grid array structure, the inner ring 30, the outer ring 31, and the free ring 32 are made of steel.

[0018] As a further improvement or preferred embodiment of the aforementioned underwater lightweight, pressure-resistant, sound-absorbing grid array structure, the tower-shaped sound-absorbing cavities are evenly arranged in a circular array or a rectangular array.

[0019] A further improvement or preferred embodiment of the aforementioned underwater lightweight pressure-resistant sound-absorbing grid array structure, the array frame 2 and the sound-absorbing core layer 4 are made of polyurethane damping sound-absorbing material with a density of 900~1000 , hydrostatic compressive strength 1~2 , the linear elastic strain range is 0~0.3; the plastic section strain range is 0.3~0.5;

[0020] The array frame 2 is made by RTM vacuum forming process; the surface panel 1 and the covering layer are obtained by wet winding forming process; the winding angle during the processing is 10°~30°, and the design tension is 5~35N; the reinforcing fiber used in the processing is glass fiber or aramid fiber, and the resin matrix is polyester resin or vinyl ester resin, and the fiber-resin mass ratio is within the content range of 0.8~1.5.

[0021] As a further improvement or preferred embodiment of the aforementioned underwater lightweight pressure-resistant sound-absorbing grid array structure, the ratio of the thickness of the upper panel 10 and the lower panel 11 to the thickness of the grid plate 20 is in the range of 0.05 to 0.10.

[0022] The array filling arrangement design of the high-strength wave-transmitting material grid and the lightweight pressure-resistant sound-absorbing material multi-layer array structural unit is such that the ratio of the thickness of the high-strength wave-transmitting material grid to the central axis spacing of adjacent lightweight pressure-resistant sound-absorbing material multi-layer array structural units ranges from 0.02 to 0.05.

[0023] Its beneficial effects are:

[0024] 1. The present invention has a simple structure and good mechanical and acoustic properties. The grid array structure of the present application has a small overall thickness, is lightweight and pressure-resistant, is easy to use, and has good underwater pressure-bearing capacity and acoustic stealth capability.

[0025] 2. The assembly method is simple, the water sealing performance is good, the installation and use have low requirements for the basic structure and equipment, the plate array structure is evenly distributed, the internal sound absorption unit has an independent closed structure, can be used in combination, the shape setting has a high degree of freedom, can be adapted to various types of surfaces or structures, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of an underwater lightweight, pressure-resistant, sound-absorbing grid array structure.

[0027] Figure 2 is a cross-sectional view of the sound absorbing unit;

[0028] Figure 3 is a perspective view of the sound absorbing unit;

[0029] Figure 4 It is a schematic diagram of the internal structure of the sound absorbing unit;

[0030] The reference numerals include:

[0031] Surface panel 1, upper panel 10, lower panel 11, side panel 12, array frame 2, grid plate 20, mounting cavity 21, inner ring 30, outer ring 31, free ring 32, sound-absorbing core layer 4, cylindrical cavity 40, frustum cavity 41, and sound-transmitting port 41a. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to specific embodiments.

[0033] The underwater lightweight pressure-resistant sound-absorbing grid array structure of the present invention is mainly used for various underwater equipment or structures, especially equipment or structures with requirements in pressure resistance and sound stealth, and is used as unknown structural materials such as external protective shells.

[0034] like Figures 1 to 4 As shown in the figure, the underwater lightweight pressure-resistant sound-absorbing grid array structure mainly includes an array frame and a sound-absorbing unit array; the array frame and the sound-absorbing unit array are suitable for forming a basic necessary structure for pressure-bearing structure and realizing the acoustic stealth function. In the actual implementation process, according to the installation method required by the structure and equipment, various structures for fixed support or positioning or additional corresponding structural parts may be processed on or outside the array frame and the sound-absorbing unit array.

[0035] Among them, the array frame is composed of a surface panel 1 and an array frame 2;

[0036] The surface panel includes an upper panel 10 and a lower panel 11 arranged parallel to each other and side panels 12 around them; the array frame 2 includes a plurality of vertically arranged grid plates 20; the grid plates 20 divide the inner cavity of the surface panel into a plurality of installation cavities 21;

[0037] The sound absorbing unit array includes sound absorbing units sequentially arranged in each installation cavity 21;

[0038] The sound absorbing unit includes a cladding layer, a sound absorbing core layer 4 and a mass distribution structure arranged in the sound absorbing core layer 4;

[0039] The sound-absorbing core layer 4 fills the installation cavity 21, and the cladding layer is arranged between the sound-absorbing core layer 4 and the inner wall of the installation cavity 21. A plurality of tower-shaped sound-absorbing cavities are evenly arranged in the sound-absorbing core layer 4. The tower-shaped sound-absorbing cavities are composed of three combined cavities arranged coaxially along the vertical axis. The combined cavity is composed of a cylindrical cavity 40 at the top and a frustum cavity 41 at the bottom.

[0040] The diameter of the cylindrical cavity 40 is consistent with the diameter of the cone top of the frustum cavity 41; adjacent combined cavities are connected by the cylindrical cavity 40; the thickness of the coating layer on the top of the cylindrical cavity 40 is not less than 2 mm; the cone bottom of the frustum cavity 41 at the bottom of the combined cavity passes through the bottom of the sound-absorbing core layer 4 to form a sound-transmitting opening 41a;

[0041] The mass distribution structure is composed of an inner ring 30, an outer ring 31, and a free ring 32;

[0042] The inner ring 30 and the outer ring 31 are arranged between two adjacent combined cavities; the inner diameter of the inner ring 30 is consistent with the diameter of the cylindrical cavity 40 adjacent to its lower side and is arranged opposite to it; the outer diameter of the inner ring 30 is smaller than the cone bottom diameter of the frustum cavity 41 adjacent to its upper side; the inner diameter of the outer ring 31 is consistent with the cone bottom diameter of the frustum cavity 41 adjacent to its upper side and is arranged opposite to it; the free rings 32 are evenly arranged between each outer ring 31.

[0043] In this application, the surface composite material is mainly used to bear water pressure, so that the compression deformation of the structure under deep water pressure load is reduced. At the same time, the physical and chemical properties of the composite material are easy to control. By matching it with the impedance of water, sound waves can pass through the composite material layer more smoothly and enter the interior of the sound-absorbing structure.

[0044] The sound-absorbing core material is a mixture of polymer viscoelastic resin, hollow glass microspheres and flexible additives. After the sound wave enters the sound-absorbing core material, the sound wave energy is converted into material heat for dissipation, thereby suppressing the reflection and projection of the sound wave. Due to the low strength and modulus of the sound-absorbing core material itself, in order to solve the problem of rapid decline in sound absorption performance caused by deformation under high pressure load, a tower-shaped sound-absorbing cavity and a mass distribution structure are specially set up. The sound transmission and reflection of the tower-shaped sound-absorbing cavity structure are utilized to evenly distribute the sound waves to the inside of the sound-absorbing core material, so that it can penetrate more stably and smoothly. The mass distribution structure utilizes the difference in density between the high-density mass ring and the sound-absorbing material to increase the oscillation loss of the sound wave when it is transmitted between the materials, thereby achieving sound absorption and noise reduction.

[0045] To ensure uniform distribution of pressure bearing and sound absorption performance in different areas of the underwater lightweight pressure-resistant sound-absorbing grid array structure, the grid plates 20 are perpendicular to each other and divide the inner cavity of the surface panel into several cubic installation cavities of uniform size.

[0046] In order to further improve the adaptability to water environment and improve the structural performance, in this embodiment, the array frame 2 and the sound absorbing core layer 4 are made of polyurethane damping sound absorbing material with a density of 900~1000 , hydrostatic compressive strength 1~2 , the linear elastic strain range is 0~0.3; the plastic section strain range is 0.3~0.5; the array frame 2 is made by RTM vacuum forming process; the surface panel 1 and the covering layer are obtained by wet winding forming process; the winding angle during the processing is 10°~30°, and the design tension is 5~35N; the reinforcing fiber used in the processing technology is glass fiber or aramid fiber, and the resin matrix uses polyester resin or vinyl ester resin. The fiber-resin mass ratio is in the range of 0.8~1.5. Combined with the above-mentioned process structure design and acoustic layout scheme, the overall design can be further optimized and the pressure resistance and sound absorption performance of the overall structure can be improved.

[0047] In actual implementation, the surface panel 1 adopts an upper and lower stacking design and is glued and composited with the array frame 2 to form a high-strength wave-transparent grid structure. Finally, the RTM vacuum forming process is used to solidify and form it as a whole at room temperature to ensure the integrity of the composite interface performance between the surface panel 1 and the array frame 2 and the integrity of the array frame 2.

[0048] In order to optimize the structure, the following preferred size structure is adopted during implementation: the thickness H1 of the cylindrical cavity 40: the thickness H2 of the frustum cavity 41: the thickness H3 of the mass distribution structure = 1~1.5: 1.5~2: 1~1.5; the ratio of the thickness of the upper panel 10 and the lower panel 11 to the thickness of the grid plate 20 is in the range of 0.05~0.10.

[0049] The ratio of the thickness of the high-strength wave-transmitting material grid to the central axis spacing of adjacent lightweight pressure-resistant sound-absorbing material multi-layer array structural units ranges from 0.02 to 0.05.

[0050] In order to ensure that the sound absorption performance, pressure bearing capacity and center distribution of the array structure in each direction based on each area are more uniform and reasonable, the tower-shaped sound absorption cavity and the mass distribution structure should be evenly distributed inside the sound absorption core layer 4. In this embodiment, the tower-shaped sound absorption cavity is evenly arranged in a ring array or a rectangular array.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An underwater lightweight, pressure-resistant, sound-absorbing grid array structure, characterized in that: including an array frame and a sound absorbing unit array; The array frame is composed of a surface panel (1) and an array frame (2); The surface panel (1) includes an upper panel (10) and a lower panel (11) that are arranged parallel to each other and side panels (12) around them; the array frame (2) includes a plurality of grid plates (20) that are arranged vertically; the grid plates (20) divide the inner cavity of the surface panel (1) into a plurality of installation cavities (21); The sound absorbing unit array comprises sound absorbing units sequentially arranged in each installation cavity (21); The sound absorbing unit comprises a cladding layer, a sound absorbing core layer (4), and a mass distribution structure arranged in the sound absorbing core layer (4); The sound absorbing core layer (4) fills the installation cavity (21), and the cladding layer is arranged between the sound absorbing core layer (4) and the inner wall of the installation cavity (21); a plurality of tower-shaped sound absorbing cavities are evenly arranged in the sound absorbing core layer (4); the tower-shaped sound absorbing cavity is composed of three combined cavities arranged coaxially in a vertical direction; the combined cavity is composed of a cylindrical cavity (40) at the top and a frustum cavity (41) at the bottom; The diameter of the cylindrical cavity (40) is consistent with the diameter of the cone top of the frustum cavity (41); adjacent combined cavities are connected by the cylindrical cavity (40); the thickness of the coating layer at the top of the cylindrical cavity (40) is not less than 2 mm; the cone bottom of the frustum cavity (41) at the bottom of the combined cavity passes through the bottom of the sound-absorbing core layer (4) to form a sound-permeable opening (41a); The mass distribution structure is composed of an inner ring (30), an outer ring (31), and a free ring (32); The inner ring (30) and the outer ring (31) are arranged between two adjacent combined cavities; the inner diameter of the inner ring (30) is consistent with the diameter of the cylindrical cavity (40) adjacent to the lower side thereof and is arranged opposite to the inner ring (30); the outer diameter of the inner ring (30) is smaller than the cone bottom diameter of the frustum cavity (41) adjacent to the upper side thereof; the inner diameter of the outer ring (31) is consistent with the cone bottom diameter of the frustum cavity (41) adjacent to the upper side thereof and is arranged opposite to the inner ring (32); and the free rings (32) are evenly arranged between the outer rings (31).

2. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The grid plates (20) are perpendicular to each other and divide the inner cavity of the surface panel (1) into a plurality of cubic installation cavities of uniform size.

3. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The thickness of the grid plate (20) is much greater than the thickness of the upper panel (10) and the lower panel (11); the cladding layer is evenly coated on the surface of the sound-absorbing core layer (4), and the thickness of the cladding layer is much smaller than the size of the sound-absorbing core layer (4).

4. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The thickness H1 of the cylindrical cavity (40): the thickness H2 of the frustum cavity (41): the thickness H3 of the mass distribution structure=1~1.5:1.5~2:1~1.

5.

5. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The inner ring (30), the outer ring (31), and the free ring (32) are made of steel.

6. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The tower-shaped sound-absorbing cavities are evenly arranged in a circular array or a rectangular array.

7. The underwater lightweight pressure-resistant sound-absorbing grid array structure according to claim 1, characterized in that: The array frame (2) and the sound absorbing core layer (4) are made of polyurethane damping sound absorbing material with a density of 900-1000 , hydrostatic compressive strength 1~2 , the linear elastic strain range is 0~0.3; the plastic section strain range is 0.3~0.5; the array frame (2) is made by RTM vacuum forming process; The surface panel (1) and the covering layer are obtained by a wet winding molding process; during the process, the winding angle is 10° to 30°, the winding thickness is 1 to 2 mm, and the tension is 5 to 35 N; the reinforcing fiber used in the process is glass fiber or aramid fiber, the resin matrix is polyester resin or vinyl ester resin, and the fiber-resin mass ratio is within the content range of 0.8 to 1.5.

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