Liquid-gel gradient fluid-filled fiber composite flexible near-field blast protection structure

Abstract

The application discloses a liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure, and aims to solve the problems of limited application range and insufficient protection ability under near-field explosion of the current explosion protection device. The whole structure is a cuboid, which is composed of a composite fiber box, an explosion-proof liquid layer, an explosion-proof gel layer and a super-elastic coating. The explosion-proof liquid layer and the explosion-proof gel layer are filled in the composite fiber box, the super-elastic coating is sprayed on the outside of the composite fiber box, and the two layers are separated by a partition fiber plate. The explosion-proof liquid is a water-based material, and the explosion-proof gel is a polymer gel. The application adopts multiple layers of media, the explosion-proof liquid and the explosion-proof gel form a density gradient, can effectively resist detonation products, attenuate shock waves and fragments, has high anti-fragment penetration ability, high near-field explosion protection ability and high matching ability with the protected structure, and the protection effect is stable, so that the light armored equipment can be effectively protected.

Description

Technical Field

[0001] This invention relates to a near-field explosion protection structure, and more particularly to a liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure. Background Technology

[0002] Near-field explosion protection is an important research direction in the field of explosion protection. The difficulty of near-field explosion protection lies in its extreme uncertainty and complexity. This requires researchers to continuously deepen their understanding of explosion phenomena, improve prediction and assessment capabilities, optimize protective designs, enhance dynamic response capabilities, and implement comprehensive protective measures to address the threat of near-field explosions. Near-field explosion protection design is complex, requiring comprehensive consideration of multiple factors, such as the type, location, and explosive power of the explosive, as well as the structure, materials, and location of the protective facilities. The instantaneous nature of near-field explosions necessitates that protective facilities possess a high degree of dynamic response capability to cope with the shock wave, fragments, and detonation products generated by the explosion, in order to limit the damage and destruction range of lightly armored equipment.

[0003] Early near-field protection materials were low-carbon steel (high density, heavy, and prone to fragmentation upon breakage). Based on this, alloy steel and aluminum alloys were developed. A sandwich panel design using composite materials such as metals and ceramics was adopted as a near-field explosion protection device. However, existing near-field explosion protection devices suffer from problems such as insufficient effectiveness (with the development of weaponry, ordinary metals are no longer sufficient to protect targets), poor adaptability (unable to adapt to diverse environments), difficult maintenance (metal materials require regular maintenance), and the tendency for fragments to generate secondary fragments. To solve these problems, it is necessary to strengthen research and development of explosion protection technology, improve the design level and adaptability of protective devices, reduce their cost and maintenance difficulty, and achieve lightweight design for better promotion and application. Patent application number 201710483227.X discloses a variable wall thickness fiber composite flexible explosion-proof structure, which is a hollow rotating body structure. Although the device uses liquid, aerogel and fiber structure, the upper part of the device uses a rubber layer-liquid layer-rubber layer, and the lower part uses a fiber layer-aerogel layer-liquid layer-fiber layer. The upper part has weak protection capability, while the lower part has strong protection capability. It can be used to deal with explosives, but it is not suitable for protecting light armored equipment. Patent application number 202110729992.1 discloses a solid-liquid coupled core fiber composite flexible sandwich cylindrical explosion-proof structure. It uses fiber-reinforced plastic, high water absorption foam and explosion-proof liquid in a solid-liquid coupling form to improve the problems of low storage safety and poor explosion protection effect of explosion-proof liquid. Patents with application numbers 201710483227.X and 202110729992.1 both feature cylindrical explosion-proof structures, which have limited applicability, only suitable for handling explosives. They cannot fit well against the protected object and are unsuitable for light armor protection. The key technical challenge is how to protect light armored equipment in extremely close-range conditions, ensuring the explosion-proof structure fits snugly against the protected structure, while also being lightweight, easy to replace, and preventing secondary fragmentation after an explosion. Effective protection against shock waves, fragments, and detonation products is also crucial. Summary of the Invention

[0004] The technical problem this invention aims to solve is the limited applicability of current explosion protection devices, insufficient protection capabilities under near-field explosions (i.e., ineffective protection against the combined load of shock waves, fragments, and detonation products), poor topological compatibility with the protected object, and poor applicability. This invention provides a liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure, which improves near-field explosion protection capabilities, the compatibility with the protected structure, the protective performance of the near-field explosion protection structure, and the ability to protect lightly armored equipment in extremely close-field conditions.

[0005] The technical solution of this invention is:

[0006] The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure of the present invention is generally cuboid in shape, and consists of four parts: a composite fiber box, an explosion-proof liquid layer, an explosion-proof gel layer and a superelastic coating. The explosion-proof liquid layer and the explosion-proof gel layer are poured inside the composite fiber box, and the superelastic coating is sprayed outside the composite fiber box.

[0007] The length of the liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure is L, L is greater than the length of the protected object, satisfying 300mm<L<3000mm; the width is W, W is greater than the width of the protected object, satisfying 300mm<L<3000mm; the thickness is T, which is determined according to the explosion resistance requirement, satisfying 50mm<L<500mm.

[0008] The composite fiber box 2 is a cuboid, with a length l satisfying 0.92L<l<0.98L, a width w satisfying 0.92W<w<0.98W, and a height t of the composite fiber box satisfying 0.92T<t<0.98T. Two cubic spaces are excavated inside the composite fiber box to form a first solution cavity and a second solution cavity. The fiber boards separating the two cavities are sequentially the blast-face facing fiber composite board, the compartment fiber composite board and the blast-back face fiber composite board. The thickness of the blast-face facing fiber composite board is T1, the thickness of the compartment fiber composite board is T2, and the thickness of the blast-back face fiber composite board is T3. The compartment fiber composite board is thinner than the blast-face facing fiber composite board and the blast-back face fiber composite board, the thickness of the blast-face facing fiber composite board and the blast-back face fiber composite board are equal, T2< T1= T3.

[0009] The material of the composite fiber box is ultra-high molecular weight fiber composite material, with a density of 0.8g / cm 3 to 1.5g / cm 3 and the tensile strength is greater than 800MPa.

[0010] The first solution cavity is a cavity isolated by the blast-face facing fiber composite board and the compartment fiber composite board, with a length l1 satisfying 0.7l<l1<0.9l, a width w1 satisfying 0.7w<w1<0.9w, and a thickness t2 of the first solution cavity satisfying 0.2t<t2<0.4t. Explosion-proof liquid is filled in the first solution cavity, and the filled explosion-proof liquid forms the explosion-proof liquid layer. The explosion-proof liquid is a water-based material, for example, any one of water, glycerol and shear thickening fluid, with a density of 1.0g / cm 3 to 1.3g / cm 3between them. When an explosion shock wave acts on the first solution cavity, the explosion-proof liquid will form an explosion-proof liquid wall. When the explosion shock wave encounters the explosion-proof liquid wall, most of the shock wave is reflected back along the incident direction of the explosion shock wave, and only a small number of shock waves with very low intensity transmit through the explosion-proof liquid wall, so that the destructive power is greatly reduced. The explosion-proof liquid can generate great resistance to high-speed fragments by virtue of its own inertia, and greatly attenuate the flying speed of fragments within a very short distance, so as to reduce the destructive power.

[0011] The second solution cavity is a cavity isolated by the compartment fiberboard composite plate and the back-blast surface fiber composite plate, with a length of l2, 0.7l<l2<0.9l, a width of w2, 0.7w<w2<0.9w, and a thickness of t1, 0.2t<t1<0.4t. The second solution cavity is filled with explosion-proof gel, and the filled explosion-proof gel forms an explosion-proof gel layer. The explosion-proof gel is a polymer gel with a density of 1.3g / cm 3 to 2.0g / cm 3 , with a tensile strength of not less than 1MPa and a water absorption rate of more than 50%. When an explosion load acts on the second solution cavity, the propagation of the shock wave in the explosion-proof gel will produce a dispersion effect, which weakens the intensity of the shock wave. When long-distance low-speed fragments act on the explosion-proof gel, the explosion-proof gel plays a buffering role; the coupling effect of the compartment fiber composite plate and the back-blast surface fiber composite plate on the explosion-proof gel plays a toughening role, improving the protection effect against short-range high-speed fragments.

[0012] The entire outer surface of the composite fiber box body is sprayed with a superelastic material (such as any one of polyurea, carbon nanotubes and polymer materials) to form a superelastic coating, with a thickness of (T-t) / 2, 0.02T<(T-t) / 2<0.08T. The tensile strength of the superelastic material is greater than 30MPa, and the elongation at break is greater than 100%. When the explosion shock wave reaches the superelastic coating, the superelastic coating can weaken the intensity of the shock wave and absorb the energy generated by the explosion by changing its microstructure. In the present invention, the thickness of the composite fiber box body t=T1+T2+T3+t1+t2, and the thickness of the superelastic coating is (T-t) / 2.

[0013] The present invention can be placed near weapons and equipment, or hung on key equipment. After an explosive explodes, it will produce a combined load of shock wave, fragments and detonation products. The process of realizing anti-explosion protection by the present invention is mainly divided into the following three stages:

[0014] In the first stage, when the explosive detonates around the invention, the shock wave, fragments, and detonation products first act on the hyperelastic coating and the fiber composite plate on the explosion-facing surface of the composite fiber box. The hyperelastic has high tensile strength and elongation at break, and the fiber composite plate on the explosion-facing surface has high bending and tensile strength, which can effectively attenuate the shock wave and protect against fragments. Large, high-velocity fragments will pass through the hyperelastic coating 1 and the fiber composite plate on the explosion-facing surface and act on the first solution cavity.

[0015] In the second stage, the first solution chamber, under the influence of the shock wave, generates an explosion-proof liquid wall that couples with the fiber composite partition plate. The explosion-proof liquid wall attenuates the shock wave and resists fragmentation. Simultaneously, the second solution chamber generates an explosion-proof gel wall, which, together with the fiber composite partition plate, effectively absorbs the energy of the shock wave and attenuates high-speed fragments. Compared to a single-layer solution chamber, because the density of the explosion-proof gel is greater than that of the explosion-proof liquid, the explosion-proof liquid forms a more stable protective layer after being subjected to the shock wave. The explosion-proof liquid attenuates the shock wave and fragments, while the explosion-proof gel absorbs the energy of the shock wave and the heat generated by the explosion. Compared to traditional multi-layer fiberboard, the coupling effect of the explosion-proof liquid-partition fiberboard-explosion-proof gel effectively protects against shock waves, attenuates fragments, and resists detonation products, and absorbs the energy generated by the explosion, thus effectively dealing with the combined effects of shock waves, fragments, and detonation products in near-field explosions.

[0016] In the third stage, the back-blast surface fiber composite plate and the superelastic coating similarly attenuate the shock wave and protect against fragments, effectively reducing the destructive power of the shock wave and blocking fragments on the surrounding environment and minimizing the lethality to nearby personnel. The multi-layer fiber composite plate (blast-facing fiber composite plate, compartment fiber composite plate, and blast-affected fiber composite plate) improves the blast resistance of this invention, and the coupling of the multi-layer fiber composite plate with the explosion-proof liquid and explosion-proof gel enhances the effectiveness in dealing with the combined effects of shock wave, fragments, and detonation products.

[0017] This invention is a rectangular near-field explosion protection device that absorbs shock wave energy, protects against fragmentation, and blocks detonation products. Compared with existing technologies, this invention achieves the following beneficial effects:

[0018] (1) The present invention uses a multi-layer medium composed of superelastic coating - explosion-facing fiber composite board - explosion-proof liquid layer - partition fiber composite board - explosion-proof gel layer - back explosion-facing fiber composite board. The explosion-proof liquid and explosion-proof gel form a density gradient, which allows the explosion-proof liquid to form a more uniform explosion-proof liquid wall after being subjected to shock wave. The gradient combination of explosion-proof liquid and explosion-proof gel can not only effectively resist detonation products, attenuate shock waves and fragments, but also has a high resistance to fragment penetration under the coupling effect of composite fiber board.

[0019] (2) When the explosive TNT equivalent is large, the first solution cavity and the second solution cavity can be broken and disintegrated in sequence to form an explosion-proof liquid wall and an explosion-proof gel wall. This can not only reduce the temperature of the detonation products and suppress the flame, but also effectively attenuate, reflect and disperse the air shock wave. At the same time, under the action of the superelastic coating-detonation-explosion-facing fiber composite board-interval fiber composite board-back-detonation-facing fiber composite board, the fragmentation velocity is attenuated and fragments are adsorbed.

[0020] (3) The superelastic material, fiber composite material, explosion-proof liquid and explosion-proof gel used in this invention are all flexible materials that can adhere to the surface of the protected structure to form a tight protective layer, effectively reducing the propagation and diffusion of the explosion shock wave and improving the stability of the protection effect.

[0021] (4) The superelastic coating and fiber composite box of this invention are both low-density, high-strength materials, with light overall weight, strong explosion resistance, and convenient installation and use. If disintegration occurs under near-field explosion load, the resulting secondary fragments will hardly damage the personnel and equipment. Under extremely near-field explosion, this invention can effectively protect light armored equipment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 It is along Figure 1 Sectional view along the AA' direction;

[0024] Figure 3 These are the front view and top view of the present invention. Figure 3 (a) is a front view of the present invention. Figure 3 (b) is a top view of the present invention.

[0025] Figure 4 This is a cross-sectional view of the present invention. Figure 4 (a) is along Figure 3 (b) Sectional view along the CC' direction, Figure 4 (b) is along Figure 3 (a) Sectional view along the BB' direction.

[0026] Figure 5 This is a diagram showing the explosion damage effect of the present invention at a detonation distance of 30cm and a TNT charge of 208.1g. Detailed Implementation

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] like Figure 1 As shown, combined with Figure 2 , Figure 3 (a) and Figure 3(b), the liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure of the present invention is generally in the shape of a cuboid, and the structure consists of four parts: a composite fiber box 2, an explosion-proof liquid layer 3, an explosion-proof gel layer 4, and a superelastic coating 1. The explosion-proof liquid layer 3 and the explosion-proof gel layer 4 are poured inside the composite fiber box 2, and the superelastic coating 1 is sprayed outside the composite fiber box 2. In the present invention, the length is L, the width is W, L is greater than the length of the protected object, W is greater than the width of the protected object, and the thickness is T, which is determined according to the anti-explosion requirements.

[0029] As shown in Figure 4 (a), the composite fiber box 2 is a cuboid with a length of l, 0.92L<l<0.98L, and a width of w, 0.92W<w<0.98W, as shown in Figure 4 (b), the thickness of the composite fiber box 2 is t, 0.92T<t<0.98T. The two surfaces where the length and width of the composite fiber box 2 are located are the explosion-facing fiber composite board 21 and the back-explosion fiber composite board 25 respectively. Two cubic spaces are dug inside the composite fiber box 2 along a direction parallel to the explosion-facing fiber composite board 21 to form a first solution cavity 23 and a second solution cavity 24. A partition between the first solution cavity 23 and the second solution cavity 24 is a compartment fiber composite board 22. The surface of the first solution cavity 23 opposite to the compartment fiber composite board 22 is the explosion-facing fiber composite board 21, and the surface of the second solution cavity 24 opposite to the compartment fiber composite board 22 is the back-explosion fiber composite board 25. The explosion-facing fiber composite board 21, the compartment fiber composite board 22, and the back-explosion fiber composite board 25 are parallel to each other. The thickness of the explosion-facing fiber composite board 21 is T1, the thickness of the compartment fiber composite board 22 is T2, and the thickness of the back-explosion fiber composite board 25 is T3. The compartment fiber composite board 22 is thinner than the explosion-facing fiber composite board 21 and the back-explosion fiber composite board 25, the thicknesses of the explosion-facing fiber composite board 21 and the back-explosion fiber composite board 25 are equal, so T2 < T1 = T3.

[0030] The material of the composite fiber box 2 is ultra-high molecular weight fiber composite material, with a density of 0.8g / cm 3 to 1.5g / cm 3 and the tensile strength is greater than 800MPa.

[0031] as shown in Figure 2 and Figure 4As shown in (b), the first solution cavity 23 is a cavity isolated by the fiberboard composite panel 23 on the blast-facing side and the compartment fiberboard composite panel 22, with a length l1 satisfying 0.7l<l1<0.9l, a width w1 satisfying 0.7w<w1<0.9w, and a thickness t2 of the first solution cavity 23 satisfying 0.2t<t2<0.4t. The first solution cavity 23 is filled with explosion-proof liquid, and the filled explosion-proof liquid forms an explosion-proof liquid layer 3. The explosion-proof liquid is a water-based material, such as water, glycerin, shear thickening liquid, etc., with a density of 1.0g / cm 3 to 1.2g / cm 3 When an explosion shock wave acts on the first solution cavity 23, the explosion-proof liquid will form an explosion-proof liquid wall. When the explosion shock wave encounters the explosion-proof liquid wall, most of it is reflected back along the incident direction of the explosion shock wave, and only a small number of shock waves with very low intensity transmit through the explosion-proof liquid wall, which greatly reduces the destructive power. The explosion-proof liquid can use its own inertia to generate great resistance to high-speed fragments, and greatly attenuate the flying speed of fragments within a very short distance, so as to reduce the destructive power.

[0032] The second solution cavity 24 is a cavity isolated by the compartment fiberboard composite panel 22 and the back-blast fiber composite panel 25, with a length l2 satisfying 0.7l<l2<0.9l, a width w2 satisfying 0.7w<w2<0.9w, and a thickness t1 of the second solution cavity 24 satisfying 0.2t<t1<0.4t. The second solution cavity 24 is filled with explosion-proof gel, and the filled explosion-proof gel forms an explosion-proof gel layer 4. The explosion-proof gel is a polymer gel (such as a mixture with polyacrylic acid, polyacrylamide and other materials as main components), with a density of 1.2g / cm 3 to 2.0g / cm 3 the tensile strength is not less than 1MPa, and the water absorption rate is above 50%. When an explosion load acts on the second solution cavity 24, the propagation of the shock wave in the explosion-proof gel will produce a dispersion effect, which weakens the intensity of the shock wave. When long-distance low-speed fragments act on the explosion-proof gel, the explosion-proof gel plays a buffering role; the coupling effect of the compartment fiber composite panel 22 and the back-blast fiber composite panel 25 on the explosion-proof gel plays a toughening role, improving the protection effect against short-distance high-speed fragments.

[0033] The entire outer surface of the composite fiber box 2 is sprayed with a superelastic material to form a superelastic coating 1, the thickness of which is equal to (T-t) / 2, satisfying 0.02T<(T-t) / 2<0.08T. The superelastic material (such as any one of polyurea, carbon nanotube and polymer materials) has a tensile strength greater than 30MPa and an elongation at break greater than 100%. When an explosion shock wave reaches the superelastic coating, the superelastic coating 1 can weaken the intensity of the shock wave and absorb the energy generated by the explosion by changing its microstructure.

[0034] One embodiment of the present invention has the following parameters: L=300mm, l=290mm, l1=250mm, W=300mm, w=290mm, w1=250mm, w2=250mm, T=100mm, t=90mm, t1=20mm, t2=20mm, t3=5mm, T1=20mm, T2=10mm, T3=20mm; the box material is ultra-high molecular weight polyethylene fiber with a density of 0.98g / cm3, a strength of 5N / tex, and a modulus of 85N / tex; the explosion-proof fluid is glycerin with a density of 1.28 g / cm3. 3 The explosion-proof gel material uses SAP superabsorbent polymer (SAP) with a particle size of 150 sieve holes per inch, forming a hydrogel after absorbing water; the superelasticizer uses polyurea with a density of 1.06 g / cm³. 3 It has a tensile strength of 15 MPa and an elongation at break of 350%.

[0035] The explosive used is TNT, with 25 steel balls of 8mm diameter attached to the bottom, which are suspended 300mm from the top of the composite fiberboard.

[0036] Under the action of an explosion, the main loads generated include shock waves, fragments, and detonation products. Experiments conducted on Example 1 showed that fragments first act on the polyurea coating 1, which attenuates the fragments and produces uneven cracks. Subsequently, the fragments act on the fiber composite plate 21 facing the explosion, which is then punctured, and the fragment velocity is attenuated to a lower value. When the explosion shock wave acts on the first solution cavity 23, it is attenuated by the glycerol filling the cavity, and the explosion-proof liquid forms an explosion-proof liquid wall. When the explosion shock wave encounters this wall, most of it is reflected back in the direction from which it originated, with only a few low-intensity shock waves penetrating through, significantly reducing the destructive force. When the explosion load acts on the second solution cavity 24, the shock wave propagates through the hydrogel filling it, producing a dispersion effect that weakens the shock wave intensity. When low-velocity fragments from a long distance strike the explosion-proof gel, the gel acts as a buffer. During this process, the coupling effect between the compartment fiber composite plate 22 and the back-explosion-facing fiber composite plate 25 on the explosion-proof gel strengthens it, improving protection against high-velocity fragments at close range. When the shock wave acts on the polyurea coating 1 and the explosion-facing fiber composite plate 21, they deform together. The energy of the shock wave is mainly buffered and absorbed by the glycerol and hydrogel filled in the first solution chamber 23 and the second solution chamber 24.

[0037] Figure 5 This is a diagram illustrating the explosion damage effect of an embodiment of the present invention at a detonation distance of 30cm and a TNT charge of 208.1g. From... Figure 5As can be seen, when the embodiment of the present invention is subjected to an explosive impact at a blast distance of 30cm and a TNT charge of 208.1g, the polyurea coating 1 and the fiber composite plate 21 facing the blast are subjected to fragmentation. The polyurea coating 1 cracks, and the fiber plate 21 facing the blast is damaged and penetrated. However, due to the strong ability of the first solution cavity 23 and the second solution cavity 24 to absorb fragments and shock waves, the fiber plate 25 facing the blast is not penetrated. It can be seen that compared with traditional metal material protection, which does not consider the secondary fragmentation formed by the metal material breaking and has a large mass that is not suitable for movable structures, the present invention has a lightweight structure and good blast resistance.

Claims

1. A liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure, characterized in that... The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure has an overall cuboid shape, and is composed of four parts: a composite fiber box (2), an explosion-proof liquid layer (3), an explosion-proof gel layer (4), and a superelastic coating (1); the explosion-proof liquid layer (3) and the explosion-proof gel layer (4) are filled inside the composite fiber box (2), and the superelastic coating (1) is sprayed outside the composite fiber box (2). The superelastic has a tensile strength greater than 30 MPa and an elongation at break greater than 100%, which functions to attenuate shock waves and protect against fragments; the length of the liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure is L, L is greater than the length of the protected object, satisfying 300mm < L < 3000mm; the width is W, W is greater than the width of the protected object, satisfying 300mm < W < 3000mm; the thickness is T, satisfying 50mm < T < 500mm; The composite fiber box (2) is a cuboid, with a length of l, l < L, a width of w, w < W, and a thickness of t, t < T; the two faces where the length and width of the composite fiber box (2) are located are the explosion-facing fiber composite plate (21) and the back-explosion fiber composite plate (25) respectively; two cuboid spaces are dug inside the composite fiber box (2) along a direction parallel to the explosion-facing fiber composite plate (21), forming a first solution cavity (23) and a second solution cavity (24). The partition plate between the first solution cavity (23) and the second solution cavity (24) is the compartment fiber composite plate (22), the face of the first solution cavity (23) opposite to the compartment fiber composite plate (22) is the explosion-facing fiber composite plate (21), and the face of the second solution cavity (24) opposite to the compartment fiber composite plate (22) is the back-explosion fiber composite plate (25); the explosion-facing fiber composite plate (21), the compartment fiber composite plate (22), and the back-explosion fiber composite plate (25) are parallel to each other; the explosion-facing fiber composite plate (21) functions to attenuate shock waves and protect against fragments, with a thickness of T1, the thickness of the compartment fiber composite plate (22) is T2, and the thickness of the back-explosion fiber composite plate (25) is T3; The material of the composite fiber box (2) is ultra-high molecular weight fiber composite material; The first solution cavity (23) is a cavity defined by the explosion-facing surface fiber composite plate (21) and the compartment fiber composite plate (22), with a length of l1, l1<l, a width of w1, w1<w, and a thickness of t2, t2<t; the first solution cavity (23) is filled with explosion-proof liquid, and the filled explosion-proof liquid forms the explosion-proof liquid layer (3); the explosion-proof liquid is a water-based material with a density of 1.0g / cm 3 to 1.2g / cm 3 ; when an explosion shock wave acts on the first solution cavity (23), the explosion-proof liquid forms an explosion-proof liquid wall and couples with the compartment fiber composite plate (22). When the explosion shock wave encounters the explosion-proof liquid wall, most of the shock wave is reflected back in the incoming direction of the explosion shock wave, and only a small amount of shock wave with very low intensity transmits through the explosion-proof liquid wall. The explosion-proof liquid uses its own inertia to generate resistance to high-speed fragments, attenuate the flying speed of fragments, and reduce the destructive power; The second solution cavity (24) is a cavity isolated by the compartment fiber composite plate (22) and the back blast surface fiber composite plate (25), with a length of l2, l2<l, a width of w2, w2<w, and a thickness of t1, t1<t; the second solution cavity (24) is filled with explosion-proof gel, and the filled explosion-proof gel forms an explosion-proof gel layer (4); the explosion-proof gel is polymer gel, which requires a density of 1.2g / cm 3 to 2.0g / cm 3 with a tensile strength of not less than 1MPa and a water absorption rate of more than 50%; when an explosion load acts on the second solution cavity (24), the propagation of shock waves in the explosion-proof gel will produce a dispersion effect, weakening the intensity of the shock waves; when long-distance low-velocity fragments act on the explosion-proof gel, the explosion-proof gel plays a buffering role; the coupling effect of the compartment fiber composite plate (22) and the back blast surface fiber composite plate (25) on the explosion-proof gel plays a toughening role and improves the protection effect against short-distance high-velocity fragments; The entire outer surface of the composite fiber box (2) is sprayed with superelastic material to form the superelastic coating (1), the thickness of which is equal to (T-t) / 2; the superelastic material has a tensile strength greater than 30 MPa and an elongation at break greater than 100%; when an explosion shock wave reaches the superelastic coating, the superelastic coating (1) weakens the intensity of the shock wave, and absorbs the energy generated by the explosion by changing the microstructure.

2. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The length l of the composite fiber box (2) satisfies 0.92L < l < 0.98L, the width w satisfies 0.92W < w < 0.98W, and the thickness t of the composite fiber box (2) satisfies 0.92T < t < 0.98T; the thickness T1 of the explosion-facing fiber composite plate (21), the thickness T2 of the compartment fiber composite plate (22), and the thickness T3 of the back-explosion fiber composite plate (25) satisfy T2 < T1 = T3.

3. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The composite fiber box (2) uses ultra-high molecular weight fiber composite material with a density of 0.8 g / cm³. 3 Up to 1.5g / cm 3 Between these values, the tensile strength is greater than 800 MPa.

4. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The length l1 of the first solution cavity (23) satisfies 0.7l<l1<0.9l, the width w1 satisfies 0.7w<w1<0.9w, and the thickness t2 of the first solution cavity (23) satisfies 0.2t<t2<0.4t.

5. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The explosion-proof liquid is any one of water, glycerin and shear thickening liquid.

6. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The length l2 of the second solution cavity (24) satisfies 0.7l<l2<0.9l, the width w2 satisfies 0.7w<w2<0.9w, and the thickness t1 of the second solution cavity (24) satisfies 0.2t<t1<0.4t.

7. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The explosion-proof gel is a mixture with polyacrylic acid and polyacrylamide as main components.

8. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The thickness of the superelastic coating (1) satisfies 0.02T<(T-t) / 2<0.08T.

9. The liquid-gel gradient fluid-filled fiber composite flexible near-field explosion protection structure as described in claim 1, characterized in that... The superelastic material is any one of polyurea and carbon nanotube.

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