Composite anti-shock wave fragment panel

Abstract

The application discloses a composite anti-impact wave fragment layer plate and relates to the technical field of explosion protection. The anti-fragment structure, the anti-impact wave structure and the fiber composite reinforcing material layer are combined, so that the harm of the impact wave composite fragment can be effectively prevented; the anti-fragment structure is divided into a ceramic layer and a soft and hard interbedded metal layer; the high hardness, brittleness and crack propagation characteristics of the ceramic can effectively disperse and absorb the kinetic energy of the fragment, and the head of the fragment is abraded and upset, so that the penetration resistance is further improved; the second anti-fragment layer is composed of the hard metal plate and the soft metal plate, and the two kinds of metal with different hardness and inclined angles are matched, so that the fragment is unbalanced in force during penetration, the bullet can be effectively deflected or even broken without increasing the mass and volume of the structure, and the kinetic energy in the most dangerous direction of the fragment is further dispersed and absorbed.

Description

Technical Field

[0001] This invention belongs to the field of explosion protection technology, and in particular relates to a composite shock wave fragmentation resistant plate. Background Technology

[0002] Explosion damage is mainly manifested as injury caused by shock wave and fragmentation. Explosions occurring near buildings, bridges and other facilities in densely populated areas can cause enormous damage and lead to major casualties. For civil structures, when subjected to large shock wave loads or fragment impacts, the damage to key load-bearing components may lead to the collapse of the entire structure. For the human body, large shock wave loads and fragment impacts can cause damage to various organs.

[0003] Currently, research on shock wave composite fragment injury protection structures mainly focuses on multi-layer composite structures. The most classic composite structure is the ceramic-fiber composite reinforcement-metal panel structure. The first two layers of material are mainly used to prevent fragment penetration, while the rear metal plate is used to defend against shock wave damage. This structure mainly improves its protective performance by increasing the material thickness, but it has the problems of large footprint and heavy weight. CN108454194A discloses a multi-layer composite material containing UHMWPE fiber-aluminum foam sandwich that adds aluminum foam to the classic structure to improve the structure's explosion resistance. However, it still has the limitation of only being able to improve the structure's explosion resistance by increasing the material thickness. The issue of improving protective performance through thickness methods exists. For example, patents CN112606495A and CN116512708A disclose a biomimetic protrusion-negative Poisson's ratio composite blast-resistant protective structure and a biomimetic composite sandwich blast-resistant structure, making the protective structure more design-oriented and potentially improving its blast resistance without increasing thickness or mass. However, their design principles are mainly based on biomimicry, lacking mechanical / physical support, which may lead to poor actual blast resistance. Furthermore, in existing designs, the blast resistance performance evaluation of structures is based on their ballistic limit velocity and energy absorption angle, without considering their shock wave attenuation capability. In reality, when the protected object is a critical load-bearing component of a building or a human body, its surface will suffer catastrophic damage when subjected to a force of 1 MPa; therefore, examining the wave attenuation capability of blast-resistant structures is crucial. Summary of the Invention

[0004] This invention provides a composite shock wave fragmentation resistant plate. This plate is based on mechanical / physical mechanisms and is a composite explosion-proof protection structure consisting of ceramic-hard and soft phase metal-out-of-plane defect thin-walled multicellular material-fiber composite reinforcement material. This solves the problems of large footprint, heavy weight, poor wave damping capacity and insufficient explosion-proof performance in the existing technology.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] The present invention provides a composite shock wave resistant fragmentation plate, which consists of an anti-fragmentation structure, an anti-shock wave structure, and a fiber composite reinforcement material layer arranged sequentially from the outside to the inside.

[0007] The anti-fragmentation structure includes a first anti-fragmentation layer made of a homogeneous ceramic plate, and a second anti-fragmentation layer disposed on the inner side of the homogeneous ceramic plate and composed of hard metal plates and soft metal plates arranged obliquely at intervals.

[0008] The shock wave resistant structure is a thin columnar multicellular structure arranged vertically in an array at the bottom of the second anti-fragmentation layer. The top of the thin columnar multicellular structure that contacts the second anti-fragmentation layer has a concave notch.

[0009] The fiber composite reinforcement layer is a fiber-reinforced composite material panel;

[0010] The homogeneous ceramic plate, hard metal plate, soft metal plate, thin columnar multicellular structure, and fiber-reinforced composite material panel are fixedly connected by adhesive.

[0011] Furthermore, the hard metal plate and the soft metal plate have the same height and their sidewalls are attached to each other.

[0012] Furthermore, the hard metal plate, the soft metal plate, and the homogeneous ceramic plate form a large, non-perpendicular angle.

[0013] Furthermore, the homogeneous ceramic plate (1) is made of a single piece of ballistic ceramic made of boron carbide (B4C), boron nitride (BN), alumina (Al2O3) or silicon carbide (SiC).

[0014] Furthermore, the material of the hard metal plate includes steel, titanium alloy, chromium-molybdenum steel, nickel-based alloy, and tungsten.

[0015] Furthermore, the soft metal plate is made of various foamed metals and porous metal materials.

[0016] Furthermore, the fiber-reinforced composite panel is a composite panel formed by winding, molding or pultrusion of reinforcing fiber material and matrix material; the reinforcing fiber material includes carbon fiber, glass fiber, aramid fiber, metal fiber, high molecular weight polyethylene fiber, carbon nanotube; the matrix material includes resin, ceramic, cement, rubber.

[0017] Furthermore, the adhesives used include epoxy resin adhesives, polyurethane adhesives, acrylic adhesives, silicone adhesives, and two-component epoxy adhesives.

[0018] The present invention has the following advantages over the prior art:

[0019] (1) By combining the anti-fragmentation structure, the anti-shock wave structure, and the fiber composite reinforcement material layer, the present invention can effectively prevent damage from shock wave composite fragments.

[0020] (2) The anti-fragment structure is divided into a ceramic layer and a soft and hard metal layer. By utilizing the high hardness, brittleness and crack propagation characteristics of ceramics, the kinetic energy of the fragments can be effectively dispersed and absorbed, and the fragment head is abraded and upset, further improving its penetration resistance.

[0021] (3) The second anti-fragmentation layer is composed of hard metal plates and soft metal plates with alternating hard and soft properties. By using two metals with different hardness and tilt angles, the force on both sides of the fragment is unbalanced during the penetration process (the pressure at the hard metal is higher than the pressure at the soft metal). Without increasing the mass and volume of the structure, the bullet can be effectively deflected or even broken. This further disperses and absorbs the kinetic energy in the most dangerous direction of the fragment, so that the fragment stays in the metal layer and no longer causes damage inward. This reduces and absorbs the kinetic energy in the most dangerous direction of the fragment and reduces the penetration depth of the fragment.

[0022] (4) Thin-walled multicellular structures with prefabricated defects in the shock wave resistant section. These cell wall structures mainly undergo layer-by-layer crushing deformation during axial compression, which can further improve the energy absorption efficiency of the structure and effectively avoid excessively high initial peak values, thereby improving the wave dissipation capability of the structure. They have excellent out-of-plane compression capability and energy absorption characteristics. The out-of-plane prefabricated defects reduce the initial stress area of ​​the structure, so that these structures no longer have high initial peak values, thus improving their wave dissipation capability.

[0023] (5) Fiber composite reinforced material itself is an excellent and widely used anti-fragmentation material. Placing it in the last layer can effectively prevent damage caused by a few fragments generated by the first two parts of the material. At the same time, fiber composite reinforced material, which is an orthogonal anisotropic material made of warp and weft threads, has a good stress wave diffusion function, which can further reduce the stress on the protected object.

[0024] (6) When the fragment penetrates alone, the ceramic first passivates and upsets the fragment, absorbing a certain amount of kinetic energy. The fragment enters the metal part, and under the action of pressure difference, it deflects or even breaks, and finally stays inside the metal. At this time, the ballistic layer will have a certain amount of residual kinetic energy, which causes the thin-walled multi-cell structure with out-of-plane prefabricated defects on the inner side to produce a small amount of crushing, and finally generate a certain expected pressure on the protected object.

[0025] (7) When subjected to a shock wave alone, the anti-fragmentation layer acts as the explosion-proof panel, converting the impulse of the shock wave into the momentum of the anti-fragmentation layer, which ultimately acts as kinetic energy on the thin-walled multicellular structure with out-of-plane prefabricated defects. The structure is crushed, absorbing almost all of the kinetic energy, and finally generating the expected pressure on the protected object.

[0026] (8) When the shock wave and fragments act together, in most cases, the structural response time caused by penetration is much shorter than that caused by the shock wave. The structure first undergoes a penetration response, and the fragments remain inside the metal. Then, the residual kinetic energy of the anti-fragmentation layer and the kinetic energy of the anti-fragmentation layer given by the shock wave act together on the thin-walled multicellular structure with out-of-plane prefabricated defects. The structure collapses, absorbs almost all of the kinetic energy, and finally generates the expected pressure on the protected object.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a composite shock wave fragmentation plate according to a specific embodiment 1 of the present invention;

[0030] Figure 2 for Figure 1 Structural side view;

[0031] Figure 3 for Figure 1 Top view of the structure of the second anti-fragmentation layer, which consists of hard metal plates and soft metal plates;

[0032] Figure 4 for Figure 1 Schematic diagram of a thin columnar multicellular structure;

[0033] Figure 5 for Figure 4 Top view of the structure;

[0034] Figure 6 This is a schematic diagram illustrating the mechanism of action of the anti-fragmentation structure in specific embodiment 1;

[0035] Figure 7 This is a diagram illustrating another mechanism of action of the anti-fragmentation structure in Specific Embodiment 1;

[0036] Figure 8A comparison of the pressure exerted on the surface of the protected object when subjected to the same impact, showing a conventional multicellular cell wall structure and a thin-walled multicellular structure with out-of-plane prefabricated defects in specific embodiment 1.

[0037] Figure 9 This is a schematic diagram of the structure of a composite shock wave fragmentation plate according to a specific embodiment 2 of the present invention;

[0038] Figure 10 for Figure 9 Structural side view;

[0039] Figure 11 for Figure 9 Top view of the structure of the second anti-fragmentation layer, which consists of hard metal plates and soft metal plates;

[0040] Figure 12 for Figure 9 Schematic diagram of a thin columnar multicellular structure;

[0041] Figure 13 for Figure 12 Top view of the structure;

[0042] The attached diagram lists the components represented by each number as follows:

[0043] 1-Homogeneous ceramic plate, 2-Hard metal plate, 3-Soft metal plate, 4-Thin columnar multicellular structure, 5-Fiber-reinforced composite panel. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the terms "from outside to inside", "inner side", "oblique", "spaced", "cross", "top", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0046] This invention belongs to the field of explosion protection structures, and in particular relates to composite fragment protection structures against shock waves for buildings, bridges and human bodies. Specific Implementation Example 1:

[0048] Please see Figure 1-8As shown, a composite shock wave resistant fragmentation plate of the present invention is provided with an anti-fragmentation structure, an anti-shock wave structure, and a fiber composite reinforcement material layer arranged sequentially from the outside to the inside.

[0049] The anti-fragmentation structure includes a first anti-fragmentation layer composed of a homogeneous ceramic plate 1, and a second anti-fragmentation layer composed of hard metal plates 2 and soft metal plates 3 arranged obliquely and intersectingly on the inner side of the homogeneous ceramic plate (1). The homogeneous ceramic plate 1 is made of a single piece of ballistic ceramic made of boron carbide (B4C), boron nitride (BN), alumina (Al2O3) or silicon carbide (SiC). Of course, other materials that can achieve or achieve the corresponding effect are also within the scope of protection of this technical solution. The hard metal plate 2 and soft metal plate 3 have the same height and their sidewalls are attached to each other. The hard metal plate 2, soft metal plate 3 and homogeneous ceramic plate 1 form a large oblique angle that is not perpendicular. In this specific embodiment, both the hard metal plate 2 and soft metal plate 3 adopt a structure with parallelogram-shaped inclined surfaces. The anti-fragmentation structure can effectively prevent fragment penetration and reduce the depth of fragment penetration.

[0050] The hard metal plate 2 is made of materials including steel, titanium alloy, chromium-molybdenum steel, nickel-based alloy, and tungsten; the soft metal plate 3 is made of various foam metals and porous metal materials; of course, other materials that can achieve or reach the corresponding effect are also within the scope of protection of this technical solution.

[0051] Hard metal plate 2 and soft metal plate 3 are combined by adhesive bonding or welding. Specifically, the two metal blocks are first purchased as base materials, and then processed into the required shape using techniques such as wire cutting, laser cutting, milling, and turning. Finally, they are connected and combined by adhesive bonding or welding according to the characteristics of the materials.

[0052] like Figure 6-7 As shown, the shock wave resistant structure adopts an array of thin columnar multicellular structures 4 vertically arranged at the bottom of the second anti-fragmentation layer. The top of the thin columnar multicellular structure 4 in contact with the second anti-fragmentation layer has a concave notch. The shock wave resistant part is a thin-walled multicellular structure with out-of-plane prefabricated defects. The corresponding thin-walled multicellular structure products can be purchased directly, and then sinusoidal or triangular defects can be prefabricated by wire cutting or laser cutting. The shock wave resistant structure can meet the requirements of absorbing shock waves and residual kinetic energy of the anti-fragmentation layer and dissipating waves.

[0053] The fiber composite reinforcement layer adopts fiber reinforced composite material panel 5;

[0054] The homogeneous ceramic plate 1, hard metal plate 2, soft metal plate 3, thin column multicellular structure 4, and fiber-reinforced composite material panel 5 are fixedly connected by adhesive; the adhesive materials include epoxy resin, polyurethane, acrylic, silicone, and two-component epoxy.

[0055] Among them, the fiber-reinforced composite panel 5 is a composite panel formed by winding, molding or pultrusion molding process of reinforcing fiber material and matrix material; the reinforcing fiber material includes carbon fiber, glass fiber, aramid fiber, metal fiber, high molecular weight polyethylene fiber, carbon nanotube; the matrix material includes resin, ceramic, cement, rubber; the fiber-reinforced composite panel 5 can prevent a few fragments generated by the first two layers of material from penetrating the protected object and disperse the stress on the protected object.

[0056] This invention combines an anti-fragmentation structure, an anti-shock wave structure, and a fiber composite reinforcement layer to effectively prevent damage from shock wave composite fragments.

[0057] The anti-fragmentation structure consists of a ceramic layer and a soft-hard metal layer. By utilizing the high hardness, brittleness and crack propagation characteristics of ceramics, the kinetic energy of the fragments can be effectively dispersed and absorbed, and the fragment head is abraded and upset, further improving its penetration resistance.

[0058] The second anti-fragmentation layer consists of alternating hard and soft metal plates. By using two metals with different hardness and tilt angles, the force on both sides of the fragment is unbalanced during penetration (the pressure at the hard metal is higher than the pressure at the soft metal). Without increasing the mass and volume of the structure, it can effectively deflect or even break the bullet, further dispersing and absorbing the kinetic energy in the most dangerous direction of the fragment, so that the fragment stays in the metal layer and no longer destroys inward, thereby reducing and absorbing the kinetic energy in the most dangerous direction of the fragment and reducing the fragment penetration depth.

[0059] Thin-walled multicellular structures with prefabricated defects in the shock wave resistant section exhibit a layer-by-layer crushing deformation mode during axial compression. This further enhances the structure's energy absorption efficiency while effectively avoiding excessively high initial peak values, thus improving its wave dissipation capability. They possess superior out-of-plane compression capacity and energy absorption characteristics. Furthermore, the out-of-plane prefabricated defects reduce the initial stress-bearing area of ​​the structure, preventing a high initial peak value and further improving its wave dissipation ability.

[0060] Fiber composite reinforced materials are excellent and widely used anti-fragmentation materials. Placing them as the last layer can effectively prevent damage caused by a few fragments generated by the first two layers of materials. At the same time, fiber composite reinforced materials, which are orthotropic materials made of interwoven warp and weft threads, have good stress wave diffusion function, which can further reduce the stress on the protected object.

[0061] When a fragment penetrates the metal alone, the ceramic first passivates and upsets the fragment, absorbing a certain amount of kinetic energy. The fragment then enters the metal part, where it deflects or even breaks under the pressure difference and eventually remains inside the metal. At this point, the ballistic layer will have a certain amount of residual kinetic energy, causing the thin-walled multicellular structure with out-of-plane pre-fabricated defects on the inner side to undergo a small amount of crushing, and finally generating a certain amount of expected pressure on the protected object.

[0062] When subjected to a shock wave alone, the anti-fragmentation layer acts as a blast-facing panel, converting the impulse of the shock wave into the momentum of the anti-fragmentation layer. Ultimately, this momentum acts as kinetic energy on the thin-walled multicellular structure with out-of-plane pre-fabricated defects, causing the structure to crush and absorb almost all of the kinetic energy, eventually generating the expected pressure on the protected object.

[0063] When shock waves and fragments act together, in most cases, the structural response time caused by penetration is much shorter than that caused by the shock wave. The structure first undergoes a penetration response, with the fragments remaining inside the metal. Subsequently, the residual kinetic energy of the anti-fragmentation layer and the kinetic energy of the anti-fragmentation layer imparted by the shock wave act together on the thin-walled multicellular structure with out-of-plane pre-fabricated defects, causing the structure to crush, absorbing almost all of the kinetic energy, and finally generating the expected pressure on the protected object.

[0064] like Figure 6 As shown:

[0065] At this point, the impact point of the fragment is entirely on the soft metal. (a) is the first stage, where the fragment is abraded and upset by the ceramic. (b) is the second stage, where the fragment begins to penetrate the soft metal target. (c) is the third stage, where the fragment begins to penetrate the part where soft and hard metals coexist. The different strengths of the metals on both sides cause a pressure difference around the fragment, and the fragment deflects towards the side with less pressure (soft metal). (d) is the fourth stage, where the fragment is completely deflected, and the kinetic energy in the most dangerous direction is significantly reduced.

[0066] like Figure 7 As shown:

[0067] At this point, the impact point of the fragment is entirely on the hard metal. (a) is the first stage, where the fragment is abraded and upsetting by the ceramic. (b) is the second stage, where the fragment begins to penetrate the hard metal target. (c) is the third stage, where the fragment begins to penetrate the part where both soft and hard metals coexist. The different strengths of the metals on both sides cause a pressure difference around the fragment, and the fragment deflects towards the side with less pressure (soft metal). (d) is the fourth stage, where the fragment is completely deflected, the kinetic energy in the most dangerous direction is significantly reduced, and a second deflection may occur. The cycle of steps (c)-(d) continues.

[0068] like Figure 8The image shows a comparison of the pressure exerted on the surface of the protected object when subjected to impact between a conventional multicellular cell wall structure and a thin-walled multicellular structure with out-of-plane prefabricated defects. The thin-walled multicellular structure is made of 0.1mm thick 1060 aluminum strip with a density of 0.028g / cm³. 3 The cell wall structure has a height of 20 mm and a radius of 4 mm, and the height of the defects accounts for 20% of the total height. Specific Implementation Example 2:

[0070] like Figure 9-13 As shown, the difference between this specific embodiment and specific embodiment 1 is that:

[0071] Correspondingly, the thin column multicell structure 4 adopts a circular thin column structure with a concave defect at the top, and is arranged in an array;

[0072] Correspondingly, the hard metal plate 2 and the soft metal plate 3 adopt a structure with an isosceles trapezoidal cross section.

[0073] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A composite shock wave fragmentation resistant plate, characterized in that, From the outside in, the structure consists of an anti-fragmentation structure, an anti-shock wave structure, and a fiber composite reinforcement layer. The anti-fragmentation structure includes a first anti-fragmentation layer composed of a homogeneous ceramic plate (1), and a second anti-fragmentation layer composed of hard metal plates (2) and soft metal plates (3) arranged at intervals and crosses on the inner side of the homogeneous ceramic plate (1). The hard metal plates (2) and soft metal plates (3) are inclined at an angle to the first anti-fragmentation layer. The arrangement direction of the hard metal plates (2) and soft metal plates (3) is parallel to the in-plane direction of the first anti-fragmentation layer. The hard metal plates (2) and soft metal plates (3) are both parallelograms or isosceles trapezoids in cross section along the arrangement direction. The shock wave resistance structure is a thin columnar multicell structure (4) arranged vertically in an array at the bottom of the second anti-fragmentation layer. The top of the thin columnar multicell structure (4) that contacts the second anti-fragmentation layer has a concave notch. The hard metal plate (2) and the soft metal plate (3) have the same height and their sidewalls are attached to each other; The fiber composite reinforcement layer adopts a fiber reinforced composite material panel (5). The homogeneous ceramic plate (1), hard metal plate (2), soft metal plate (3), thin column multicellular structure (4), and fiber-reinforced composite material panel (5) are fixedly connected by adhesive. The materials of hard metal plates (2) include steel, titanium alloys, nickel-based alloys, and tungsten; The materials of the soft metal plate (3) include foam metal and porous metal materials.

2. The composite shock wave fragmentation resistant plate according to claim 1, characterized in that, The homogeneous ceramic plate (1) is made of a single piece of ballistic ceramic made of boron carbide, boron nitride, alumina or silicon carbide.

3. The composite shock wave fragmentation resistant plate according to claim 1, characterized in that, The fiber-reinforced composite panel (5) is a composite panel formed by winding, molding or pultrusion of reinforcing fiber material and matrix material; the reinforcing fiber material includes carbon fiber, glass fiber, aramid fiber, metal fiber, high molecular weight polyethylene fiber, carbon nanotube; the matrix material includes resin, ceramic, cement and rubber.

4. The composite shock wave fragmentation resistant plate according to claim 1, characterized in that, The adhesives used include epoxy resin, polyurethane, acrylic, and silicone.

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