3D printing metal-UHPGC composite corrugated sandwich plate structure

Abstract

The utility model discloses a kind of 3D printing metal-UHPGC composite corrugated sandwich panel structures, belong to metal structure protection material technical field.It includes integrally-formed 3D printing metal corrugated board, the corrugated board is formed by upper plate face, lower plate face and trapezoidal corrugated core layer between them, and UHPGC filler is filled in core layer.Metal corrugated board is integrally-formed by 316L stainless steel, trapezoidal core layer inclination 40°~60°, web side length 50~60mm.The structure is combined by 3D printing integration molding and UHPGC filling, improves the integrity and anti-penetration performance of composite corrugated sandwich panel structure, bullet residual speed reduces 25%, and low-carbon environmental protection, applicable to protection engineering field.

Description

Technical Field

[0001] This utility model relates to the field of metal structure protective materials technology, and in particular to a 3D printed metal-UHPGC composite corrugated sandwich panel structure. Background Technology

[0002] Metal sandwich panel structures, due to their advantages of high integrity, high rigidity, and outstanding performance, have been widely used in the field of blast and penetration resistance in protective engineering. Researchers have found that, compared with sinusoidal honeycomb panels, flat panels, and curved panels, corrugated panels have excellent energy absorption and ballistic deflection capabilities, exhibiting superior resistance to projectile penetration. However, ordinary hollow metal corrugated panels occupy a large volume due to their large corrugated cavities, resulting in low space utilization. Filling the corrugated core with a material can improve the overall structure's integrity, and the web of the corrugated core panel also provides additional constraint on the filling material, further enhancing the structural energy absorption performance of the metal corrugated sandwich panel structure under projectile penetration, making it an ideal structural form for resisting projectile penetration.

[0003] Ultra-high performance concrete (UHPC), utilizing the "maximum density theory" combined with fiber reinforcement technology, achieves superior mechanical properties and has proven highly effective in protective engineering, particularly in its impact resistance. Traditional corrugated metal sandwich panels suffer from low space utilization, insufficient structural integrity, and limited penetration resistance in hollow structures. Although attempts have been made to fill the corrugated core with concrete, the resulting corrugated sandwich panel structures still exhibit insufficient impact and erosion resistance. Utility Model Content

[0004] The purpose of this invention is to provide a 3D printed metal-UHPGC composite corrugated sandwich panel structure, which has the advantages of lightweight structure, high strength, impact resistance and penetration resistance.

[0005] To achieve the above objectives, this utility model provides a 3D printed metal-UHPGC composite corrugated sandwich panel structure, including a 3D printed metal corrugated plate, wherein the 3D printed metal corrugated plate is composed of an upper plate surface, a lower plate surface, and a trapezoidal corrugated core layer between the upper plate surface and the lower plate surface, and the trapezoidal corrugated core layer is filled with UHPGC.

[0006] Preferably, the dimensions of the 3D printed metal-UHPGC composite corrugated sandwich panel structure are 200-300mm × 200-300mm × 40-60mm.

[0007] Preferably, the 3D printed corrugated metal sheet is a one-piece molded 316L stainless steel corrugated metal sheet.

[0008] Preferably, the inclination angle of the trapezoidal corrugated core layer is 40° to 60°, the side length of the web is 50 to 60 mm, and the length of the platform is 3 to 5 mm.

[0009] Preferably, the thickness of the upper plate, lower plate, web, and platform is 0.1 to 0.5 mm.

[0010] 3D printing technology produces specimens with uniform and low-defect microstructures, significantly improving material strength. It also reduces the need for welding at the joints between the upper and lower layers and the core layer of corrugated metal structures, enhancing structural integrity. Ultra-high performance polymer concrete (UHPGC) is a novel ultra-high performance concrete material that possesses the same excellent penetration resistance as traditional ultra-high performance concrete, while consuming fewer natural resources and reducing carbon dioxide emissions. Using UHPGC as the core filler not only allows for the absorption of impact energy through cracks and fractures, but the core web also provides additional constraint on the UHPGC core material, further improving damage tolerance.

[0011] Therefore, the present invention, employing the above-mentioned 3D printed metal-UHPGC composite corrugated sandwich panel structure, has the following beneficial effects:

[0012] (1) The metal panels prepared by 3D printing technology have the characteristics of dense structure and no welding defects, which significantly improves the overall strength and integrity of the structure.

[0013] (2) When subjected to penetration loads, UHPGC core material can absorb a large amount of energy through microcrack propagation and fracture mechanisms, thereby achieving excellent impact resistance. At the same time, the corrugated core structure provides three-dimensional constraints on the infill concrete core material, further enhancing its damage tolerance and penetration resistance stability.

[0014] (3) The use of geopolymer concrete materials has the characteristics of low carbon and environmental protection, green and efficient manufacturing process, and has good industrial promotion value.

[0015] (4) According to the penetration test, compared with the traditional pure concrete structure, the damage area of ​​the sandwich panel structure on the front and back is significantly reduced, the bullet residual velocity is reduced by up to 25%, and it has significant energy absorption and anti-penetration effect.

[0016] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the fabrication process of a 3D-printed metal-UHPGC composite corrugated sandwich panel structure according to an embodiment.

[0018] Figure 2This is a schematic diagram of the structure of the 3D printed metal corrugated plate in the embodiment;

[0019] Figure 3 This is a schematic diagram of the 3D printed metal-UHPGC composite corrugated sandwich panel structure of the embodiment;

[0020] Figure 4 Figure 1 shows the test results of the penetration resistance of the pure UHPGC board and the 3D printed metal-UHPGC composite corrugated sandwich panel structure of the embodiment; where (a) is the pure UHPGC board; (b) is the 3D printed metal-UHPGC composite corrugated sandwich panel structure.

[0021] Figure 5 Numerical simulation diagrams of the penetration resistance test of pure UHPGC board and 3D printed metal-UHPGC composite corrugated sandwich panel structure of the embodiment; wherein, (a) is pure UHPGC board; (b) is 3D printed metal-UHPGC composite corrugated sandwich panel structure;

[0022] Figure Labels

[0023] 1. 3D printed metal corrugated sheet; 2. Top plate surface; 3. Bottom plate surface; 4. Trapezoidal corrugated core layer; 5. Web plate; 6. Platform; 7. UHPGC filler. Detailed Implementation

[0024] This invention provides a 3D-printed metal-UHPGC composite corrugated sandwich panel structure with excellent penetration resistance. The entire structure consists of a 3D-printed metal corrugated plate and ultra-high performance geopolymer concrete (UHPGC) material filled inside the 3D-printed metal corrugated plate. The 3D-printed metal corrugated plate is integrally 3D printed using laser powder bed melting (LPBF) technology, including an upper plate surface, a lower plate surface, and a trapezoidal corrugated core layer between the upper and lower plate surfaces. The core layer contains a trapezoidal corrugated grid structure, with UHPGC filled within the grid, thus forming an integrated metal-concrete composite corrugated sandwich panel structure.

[0025] In this invention, the UHPGC filler mainly consists of S95 finely ground blast furnace slag (GGBFS), F-grade fly ash (FA), silica fume (SF), alkaline activator (NaOH particles and Na2SiO3 solution), fine aggregate, high-efficiency water-reducing agent, and chopped steel fibers. The length of the chopped steel fibers is 6-12 mm, and the volumetric content is 1%-3%. A homogeneous mixture is prepared through dry mixing, wet mixing, and steel fiber dispersion mixing. The manufacturing process sequentially includes structural design, corrugated plate 3D printing, UHPGC preparation, filling, and 90℃ hot water curing and room temperature standard curing, ultimately resulting in a composite sandwich panel with complete structure and excellent performance.

[0026] This invention utilizes 3D printing technology to fabricate corrugated plates, ensuring structural integrity, sufficient stretching of each trapezoidal grid, and uniform pore size distribution. The trapezoidal grids are filled with ultra-high performance concrete, which densely fills the grids, effectively improving the plate's penetration resistance. Simultaneously, the ultra-high performance concrete core absorbs projectile penetration energy through cracks and fractures, and the core web provides additional constraint on the core material, further enhancing damage tolerance. This results in the 3D-printed metal-UHPGC composite corrugated sandwich panel structure exhibiting excellent overall penetration resistance.

[0027] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0028] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] The specific connection methods of each part all adopt conventional methods such as bolts, rivets, and welding that are mature in existing technology. The machinery, parts and equipment all adopt conventional models in existing technology. In addition, the circuit connection adopts conventional connection methods in existing technology, which will not be described in detail here.

[0030] Example

[0031] like Figures 2-3As shown, this embodiment provides a 250mm (length) × 250mm (width) × 44.8mm (thickness) 3D printed metal-UHPGC composite corrugated sandwich panel structure, including a 3D printed metal corrugated plate 1 and UHPGC filler 2 filled inside the 3D printed metal corrugated plate. The 3D printed metal corrugated plate 1 is composed of an upper plate surface 2, a lower plate surface 3, and a trapezoidal corrugated core layer 4 between the upper plate surface 2 and the lower plate surface 3. It is integrally 3D printed using laser powder bed melting (LPBF) technology, and the material is 316L stainless steel. The inclination angle of the trapezoidal corrugated core layer is 60°, the side length of the web 5 of the trapezoidal corrugated core layer is 50.8mm, the length of the platform 6 of the trapezoidal corrugated core layer is 3.7mm, and the thickness of the upper plate surface 2, the lower plate surface 3, the web 5, and the platform 6 is 0.2mm.

[0032] The above methods for fabricating 3D printed metal-UHPGC composite corrugated sandwich panel structures are as follows: Figure 1 As shown, the specific steps include:

[0033] Step 1: Structural design. Through commercial finite element model, the influence of various parameters of the corrugated plate is analyzed to design a composite corrugated sandwich panel with excellent penetration resistance, theoretically ensuring that all components of the structure can perform well in terms of penetration resistance.

[0034] Step 2: 316L stainless steel corrugated sheets were fabricated using laser powder bed melting technology. The process was performed using an EOS-m290 machine (EOS GmbH, k-rail, Germany) provided by Suzhou XDM 3D Printing Technology Co., Ltd., with a scanning angle of 67° between adjacent layers. An argon atmosphere was used as a protective atmosphere to prevent the molten metal from reacting with oxygen. To mitigate residual stress that might result from high-temperature melting, the corrugated sheets underwent post-heat treatment in the furnace, including heating from room temperature (20±5℃) to 400℃ at a rate of 6.5℃ / min for 4 hours, followed by gradual cooling to room temperature at a rate of 1℃ / min.

[0035] Step 3: Prepare ultra-high performance geopolymer concrete filler material using a 0.5-ton capacity machine. 3 In a concrete mixer, the binder material and fine aggregate are dry-mixed at low speed for 6 minutes. Then, the alkaline activator and excess water are added to the mix and wet-mixed for 8 minutes. Note that the alkaline activator needs to be allowed to reach room temperature under dry conditions before being added to the dry mixture. Next, the high-efficiency water-reducing agent is diluted and added to the mixture, and the mixture is stirred for 10 minutes until a homogeneous mixture is obtained. Finally, steel fibers are dispersed in the mixture and stirred for 5 minutes to achieve a uniform and random distribution.

[0036] Step 4: Filling with ultra-high performance geopolymer concrete. The freshly prepared ultra-high performance geopolymer concrete mixture is randomly poured into each trapezoidal grid under natural conditions, and then vibrated to remove air bubbles from the mixture and maintain the uniform distribution of fibers.

[0037] Step 5: Curing in 90℃ hot water for 2 days, followed by standard curing at a stable ambient temperature of 25±5℃ and relative humidity of 50±5%, to produce a 3D printed metal-UHPGC composite corrugated sandwich panel structure with excellent penetration resistance.

[0038] Penetration tests were used to evaluate the penetration resistance of pure ultra-high performance polymer concrete slabs and 3D-printed metal-UHPGC composite corrugated sandwich panel structures. Existing equipment was used for the penetration tests, including firing, velocity measurement, and recovery facilities. The bullets were pointed, 15mm in diameter, 94mm in length, with a nose radius of curvature (CRH) ratio of 3.0, made of NP450 armor steel, with a yield strength of 1140MPa, an ultimate strength of 1480MPa, and an average mass of 114.5g. In addition, specially designed closed-cell structures of polycarbonate and 7075-T6 aluminum alloy, as well as a polycarbonate baffle, were fabricated and fixed to the bullet to ensure airtightness and ballistic stability during firing. The bullets were fired using a 20mm caliber air gun system, propelled by a combined explosion of oxygen, nitrogen, and hydrogen, with an impact velocity of 400m / s. The target was positioned 2.5 meters in front of the air gun system, its bottom edge securely embedded in a steel frame. Two G-shaped clips were used to further anchor the target's two corners along the diagonal direction. Two high-speed cameras (PHOTRON SA-Z) with a resolution of 1024×215 pixels and a frame rate of 20,000 frames per second were used to measure the bullet's impact velocity and residual velocity, and to capture the bullet's trajectory. Several sandbags and wooden planks were placed 1.5 meters behind the target to intercept target fragments and recover any bullets that penetrated the target. The experimental results are as follows: Figure 4 As shown.

[0039] Simultaneously, the penetration test was numerically simulated using the commercial finite element software package ABAQUS in three dimensions to analyze the penetration resistance performance of the 3D-printed metal-UHPGC composite corrugated sandwich panel structure. The bullet was modeled as a three-dimensional (3D) discrete rigid shell, meshed using four-node three-dimensional bilinear rigid quadrilateral elements (R3D4); the target plate was defined as a deformable target, modeled as a three-dimensional (3D) deformable continuum, meshed using subtractive eight-node solid elements (C3D8R), with a mesh element size of 2mm × 2mm × 2mm. Figure 5 As shown in the figure. The experimental results were compared with the numerical simulation results, and the comparison revealed good consistency between the experimental values ​​and the numerical values, achieving good consistency between the experiments and the finite element simulation.

[0040] The dynamic response and damage mechanism of a 3D-printed metal-UHPGC composite corrugated sandwich panel structure under bullet penetration were investigated using experimental and numerical simulation methods. The 3D-printed metal-UHPGC composite corrugated sandwich panel structure significantly improved resistance to bullet penetration. Besides increased structural strength and ductility, a large amount of the bullet's kinetic energy was absorbed through the plastic expansion and fracture of the two front and rear panels of the metal corrugated panel, as well as the overall deformation (tension) of the core plate. Simultaneously, the 3D-printed metal corrugated panel provided lateral constraint to the UHPGC core material during bullet penetration. This constraint not only enhanced the tensile strength and toughness of the UHPGC but also suppressed its lateral volume expansion, thus delaying impact failure. Furthermore, combined with a higher impedance boundary, the metal corrugated panel structure also mitigated the adverse effects of the UHPGC free surface. In addition, the interaction between the bullet and the trapezoidal core plate of the metal corrugated panel helped to alter the bullet's trajectory, causing lateral deflection and absorbing more of the bullet's kinetic energy.

[0041] In summary, the 3D-printed metal-UHPGC composite corrugated sandwich panel structure provided by this utility model is characterized by its lightweight, high strength, and excellent penetration resistance. Its areal density is 149.85 kg / m³. 2 Compared to pure ultra-high performance polymer (UHPGC) concrete panels, the 3D-printed metal-UHPGC composite corrugated sandwich panel structure exhibits significantly reduced localized damage on both the front and back sides, a 25% decrease in residual velocity, and a marked improvement in resistance to bullet penetration. Furthermore, since the ultra-high performance concrete material used in this invention is a green adhesive material synthesized from various aluminum- and silicon-rich aluminosilicate materials, the 3D-printed metal-UHPGC composite corrugated sandwich panel structure of this invention features low energy consumption, extremely low carbon footprint, and is environmentally friendly. Simultaneously, the metal corrugated panel of this invention is manufactured using a 3D printing method, resulting in high material utilization, a simple manufacturing process, and high integrity of the formed components with excellent mechanical properties.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A 3D-printed metal-UHPGC composite corrugated sandwich panel structure, characterized in that: The invention includes a 3D printed metal corrugated plate, which is composed of an upper plate surface, a lower plate surface, and a trapezoidal corrugated core layer between the upper plate surface and the lower plate surface, wherein the trapezoidal corrugated core layer is filled with UHPGC.

2. The 3D printed metal-UHPGC composite corrugated sandwich panel structure according to claim 1, characterized in that: The dimensions of the 3D printed metal-UHPGC composite corrugated sandwich panel structure are 200~300mm×200~300mm×40~60mm.

3. The 3D printed metal-UHPGC composite corrugated sandwich panel structure according to claim 2, characterized in that: The 3D printed metal corrugated sheet is a one-piece molded 316L stainless steel metal corrugated sheet.

4. The 3D printed metal-UHPGC composite corrugated sandwich panel structure according to claim 3, characterized in that: The trapezoidal corrugated core layer has an inclination angle of 40° to 60°, a web side length of 50 to 60 mm, and a platform length of 3 to 5 mm.

5. The 3D printed metal-UHPGC composite corrugated sandwich panel structure according to claim 4, characterized in that: The thickness of the upper plate, lower plate, web, and platform is 0.1–0.5 mm.

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