Broadband anti-sound double-lattice structure based on additive manufacturing as well as preparation method and application of broadband anti-sound double-lattice structure

Abstract

The invention discloses a broadband anti-sound double-lattice structure based on additive manufacturing and a manufacturing method and application thereof, and belongs to the technical field of additive manufacturing of lattice metal. The structure is formed by connecting a three-period minimal curved surface Gyandroid structure and a Spit-P structure in series and is integrally generated by adopting a parameterized modeling method, the two structures are gradually transited and smoothly regulated and controlled through a Ramp function, and the two structures are mutually compensated in acoustic response by controlling the structure parameters of the two three-period minimal curved surface lattice structures and adopting a series coupling design, so that the acoustic response of the Gyandroid structure and the Spit-P structure is enhanced, and the acoustic response of the Gyandroid structure and the Spit-P structure is enhanced. The problem that a single structure has a band gap is solved through series connection of the two structures, and the average anti-sound coefficient larger than 0.6 is achieved within the broadband of 50-4000 Hz underwater. The adopted material is 316L stainless steel, the adopted manufacturing mode is selective laser melting and welding, high-precision preparation of the double-lattice structure is achieved by optimizing double-structure transition area additive manufacturing printing process parameters, and the manufacturing method is suitable for unmanned underwater vehicles and sonar structure sound baffles.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology for lattice metals, specifically relating to a broadband anti-acoustic dual-lattice structure based on additive manufacturing, its manufacturing method, and its application. Background Technology

[0002] Additive manufacturing, also known as rapid prototyping, 3D printing, and freeform manufacturing, is a technology that directly constructs three-dimensional objects from computer-aided design models by depositing, solidifying, and joining materials, enabling rapid part manufacturing without additional cumbersome processing steps. Compared to traditional manufacturing methods such as machining and casting, additive manufacturing systems exhibit higher efficiency and flexibility in production, providing a completely new perspective on part design and material processing.

[0003] Lattice structures are a class of artificially designed periodic structures whose unique periodic arrangement gives them many unique properties. By designing and adjusting the cell structure and porosity, effective performance control can be achieved. They have attracted widespread attention in fields such as mechanics, electromagnetics, optics, and acoustics, and are considered one of the most promising next-generation lightweight multifunctional materials. In recent years, lattice structure design has generally focused on improving material performance, and the development of multifunctional lattice structures has become an increasingly important trend.

[0004] Acoustic baffles are a key component of underwater sonar systems, requiring pressure resistance and acoustic reflectivity. In hydrophone arrays, they function to shield noise, isolate vibrations, decouple, reflect sound, or absorb sound waves, improving the directivity and signal gain of the hydrophones. To reflect incident sound waves as much as possible, acoustic baffles must have a significant impedance mismatch with water and minimal sound attenuation. For the application of acoustic reflectors in underwater acoustics, materials with a significant impedance mismatch with water are typically used. Due to the significant impedance mismatch between air and water, air is an ideal acoustic reflector, especially for low frequencies, where large air cavity baffles offer significant advantages. However, in early applications of acoustic reflectors, the air cavity enclosed by steel plates was prone to deformation under high hydrostatic pressure and was difficult to recover, limiting its application. Internal reinforcement altered the cavity structure, but this narrowed the operating bandwidth. Currently, acoustic reflectors are generally made of materials such as rubber and polyurethane foam. These materials can withstand a certain amount of pressure through pre-compression and other means, but their load-bearing capacity is limited. Under extreme environmental conditions such as deep-sea high pressure, these acoustic reflectors are prone to deformation or even damage to their internal structure, resulting in failure, affecting their acoustic performance, and seriously hindering underwater information transmission.

[0005] Developing broadband acoustic reflective lattice structures through lattice design holds great potential. However, the inherent bandgap characteristic of lattice structures makes their acoustic performance highly unstable. Therefore, it is necessary to artificially design solutions to address the bandgap issue and meet broadband acoustic reflective requirements. Series connection is a preferred method, but the interfaces between different lattice structures occupy spatial coordinates. Traditional Boolean connections typically require large Boolean radii, increasing redundancy and potentially hindering the structure's functional performance. Furthermore, post-additive manufacturing powder cleaning is difficult, leading to powder blockage. Additionally, due to the complexity of lattice structures, incompatibility between upper and lower structures often results in hard connections, and printing in transition zones can lead to suspended designs and printing failures. Therefore, research is needed on series modeling and transition methods for lattice structures. Simultaneously, when using selective laser melting (SLM) technology to print lattice structures, the small-section, discontinuous nature of the printing process makes it prone to failure due to excessive power causing blade damage, while insufficient power results in inadequate mechanical properties. Therefore, additive manufacturing process optimization is required for lattice structures, especially for the transition regions of three-period minimal curved surface structures.

[0006] To address the above issues, this invention designs a broadband acoustic dual-lattice structure. The lattice structure is composed of a three-period minimal surface Gyroid and a Split-P structure connected in series. A ramp function is used to achieve a gradual transition and smooth control of the dual-lattice structure, resulting in severe impedance mismatch, thus achieving broadband acoustic reflection underwater from 50Hz to 4000Hz. This invention also develops a method for fabricating this broadband acoustic dual-lattice structure. By optimizing the additive manufacturing process and using different printing parameters in the transition and non-transition regions, problems such as printing failure, poor printing quality, and low density caused by the transition between the two lattice structures are solved. This achieves high-precision and efficient fabrication of a broadband acoustic dual-lattice structure based on additive manufacturing. Summary of the Invention

[0007] The purpose of this invention is to provide a broadband acoustic dual-lattice structure based on additive manufacturing, its fabrication method, and its application. One objective is to design an underwater dual-lattice structure with broadband acoustic reflection capabilities. This is achieved by designing two three-period minimal surfaces in series, using a parametric modeling method to generate an integrated structure. The two structures are progressively transitioned and smoothly controlled using a ramp function. By controlling the structural parameters of the two three-period minimal surface lattice structures, the average acoustic reflection coefficient is greater than 0.6 in a broadband frequency range of 50Hz to 4000Hz underwater. Another objective of this invention is to achieve high-precision and efficient integrated fabrication of the dual-lattice structure by optimizing the additive manufacturing process and the printing parameters of the structural transition zone.

[0008] To achieve the above objectives, the present invention employs the following technical solution: A broadband acoustic dual-array structure based on additive manufacturing is proposed. This structure consists of a three-period minimal surface structure (Gyroid structure) and a Split-P structure connected in series. The integrated design is achieved through parametric implicit modeling combined with Ramp function control. The outer surface of the structure is sealed with a skin. The average acoustic coefficient is greater than 0.6 in a broadband frequency range of 50Hz to 4000Hz underwater.

[0009] Furthermore, the parametric implicit modeling employs piecewise function control. This is achieved by solving the implicit function control equations for the Gyroid and Split-P structures, and using the Ramp function to realize the gradual transition and smooth control of the dual-structure lattice structure. The piecewise function for the integrated parametric implicit modeling design is as follows: in: Gyroid(x,y,z)=cos(x) sin(y) + cos(y) sin(z) + cos(z) sin(x) = 0, Split-P(x,y,z)=1.1 (sin(2x) cos(y) sin(z) + sin(2y) cos(z) sin(x)+sin (2z) cos(x) sin(y))-0.2 (cos(2x) cos(2y) + cos(2y) cos(2z)+cos(2z) cos(2x))- 0.4 (cos(2y)+cos(2z)+cos(2x))=0, Ramp(x,y,z)=k(z) Split-P(x,y,z)+(1-k(z)) Gyroid(x,y,z))=0, in ; h 1 The lowest point of the lattice structure z coordinate, h 4 The highest point of the lattice structure z coordinate, h2 For the transition zone structure in z Minimum value in direction, h 3 For the transition zone structure in z Maximum value in direction, k(z) for Ramp The parameterized transition equation of the function controls the absolute value of the slope of k(z) to be in the interval (0.025, 0.5).

[0010] Furthermore, the modeling steps for the structure are as follows: Step 1: Based on the unified parameterized implicit function control method, Gyroid and Split-P three-period minimal surface structural units with complementary acoustic characteristics are generated simultaneously through piecewise functions. The Ramp function is used to realize the gradual transition and smooth control between the two structural units.

[0011] Step 2: Add skin to the outer surface of the dual-lattice structure model after completing Step 1 for sealing, and finally form a dual-lattice structure model with wideband acoustic performance.

[0012] Furthermore, the unit cell sizes of the Gyroid structure and the Split-P structure are equal, and the thicknesses of the two structures are equal in the Z direction; the thickness of the bistructure composed of the two structures is greater than or equal to 40 mm, and the number of layers in each unit cell is at least 2; the porosity of the bilattice structure is controlled at 50%~90% respectively; and the unit cell size is 5 mm~20 mm.

[0013] Furthermore, the outer surface skin of the structure has a uniform thickness of 1~2mm.

[0014] A method for fabricating a broadband anti-acoustic dual-lattice structure based on additive manufacturing is disclosed, employing selective laser melting additive manufacturing and welding processes. The specific steps are as follows: Step 1: Obtain a 3D model file of a broadband anti-acoustic dual-array structure by constructing a 3D model, and perform process adaptability design on the 3D model to obtain a printable 3D model.

[0015] Step 2: The 3D model is sliced ​​using slicing software, and a broadband anti-acoustic dual-array structure, bottom and side skins are prepared using selective laser melting additive manufacturing process; the metal material used is 316L stainless steel powder with a particle size of 15μm~53μm. Set the range [ h 2 -0.1, h 3 +[0.1] is the transition zone for printing the structure, and the other zones are non-transition zones. Within the transition zone, a fine printing strategy with low power and small layer thickness is adopted, with a laser power of 100W~150W, a scanning rate of 800mm / s~1200mm / s, a layer thickness of 0.02mm, a scanning angle of 67°, and a scanning interval of 80μm. In the non-transition zone, conventional printing parameters are used: laser power of 180W~260W, a scanning rate of 800mm / s~1200mm / s, a layer thickness of 0.03mm~0.05mm, a scanning angle of 45°~90°, and a scanning interval of 80μm~100μm.

[0016] Step 3: Clean the residual powder inside the additive manufacturing double lattice structure; perform heat treatment on the structure at a temperature of 1010℃~1150℃ for 30min~120min, followed by water cooling; after heat treatment, weld and seal the structure using 316L stainless steel of the same material to form a completely sealed structure.

[0017] An application of a broadband acoustic dual-array structure based on additive manufacturing, wherein the structure is applied to a broadband acoustic component of underwater equipment.

[0018] Beneficial effects of this invention: 1) Wideband acoustic reflection: To address the urgent need for wideband acoustic reflection structures underwater, this invention designs a three-period minimal surface Gyroid and a Split-P structure in series. The series coupling design allows the two structures to compensate for each other in acoustic response. By connecting the two structures in series, the limitations of the acoustic transmission frequency band of a single structure are overcome. Using a parametric modeling method, the two structures are gradually transitioned and smoothly controlled through the Ramp function. An average acoustic reflection coefficient greater than 0.6 is achieved in the wideband of 50Hz~4000Hz underwater.

[0019] 2) High-precision fabrication of dual-lattice structures: Since there is a printing transition region in the dual-lattice structure, the transition region is prone to printing risks, leading to printing failure. This invention optimizes the additive manufacturing process by using a low-power, small-layer-thickness strategy for printing the transition region of the dual-lattice structure, while using a large-layer-thickness strategy for printing the non-transition region. This solves the problems of printing failure, poor printing quality, and low density caused by the transition between the two lattice structures, achieving efficient and high-precision fabrication of dual-lattice structures and improving printing quality. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a cross-sectional view of the internal structure of the dual-lattice structure.

[0022] Figure 2 This is a diagram of the unsealed double-lattice structure at the top.

[0023] Figure 3 This is a diagram of a dual-lattice structure without transition.

[0024] Figure 4 This is a diagram of a dual-lattice structure after the function transition and smoothing.

[0025] Figure 5 The image shows the macroscopic morphology of the prepared dual-lattice structure.

[0026] Figure 6 The graph shows the variation of the acoustic performance of the dual-structure in Example 1 with frequency.

[0027] Figure 7 The graph shows the variation of the acoustic performance of the dual-structure in Example 2 with frequency.

[0028] Figure 8 The graph shows the variation of the acoustic performance of the dual-structure in Example 3 with frequency.

[0029] Figure 9 The graph shows the variation of the acoustic performance of the dual-structure in Example 4 with frequency.

[0030] Figure 10 The graph shows the variation of the acoustic performance of a single structure with frequency. Detailed Implementation

[0031] The preparation method of the present invention will be described in detail below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] Example 1 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has 4 units in the thickness direction, with a unit cell size of 5 mm. 5mm The internal double structure has a height of 40mm and a porosity of 90%. The porosity of the double lattice structure is 90%, h2 is 19, h3 is 21, and the slope of k(z) is 0.5. A smooth transition double structure model file is obtained by using parametric modeling method. Figure 3 These are the two structures before the transition. Figure 4 The structure is smoothed using a function transition and then sealed with a 1mm thick sealing skin, resulting in a reflective dual-lattice structure model. The 3D model is then designed for process adaptability to obtain a printable 3D model.

[0033] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is fabricated using selective laser melting additive manufacturing (SLM). The metal material used is 316L stainless steel. The transition zone of the dual-lattice structure is printed using a low-power, small-layer-thickness strategy: 150W power, 1200mm / s scanning rate, 0.02mm layer thickness, 67° scanning angle, and 80μm scanning interval. The non-transition zone uses 260W printing parameters: 1200mm / s scanning rate, 0.05mm layer thickness, 45° scanning angle, and 80μm scanning interval. The powder particle size for fabricating the anti-acoustic dual-lattice structure is 15~53μm.

[0034] Step 3: Clean the powder inside the lattice structure, heat treat at 1010℃ for 120 minutes, water cool, and seal by welding after heat treatment to form a double lattice structure.

[0035] The underwater test reflection coefficient results are as follows Figure 6 As shown, its average reflection coefficient is 0.85 in the range of 50~4000Hz.

[0036] Example 2 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has two units in the thickness direction, with a unit cell size of 10 mm. 10mm The internal double structure has a height of 40mm and a porosity of 80%, with h2 = 18 and h3 = 22. The k(z) control slope is 0.25. A parametric modeling method is used to obtain a smoothly transitioned double structure model file. It is then sealed with a 1.5mm thick sealing skin to obtain an anti-acoustic double lattice structure model. The 3D model is then designed for process adaptability to obtain a printable 3D model.

[0037] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is fabricated using selective laser melting additive manufacturing (SLM). The metal material used is 316L stainless steel. The transition zone of the dual-lattice structure is printed using a low-power, small-layer-thickness strategy: 130W power, 1000mm / s scanning rate, 0.02mm layer thickness, 67° scanning angle, and 80μm scanning interval. The non-transition zone uses 220W printing parameters: 1000mm / s scanning rate, 0.04mm layer thickness, 67° scanning angle, and 90μm scanning interval. The powder particle size for preparing the anti-acoustic dual-lattice structure is 15~53μm.

[0038] Step 3: Clean the powder inside the lattice structure, heat treat at 1070℃ for 60 minutes, water cool, and seal by welding after heat treatment to form a double lattice structure.

[0039] The underwater test reflection coefficient results are as follows Figure 7 As shown, its average reflection coefficient is 0.83 in the range of 50~4000Hz.

[0040] Example 3 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has two units in the thickness direction, with a unit cell size of 15 mm. 15mm The internal double structure has a height of 60mm and a porosity of 65%, with h2 = 27.5 and h3 = 32.5. A slope of k(z) of 0.2 was used to obtain a smoothly transitioned double structure model file using parametric modeling. A 2mm thick sealing layer was then applied to obtain a reflective double lattice structure model. Finally, the 3D model was designed for process adaptability to produce a printable 3D model.

[0041] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is fabricated using selective laser melting additive manufacturing (SLM). The metal material used is 316L stainless steel. The transition zone of the dual-lattice structure is printed using a low-power, small-layer-thickness strategy: 130W power, 1000mm / s scanning rate, 0.02mm layer thickness, 67° scanning angle, and 80μm scanning interval. The non-transition zone uses 220W printing parameters: 1000mm / s scanning rate, 0.04mm layer thickness, 67° scanning angle, and 90μm scanning interval. The powder particle size for preparing the anti-acoustic dual-lattice structure is 15~53μm.

[0042] Step 3: Clean the powder inside the lattice structure, heat treat at 1070℃ for 60 minutes, water cool, and seal by welding after heat treatment to form a double lattice structure.

[0043] The underwater test reflection coefficient results are as follows Figure 8 As shown, its average reflection coefficient is 0.83 in the range of 50~4000Hz.

[0044] Example 4 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has two units in the thickness direction, with a unit cell size of 20 mm. 20mm The internal double structure has a height of 60mm and a porosity of 50%, with h2 = 30 and h3 = 50. The k(z) control slope is 0.025. A parametric modeling method is used to obtain a smoothly transitioned double structure model file. It is then sealed with a 1mm thick sealing skin to obtain an anti-acoustic double lattice structure model. Process adaptability design is performed on the 3D model to obtain a printable 3D model.

[0045] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is fabricated using selective laser melting additive manufacturing (SLM). The metal material used is 316L stainless steel. The transition zone of the dual-lattice structure is printed using a low-power, small-layer-thickness strategy: 100W power, 1000mm / s scanning rate, 0.02mm layer thickness, 67° scanning angle, and 80μm scanning interval. The non-transition zone uses 180W printing parameters: 800mm / s scanning rate, 0.03mm layer thickness, 67° scanning angle, and 100μm scanning interval. The powder particle size for preparing the anti-acoustic dual-lattice structure is 15~53μm.

[0046] Step 3: Clean the powder inside the lattice structure, heat treat at 1150℃ for 30 minutes, water cool, and seal by welding after heat treatment to form a double lattice structure.

[0047] The underwater echo coefficient results are as follows Figure 9 As shown, its average reflection coefficient is 0.81 in the range of 50~4000Hz.

[0048] Comparative Example 1 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has two units in the thickness direction, with a unit cell size of 10 mm. 10mm The internal double structure has a height of 40mm and is 10mm thick. Without the transition method proposed in this invention, a double-structure model file is obtained. It is then sealed with a 1.5mm thick sealing skin, resulting in a reflective double-lattice structure model. The 3D model is then designed for process adaptability to obtain a printable 3D model.

[0049] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is then fabricated using selective laser melting additive manufacturing. The metal material used is 316L stainless steel, and the printing parameters are 220W, scanning rate of 1000mm / s, layer thickness of 0.04mm, scanning angle of 67°, and scanning interval of 90μm. The powder particle size used to fabricate the anti-acoustic dual-lattice structure is 15~53μm.

[0050] Printing failed due to a lack of interface transition; only the lower-level structure could be printed.

[0051] Comparative Example 2 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Simultaneously generate Gyroid and Split-P structures using implicit functions. Each structure has two units in the thickness direction, with a unit cell size of 10 mm. 10mm The internal double structure has a height of 40mm and a porosity of 80%, with h2 = 18 and h3 = 22. The k(z) control slope is 0.25. A parametric modeling method is used to obtain a smoothly transitioned double structure model file. It is then sealed with a 1.5mm thick sealing skin to obtain an anti-acoustic double lattice structure model. The 3D model is then designed for process adaptability to obtain a printable 3D model.

[0052] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is then fabricated using selective laser melting additive manufacturing. The metal material used is 316L stainless steel. The printing parameters for both the transition and non-transition regions are 220W, a scanning rate of 1000mm / s, a layer thickness of 0.04mm, a scanning angle of 67°, and a scanning interval of 90μm. The powder particle size used to prepare the anti-acoustic dual-lattice structure is 15~53μm.

[0053] The transition zone and non-transition zone use the same printing process parameters, which caused the printing to fail during the transition zone printing process.

[0054] Comparative Example 3 An anti-acoustic load-bearing dual-lattice structure and its preparation method are described below: Step 1: Generate a Gyroid structure using implicit function control. The height of the internal dual structure is 40mm, and the porosity of the dual-lattice structure is 90%. Seal it with a 1mm thick sealing skin to obtain an anti-acoustic dual-lattice structure model. Perform process adaptability design on the 3D model to obtain a printable 3D model.

[0055] Step 2: The 3D model of the lattice structure established in Step 1 is sliced ​​using slicing software. A dual-lattice structure is then fabricated using selective laser melting additive manufacturing. The metal material used is 316L stainless steel, and the printing parameters are 260W, scanning rate of 1200mm / s, layer thickness of 0.05mm, scanning angle of 45°, and scanning interval of 80μm. The powder particle size for fabricating the anti-acoustic dual-lattice structure is 15~53μm.

[0056] Step 3: Clean the powder inside the lattice structure, heat treat at 1010℃ for 120 minutes, water cool, and seal by welding after heat treatment.

[0057] The underwater test reflection coefficient results are as follows Figure 10 As shown, the results indicate that it does not possess broadband acoustic reflection performance. A cross-sectional view of the internal structure of the dual-array structure is shown below. Figure 1 The diagram of the unsealed double-lattice structure at the top is shown below. Figure 2 .

[0058] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A broadband anti-acoustic dual-array structure based on additive manufacturing, characterized in that, The structure is composed of two three-period minimal surface structures, the Gyroid structure and the Split-P structure, connected in series. It achieves integrated design through parametric implicit modeling combined with Ramp function control, and the outer surface of the structure is sealed with skin. The average acoustic reflection coefficient is greater than 0.6 in a wide frequency band of 50Hz to 4000Hz underwater.

2. The broadband anti-acoustic dual-array structure based on additive manufacturing as described in claim 1, characterized in that, The parametric implicit modeling employs piecewise function control. This is achieved by solving the implicit function control equations for the Gyroid and Split-P structures, and using the Ramp function to realize the gradual transition of the dual-structure lattice structure and smooth interface adjustment. The piecewise function for the integrated parametric implicit modeling design is as follows: in: Gyroid(x,y,z)=cos(x) sin(y) + cos(y) sin(z) + cos(z) sin(x) = 0, Split-P(x,y,z)=1.1 (sin(2x) cos(y) sin(z) + sin(2y) cos(z) sin(x) + sin(2z) cos(x) sin(y))-0.2 (cos(2x) cos(2y) + cos(2y) cos(2z)+cos(2z) cos(2x))-0.4 (cos(2y)+cos(2z)+cos(2x))=0, Ramp(x,y,z)=k(z) Split-P(x,y,z)+(1-k(z)) Gyroid(x,y,z))=0, in ； h 1 The lowest point of the lattice structure z coordinate, h 4 The highest point of the lattice structure z coordinate, h 2 For the transition zone structure in z Minimum value in direction, h 3 For the transition zone structure in z Maximum value in direction, k(z) for Ramp The parameterized transition equation of the function controls the absolute value of the slope of k(z) to be in the interval (0.025, 0.5).

3. The broadband anti-acoustic dual-array structure based on additive manufacturing according to claim 1, characterized in that, The modeling steps for the structure are as follows: Step 1: Based on the unified parameterized implicit function control method, Gyroid and Split-P three-period minimal surface structural units are generated simultaneously through piecewise functions, and the Ramp function is used to realize the gradual transition and smooth control between the two structural units. Step 2: Add skin to the outer surface of the dual-lattice structure model after completing Step 1 for sealing, and finally form a dual-lattice structure model with wideband acoustic performance.

4. The broadband anti-acoustic dual-array structure based on additive manufacturing according to claim 1, characterized in that, The unit cell sizes of the Gyroid structure and the Split-P structure are equal, and the thicknesses of the two structures are equal in the Z direction; the thickness of the bistructure composed of the two structures is greater than or equal to 40 mm and the number of layers in each unit cell is at least 2; the porosity of the bilattice structure is controlled at 50%~90%; and the unit cell size is 5 mm~20 mm.

5. A broadband anti-acoustic dual-array structure based on additive manufacturing as described in claim 1, characterized in that, The outer surface skin of the structure has a uniform thickness of 1~2mm.

6. A method for preparing a broadband anti-acoustic dual-array structure based on additive manufacturing according to any one of claims 1 to 5, characterized in that, The material is prepared using selective laser melting additive manufacturing and welding processes. The specific steps are as follows: Step 1: Obtain a 3D model file of a broadband anti-acoustic dual-array structure by constructing a 3D model, and perform process adaptability design on the 3D model to obtain a printable 3D model; Step 2: The 3D model is sliced ​​using slicing software, and a broadband anti-acoustic dual-array structure, bottom and side skins are prepared using selective laser melting additive manufacturing process; the metal material used is 316L stainless steel powder with a particle size of 15μm~53μm. Set the range [ h 2 -0.1, h 3 + [0.1] is the transition zone for printing the structure, and the other zones are non-transition zones. Within the transition zone, a fine printing strategy with low power and small layer thickness is adopted, with a laser power of 100~150W, a scanning rate of 800mm / s~1200mm / s, a layer thickness of 0.02mm, a scanning angle of 67°, and a scanning interval of 80μm. In the non-transition zone, conventional printing parameters are used: laser power of 180W~260W, a scanning rate of 800mm / s~1200mm / s, a layer thickness of 0.03mm~0.05mm, a scanning angle of 45°~90°, and a scanning interval of 80μm~100μm. Step 3: Clean the residual powder inside the additive manufacturing double lattice structure; perform heat treatment on the structure at a temperature of 1010℃~1150℃ for 30min~120min, followed by water cooling; after heat treatment, weld and seal the structure using 316L stainless steel of the same material to form a completely sealed structure.

7. An application of a broadband anti-acoustic dual-array structure based on additive manufacturing. According to claim 1, a broadband anti-acoustic dual-array structure based on additive manufacturing is characterized in that, The structure is applied to broadband acoustic components of underwater equipment.

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