Foam-filled three-period extremely-small-curved-surface porous structure sandwich panel and preparation method thereof
By using foam-filled, three-cycle, minimally curved, porous sandwich panels and 3D printing technology to form a single unit, the impact risk and lightweight requirements of aerospace vehicles during high-speed flight are solved, achieving excellent load-bearing performance and efficient energy absorption.
Patent Information
- Application Number
- CN202511544861.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-28
- Publication Date
- 2026-01-16
AI Technical Summary
In existing technologies, aerospace vehicles are at high risk of being impacted by sand, gravel, rain, snow, etc. during high-speed flight, and the need for lightweighting has not been effectively addressed. Porous structure designs are difficult to achieve excellent load-bearing performance and efficient energy absorption.
A sandwich panel with a three-period minimal curved surface porous structure filled with foam is used. The upper inner layer, lower inner layer and core are integrally formed by 3D printing technology. The core is composed of a three-period minimal curved surface porous structure cell array filled with foam material. The compressive strength of the outer layer is higher than that of the inner layer. By utilizing the contact coupling effect between the foam material and the minimal curved surface porous structure, the deformation mode of the sandwich panel is changed to absorb energy.
It improves the mechanical properties and energy absorption efficiency of sandwich panels, achieving excellent load-bearing performance and efficient energy absorption, and overcomes the problems of stress concentration and uneven force transmission at connection/contact positions in existing technologies.
Smart Images
Figure CN121340701A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of composite structure technology, and in particular to a foam-filled three-period minimal curved surface porous structure sandwich panel and its preparation method. Background Technology
[0002] With the rapid development of the aerospace field, aircraft are operating at increasingly higher speeds, which in turn increases the risk of impacts and collisions from sand, rain, snow, hail, and other elements. Furthermore, lightweighting is one of the core development requirements in the aerospace industry, aiming to improve fuel efficiency, payload capacity, and maneuverability by reducing the structural weight coefficient. The main approaches to achieving lightweighting include: material lightweighting (such as replacing metals with thermoplastic polymers), structural lightweighting (replacing solid structures with lattice structures), and process lightweighting (such as replacing modular assembly structures with fused polymer deposition modeling (FDM) integrated structures).
[0003] Polymer materials, with their excellent specific strength, high specific stiffness, and physical / chemical properties, combined with the design freedom and manufacturing flexibility of fused deposition modeling (FDM) additive manufacturing technology, can rapidly form fully functional and structurally complex porous lattice structures. This effectively reduces the number of components and design space while increasing structural design freedom, liberating the manufacturing process and design constraints of lattice structures, and achieving a high degree of synergistic optimization of materials, structure, and process. This provides a new solution for the design and application of lightweight, functionally integrated components under complex working conditions. In this application context, various lightweight load-bearing and energy-absorbing protective structures, such as porous metal / non-metal foams, honeycomb structures, and three-dimensional lattice structures, have been widely applied and have achieved significant economic and social benefits. Among these, foam materials have high porosity, while honeycomb or three-dimensional lattice structures possess excellent load-bearing capacity. Combining these two materials achieves complementary advantages in mechanical properties, becoming a new approach for designing composite lightweight porous sandwich panels.
[0004] Inspired by biomimicry in nature, TriplyPeriodicMinimalSurfaces (TPMS) possess porous characteristics and are topologically smooth and interconnected. By modifying the implicit function expression parameters of TPMS, precise control over the size and shape of the pores can be achieved, resulting in different types of fully connected porous structures. For a long time, TPMS porous structures have not received sufficient attention due to their difficulty in manufacturing. However, with the rapid development of 3D printing technology, the large-scale manufacturing of TPMS porous structures is no longer an insurmountable obstacle. Furthermore, applying the mathematically superior topological properties of TPMS to the design of porous composite structures, utilizing its topologically smooth and interconnected characteristics to improve the smoothness and controllability of the load-bearing capacity of the composite porous sandwich panel, and fully leveraging the energy absorption enhancement effect of the interaction between the TPMS structural wall and the foam material during plastic deformation, achieves both lightweighting and improved energy absorption efficiency—a previously unmentioned approach in existing technologies. Summary of the Invention
[0005] This application provides a foam-filled three-period minimal curved surface porous structure sandwich panel and its preparation method. Foam material is filled into interconnected pores of three-period minimal curved surfaces to form a composite sandwich panel structure, which simultaneously possesses excellent load-bearing performance and high energy absorption efficiency.
[0006] In one aspect, this application provides a foam-filled three-period minimal curved surface porous structure sandwich panel, including an upper inner layer plate, a lower inner layer plate, a core, an upper outer layer plate, and a lower outer layer plate; The core is connected between the inner surfaces of the upper inner layer plate and the lower inner layer plate, and is integrally formed with the upper inner layer plate and the lower inner layer plate; the outer surface of the upper inner layer plate is connected to the upper outer layer plate, and the outer surface of the lower inner layer plate is connected to the lower outer layer plate; The core comprises a three-period minimal curved porous structure cell array filled with foam material; the compressive strength of the upper outer layer is greater than that of the upper inner layer; and the compressive strength of the lower outer layer is greater than that of the lower inner layer.
[0007] Furthermore, the core is integrally formed with the upper inner layer plate and the lower inner layer plate using 3D printing technology.
[0008] Furthermore, the dimensions of the upper outer layer are the same as those of the upper inner layer; the dimensions of the lower outer layer are the same as those of the lower inner layer.
[0009] Furthermore, the cell surface type of the three-period minimal surface porous structure cell array includes G surface, I surface, P surface or Z surface.
[0010] Furthermore, when the cell surface of the three-period minimal surface porous structure cell array is a G-surface, an I-surface, or a Z-surface, the foam material completely fills the inside and outside of each cell of the three-period minimal surface porous structure cell array.
[0011] Furthermore, when the cell surface of the three-period minimal surface porous structure cell array is a P-surface, the foam material only fills the interior of the cell wall of each cell in the three-period minimal surface porous structure cell array.
[0012] Furthermore, the matrix material of the foam material includes polyurethane, cement, or polyvinyl chloride; the relative density of the foam material is between 20 kg / m³. 3 Up to 300kg / m 3 between.
[0013] Furthermore, the materials of the upper outer layer and the lower outer layer are polymers or composite materials.
[0014] Secondly, this application provides a method for preparing the foam-filled three-period minimal curved surface porous structure sandwich panel as described above, comprising: A three-dimensional geometric model of a three-period minimal surface porous cell array and its upper and lower inner layers was constructed using 3D modeling software. The three-dimensional geometric model is converted into a 3D printing execution format file and the edges of the three-dimensional geometric model are trimmed. The three-period minimal surface porous structure cell array and upper inner layer plate and lower inner layer plate are generated in one piece by 3D printing. A three-period minimal surface porous structure cell array is filled with foam material to make an upper outer layer plate and a lower outer layer plate. The upper outer layer plate is connected to the upper inner layer plate, and the lower outer layer plate is connected to the lower inner layer plate to obtain a foam-filled three-period minimal surface porous structure sandwich panel.
[0015] Furthermore, the 3D printing molding method includes fused deposition modeling and selective laser sintering, and the constituent materials are polymers or composite materials.
[0016] The above-mentioned technical solution of this application has the following advantages: This application provides a foam-filled three-period minimally curved porous structure sandwich panel and its preparation method. When subjected to external impact and compressive loads, the foam-filled three-period minimally curved porous structure sandwich panel alters the overall deformation mode of the sandwich panel due to the contact coupling between the foam filling material and the minimally curved porous structure. The foam-filled three-period minimally curved porous composite structure absorbs energy through the fracture deformation of the minimally curved lattice structure and the elastic deformation of the filled polyurethane foam. This results in a significant improvement in the mechanical properties of the foam-filled three-period minimally curved porous composite structure compared to hollow minimally curved porous structures. Compared to existing lattice or honeycomb structures, the minimally curved porous structure exhibits macroscopic isotropy, leveraging the energy absorption enhancement effect of the interaction between the bending of the porous structure wall and the compression of the foam material during plastic deformation. This gives it both excellent load-bearing capacity and high energy absorption efficiency. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 A schematic diagram of the multi-configuration minimal surface lattice structure provided in the embodiments of this application; Figure 2 This is a schematic diagram of the foam filling of a minimal curved surface lattice structure provided in an embodiment of this application; Figure 3 This is a schematic diagram of the TPMS-Gyroid surface and lattice structure provided in an embodiment of this application; Figure 4 Schematic diagrams of TPMS-Gyroid lattice structures with different numbers of unit cells and wall thicknesses provided for embodiments of this application; Figure 5 Comparison of mass and stress-strain curves for thin-walled lattices, rod-shaped lattices, and foam-filled thin-walled lattices provided in the embodiments of this application. Detailed Implementation
[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.
[0020] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.
[0021] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0023] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.
[0024] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.
[0025] This application provides a foam-filled three-period minimal curved surface porous structure sandwich panel, including an upper inner layer, a lower inner layer, a core, an upper outer layer, and a lower outer layer. The core is connected between the inner surfaces of the upper inner layer and the lower inner layer and is integrally formed with the upper inner layer and the lower inner layer. The outer surface of the upper inner layer is connected to the upper outer layer, and the outer surface of the lower inner layer is connected to the lower outer layer. The core includes a three-period minimal curved surface porous structure cell array filled with foam material. The compressive strength of the upper outer layer is greater than that of the upper inner layer, and the compressive strength of the lower outer layer is greater than that of the lower inner layer.
[0026] When a foam-filled three-period minimally curved porous structure sandwich panel is subjected to external impact and compressive loads, the contact coupling between the foam filler material and the minimally curved porous structure alters the overall deformation mode of the sandwich panel. The foam-filled three-period minimally curved porous composite structure absorbs energy through the fracture deformation of the minimally curved lattice structure and the elastic deformation of the filled polyurethane foam. This results in significantly improved mechanical properties compared to hollow minimally curved porous structures. Compared to existing lattice or honeycomb structures, the minimally curved porous structure exhibits macroscopic isotropy, leveraging the energy absorption enhancement effect of the interaction between the bending of the porous structure wall and the compression of the foam material during plastic deformation. This gives it both excellent load-bearing capacity and high energy absorption efficiency.
[0027] In some embodiments, the core is integrally formed with the upper inner layer plate and the lower inner layer plate using 3D printing technology.
[0028] In some embodiments, the dimensions of the upper outer layer are the same as the dimensions of the upper inner layer; the dimensions of the lower outer layer are the same as the dimensions of the lower inner layer.
[0029] In some embodiments, the cell surface type of the three-period minimal surface porous structure cell array includes G surface, I surface, P surface or Z surface.
[0030] In some embodiments, when the cell surface of the three-period minimal surface porous structure cell array is a G-surface, an I-surface, or a Z-surface, the foam material completely fills the inside and outside of each cell of the three-period minimal surface porous structure cell array.
[0031] In some embodiments, when the cell surface of the three-period minimal surface porous structure cell array is a P-surface, the foam material is only filled inside the cell wall of each cell in the three-period minimal surface porous structure cell array.
[0032] In some embodiments, the matrix material of the foam material includes polyurethane, cement, or polyvinyl chloride; the relative density of the foam material is between 20 kg / m³. 3 Up to 300kg / m 3 between.
[0033] In some embodiments, the upper outer layer and the lower outer layer are made of polymer or composite materials.
[0034] This application provides a foam-filled three-period minimal curved surface porous structure sandwich panel, including an upper inner layer, a lower inner layer, a core integrally formed with the two layers, an upper outer layer, and a lower outer layer. The core includes foam material and a three-period minimal curved surface porous structure cell array. The foam material fills the three-period minimal curved surface porous structure cell array. The integral forming means that the upper inner layer, the lower inner layer, and the three-period minimal curved surface porous structure cell array are integrally formed using 3D printing technology. The outer surface of the upper inner layer is connected to the upper outer layer with a size matching it, and the outer surface of the lower inner layer is connected to the lower outer layer with a size matching it. The compressive strength of the upper outer layer is greater than that of the upper inner layer, and the compressive strength of the lower outer layer is greater than that of the lower inner layer.
[0035] like Figure 1 As shown, the cell element surface of the three-period minimal surface porous structure is a G-surface, I-surface, P-surface, or Z-surface, or other minimal surface lattice structures. When the cell element surface of the three-period minimal surface porous structure is a P-surface, the foam material only fills the interior of the cell wall of the three-period minimal surface porous structure. The matrix material of the foam material includes polyurethane, cement, or polyvinyl chloride; the relative density of the foam material is between 20 kg / m³. 3 Up to 300kg / m 3 The density of the foam material is directly proportional to the impact strength that the foam material-filled three-period minimal curved porous sandwich panel needs to withstand.
[0036] This application also provides a method for preparing a foam-filled three-period minimal curved surface porous structure sandwich panel as described above, comprising: constructing a three-dimensional geometric model of a three-period minimal curved surface porous structure cell array and an upper inner layer plate and a lower inner layer plate using three-dimensional modeling software; converting the three-dimensional geometric model into a 3D printing executable format file and trimming the edges of the three-dimensional geometric model; integrally generating the three-period minimal curved surface porous structure cell array and the upper inner layer plate and the lower inner layer plate using a 3D printing molding method; filling the three-period minimal curved surface porous structure cell array with foam material to fabricate an upper outer layer plate and a lower outer layer plate; connecting the upper outer layer plate to the upper inner layer plate and connecting the lower outer layer plate to the lower inner layer plate to obtain a foam-filled three-period minimal curved surface porous structure sandwich panel. A schematic diagram of the minimal curved surface lattice structure foam filling is shown below. Figure 2 As shown.
[0037] In some embodiments, the 3D printing method includes fused deposition modeling and selective laser sintering, and the constituent materials are polymers or composite materials.
[0038] A method for fabricating a foam-filled three-period minimal surface porous structure sandwich panel includes: generating a cloud model of a three-period minimal surface porous structure cell array; constructing a three-dimensional geometric model of the core and its connected upper and lower inner layers, satisfying the core's external dimensions and the characteristic parameters of the three-period minimal surface porous structure cell structure, using 3D modeling software; converting the established 3D geometric model into a 3D printing executable format file and trimming the edges of the 3D geometric model; and then using 3D printing to integrally generate the core and the upper and lower inner layers.
[0039] A foam of a certain relative density is obtained and filled into a three-period minimal curved porous structure cell array to form a foam-filled core. Two plates with lengths and widths consistent with the upper and lower inner layers are fabricated as the upper and lower outer layers, respectively. The upper outer layer is connected to the upper inner layer, and the lower outer layer is connected to the lower inner layer to obtain a foam-filled three-period minimal curved porous structure sandwich panel. The compressive strength of the upper outer layer is greater than that of the upper inner layer, and the compressive strength of the lower outer layer is greater than that of the lower inner layer.
[0040] The characteristic parameters of the three-period minimal surface porous structure include the minimum surface cell size and the minimum surface wall thickness. 3D printing methods include fused deposition modeling (FDM) and selective laser sintering (SLS). The 3D printing components are polymers or composite materials, including nylon, PLA, and TPU. The upper and lower outer layers are composed of polymers or composite materials, such as carbon fiber composites, glass fiber composites, and hemp fiber composites. If non-metallic plates are present between the upper and lower outer layers and the upper and lower inner layers, they are connected using adhesive bonding.
[0041] The following is a description through specific embodiments.
[0042] Example Preliminary structural design: Based on the implicit functions of the TPMS-Gyroid lattice structure and using MATLAB software for programming and calculation, the design and modeling of Gyroid cubes with different wall thicknesses and unit cell sizes were realized. The trigonometric function equations of the Gyroid surface are as follows: In the formula, ( x , y , z ) represents the spatial coordinates of a specific point on the Gyroid surface; parameters c Determines the size of the unit cell; parameters tControlling the volume enclosed by the Gyroid surface, TPMS-Gyroid surface, such as Figure 3 As shown in (1), the Gyroid surface is a two-sided surface that divides space into two non-intersecting and interwoven subspaces. By giving the Gyroid surface a certain thickness, a solidified thin-walled lattice structure is formed, such as... Figure 3 As shown in (2)~(3). The trigonometric function equations of the TPMS-Gyroid lattice structure are as follows: Large-size TPMS-Gyroid lattice structures can be used in x , y and z The Gyroid units are repeated in the same direction to construct the structure. Based on the above equations, TPMS-Gyroid lattice structures with different numbers of unit cells and wall thicknesses are designed as follows: Figure 4 As shown.
[0043] Compression characteristics and energy absorption analysis: Samples with different geometries exhibit similar four-stage mechanical responses, but their overall mechanical properties differ. The first stage is the elastic deformation stage, where stress increases linearly with increasing strain, and the slope represents the compressive modulus. The second stage is the elastoplastic deformation stage, starting from the point where the stress-strain curve deviates from the linear response. The nominal yield strength is defined as the stress at which the stress-strain curve deviates 0.2% from the linear elastic region under axial loading. In the elastoplastic deformation stage, stress increases non-linearly with increasing strain until it reaches the maximum stress, i.e., the ultimate strength. After reaching the ultimate strength, the stress-strain curve gradually decreases in stress after a brief yield plateau period, entering the third stage, i.e., a long plateau region of stress fluctuation.
[0044] Finally, most of the thin walls in the TPMS-Gyroid lattice structure are broken and compressed together, and the stress-strain curve enters the densification stage. The stress increases sharply with increasing strain, entering a region of rapid stress rise. Different deformation mechanisms exist in each stage. In the initial loading stage, the inclined walls in the unit cell begin to bend under pressure, while the vertical walls begin to tensile and compressive deformation, with the whole structure in a linear elastic deformation stage. When a certain critical stress is reached, the walls begin to yield and undergo local collapse or even fracture due to plastic deformation. Ultimately, the contact and accumulation of different walls make the overall structural region denser, leading to a rapid rise in the stress-strain curve.
[0045] Foam-filled composite structure: Two types of polyurethane foaming agents are quickly poured into a covered container, stirred rapidly for 3-5 seconds, and then a 3D printed part containing a porous structure with extremely small curved surfaces is quickly placed inside and the container is covered. During this process, a relative density of 100 kg / m³ is obtained. 3The foam material is used, and the pressure formed in the container after foaming is used to make the foam material fully and evenly fill the micro-curved porous structure. After the foam material is fully shaped for about 5 minutes, the excess foam on the four sides of the porous structure is removed to form a polyurethane foam-filled G-type three-dimensional periodic micro-curved porous structure core.
[0046] A comparison of the mass and stress-strain curves of thin-walled lattices, rod-shaped lattices, and foam-filled thin-walled lattices is shown in the figure below. Figure 5 As shown in the figure. The results indicate that under quasi-static compressive load from the outside of the panel, the contact coupling between the foam filling material and the micro-surface porous structure alters the deformation mode of the overall sandwich panel structure. This results in a significant improvement in the mechanical properties of the foam-filled three-period micro-surface porous composite structure compared to the hollow micro-surface porous structure. Compared to the lattice structure or honeycomb structure in the prior art, the micro-surface porous structure exhibits macroscopic isotropy and can leverage the energy absorption enhancement effect of the interaction between the wall bending and foam material compression during plastic deformation.
[0047] Compared to existing lattice or honeycomb structures, the micro-curved porous structure exhibits macroscopic isotropy, facilitating optimal load-bearing capacity under oblique loads. The sandwich panels are all double-layered, with the outer and inner layers connected. The inner layer is integrally printed and fused with the micro-curved porous structure within the core, overcoming stress concentration and uneven force transmission at connection / contact points. This allows for uniform force distribution to each cell and also facilitates optimized configuration of materials and thicknesses for both the inner and outer layers.
[0048] The outer panel has a higher compressive strength than the inner panel. When subjected to external impact, the outer panel possesses a certain load-bearing capacity and resistance to impact deformation, effectively maintaining its shape and distributing the force to the inner panel, thus preventing localized collapse and crushing. This is particularly evident under oblique loads. There are various types of three-period minimal surfaces. Based on stress simulation, this application selected four surface types: P-type, G-type, I-type, and Z-type. These surface types exhibit uniform deformation under load, meeting the basic requirements for energy absorption.
[0049] For G-type, I-type, and Z-type surfaces, the foam completely fills the inside and outside of each cell of the three-period minimal surface porous structure. For the P-type inner surface, the foam only fills the inside of each cell of the three-period minimal surface porous structure (formed by removing excess foam from the outside of the cell). This incomplete filling method can bring excellent energy absorption and lightweight effect. This is because incomplete filling provides space for the deformation of the cell wall, allowing the cell wall to deform in the best energy absorption way. In addition, the movement of the foam is restricted by the cell wall, the upper and lower inner plates, and the surrounding structure. The energy absorption effect is similar to that of complete filling, but it has the effect of lightweight compared to complete filling.
[0050] This application also discloses a method for preparing a foam-filled three-period minimal curved surface porous structure sandwich panel. The topological smoothness and controllability of the minimal curved surface structure give the foam-filled three-period minimal curved surface porous structure sandwich panel strong design flexibility. Utilizing 3D printing rapid prototyping technology and the topological connectivity characteristics of the minimal curved surface itself, the steps of preparing the minimal curved surface porous structure in the core and filling the internal foam are simplified, saving a significant amount of manpower and time. This application embodiment allows selection of the foam density based on the required impact velocity. Different foam densities can be applied to different impact velocity scenarios; high-density foam cores can be used for high impact velocities, while low-density foams can be used for lower impact velocities.
[0051] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.
[0052] It should be clarified that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. This application is not limited to the specific structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.
[0053] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A foam-filled tri-periodic minimal surface porous structure sandwich panel, characterized in that, The sandwich panel comprises an upper inner layer, a lower inner layer, a core, an upper outer layer and a lower outer layer. The core is connected between the inner surfaces of the upper inner layer and the lower inner layer and is integrally formed with the upper inner layer and the lower inner layer; the outer surface of the upper inner layer is connected with the upper outer layer, and the outer surface of the lower inner layer is connected with the lower outer layer. The core comprises an array of three-period minimal surface porous structure cells filled with a foamed material; the compressive strength of the upper outer layer is greater than that of the upper inner layer; and the compressive strength of the lower outer layer is greater than that of the lower inner layer.
2. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 1, wherein, The core, the upper inner layer and the lower inner layer are integrally formed by using a 3D printing technology.
3. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 1, wherein, The size of the upper outer layer is the same as that of the upper inner layer; and the size of the lower outer layer is the same as that of the lower inner layer.
4. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 1, wherein, The cell surface type of the array of three-period minimal surface porous structure cells comprises G surface, I surface, P surface or Z surface.
5. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 4, wherein, When the cell surface of the array of three-period minimal surface porous structure cells is G surface, I surface or Z surface, the foamed material is completely filled in and out of each cell of the array of three-period minimal surface porous structure cells.
6. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 4, wherein, When the cell surface of the array of three-period minimal surface porous structure cells is P surface, the foamed material is only filled in the cell wall of each cell of the array of three-period minimal surface porous structure cells.
7. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 1, wherein, The matrix material of the foam material comprises polyurethane, cement or polyvinyl chloride; the relative density of the foam material is between 20 kg / m 3 and 300 kg / m 3 .
8. The foam-filled tri-periodic minimal surface porous structure sandwich panel of claim 1, wherein, The materials of the upper outer layer and the lower outer layer are polymers or composite materials.
9. A method of making a foam-filled tri-periodic minimal surface porous structure sandwich panel according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: constructing a three-dimensional geometric model of the array of three-period minimal surface porous structure cells, the upper inner layer and the lower inner layer by using a three-dimensional modeling software; converting the three-dimensional geometric model into a 3D printing execution format file and performing edge cutting processing on the three-dimensional geometric model, and integrally generating the array of three-period minimal surface porous structure cells, the upper inner layer and the lower inner layer by using a 3D printing forming mode; filling the array of three-period minimal surface porous structure cells with a foamed material, manufacturing the upper outer layer and the lower outer layer, connecting the upper outer layer with the upper inner layer, connecting the lower outer layer with the lower inner layer, and obtaining a foamed filling three-period minimal surface porous sandwich panel.
10. The method for preparing a foam-filled three-period minimal curved surface porous sandwich panel as described in claim 9, characterized in that, The 3D printing forming mode comprises fused deposition manufacturing and laser selective sintering, and the constituent material is a high polymer or a composite material.