A bionic structure composite armor and a preparation method thereof

Abstract

The application provides a kind of composite armor of bionic structure and its preparation method, including sequentially superimposed bulletproof layer, transition layer and energy absorption layer, bulletproof layer includes titanium alloy panel and a plurality of ceramic hemispheres, adhesive and low surface density high performance fiber woven fabric or prepreg are used between the two to bond.The application simulates the macro-micro organization framework of the nacre layer of shell, so that the composite armor has the characteristics of high specific energy absorption, can resist multiple high-speed impacts, the hemispherical convex structure of titanium alloy panel can effectively protect multiple bullet types, each independent ceramic hemisphere does not affect each other, high-hardness ceramic hemisphere can blunt and grind the projectile, the cambered surface design of bulletproof layer can change the penetration direction of the projectile, the ceramic hemisphere can make the failure mode deflect between layers, greatly improving the multi-hit bullet performance of the armor plate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bulletproof armor, and particularly relates to a composite armor with a bionic structure and a preparation method thereof. BACKGROUND

[0002] The protective materials and structures used by modern special equipment need to withstand the high-speed impact load of bullets, shells and explosion fragments, and are widely used in armored vehicles, helicopters and ships and other transport tools as well as individual soldier and police protective equipment. As a typical structure, the "ceramic / composite back plate" armor has gradually been difficult to meet the requirements of modern armor protection due to the limitations of the performance of the material itself, and the secondary bulletproof ability is relatively weak. Part of the "metal / ceramic + constraint material" structure armor adopts polymer bonding, and the interface bonding strength is not high enough and lacks an effective detection method to evaluate the bonding strength, which affects the bulletproof performance.

[0003] With the improvement of the lightweight index, in addition to the superior bulletproof ability, the areal density of the special equipment is also an important factor for assembly, and considering the mobility and flexibility of the combat platform and the transport tool, the lightweight and high-strength composite armor is a problem that needs to be solved urgently at present. SUMMARY

[0004] Therefore, the present application provides a composite armor with a bionic structure and a preparation method thereof, and specifically relates to:

[0005] A composite armor with a bionic structure, characterized by comprising a bulletproof layer, a transition layer and an energy absorption layer which are stacked in sequence, wherein the bulletproof layer comprises a titanium alloy panel and a plurality of ceramic hemispheres, and the two are bonded by using an adhesive and a low-areal-density high-performance fiber woven fabric or a prepreg.

[0006] The titanium alloy panel of the bulletproof layer comprises a flat plate body, a plurality of hemispherical protrusions protruding from the bullet impact surface are formed on the flat plate body, the hemispherical protrusions comprise large-diameter hemispherical shells and small-diameter hemispherical shells, each large-diameter or small-diameter hemispherical shell forms a large-diameter or small-diameter hemispherical groove on the back bullet impact surface of the flat plate body, the outer diameter of the large-diameter hemispherical shell is larger than that of the small-diameter hemispherical shell, the large-diameter hemispherical shells are arranged in an array, the outer surfaces of two adjacent large-diameter hemispherical shells in the same row or the same column are tangent to each other, and the small-diameter hemispherical shells are arranged in the gaps between the four large-diameter hemispherical shells, that is, each small-diameter hemispherical shell is adjacent to four large-diameter hemispherical shells, each large-diameter hemispherical groove contains a large-diameter ceramic hemisphere fixed therein, each small-diameter hemispherical groove contains a small-diameter ceramic hemisphere fixed therein, and the circular bottom surfaces of the large-diameter and small-diameter ceramic hemispheres are flush with the back bullet impact surface of the flat plate body.

[0007] The hemispherical grooves and the hemispherical surfaces of the ceramic hemispheres are further bonded by the adhesive and the high-performance fiber woven fabric or the prepreg.

[0008] The outer diameter radius of the large-diameter hemispherical shell ranges from 10 to 25 mm, and the inner diameter of the large-diameter hemispherical groove formed by the large-diameter hemispherical shell is 2-8 mm smaller than the outer diameter.

[0009] The thickness of the plate body of the flat plate body is 3-10 mm;

[0010] The transition layer is a sandwich structure composed of two layers of carbon fiber prepreg and a high-strength steel wire grid sandwiched in the middle.

[0011] The energy-absorbing layer is a PE plate pressed from PE fiber prepreg.

[0012] The preparation method of the bionic structure composite armor described above, characterized in that it comprises:

[0013] S1, pretreatment of large and small diameter ceramic hemispheres, using a pneumatic polishing head to install 80-300 mesh sandpaper to polish the curved surface, then clean with alcohol, and wait for use;

[0014] S2, bulletproof layer preparation, clean the titanium alloy plate with alcohol, apply adhesive on the surface of each large and small diameter hemispherical groove, hand lay a layer of high-performance fiber woven cloth or prepreg, also apply adhesive on the surface of each large and small diameter ceramic hemisphere, then embed the large and small diameter ceramic hemispheres into the corresponding large and small diameter hemispherical grooves, then put the bulletproof layer into a vacuum bag and vacuumize, then put it into a pressure kettle for stage heating and vacuumizing, and get the bulletproof layer preform after cooling;

[0015] S3, transition layer preparation, carbon fiber twill fabric prepreg is laid according to 0° / 90° orthogonal, and a high-strength steel wire grid is placed in the middle layer, then the whole is wrapped with a separation film, and is pressed into shape by a press;

[0016] S4, energy-absorbing layer preparation, the PE fiber laminated plate is formed by pressing PE fiber prepreg by a press, and the overall areal density is 7-10 kg / m2;

[0017] S5, composite molding, the energy-absorbing layer, the transition layer and the bulletproof layer are sequentially laid to form a composite armor preform, a hot melt adhesive film is placed in each bonding surface, the thickness of the hot melt adhesive film layer is 0.1-0.16 mm, the areal density is 110±16 g / m2, and the material is one of PU adhesive film, EVA adhesive film, polyurethane adhesive film, thermosetting adhesive film, thermoplastic adhesive film and phenolic resin adhesive film; the composite armor preform is put into a vacuum bag and vacuumized, then is put into a pressure kettle for stage heating and vacuumizing, and a molded part is obtained after cooling.

[0018] The stage heating and vacuumizing operation steps in S2 are as follows: the first stage time is 10-30 min, the vacuumizing pressure is 0.5-0.8 MPa, and the temperature is 60-80 DEG C; the second stage time is 20-40 min, the vacuumizing pressure is 0.8-1.2 MPa, and the temperature is 80-100 DEG C; and the third stage time is 20-70 min, the vacuumizing pressure is 1-2.5 MPa, and the temperature is 90-150 DEG C.

[0019] The forming process in S3 comprises the following steps: the first stage is mold clamping and temperature rising, the pressure is kept at 0.25-0.5 MPa, and the material temperature is raised to 65-80 DEG C; the second stage is pressure and temperature rising, the pressure is increased to 1-3 MPa, and the material temperature is raised to 118-135 DEG C; and the third stage is temperature and pressure keeping for 50-90 min, until the temperature is reduced to below 50 DEG C, then the mold is opened and the product is taken out.

[0020] The forming process in S4 is as follows: the first stage is mold clamping and temperature rising, the pressure is kept at 1-3 MPa, and the material temperature is raised to 65-80 DEG C; the second stage is pressure and temperature rising, the pressure is increased to 4-5 MPa, and the material temperature is raised to 80-95 DEG C, during which the mold is opened and exhausts 2-4 times; the third stage is mold clamping, the pressure is increased to 7-10 MPa, and the temperature is continuously raised to 120-128 DEG C; and the fourth stage is temperature and pressure keeping for 40-50 min, until the temperature is reduced to below 35 DEG C, then the mold is opened and the product is taken out.

[0021] The stage heating and vacuumizing operation steps in S5 are as follows: the first stage time is 15-50 min, the vacuumizing pressure is 1-1.5 MPa, and the temperature is 75-110 DEG C; the second stage time is 40-100 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150 DEG C; and the third stage time is 20-70 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150 DEG C.

[0022] The unique bulletproof layer and the multi-layer structure design of the application imitate the macro and micro organization framework of the shell nacre layer, so that the composite armor has the characteristics of high specific energy absorption, can resist multiple high-speed impacts, the hemispherical convex structure of the titanium alloy panel can effectively protect against multiple bullet types such as sharp bullet, spherical bullet and blunt bullet, the independent ceramic hemispheres do not affect each other, the high-hardness ceramic balls can blunt and grind the bullet body, the camber surface design of the bulletproof layer can change the bullet penetration direction, the ceramic hemispheres can make the damage mode deflect between layers, and the anti-multiple-bullet performance of the armor plate is greatly improved; the transition layer adopts the carbon fiber plate embedded with steel wire grid, which can intercept part of the abraded and fragmented bullet fragments, and reduce the impact strength on the back plate. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in conjunction with the description of the application. The embodiments of the application, together with its description, are used to explain the application and do not constitute improper limitations on the application. Other related drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0024] Figure 1 Fig. 1 is a schematic view of a titanium alloy plate, wherein (A) is a front view, (B) is a left view, and (C) is a perspective view;

[0025] Figure 2 Fig. 2 is a schematic view of a titanium alloy plate in a state of a hemispherical groove opening upward, wherein (A) is a front view, (B) is a left view, and (C) is a perspective view;

[0026] Figure 3 Fig. 3 is a schematic view of a large-diameter ceramic hemisphere and a small-diameter ceramic hemisphere in a comparative relationship, wherein (A) is a front view, (B) is a left view, and (C) is a perspective view;

[0027] Figure 4 Fig. 4 is a schematic view of a composite armor according to the present application, wherein (A) is an exploded view, and (B) is a perspective view.

[0028] In the drawings, the reference signs are as follows: titanium alloy plate 1; plate body 10; large-diameter hemispherical shell 11; small-diameter hemispherical shell 12; large-diameter hemispherical groove 110; small-diameter hemispherical groove 120; large-diameter ceramic hemisphere 21; small-diameter ceramic hemisphere 22; large piece of woven fabric 31; small piece of woven fabric 32; carbon fiber prepreg 4; high-strength steel wire grid 5; carbon fiber prepreg 6; energy absorption layer 7. DETAILED DESCRIPTION

[0029] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] In the description of the embodiments of the present application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is placed, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present application or simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed or operated in a particular orientation, and therefore should not be understood as a limitation on the present application.

[0031] The "multiple" in the present application refers to two or more (including two). The terms "first", "second", etc. are only used for differentiation and description, and should not be understood as indicating or implying relative importance.

[0032] Unless specifically stated and defined otherwise, the terms "set", "install", "connect" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium.

[0033] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0034] As shown in the drawings, the present application is a three-layer composite structure, including a ballistic-resistant layer, a transition layer and an energy-absorbing layer (see Figure 4 ) formed by hot pressing, the ballistic-resistant layer includes a titanium alloy panel and ceramic hemispheres, and an adhesive and a low-areal-density high-performance fiber woven fabric or a prepreg are used for bonding between the two; the transition layer is a sandwich structure, which is formed by hot pressing of two layers of carbon fiber prepregs (4, 6) and a high-strength steel wire grid net 5 (core layer) sandwiched therebetween; the energy-absorbing layer 7 is a PE plate formed by pressing PE fiber prepregs as an energy-absorbing buffer structure.

[0035] The local macrostructure of the ballistic-resistant layer imitates the nacreous layer of a shell, and the excellent performance of matching strength and toughness after the soft phase and the hard phase are combined is realized by using a variety of material systems for toughening and compounding, which can not only cope with the penetration of the projectile with high hardness, high strength and high elastic modulus, but also meet the impact resistance and collapse resistance required by the armor with high ductility and toughness.

[0036] Specifically, the titanium alloy panel of the ballistic-resistant layer, as shown in Figure 1 and Figure 2 , includes a flat plate body 10, a plurality of semispherical protrusions protruding from the projectile-facing surface of the flat plate body 10 are formed on the flat plate body 10: large-diameter semispherical shells 11 and small-diameter semispherical shells 12, each large-diameter semispherical shell 11 forms a notch in the large-diameter semispherical groove 110 on the back of the projectile-facing surface of the flat plate body 10, and each small-diameter semispherical shell 12 forms a notch in the small-diameter semispherical groove 120 on the back of the projectile-facing surface of the flat plate body 10.

[0037] The thickness of the plate body of the flat plate body 10 is 3-10mm; the outer diameter of the large-diameter semispherical shell 11 is greater than the outer diameter of the small-diameter semispherical shell 12; all the large-diameter semispherical shells 11 are arranged in an array, and the outer surfaces of two adjacent large-diameter semispherical shells 11 in the same row or the same column abut, as shown in Figure 1 , the profile lines of the large-diameter semispherical shells 11 on the projectile-facing surface of the flat plate body are tangent to each other; the small-diameter semispherical shells 12 are arranged in the gaps between the four large-diameter semispherical shells, i.e., each small-diameter semispherical shell 12 is surrounded by four large-diameter semispherical shells 11.

[0038] Preferably, the outer diameter radius of the large-diameter hemispherical shell 11 is in the range of 10-25mm, and the inner diameter of the large-diameter hemispherical groove 110 formed by the large-diameter hemispherical shell 11 is 2-8mm smaller than the outer diameter; the outer diameter of the small-diameter hemispherical shell 12 is determined according to the actual size of the gap between the large-diameter hemispherical shells.

[0039] Each large-diameter hemispherical groove 110 contains a fixed large-diameter ceramic hemisphere 21, and each small-diameter hemispherical groove 120 contains a fixed small-diameter ceramic hemisphere 22. The round bottom surfaces of the large-diameter ceramic hemisphere 21 and the small-diameter ceramic hemisphere 22 are flush with and coplanar with the back elastic plate surface of the flat plate 10. Because the inner diameter of the large-diameter hemispherical groove 110 formed by the large-diameter hemispherical shell 11 is 2-8mm smaller than the outer diameter, even adjacent large-diameter and small-diameter ceramic hemispheres do not directly abut against each other, but leave a gap filled by the flat plate.

[0040] The hemispherical groove and the surface of the ceramic hemisphere are further bonded together by an adhesive using high-performance woven fabric or prepreg, as in this embodiment. Figure 4 As shown, a large piece of woven fabric 31 is bonded to the hemispherical surface of the large-diameter hemispherical groove 110 and the large-diameter ceramic hemispherical 21 by adhesive bonding, and a small piece of woven fabric 32 is bonded to the hemispherical surface of the small-diameter hemispherical groove 120 and the small-diameter ceramic hemispherical 22 by adhesive bonding.

[0041] The biomimetic structure, combining a titanium alloy panel with arrayed, staggered protrusions of varying sizes and independent ceramic hemispheres, serves as the projectile-facing surface. The protrusions on the titanium alloy panel effectively protect against various projectile types, including pointed, spherical, and blunt-nosed projectiles. The individual ceramic hemispheres do not interfere with each other. The high-hardness ceramic hemispheres utilize their hemispherical surfaces to blunt and abrade the projectile. The hemispherical protrusions of the ballistic protection layer can alter the projectile's penetration direction, and the ceramic hemispheres can deflect the damage mode between layers, greatly enhancing the armor plate's resistance to multiple projectiles.

[0042] Adding adhesive to the bonding surface of the titanium alloy and ceramic hemisphere at the weakest point, and bonding high-performance fiber woven fabric or prepreg with adhesive, can effectively improve the interfacial bonding strength compared to using adhesive alone. This effectively solves the macroscopic interface problem between the two material units. When the interface is damaged, the adhesive bonding strength is broken and the high-performance fiber woven fabric or prepreg is torn, thereby improving the tear resistance when penetrated and achieving the effect of dissipating the kinetic energy of the projectile.

[0043] The low surface density high performance fiber woven cloth or prepreg is a non-metallic material with excellent performance, the high performance fiber can be glass fiber, carbon fiber, etc., the single layer thickness is about 0.03-0.25mm, the gram weight is 30-200g / m2, and the titanium alloy panel and the ceramic ball are bonded by the adhesive as the interface reinforcing material, and the adhesive can be selected from one of epoxy adhesive, polyurethane adhesive, polyacrylic adhesive or silicone adhesive.

[0044] In the transition layer, the high-strength and high-modulus carbon fiber prepreg is pressed into a carbon fiber plate, which can improve the stiffness of the intermediate transition layer, fully exert the performance of the material itself, and synergistically improve the overall ballistic performance of the composite structure. The high-strength steel wire grid in the carbon plate can intercept part of the eroded and fragmented bullet fragments, reducing the impact strength on the back plate.

[0045] The material of the large and small diameter ceramic hemispheres can be one of boron carbide ceramic, silicon carbide ceramic or alumina ceramic, and the radii of the large and small diameter ceramic hemispheres are 2-5mm smaller than the inner diameters of the large and small diameter hemispherical grooves, so that the adhesive can be clamped and bonded after the high-performance fiber woven cloth or prepreg is bonded, and the circular bottom surface of the large and small diameter ceramic hemispheres can still be flush with the back plate surface of the flat plate 10. Before being loaded into the hemispherical groove, a pneumatic polishing head with 80-300 mesh sandpaper is used to polish the hemispherical surface of the ceramic hemisphere, and then the ceramic hemisphere is cleaned with alcohol and waited for compounding.

[0046] The transition layer is made of high-strength and high-modulus carbon fiber twill fabric prepreg, which is molded by a molding press. During laying, it is arranged in 0° / 90° orthogonal arrangement, and a high-strength steel wire grid is placed in the middle layer, and then the whole is molded and formed. The forming process is as follows: the first stage is to close the mold and heat, keep the pressure at 0.25-0.5MPa, and the material temperature rises to 65-80℃; the second stage is to increase the pressure and temperature, the pressure increases to 1-3MPa, and the material temperature rises to 118-135℃; the third stage is to keep the temperature and pressure for 50-90min, and the temperature is reduced to below 50℃, then the mold is opened and the product is taken out.

[0047] The steel wire diameter of the high-strength spring steel wire mesh is 2-5mm, the tensile strength is above 1500MPa, the elongation at break is not more than 4%, and the mesh size is 6-10mm.

[0048] The energy-absorbing layer is formed by pressing the PE fiber prepreg with a molding press, and the PE fiber used for the prepreg is high-strength and high-modulus material, with a fiber tensile strength greater than or equal to 40 cN / dtex and a tensile strength greater than 1500 cN / dtex. The forming process is as follows: the first stage is to heat the mold with a pressure of 1-3 MPa, and the material temperature is raised to 65-80℃; the second stage is to increase the pressure to 4-5 MPa and the material temperature to 80-95℃, and the mold is opened and vented 2-4 times during this period. The third stage is to increase the pressure to 7-10 MPa after closing the mold, and continuously heat to 120-128℃, and the fourth stage is to keep the temperature and pressure for 40-50 min, and cool to below 35℃ before demolding and taking out the part.

[0049] Embodiment of the preparation method:

[0050] (1) Pretreatment of large and small diameter ceramic hemispheres

[0051] The ceramic balls are boron carbide ceramics with radii of 15 mm and 6.5 mm, respectively. The arc surfaces are polished using a pneumatic polishing head with 80-300 mesh sandpaper, and then cleaned with alcohol. Wait to be combined with titanium alloy plates.

[0052] (2) Preparation of bulletproof layer

[0053] The titanium alloy plate flat area has a thickness of 4 mm, the hollow hemisphere A has an outer diameter of 18 mm and an inner diameter of 14 mm, the hollow hemisphere B has an outer diameter of 10.5 mm and an inner diameter of 6.5 mm, and the ceramic hemisphere A has a radius of 13 mm and the ceramic hemisphere B has a radius of 6.5 mm. After cleaning the back of the titanium alloy plate with alcohol, apply adhesive, hand lay a layer of glass fiber woven cloth, and apply adhesive on the curved surfaces of each ceramic hemisphere. Then, embed the ceramic balls of two sizes into the titanium alloy panel, and then place the entire bulletproof layer into a vacuum bag and vacuumize it, and then put it into a pressure tank for staged heating and vacuumizing. After cooling, a preform is obtained. The operation steps are as follows: the first stage time is 10-30 min, the vacuumizing pressure is 0.5-0.8 MPa, and the temperature is 60-80℃; the second stage time is 20-40 min, the vacuumizing pressure is 0.8-1.2 MPa, and the temperature is 80-100℃; the third stage time is 20-70 min, the vacuumizing pressure is 1-2.5 MPa, and the temperature is 90-150℃.

[0054] (3) Preparation of transition layer

[0055] The carbon fiber twill fabric prepreg has a grammage of 130 g / m2, is placed according to 0° / 90° orthogonal lamination, and a high-strength steel wire grid net is placed in the middle layer. The steel wire diameter of the high-strength spring steel wire net is 3 mm, the tensile strength is greater than 1500 MPa, the elongation at break is not greater than 4%, and the grid size is 8 mm. Then the whole is wrapped with a release film, and is pressed and formed by using a 1000t molding machine. The forming process is as follows: the first stage is mold closing and temperature rising, the pressure is kept at 0.25-0.5 MPa, and the material temperature is raised to 65-80℃; the second stage is pressure and temperature rising, the pressure is increased to 1-3 MPa, and the material temperature is raised to 118-135℃; the third stage is pressure and temperature maintaining for 50-90 min, and the temperature is reduced to below 50℃, then the mold is opened and the product is taken out.

[0056] (4) Energy absorption layer preparation

[0057] The PE fiber laminated plate is formed by molding the PE fiber prepreg by a 1000t molding machine. The PE fiber prepreg has a grammage of 120 g / m2, and the overall areal density is 6-10 kg / m2. The forming process is as follows: the first stage is mold closing and temperature rising, the pressure is kept at 1-3 MPa, and the material temperature is raised to 65-80℃; the second stage is pressure and temperature rising, the pressure is increased to 4-5 MPa, and the material temperature is raised to 80-95℃, during which the mold is opened for 2-4 times for exhaust. The third stage is mold closing and pressure increasing to 7-10 MPa, and the temperature is continuously raised to 120-128℃. The fourth stage is pressure and temperature maintaining for 40-50 min, and the product is taken out after cooling to below 35℃.

[0058] (5) Composite forming

[0059] The composite armor preform is formed by sequentially placing the PE fiber laminated plate, the transition layer and the bulletproof layer (the crack stopping layer faces upward) in order. A hot melt adhesive film is placed in each bonding surface. The thickness of the hot melt adhesive film layer is 0.1-0.16 mm, the areal density is 110±16 g / m2, and the material can be one of PU film, EVA film, polyurethane film, thermosetting film, thermoplastic film and phenolic resin film. The composite armor preform is placed in a vacuum bag after vacuumizing, and is then subjected to stage heating and vacuumizing in a pressure tank. The formed product is obtained after cooling. The operation steps are as follows: (1) the first stage time is 15-50 min, the vacuumizing pressure is 1-1.5 MPa, and the temperature is 75-110℃; (2) the second stage time is 40-100 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150℃; (3) the third stage time is 20-70 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150℃.

[0060] The composite armor prepared in the above examples was subjected to a 54 type 12.7 mm semi-speed (488+10 m / s) armor-piercing incendiary bullet shooting test at a normal angle of 0° and a shooting distance of 100 m. The parameters of the composite armor and the test results are shown in Table 1, and the sample after shooting was disassembled and analyzed.

[0061] Table 1: Comparison of parameters of composite armor and test results

[0062]

[0063] The above description is merely preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite armor of biomimetic structure, characterized in that, The ballistic-resistant layer, the transition layer and the energy-absorbing layer are sequentially stacked, the ballistic-resistant layer comprises a titanium alloy panel and a plurality of ceramic hemispheres, and the two are bonded by using an adhesive and a low-areal-density high-performance fiber woven fabric or a prepreg; The titanium alloy panel of the ballistic-resistant layer comprises a flat plate body, a plurality of hemispherical protrusions protruding from the ballistic-resistant surface are formed on the flat plate body, the hemispherical protrusions include large-diameter hemispherical shells and small-diameter hemispherical shells, each large-diameter or small-diameter hemispherical shell forms a large-diameter or small-diameter hemispherical groove on the back of the flat plate body, the outer diameter of the large-diameter hemispherical shell is larger than that of the small-diameter hemispherical shell, the large-diameter hemispherical shells are arranged in an array, the outer surfaces of two adjacent large-diameter hemispherical shells in the same row or column are tangent to each other, and the small-diameter hemispherical shells are arranged in the gaps between the four large-diameter hemispherical shells, that is, each small-diameter hemispherical shell is adjacent to four large-diameter hemispherical shells, each large-diameter hemispherical groove contains a large-diameter ceramic hemisphere fixed therein, each small-diameter hemispherical groove contains a small-diameter ceramic hemisphere fixed therein, and the circular bottom surfaces of the large-diameter and small-diameter ceramic hemispheres are flush with the back of the flat plate body; The transition layer is a sandwich structure composed of two layers of carbon fiber prepregs and a high-strength steel wire grid sandwiched therebetween and hot-pressed to form the transition layer; The energy-absorbing layer is a PE plate formed by pressing PE fiber prepregs.

2. A composite armor of biomimetic structure according to claim 1, characterized in that, The hemispherical grooves and the hemispherical surfaces of the ceramic hemispheres are also bonded by using an adhesive and a high-performance fiber woven fabric or a prepreg.

3. A composite armor of biomimetic structure according to claim 1, characterized in that, The radius of the outer diameter of the large-diameter hemispherical shell ranges from 10 mm to 25 mm, and the inner diameter of the large-diameter hemispherical groove formed by the large-diameter hemispherical shell is 2-8 mm smaller than the outer diameter.

4. A composite armor of biomimetic structure according to claim 1, characterized in that, The thickness of the flat plate body is 3-10 mm.

5. A method of preparing a bionic structured composite armor as claimed in claim 1, wherein, The method comprises the following steps: S1, pretreatment of large-diameter and small-diameter ceramic hemispheres, a pneumatic polishing head is used to install 80-300 mesh sandpaper to polish the curved surface, then the curved surface is cleaned with alcohol, and the large-diameter and small-diameter ceramic hemispheres are prepared for use; S2, preparation of the ballistic-resistant layer, the titanium alloy plate is cleaned with alcohol, adhesive is applied to the surfaces of the large-diameter and small-diameter hemispherical grooves, a layer of high-performance fiber woven fabric or prepreg is hand-pasted, adhesive is also applied to the hemispherical surfaces of the large-diameter and small-diameter ceramic hemispheres, then the large-diameter and small-diameter ceramic hemispheres are respectively embedded in the corresponding large-diameter and small-diameter hemispherical grooves, then the entire ballistic-resistant layer is placed in a vacuum bag to be in a vacuum state, and then the vacuum bag is placed in an autoclave for stage heating and vacuumizing, and a ballistic-resistant layer preform is obtained after cooling; S3, preparation of the transition layer, carbon fiber twill fabric prepregs are arranged in a cross-laid manner, a high-strength steel wire grid is placed in the middle layer, then the entire layer is wrapped with a release film, and then the layer is pressed into shape by using a press; S4, preparation of the energy-absorbing layer, the PE fiber laminated plate is formed by pressing PE fiber prepregs by using a press, and the areal density of the entire layer is 7-10 kg / m2; S5, composite molding, the energy-absorbing layer, the transition layer and the ballistic-resistant layer are sequentially laid to form a composite armor preform, hot melt adhesive film is arranged in the bonding surfaces, the thickness of the hot melt adhesive film layer is 0.1-0.16 mm, the areal density of the hot melt adhesive film layer is 110±16 g / m2, and the material of the hot melt adhesive film layer is one of PU adhesive film, EVA adhesive film, polyurethane adhesive film, thermosetting adhesive film, thermoplastic adhesive film and phenolic resin adhesive film, the composite armor preform is placed in a vacuum bag to be in a vacuum state, then the vacuum bag is placed in an autoclave for stage heating and vacuumizing, and a molded part is obtained after cooling.

6. A method of preparing a bionic structured composite armor according to claim 5, wherein, The step of the stage heating and vacuumizing operation in S2 is as follows: the first stage time is 10-30 min, the vacuumizing pressure is 0.5-0.8 MPa, and the temperature is 60-80 ℃; the second stage time is 20-40 min, the vacuumizing pressure is 0.8-1.2 MPa, and the temperature is 80-100 ℃; the third stage time is 20-70 min, the vacuumizing pressure is 1-2.5 MPa, and the temperature is 90-150 ℃; The forming process in S3 comprises: the first stage is mold clamping and temperature rising, the pressure is kept at 0.25-0.5 MPa, and the material temperature is raised to 65-80 ℃; the second stage is pressure and temperature rising, the pressure is increased to 1-3 MPa, and the material temperature is raised to 118-135 ℃; the third stage is pressure and temperature keeping for 50-90 min, and the temperature is reduced to below 50 ℃, then the mold is opened and the product is taken out.

7. A method of preparing a bionic structured composite armor according to claim 5, wherein, The forming process in S4 is as follows: the first stage is mold clamping and temperature rising, the pressure is kept at 1-3 MPa, and the material temperature is raised to 65-80 ℃; the second stage is pressure and temperature rising, the pressure is increased to 4-5 MPa, and the material temperature is raised to 80-95 ℃, during which the mold is opened and exhausted 2-4 times; the third stage is mold clamping and pressure increasing to 7-10 MPa, and the temperature is continuously raised to 120-128 ℃; the fourth stage is pressure and temperature keeping for 40-50 min, and the temperature is cooled to below 35 ℃, then the mold is opened and the product is taken out; The step of the stage heating and vacuumizing operation in S5 is as follows: the first stage time is 15-50 min, the vacuumizing pressure is 1-1.5 MPa, and the temperature is 75-110 ℃; the second stage time is 40-100 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150 ℃; the third stage time is 20-70 min, the vacuumizing pressure is 1.5-4 MPa, and the temperature is 90-150 ℃.

Images