A penetration resistant composite structure and method of making the same

Abstract

The embodiment of the present application discloses an anti-penetration multi-composite structure, which comprises a plurality of single-layer plate shell structures spirally stacked with a certain rotation angle to form a three-dimensional integral structure, and the single-layer plate shell structures are connected by homogeneous thin layers; the single-layer plate shell structures are formed by embedding two materials with different elastic modulus according to space-filling curves of geometric shapes, widths or orders. The embodiment of the present application also discloses a preparation method of the anti-penetration multi-composite structure. By using the space-filling curve to design the plate shell structure with soft and hard materials, and rotating and stacking the plate shell structures with different geometric forms and different scales, the interface area of the soft and hard materials and the expansion path thereof are greatly increased without changing the overall thickness of the structure, the overall toughness of the structure is improved, and the structure can delay the damage time when subjected to a large impact load to achieve the anti-penetration effect.

Description

Technical Field

[0001] This invention relates to the field of impact-resistant and protective composite structure technology, and in particular to a penetration-resistant composite structure and its preparation method. Background Technology

[0002] Penetration-resistant protective structures have wide applications in daily life and various engineering fields, such as motorcycle helmets, bulletproof vests, helicopter underbody plates, and tank armor. With the rapid development of my country's industrial technology and the increasing demands for national defense security, higher requirements have been placed on the protective capabilities of penetration-resistant structures under high-speed, high-dynamic loads. Based on this, researchers have drawn inspiration primarily from natural biological impact-resistant structures, using different materials to design and manufacture various penetration-resistant composite structures, including layered structures, brick-concrete structures, overlapping structures, fiber-reinforced structures, stacked spiral structures, and others. In these composite structures, the alternating layers of soft and hard materials, or fibers, are often arranged in a certain regular pattern. When encountering impact loads, energy is dissipated through interlaminar shearing and crack propagation of the soft and hard materials, thus achieving the purpose of structural impact resistance. Therefore, the geometric path between the soft and hard materials has a significant impact on the structure's impact resistance or penetration resistance. However, the design ideas of existing impact-resistant structures mainly focus on the geometry of the hard structure (layered, blocky, fiber, etc.) and the geometric morphology of the soft and hard materials (e.g., overlapping, spiral, interlocking, etc.), lacking fine-grained control over the geometric path between the soft and hard materials. Summary of the Invention

[0003] The technical problem to be solved by the embodiments of the present invention is to provide a penetration-resistant composite structure and its preparation method. This structure can delay the failure time of the structure under large impact loads, thus achieving a penetration-resistant effect.

[0004] To address the aforementioned technical problems, embodiments of the present invention provide a penetration-resistant multi-composite structure, comprising multiple single-layer shell-like structures spirally stacked at a certain rotation angle to form a three-dimensional integral structure, wherein each single-layer shell-like structure is interconnected by a homogeneous thin layer; each single-layer shell-like structure is formed by interlocking two materials with different elastic moduli according to spatial filling curves of geometric shape, width, and order.

[0005] The space-filling curve is at least one of the following types: Hilbert, Peano, Gosper, Moore, and Sierpinski.

[0006] The width of the space-filling curve in each of the single-layer shell structures is 1 / 500 to 1 / 50 of the maximum value of the length and width of the single-layer shell structure.

[0007] The space-filling curve is one or more of order 3-20.

[0008] In the single-layer shell structure, the space-filling curve is made of soft material, while the rest is made of hard material, and the ratio of the elastic modulus of the hard material to that of the soft material is greater than 1.5:1.

[0009] The number of the single-layer shell-like structure is at least 3 layers.

[0010] The homogeneous thin layer is composed of the soft material, or a third material with an elastic modulus 13 times that of the soft material, and its thickness is 1 / 5 to 1 / 50 of the thickness of the single-layer plate-shell structure.

[0011] The rotation angle when multiple single-layer shell-like structures are stacked is generated by rotating each single-layer shell-like structure relative to the in-plane coordinates of the upper surface single-layer shell-like structure; the rotation angle can be uniformly varied, linearly gradient varied, or nonlinearly gradient varied.

[0012] Accordingly, embodiments of the present invention also provide a method for preparing the above-mentioned anti-penetration composite structure, comprising the following steps: S1: Based on the actual application scenario requirements, the overall geometry of the anti-penetration composite structure is initially determined, and a material combination of soft materials, hard materials, and homogeneous thin-layer materials with appropriate mechanical properties is selected; S2: Use 3D modeling software to create a penetration-resistant composite structure with N layers containing single-layer shell-like structures, and determine the geometric parameters of the structure, including: the geometry of the space-fill curve in each single-layer shell-like structure and the width of the space-fill curve. Order of space-filling curve Thickness of each single-layer shell structure Homogeneous thin layer thickness Rotation angle Rotation angle method, where i = (1, 2, 3, …, N); S3: The 3D model of the anti-penetration composite structure in S2 is converted into a finite element model using finite element modeling software. The material mechanical properties determined in S1 are assigned. The crack propagation mode, penetration depth, energy absorption magnitude, and peak impact load of the anti-penetration composite structure model are calculated, simulated and evaluated using the finite element method. Then, the mechanical properties of the material combination in S1 and the geometric parameters in S2 are optimized and adjusted to obtain an anti-penetration composite structure design model that meets the requirements of actual application scenarios. S4: A penetration-resistant composite structure is prepared by using a multi-material additive manufacturing method, and a shell is attached to its outer surface to complete the preparation of the penetration-resistant composite structure.

[0013] The overall geometry of the anti-penetration composite structure is one of the following: flat plate, flat shell, cylindrical shell, and spherical shell. The material combination of the soft material, hard material, and homogeneous thin-layer material includes a combination of three types of materials: ceramic, metal, and polymer.

[0014] In step S2, the total thickness H of the composite structure with N single-layer shell-like structures is... The rotation angle method can be uniform, linear gradient, or nonlinear gradient.

[0015] The finite element method includes, but is not limited to, explicit dynamics, extended finite element method, and interface adhesion element method.

[0016] The additive manufacturing methods include, but are not limited to, photopolymerization, melt extrusion, selective laser melting, and direct ink writing.

[0017] Implementing the embodiments of the present invention has the following beneficial effects: (1) The present invention provides a penetration-resistant composite structure. Due to the design of space-filling soft materials of different orders, the propagation path of cracks along the soft materials in the structure is greatly increased, thereby dissipating more energy during crack propagation. Moreover, the rotation and stacking of each single-layer plate increases the number of deflections during crack propagation, thus greatly improving the overall penetration resistance of the structure.

[0018] (2) The present invention provides a penetration-resistant composite structure in which each single-layer plate is made of space-filled curved soft and hard materials with different geometric shapes, different orders and different widths. By adjusting the order, the soft and hard interlocking scale of the single-layer plate can be adjusted from micrometer level to meter level or even tens of meters level, thereby achieving the penetration resistance of the overall composite structure at multiple scales.

[0019] (3) The present invention provides a design and preparation method for a penetration-resistant composite structure, which can adjust many structural parameters, including the interlocking parameters of single-layer plates and the parameters between each single-layer plate, and can meet the needs of various practical application scenarios such as national defense anti-riot structure and aviation impact protection. Attached Figure Description

[0020] Figure 1 A schematic diagram of a space-filled curved anti-penetration composite structure provided for an exemplary embodiment of the present invention; Figure 2 A schematic diagram of the geometry of the anti-penetration composite structure in which Peano-type and Sierpinski-type space-filling curve soft materials are embedded, provided as an exemplary embodiment of the present invention; Figure 3A schematic diagram of a penetration-resistant composite structure inlaid with third-order Hilbert-type soft material, fourth-order Hilbert-type soft material, and fifth-order Hilbert-type soft material, provided for an exemplary embodiment of the present invention; Figure 4 A schematic diagram of an anti-penetration composite structure consisting of eight single-layer plate-shell-like structures with gradually varying thickness from top to bottom, provided as an exemplary embodiment of the present invention; Figure 5 A schematic diagram of a penetration-resistant composite structure consisting of a single-layer plate-shell structure with 6 layers of mixed thickness, provided as an exemplary embodiment of the present invention; Figure 6 A schematic diagram of an anti-penetration composite structure formed by rotating a 5-layer uniform thickness single-layer shell structure 1 at a 30° angle, as an exemplary embodiment of the present invention. Figure 7 A schematic diagram of a linear gradient rotational anti-penetration composite structure formed by a 6-layer single-layer plate-shell structure 1 with a rotation angle increment of 20°, provided as an exemplary embodiment of the present invention. Figure 8 A schematic diagram of a nonlinear hybrid gradient rotation anti-penetration composite structure of a uniform single-layer plate-shell structure 1 with a rotation of 0°, 30°, 90°, 60°, and 30°, provided as an exemplary embodiment of the present invention; Figure 9 The diagram shows the steps of the preparation method of the anti-penetration composite structure provided by the present invention. Detailed Implementation

[0021] The present invention will become clearer from the following detailed description with reference to the accompanying drawings and preferred embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. The described embodiments are only some, not all, of the embodiments of the present invention. The modules of the embodiments of the present invention described and exemplified herein can typically be arranged and designed in various different configurations.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "connected," "joined," and "overlapping" should be interpreted broadly. For example, they can refer to direct 3D printing connections, mechanical welding connections, or adhesive bonding connections; the relative positions of the overlapped parts can be vertical or staggered. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Combination such as Figure 1As shown in the schematic diagram, an embodiment of the present invention provides a space-filled curved anti-penetration composite structure. The overall structure is formed by spirally stacking single-layer shell-like structures 1, with each single-layer shell-like structure 1 connected to the others by a homogeneous thin layer 2. The upper and lower surfaces of the overall structure are covered with an outer shell 3. Moreover, the single-layer shell-like structure 1 is formed by interlocking rigid material 11 and soft material 12 with a Hilbert-type space-filled curve.

[0024] In this embodiment, the space-filling curve geometry of the soft material 12 embedded in each single-layer shell structure can be preferably changed or combined in various ways. Figure 1 The space-filling curve geometry shown is of the Hilbert type. Figure 2 a and Figure 2 b are schematic diagrams of the structure of Peano-type and Sierpinski-type space-filling curve soft materials 12, respectively.

[0025] In this embodiment, the cross-sectional dimensions of the space-filling curved soft material 12 in each single-layer shell structure can be preferably adjusted to achieve an optimal volume ratio of rigid material 11 to soft material 12 in the overall structure. In a preferred embodiment, the width of the soft material 12 can be 1 / 500 to 1 / 50 of the maximum value of the overall length and width of the composite structure. For example, if the overall anti-penetration composite structure is 10cm*8cm, the width of the soft material 12 is preferably between 0.2mm and 2mm.

[0026] In this embodiment, the order of the soft material 12 with a certain space-filling curve geometry in each single-layer shell structure 1 can be preferably changed or combined in various ways to control the complexity of the soft-hard interface, thereby achieving a toughening effect and penetration resistance. In a preferred embodiment, the order can be an integer from 3 to 20. Figure 3 a presents a third-order Hilbert-type soft material 12, Figure 3 b presents a fourth-order Hilbert-type soft material 12. Figure 3 c presents a fifth-order Hilbert-type soft material 12.

[0027] In this embodiment, the space-filling curves in each single-layer shell structure 1 are made of soft material 12, while the remaining areas are made of hard material 11. The elastic moduli of the hard material 11 and the soft material 12 can be appropriately adjusted. In a preferred embodiment, the elastic modulus of the hard material 11 is at least twice that of the soft material 12. For example, the single-layer shell structure 1 can be formed by interlocking PLA hard material 11 with an elastic modulus of 3500 MPa and TPU soft material 12 with an elastic modulus of 500 MPa using a Hilbert-type space-filling curve.

[0028] In this embodiment, the number of layers in the three-dimensional integral structure formed by spirally stacking multiple single-layer shell-like structures 1 at a certain rotation angle can be adjusted according to actual needs. In a preferred embodiment, the penetration-resistant composite structure contains at least 3 layers of single-layer shell-like structures 1. For example... Figure 1 The penetration-resistant composite structure shown is 10cm*8cm in size and consists of 5 single-layer shell-like structures 1.

[0029] In this embodiment, the multiple single-layer shell-like structures 1 constituting the anti-penetration composite integral structure can be of equal thickness or of non-equal thickness. For example, Figure 1 The anti-penetration composite structure shown consists of five uniformly thick single-layer plate-shell structures 1. Figure 4 The anti-penetration composite structure shown consists of 8 single-layer plate-shell-like structures with gradually varying thickness from top to bottom; Figure 5 The penetration-resistant composite structure shown consists of a single-layer plate-shell structure with a mixed thickness of 6 layers.

[0030] In this embodiment, the homogeneous thin layer 2 connecting the single-layer shell-like structures 1 can be made of the soft material 12, or it can be made of a third material with an elastic modulus different from that of the hard material 11 and the soft material 12. Furthermore, the thickness of the homogeneous thin layer 2 can be 1 / 5 to 1 / 50 of the thickness of each single-layer shell-like structure 1. In a preferred embodiment, the elastic modulus of the homogeneous thin layer 2 is in the range of 0.5 to 1.5 times the elastic modulus of the soft material 12.

[0031] In this embodiment, when multiple single-layer shell-like structures 1 are stacked to form a penetration-resistant composite structure, each single-layer shell-like structure 1 can rotate relative to each other by a certain angle. The magnitude of the rotation angle is defined by the in-plane coordinate rotation of each single-layer shell-like structure relative to the upper surface single-layer shell-like structure 1. This rotation angle can be uniformly varied, linearly gradient varied, or non-linearly gradient varied. By using different rotation methods, the overall composite structure can achieve crack deflection between the single-layer shell-like structures 1 when subjected to penetration force, thereby obtaining a penetration-resistant effect. In a preferred embodiment, the rotation angle of the single-layer shell-like structure 1 is 30° to 90°. Figure 6 A schematic diagram of a penetration-resistant composite structure formed by rotating a 5-layer, uniformly thick, single-layer shell-like structure 1 at a 30° angle. Figure 7 A schematic diagram of a linear gradient rotational anti-penetration composite structure formed by a 6-layer, gradually thickened single-layer plate-shell structure with a rotation angle increment of 20°. Figure 8 A schematic diagram of a uniform single-layer plate-shell structure 1 with a nonlinear mixed gradient rotation of 0°, 30°, 90°, 60°, and 30° to resist penetration composite structure.

[0032] In this embodiment, the outer surface of the overall three-dimensional structure can be covered with shells 3 of different materials and thicknesses. In a preferred embodiment, the shell 3 can be designed and selected according to the usage environment, thereby improving the durability of the penetration-resistant composite structure. For example, in high-humidity environments such as underwater, the shell 3 can be made of waterproof and impermeable materials; in high-temperature environments, the shell 3 can be made of thermally protective materials.

[0033] This invention also provides a method for preparing a penetration-resistant composite structure, such as... Figure 9 As shown, the specific steps include the following: Step S1: Based on the actual application scenario requirements, preliminarily determine the overall geometry (length, width, thickness, curvature, etc.) of the anti-penetration composite structure, and select a material combination of hard material 11, soft material 12 and homogeneous thin layer 2 with appropriate mechanical properties. Step S2: Using 3D modeling software, a penetration-resistant composite structure with N layers including the single-layer shell-like structure 1 is established. The geometric parameters of the structure are determined, including: the geometry of the space-filling curve in each single-layer shell-like structure 1, and the width of the space-filling curve. Order of space-filling curve Thickness of each single-layer shell structure Homogeneous thin layer thickness Rotation angle Rotation angle method, where i = (1, 2, 3, …, N); Step S3: The 3D model of the anti-penetration composite structure in step S2 is converted into a finite element model using finite element modeling software. The material mechanical properties determined in step S1 are assigned to it. The crack propagation mode, penetration depth, energy absorption magnitude, and peak impact load of the anti-penetration composite structure model are calculated, simulated, and evaluated using the finite element method. Then, the mechanical properties of the material combination described in step S1 and the geometric parameters described in step S2 are optimized and adjusted to obtain a refined anti-penetration composite structure design model that meets the needs of actual application scenarios. Step S4: A penetration-resistant composite structure is prepared by a multi-material additive manufacturing method, and a shell 3 is attached to its outer surface to complete the preparation of the penetration-resistant composite structure.

[0034] Furthermore, in step S1, the overall geometry of the anti-penetration composite structure can be one of a flat plate, a flat shell, a cylindrical shell, or a spherical shell, and the material combination of the hard material 11, the soft material 12, and the homogeneous thin layer 2 includes, but is not limited to, a combination of materials from the three categories of ceramics, metals, and polymers. Further, in step S2, the total thickness H of the composite structure with N layers of the single-layer shell-like structure is... In specific embodiments, the rotation angle method can be a uniform method, a linear gradient method, or a non-linear gradient method; Furthermore, in step S3, the finite element method includes, but is not limited to, explicit dynamics, extended finite element method, and interface adhesion element method; Furthermore, in step S4, the additive manufacturing method includes, but is not limited to, photopolymerization, melt extrusion, selective laser melting, and direct ink writing.

[0035] It should be understood that in the structural design and manufacturing method of this application, each component or step can be disassembled and / or recombined. Such disassembly and / or recombination should be considered equivalent solutions of this application. It should also be noted that in the apparatus, equipment, and method of this application, each component or step can be disassembled and / or recombined. Such disassembly and / or recombination should be considered equivalent solutions of this application.

Claims

1. A penetration-resistant composite structure, characterized in that, It includes multiple single-layer shell-like structures spirally stacked at a certain rotation angle to form a three-dimensional integral structure, and each of the single-layer shell-like structures is connected to each other by a homogeneous thin layer; each of the single-layer shell-like structures is formed by two materials with different elastic moduli interlocking according to a certain geometric shape, width and order of space-filling curves; the space-filling curves in the single-layer shell-like structures are made of soft materials, and the rest are made of hard materials, and the ratio of the elastic moduli of the hard materials to the soft materials is greater than 1.5:

1.

2. The anti-penetration composite structure according to claim 1, characterized in that, The space-filling curve is at least one of the following types: Hilbert, Peano, Gosper, Moore, and Sierpinski.

3. The anti-penetration composite structure according to claim 2, characterized in that, The width of the space-filling curve in each of the single-layer shell structures is 1 / 500 to 1 / 50 of the maximum value of the length and width of the single-layer shell structure.

4. The anti-penetration composite structure according to claim 3, characterized in that, The space-filling curve is one or more of order 3-20.

5. The anti-penetration composite structure according to claim 1, characterized in that, The number of single-layer shell-like structures is at least 3 layers.

6. The anti-penetration composite structure according to claim 5, characterized in that, The homogeneous thin layer is composed of the soft material, or a third material with an elastic modulus 1-3 times that of the soft material, and its thickness is 1 / 5-1 / 50 of the thickness of the single-layer plate-shell structure.

7. The anti-penetration composite structure according to claim 6, characterized in that, The rotation angle when multiple single-layer shell-like structures are stacked is generated by rotating each single-layer shell-like structure relative to the in-plane coordinates of the upper surface single-layer shell-like structure; the rotation angle can be uniformly varied, linearly gradient varied, or nonlinearly gradient varied.

8. A method for preparing the anti-penetration composite structure according to claim 1, characterized in that, Includes the following steps: S1: Based on the actual application scenario requirements, the overall geometry of the anti-penetration composite structure is initially determined, and a material combination of soft materials, hard materials, and homogeneous thin-layer materials with appropriate mechanical properties is selected; S2: Use 3D modeling software to create a penetration-resistant composite structure with N layers containing single-layer shell-like structures, and determine the geometric parameters of the structure, including: the geometry of the space-fill curve in each single-layer shell-like structure and the width of the space-fill curve. Order of space-filling curve Thickness of each single-layer shell structure Homogeneous thin layer thickness Rotation angle Rotation angle method, where i = (1, 2, 3, …, N); S3: The 3D model of the anti-penetration composite structure in S2 is converted into a finite element model using finite element modeling software. The mechanical properties of the material combination determined in S1 are assigned. The crack propagation mode, penetration depth, energy absorption magnitude, and peak impact load of the anti-penetration composite structure model are calculated, simulated and evaluated using the finite element method. Then, the mechanical properties of the material combination in S1 and the geometric parameters of S2 are optimized and adjusted to obtain an anti-penetration composite structure design model that meets the requirements of actual application scenarios. S4: A penetration-resistant composite structure is prepared by using a multi-material additive manufacturing method, and a shell is attached to its outer surface to complete the preparation of the penetration-resistant composite structure.

9. The preparation method according to claim 8, characterized in that, The overall geometry of the anti-penetration composite structure is one of the following: flat plate, flat shell, cylindrical shell, and spherical shell. The material combination of the soft material, hard material, and homogeneous thin-layer material includes a combination of three types of materials: ceramics, metals, and polymers.

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