阅读说明：本技术 折叠式防爆围栏的设计、制作方法及其产品 (Design and manufacturing method of folding type explosion-proof fence and product thereof ) 是由 黄广炎 卞晓兵 王涛 于 2021-08-23 设计创作，主要内容包括：本发明公开了折叠式防爆围栏的设计、制作方法及其产品,设计包括：根据爆炸物的当量和类型,结合需要防护的产品的安全距离,设计所述防爆围栏的基本信息；设计防爆能力,确定所述防爆围栏用的板材的厚度；制作方法包括：确定防爆围栏的制作工艺；对所述防爆围栏进行实爆测试,确定围栏是否满足设计需要；完成所述防爆围栏的制作；产品为一体式且可折叠的防爆围栏,包括通过多层纤维层压制成型的板材以及置于板材之间的折叠区,板材之间通过折叠区可折叠,首尾板材之间固定连接；本发明能够满足子弹防护要求和爆炸防护需求,同时可以折叠成一体式的结构,能够减少布置时间,为排爆决策和处置提供了基础条件。(The invention discloses a design and manufacturing method of a folding type explosion-proof fence and a product thereof, wherein the design comprises the following steps: designing basic information of the explosion-proof fence according to the equivalent weight and the type of explosives and the safety distance of a product to be protected; designing explosion-proof capacity, and determining the thickness of a plate for the explosion-proof fence; the manufacturing method comprises the following steps: determining a manufacturing process of the explosion-proof fence; performing an actual explosion test on the explosion-proof fence to determine whether the fence meets the design requirement; completing the manufacture of the explosion-proof fence; the product is an integrated and foldable anti-explosion fence, and comprises plates formed by pressing a plurality of fiber layers and folding areas arranged among the plates, wherein the plates are foldable through the folding areas, and the plates at the head and the tail are fixedly connected; the bullet protection device can meet bullet protection requirements and explosion protection requirements, can be folded into an integrated structure, can reduce arrangement time, and provides basic conditions for explosive ordnance disposal decision and disposal.)

1. The design of foldable explosion-proof rail, its characterized in that: the design includes the following steps:

designing basic information of the explosion-proof fence according to the equivalent weight and the type of explosives and the safety distance of a product to be protected; the basic information of the explosion-proof fence comprises: the diameter x of an inscribed circle of the fence, the height y of the fence and the number m of fence plates;

designing the explosion-proof capacity so as to determine the thickness of the plate for the explosion-proof fence; the explosion-proof capability is mainly divided into: explosion-proof non-disintegration ability and fragment-proof non-penetration ability.

2. A folding explosion proof enclosure as claimed in claim 1 wherein the enclosure inscribed circle diameter x is designed to be:

x≥X_d

wherein M is the TNT equivalent of the explosive, ρ is the density of the explosive, and X_dThe outer package size for the explosive;

the height y of the fence is designed as follows: for a fence with an inscribed circle diameter of x, considering that the safety distance is L, if an object with the height of h needs to be protected, the height y of the fence is designed as follows:

n is a safety coefficient, and for the extreme problem of explosion, n can be 2-5, so that fragments are prevented from flying out of the top of the fence and impacting on an object at a safe distance under an extreme condition;

designing the number m of the plates: the number of actual plates needs to be designed by combining the pressing capacity of a press, and the number of the plates is selected to be m:

wherein: the maximum pressable length of the press is a, and the radius of the inscribed circle of the fence is R.

3. The design of a folding explosion-proof enclosure according to claim 1, wherein the explosion-proof non-dismantling capability in step two is as follows: the tensile strength at the edge of the anti-explosion fence is designed, so that the structural integrity under the condition of shock waves is met, and the joint cannot be torn due to the shock waves; fragment-proof non-penetrating ability: calculating fragment flying speed and fragment mass of the explosive to be protected to obtain maximum kinetic energy of fragments, selecting corresponding protective materials to perform ballistic experiments, and achieving reasonable protective layer thickness design according to actual target practice results.

4. A folding explosion proof enclosure design according to claim 3 wherein said explosion proof unresolvable capability:

when explosion occurs in the air, according to the calculation formula of shock wave overpressure in the air of Henrych:

in the formula (I), the compound is shown in the specification,is a proportional distance, which is calculated as:

the calculated tensile strength at the edges is at least guaranteed:

wherein t is the thickness of the fence;

when m is larger (m is more than or equal to 10), the fence can be approximately regarded as a cylinder, and the tensile strength at the edge can simplify calculation and design:

5. the design of a folding explosion-proof enclosure according to claim 3, wherein the fragment-proof impenetrability:

for explosive with fragments, if the fragments are in a closed metal shell structure (such as water pipe bomb, standard grenade and the like), the speed V of the fragments is V₀The calculation can be made according to the gurney formula:

wherein the content of the first and second substances,is a parameter of the explosive, for TNT explosives,beta is the ratio of the weight of the explosive to the weight of the metal shell; if the explosive with the prefabricated fragments is treated, the speed of the prefabricated fragments is generally 10 to 20 percent lower than that of the fragments of the closed structure, and the steel balls and the nails are generally adopted for the prefabricated fragmentsSeed form, etc., the weight of the broken pieces is about 1-10g

For the quality of random fragmentation, the solution can be obtained by the following formula:

wherein, K is generally 0.2,u is the Poisson's ratio of the material.

ρ_eIs the explosive density, p_mIs the metal density of the shell, D_eIs the explosive detonation velocity (m/s), delta is the shell wall thickness, l is the warhead length, C_eIs the propagation velocity of elastic waves in explosives, C_pIs the elastic wave propagation velocity of the shell material.

6. The design of a folding explosion-proof enclosure according to claim 5, wherein the quality of the fragments is evaluated using either the following formula:

wherein R is the outer radius of the shell, R is the inner radius of the shell, and δ is the wall thickness of the shell.

7. Method for manufacturing a foldable explosion-proof enclosure, characterized in that the manufacturing of an explosion-proof enclosure is performed according to any of the claims 1-6, said manufacturing method comprising the steps of:

s1, determining the manufacturing process of the explosion-proof fence; according to the obtained basic information and thickness parameters of the explosion-proof fence, the processes of cutting, sewing and pressing are carried out;

s2, carrying out a real explosion test on the explosion-proof fence to determine whether the fence meets the design requirements;

and S3, finishing the manufacture of the explosion-proof fence.

8. The method for manufacturing a foldable explosion-proof enclosure according to claim 7, wherein in step S1, according to the basic information and thickness parameters of the explosion-proof enclosure, the fiber cloth is cut to meet the design requirements of the explosion-proof enclosure;

sewing the fiber cloth by using a high-strength sewing line, wherein the sewing position is the periphery of the position to be pressed; in the folding part, a gap with the distance of 3-5 times of the thickness of the fence is reserved according to the thickness requirement, so that the folding part is convenient to fold, wherein the even layers or the odd layers are extracted from the head and the tail of the fiber cloth, so that the head and the tail are convenient to be pressed;

and pressing, namely pressing the designed second plate, sequentially pressing, removing the sewing line when pressing the last plate, and performing a pressing process to form the explosion-proof fence.

9. The method of making a foldable explosion-proof enclosure according to claim 7, wherein the pressing process is: the cross arrangement pressing process comprises the steps of crossing arrangement layering of each layer of a first plate and a last plate in a pressing design, uniformly coating a double-component polyurethane adhesive between the layers in the process of crossing arrangement layering, fixing pressing molds on the upper surface and the lower surface after layering is finished, fastening by using bolts, and curing at normal temperature to form an integrated explosion-proof fence structure;

or suppress the panel of head and the tail alone, then adopt the component to glue and carry out sticky with the panel that the head and the tail suppression is good, can punch through the panel of present head and the tail junction at last, then adopt the high strength fiber rope to connect, form the explosion-proof fence structure of integral type.

10. The product prepared by the manufacturing method according to claim 7, wherein the product is an integral and foldable explosion-proof enclosure, the product comprises plates formed by pressing multiple fiber layers and folding areas arranged between the plates, the plates are foldable through the folding areas, and the plates are fixedly connected end to end.

Technical Field

The invention relates to the technical field of explosion-proof fences, in particular to a design and manufacturing method of a folding explosion-proof fence and a product thereof.

Background

Explosive terrorism is the most destructive mode in the current terrorist attack, and explosives have various forms, are not definite in initiation mode and are not clear in destructive power. When compiling explosive disposal manuals, countries generally require that disposal time be as short as possible and adopt non-contact disposal methods as possible.

Conventional explosion handling devices include explosion blankets, explosion cans, and explosion ball devices. The explosion-proof blanket is generally aimed at 1 82-2 grenades, and its internal diameter is 400mm generally, and the size of generally handling the explosive is 1 schoolbag. In the process of using the explosion-proof blanket, firstly, the inner fence and the outer fence are required to cover the explosive substances, and then the blanket is covered, and is generally accommodated at the corners at ordinary times. The weight of the explosion-proof tank/ball is generally 500-2000 tons, the explosion-proof tank/ball generally needs to be matched with a trailer, a robot and the like for handling, the robot needs to be operated to clamp explosives into the explosion-proof ball, and the explosives cannot be handled in a non-contact mode.

Traditional equipment is based on steel protective structure, can reach optimal protective efficiency through processing into corresponding spherical or annular structure, and to explosion protection, there is a comparatively mature design, but to combined material, processing into spherical or ring cylindricality, it is comparatively difficult to realize in the technology. The method for shielding the explosive through the explosion-proof fence is a new direction in the current explosion-proof technical field, and the design of the equipment is finally completed mainly through processing, testing, improving, reprocessing and testing in the design process of the explosion-proof fence. Corresponding tests are required to be continuously carried out in the design process, the cost is high, and the time consumption is long. At present, no corresponding design method can be referred to, corresponding design is generally carried out according to experience, a plurality of designs refer to the protection capability of corresponding fence structures under bullet design, and the design mode does not consider the effects of explosion shock waves and fragments existing in the actual explosion process. Although there is no design method patent of the explosion-proof fence at present, there are also some open design structure schemes of the explosion-proof fence, such as the explosion-proof fence designed by CN201621149158.6, which is assembled on site by using a plurality of explosion-proof unit plates, in the actual process of explosive disposal, because it needs to be assembled on site, the disposal time is long, and in the process of assembling, it needs to pass through bolt metal objects, there is a danger of falling and flying, which is easy to cause damage to a greater extent, and the application of the explosion-proof fence is limited to a certain extent.

Disclosure of Invention

The invention aims to provide a design and manufacturing method of a folding type explosion-proof fence and a product thereof, which solve the problems of bullet protection and explosion protection and the problems of no consideration of explosion shock waves, fragment comprehensive protection and long assembly time in the actual explosion process.

The invention relates to a folding type explosion-proof enclosure, which is designed by the following steps:

designing basic information of the explosion-proof fence according to the equivalent weight and the type of explosives and the safety distance of a product to be protected; the basic information of the explosion-proof fence comprises: the diameter x of an inscribed circle of the fence, the height y of the fence and the number m of fence plates;

designing the explosion-proof capacity so as to determine the thickness of the plate for the explosion-proof fence: the explosion-proof capability is mainly divided into: explosion-proof non-disintegration ability and fragment-proof non-penetration ability. And obtaining related design data of the explosion-proof fence through the first step and the second step, wherein the related design data comprises the diameter x of the inscribed circle of the fence, the height y of the fence, the number m of fence plates and the thickness of the plates.

The further technical scheme of the invention is as follows: according to the equivalent weight and type of the explosive, the safety distance of the product and the design size, the expansion volume of the explosion is 800-1600 times of the initial volume for the standard explosive (TNT), so that the action zone of the product can be determined. For non-standard explosives, the equivalent weight needs to be converted into standard explosive TNT.

TABLE 1 conversion of common explosives

There are two main modes of damage to an explosion, one being shock waves and one being fragments. For explosives, upon near field detonation, the expansion volume of the detonation is 800-1600 times the initial volume for standard explosives (TNT), from which the region of action of the product can be determined. In spherical explosion, the limit radius of the volume of the explosion product is 10 times of the original radius of the explosive. It can be determined that the action field of the explosive product is confined to a very small distance. For this reason it is considered that: when r is less than or equal to 10re, the region is used as the action region of the explosive product, when r is (10-20) re, the region is used as the combined action region of the explosive product and the shock wave, and when r is greater than 20re, the region is used as the main action region of the shock wave. It has been shown in a number of experiments that the pressure drop near the explosive charge, i.e. r.ltoreq.10 re, is inversely proportional to the cube of the distance, when r >10re, the pressure drop is inversely proportional to the square of the distance, indicating a slow pressure drop, and at a long distance, the pressure drop is inversely proportional to the distance, indicating a slower pressure drop. The shapes of the isopressure surfaces of different explosive charges are different. When the explosive is exploded, the limit radius of the volume of the explosive product is 10 times of the original explosive loading radius. Generally, when the radius reaches more than 10 times of the explosive, the shape of the explosive has less influence on the calculation of the shock wave, so that the equivalent explosive can be a spherical charge. Firstly, aiming at the protection requirement of TNT explosive with equivalent M, calculating the diameter D of the explosive, and then determining the diameter of explosive products as D equal to 10D, generally speaking, the diameter x of an inscribed circle of the explosion-proof fence should be at least larger than the diameter of the explosive products, generally x can be designed according to the overall size of the explosive, generally speaking, the size of the explosive and the attached camouflage structure should be larger than or equal to 300mm (the size of a common backpack), so the design of x should comprehensively consider the acting diameter of the explosive and the diameter of the disposed explosive.

The further technical scheme of the invention is as follows: the diameter design of the fence: the design of the diameter x of the inscribed circle is as follows:

x≥X_d

wherein M is the TNT equivalent of the explosive, ρ is the density of the explosive, and X_dThe outer package size of the explosive is generally equal to or larger than 300 mm.

The further technical scheme of the invention is as follows: and designing the height of the fence. For a fence with an inscribed circle diameter of x, considering that the safety distance is L, if an object with the height of h needs to be protected, the height of the fence is designed as follows:

and n is a safety factor, and can be 2-5 aiming at the extreme problem of explosion, so that fragments are prevented from flying out from the top of the fence and colliding with an object at a safe distance under the extreme condition.

The further technical scheme of the invention is as follows: and (5) designing the number of the plates. Explosion-proof rail generally adopts the symmetrical formula design, and for the stability of assurance structure, the panel quantity that encloses into explosion-proof rail is generally better more than 6. The actual number of sheets needs to be designed in combination with the press capacity of the press. If the maximum pressable length of the press is a, the number of the plates is m, and the radius of the inscribed circle of the fence is R.

The further technical scheme of the invention is as follows: and designing explosion-proof capacity.

When explosion occurs in the air, according to the calculation formula of shock wave overpressure in the air of Henrych:

in the formula (I), the compound is shown in the specification,is a proportional distance, which is calculated as:

the calculated tensile strength at the edges is at least guaranteed:

wherein t is the thickness of the fence.

When m is larger (m is more than or equal to 6), the fence can be approximately regarded as a cylinder, and the tensile strength at the edge can simplify calculation and design:

when the above conditions are met, the structural integrity under the shock wave conditions can be met, and the joints cannot be torn by the shock waves. Considering the dynamic response of the material under the dynamic load, a safety factor of 2 can be taken, and then a tensile testing machine can be used for testing the mechanical properties of the material at the joint.

The further technical scheme of the invention is as follows: designing fragment prevention capacity:

for explosive with fragments, if the fragments are in a closed metal shell structure (such as a water pipe bomb, a standard grenade and the like), the fragment speed can be calculated according to a gurney formula:

wherein the content of the first and second substances,is a parameter of the explosive, for TNT explosives,beta is the ratio of the weight of the explosive to the weight of the metal casing, and generally speaking, the ratio of the explosive to the weight of the metal casing is between 0.1 and 1 for standard ammunition or self-made explosive.

For the quality of the fragment, the solution can be made by the following empirical formula:

wherein, K is generally 0.2,u is the Poisson's ratio of the material.

ρ_e1630kg/m for TNT explosive, for explosive density³，ρ_mFor the case metal density, 7800kg/m is typical for steel³，D_eIs the detonation velocity (m/s) of the explosive, for TNT explosive, the detonation velocity is 6500m/s, delta is the wall thickness of the shell, l is the length of the warhead, C_eIs the propagation velocity of elastic waves in explosives, and is generally 1600m/s, C for TNT explosives_pIs the propagation velocity of the elastic waves of the material of the shell, which is generally 5000m/s for steel,ak is the impact toughness (kg/cm) of the material³)。

Or the following formula is adopted for evaluation:

wherein R is the outer radius of the shell, R is the inner radius of the shell, and δ is the wall thickness of the shell.

If the explosive with the prefabricated fragments is treated, the speed of the prefabricated fragments is generally 10-20% lower than that of the fragments of the closed structure, the prefabricated fragments generally adopt the forms of steel balls, nails and the like, and the weight of the fragments is about 1-10 g.

The fragment flying speed and the fragment mass of the explosive to be protected can be obtained through calculation, the maximum kinetic energy of the fragments is obtained, then the corresponding protective material is selected for carrying out a ballistic experiment, and the reasonable protective layer thickness design can be achieved according to the actual target practice result. If the fiber composite material is adopted, the fiber composite material is pressed into plates with different thicknesses, and then a target practice test is carried out to obtain the corresponding plate thickness.

The manufacturing method of the folding type explosion-proof fence comprises the following steps:

s1, determining the manufacturing process of the explosion-proof fence; according to the basic information and the thickness parameters of the explosion-proof fence obtained in the first step and the second step, the processes of cutting, sewing and pressing are carried out;

s2, carrying out a real explosion test on the explosion-proof fence to determine whether the fence meets the design requirements;

and S3, finishing the manufacture of the explosion-proof fence.

The further technical scheme of the invention is as follows: manufacturing the fence plate:

selecting one or more of high-strength fiber cloth (PE cloth, aramid cloth, PBO cloth, and glass fiber cloth).

According to the obtained basic information of the explosion-proof fence and the parameters of the layer number, firstly, cutting fiber cloth to meet the size design requirement;

the method comprises the following steps of sewing fiber cloth by using a high-strength sewing line (the sewing line is one or a mixture of sewing lines formed by fibers such as PE (polyethylene), aramid fiber, PBO (Poly-p-phenylene benzobisoxazole), glass fiber cloth and the like), wherein the sewing size is the design size of a target plate, the target plate is a plate formed in a subsequently pressed area, and dislocation or movement among multiple layers of fiber cloth layers in the pressing process can be avoided after sewing, so that the main purpose of the step is to preliminarily fix the multiple layers of fiber cloth, and the condition of offset or disorganization in the pressing process of a press is avoided; in the folding part, a gap with the distance between the plates being 3-5 times of the thickness of the plates is generally reserved according to the thickness requirement, and the folding part does not need to be pressed, so that the plates can be folded. The even layers (or the odd layers) are extracted from the head and the tail of the fiber cloth, so that the head and the tail can be conveniently pressed.

And (3) establishing a pressing process, pressing according to the pressing process, firstly pressing the designed second plate, sequentially pressing, removing the sewing line when pressing the last plate, and pressing after cross arrangement.

The cross arrangement pressing process comprises the steps of crossing arrangement and layering of each layer of a first plate and a last plate in a pressing design, and uniformly coating a two-component polyurethane adhesive between the layers in the process of crossing arrangement and layering. After the layering is finished, fixing pressing molds on the upper surface and the lower surface, fastening by using bolts, and curing for 12 hours at normal temperature to form an integrated explosion-proof fence structure; as shown in fig. 5.

The further technical scheme of the invention is as follows: if the conditions of the press do not allow the cross arrangement pressing process (probably because the overall structure of the press is too large, the rail cannot be subjected to an end-to-end combined pressing scheme), the PE plates at the ends can be independently pressed, then the plates pressed at the ends are glued by component glue, finally, the PE plates at the end-to-end joints can be punched, and then high-strength fiber ropes are used for connection; as shown in fig. 6 and 7. And after 2, checking the explosion-proof capacity strength, and confirming the safety of the structure.

The further technical scheme of the invention is as follows: in the actual explosion test, after the corresponding equivalent explosive is generally adopted for actual explosion, whether the rail is disassembled or not is checked, and whether the design of the explosion-proof rail is met or not is judged whether the plate of the rail is broken or not. And if the real explosion test is passed, finishing the design and manufacture of the fence, and if the real explosion test is not passed, adjusting the explosion-proof performance of the fence again.

The product prepared by the manufacturing method is an integrated and foldable explosion-proof fence, and comprises plates formed by pressing multiple fiber layers and folding areas arranged among the plates, wherein the plates are foldable through the folding areas, and the plates are fixedly connected end to end.

The invention has the beneficial effects that: (1) the design method of the explosion-proof fence can be used for designing and manufacturing explosives with different equivalent weights to obtain a design scheme with the protection performance meeting the requirement;

(2) the folding type explosion-proof fence is composed of a plurality of square foldable plates, is good in portability, is formed by hot pressing one or more of high-strength PE (polyethylene), aramid fiber, PBO (Poly-p-phenylene benzobisoxazole) and glass fiber, is light in structure, has good anti-elasticity capability, does not have metal objects in the structure, and is small in secondary damage;

(3) the fence adopts multi-section respective folding and hot pressing, has complete structure and good consistency;

the manufacturing method of the folding type explosion-proof fence can meet bullet protection requirements and explosion protection requirements, can be folded into an integrated structure, can reduce arrangement time, and provides basic conditions for explosive disposal decision and disposal.

Drawings

Fig. 1 is a flow chart of a method for manufacturing a folding explosion-proof enclosure provided by the invention;

FIG. 2 is an expanded view of the explosion-proof enclosure provided by the present invention;

FIG. 3 is a schematic view of a sequentially pressed sheet according to the present invention;

FIG. 4 is a schematic structural view of head and tail plate pressing provided by the invention;

FIG. 5 is a schematic structural view of an integrated explosion-proof enclosure according to a second embodiment of the present invention;

fig. 6 is a schematic structural diagram of an explosion-proof enclosure in the third embodiment of the invention;

fig. 7 is a schematic structural view of an explosion-proof enclosure in the third embodiment of the invention;

fig. 8 is a schematic view of the state of the folded plate provided by the invention.

Reference numerals:

a-a pressed plate, b-a plate in a state to be pressed, c-a plate joint, d-a plate in a non-pressed state, and e-a press;

1-ground, 2-lower press, 3-pressing plates from head to tail, 4-upper press, and 5-pressed plates.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It should be noted that the structures, ratios, sizes, and the like shown in the drawings attached to the present specification are only used for matching the disclosure of the present specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions of the present invention, so that the present invention has no technical essence, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

The design of a folding explosion-proof enclosure as shown in fig. 1-8, comprising the steps of:

designing basic information of the explosion-proof fence according to the equivalent weight and the type of explosives and the safety distance of a product to be protected; the basic information of the explosion-proof fence comprises: the diameter x of an inscribed circle of the fence, the height y of the fence and the number m of fence plates;

designing the explosion-proof capacity so as to determine the thickness of the plate for the explosion-proof fence: the explosion-proof capability is mainly divided into: explosion-proof non-disintegration ability and fragment-proof non-penetration ability; and obtaining related design data of the explosion-proof fence.

The design of the diameter x of the inscribed circle of the fence is as follows:

x≥X_d

wherein M is the TNT equivalent of the explosive, ρ is the density of the explosive, and X_dThe size of the outer package of the explosive is generally equal to or larger than 300 mm;

the height y of the fence is designed as follows: for a fence with an inscribed circle diameter of x, considering that the safety distance is L, if an object with the height of h needs to be protected, the height y of the fence is designed as follows:

n is a safety coefficient, and for the extreme problem of explosion, n can be 2-5, so that fragments are prevented from flying out of the top of the fence and impacting on an object at a safe distance under an extreme condition;

designing the number m of the plates: the number of actual plates needs to be designed by combining the pressing capacity of a press, and the number of the plates is selected to be m:

wherein: the maximum pressable length of the press is a, and the radius of the inscribed circle of the fence is R.

The explosion-proof non-disassembly capability in the step two: the tensile strength at the edge of the anti-explosion fence is designed, so that the structural integrity under the condition of shock waves is met, and the joint cannot be torn due to the shock waves; fragment-proof non-penetrating ability: calculating fragment flying speed and fragment mass of the explosive to be protected to obtain maximum kinetic energy of fragments, selecting corresponding protective materials to perform ballistic experiments, and achieving reasonable protective layer thickness design according to actual target practice results.

The explosion-proof non-disintegrating ability:

when explosion occurs in the air, according to the calculation formula of shock wave overpressure in the air of Henrych:

in the formula (I), the compound is shown in the specification,is a proportional distance, which is calculated as:

the calculated tensile strength at the edges is at least guaranteed:

wherein t is the thickness of the fence;

when m is larger (m is more than or equal to 6), the fence can be approximately regarded as a cylinder, and the tensile strength at the edge can simplify calculation and design:

the fragment prevention ability:

for explosive with fragments, if the fragments are in a closed metal shell structure (such as water pipe bomb, standard grenade and the like), the speed V of the fragments is V₀The calculation can be made according to the gurney formula:

wherein the content of the first and second substances,is a parameter of the explosive, for TNT explosives,beta is the ratio of the weight of the explosive to the weight of the metal shell; generally, for pre-broken explosives, the velocity will generally be 20% to 30% lower than the calculated velocity. The prefabricated fragments generally adopt the forms of steel balls, nails and the like, and the weight of the fragments is about 1-10 g.

For the quality of random fragmentation, the solution can be obtained by the following formula:

wherein, K is generally 0.2,u is the Poisson's ratio of the material.

ρ_eIs the explosive density, p_mIs the metal density of the shell, D_eIs the explosive detonation velocity (m/s), delta is the shell wall thickness, l is the warhead length, C_eIs the propagation velocity of elastic waves in explosives, C_pIs the elastic wave propagation velocity of the shell material.

The quality of the fragments is evaluated by adopting the following formula:

wherein R is the outer radius of the shell, R is the inner radius of the shell, and δ is the wall thickness of the shell.

The manufacturing method of the folding type explosion-proof fence comprises the following steps:

s1, determining the manufacturing process of the explosion-proof fence; according to the obtained basic information and thickness parameters of the explosion-proof fence, the processes of cutting, sewing and pressing are carried out;

s2, carrying out a real explosion test on the explosion-proof fence to determine whether the fence meets the design requirements;

and S3, finishing the manufacture of the explosion-proof fence.

According to the basic information and the thickness parameters of the explosion-proof fence obtained in the first step and the second step in the S1, firstly, cutting fiber cloth to enable the fiber cloth to meet the design requirements of the explosion-proof fence;

the fiber cloth is sewn by high-strength sewing lines, the sewing size is the design size of the target plate, gaps with the interval being 3-5 times of the thickness of the plate are reserved at the folding part according to the thickness requirement as shown in figure 2, and the folding part is not subjected to pressing treatment as shown in figure 8; the even layers or the odd layers are extracted from the head and the tail of the fiber cloth, so that the head and the tail are conveniently pressed;

pressing according to a pressing process, first pressing the designed second plate, as shown in fig. 3; sequentially pressing, namely removing the sewing lines when the last plate is pressed, and pressing after crossed arrangement; as shown in fig. 4;

the cross arrangement pressing process comprises the steps of crossing arrangement layering of each layer of a first plate and a last plate in a pressing design, uniformly coating a double-component polyurethane adhesive between the layers in the cross arrangement layering process, fixing pressing molds on the upper surface and the lower surface after layering is finished, fastening by using bolts, and curing at normal temperature to form an integrated explosion-proof fence structure, as shown in fig. 5.

In the pressing process, if the pressing machine conditions do not allow the cross arrangement pressing process, the PE plates at the head and the tail can be independently pressed, then the plates pressed at the head and the tail are glued by component glue, finally, the PE plates at the head and the tail connecting positions can be punched, and then the PE plates are connected by the high-strength fiber ropes, as shown in fig. 6 and 7.

The fiber cloth comprises at least one of PE cloth, aramid cloth, glass fiber cloth and PBO cloth, and the high-strength sewing thread is at least one of sewing threads consisting of PE, aramid, glass fiber and PBO material fibers.

The product prepared by the manufacturing method is an integrated and foldable explosion-proof fence, and comprises plates formed by pressing multiple fiber layers and folding areas arranged among the plates, wherein the plates are foldable through the folding areas, and the plates are fixedly connected end to end.

The first embodiment is as follows: for example, the fence with the safety distance of 5m is formed by the explosive with 1kg of phi 8 steel balls and the explosion-proof capacity of 1kgTNT equivalent. The design is as follows:

spherical explosives such as 1kg of TNT, with a density of 1.63g/cm³The radius thereof was 53 mm. Therefore, the minimum inner diameter of the explosion-proof fence can be determined to be 1060mm, a certain redundancy is comprehensively considered, the redundancy is designed according to 1.5 times, and the inner diameter of the explosion-proof fence is designed to be 1600 mm.

If the required safety distance is 5m, the protection target is a human body, the equivalent height of the human body is 1.8m, the safety coefficient is 3, and the height of the fence is 1.0m through comprehensive calculation. The cost and the processing manufacturability are comprehensively considered, and the number of the blocks of the fence is 10.

By means of the calculation, the user can select,

considering that the speed of the prefabricated fragment is reduced by about 20-30 percent, the v is taken₀1.264(km/s), the kinetic energy criterion for protection is that, according to a weight of 2g of phi 8 fragments: 1598J, the adopted protective material needs to meet the protective capability in the state, the number of PE cloth layers of the protective fragments in the state is 80 through ballistic experiments or simulation experiments, the safety factor of 2 times is comprehensively considered, and the number of the PE cloth layers is 160 (the bulletproof capability is improved to a certain extent after the common PE cloth is pressed into a plate).

The shock wave overpressure at 0.8m for 1kg of explosive is 1.33Mpa, and the calculated connection strength at the edge needs to reach 1.33 Mpa. The tensile strength of the material is 106.4Mpa after calculation according to the safety coefficient of 2, so the comprehensive consideration is that if the connecting position is connected by adopting a high-strength rope, 10 connecting holes are adopted. (UHMWPE or aramid yarns are adopted as the ropes, and the tensile strength of the ropes can meet the requirements).

The comprehensive results show that under the action of 1kg of explosive, the protective fence has an inner diameter of 1.6m and a height of 1.0m, and the target plate has a density of 150g/m²The number of the required layers of the PE cloth is 160.

Example two:

manufacturing the fence plate:

a high strength fiber cloth such as PE cloth is selected. According to the basic information of the explosion-proof fence and the parameters of the layer number obtained in the first embodiment, firstly, cutting fiber cloth to meet the size design requirement;

and sewing the fiber cloth by using a high-strength sewing thread, wherein the sewing thread is a sewing thread consisting of PE fibers, and the sewing size is the designed size of the target plate. The main purpose of this step is to carry out preliminary fixed with a plurality of fibre cloth, avoid the condition that the drift or disorderly break apart to appear in the press pressing process, in the folding part, according to the thickness demand, reserve the clearance that the thickness is 3-5 times of panel thickness generally. The even layers or the odd layers are extracted from the head and the tail of the fiber cloth, so that the head and the tail can be conveniently pressed, as shown in fig. 4.

And (3) establishing a pressing process, pressing according to the pressing process, firstly pressing the designed second plate, sequentially pressing, as shown in figure 3, removing the sewing line when pressing the last plate, and pressing after cross arrangement, as shown in figure 4.

The cross arrangement pressing process comprises the steps of crossing arrangement and layering of each layer of a first plate and a last plate in a pressing design, and uniformly coating a two-component polyurethane adhesive between the layers in the process of crossing arrangement and layering. After the layering is finished, fixing pressing molds on the upper surface and the lower surface, fastening by using bolts, and curing for 12 hours at normal temperature to form an integrated explosion-proof fence structure; as shown in fig. 5.

Example three:

manufacturing the fence plate:

a high strength fiber cloth such as PE cloth is selected. According to the basic information of the explosion-proof fence and the parameters of the layer number obtained in the first embodiment, firstly, cutting fiber cloth to meet the size design requirement;

and sewing the fiber cloth by using a high-strength sewing thread, wherein the sewing thread is a sewing thread consisting of PE fibers, and the sewing size is the designed size of the target plate. The main purpose of this step is to carry out preliminary fixed with a plurality of fibre cloth, avoid the condition that the drift or disorderly break apart to appear in the press pressing process, in the folding part, according to the thickness demand, reserve the clearance that the thickness is 3-5 times of panel thickness generally. The even layers or the odd layers are extracted from the head and the tail of the fiber cloth, so that the head and the tail can be conveniently pressed, as shown in fig. 4.

A pressing process is formulated, pressing is carried out according to the pressing process, firstly, a designed second plate is pressed, and sequential pressing is carried out, as shown in fig. 3, when a last plate is pressed, a sewing line is removed, if the pressing conditions do not allow the adoption of the cross arrangement pressing process (probably because the whole structure of the pressing machine is too large, the rail cannot be subjected to an end-to-end combined pressing scheme), the PE plates at the head and the tail can be singly pressed, then the plates pressed at the head and the tail are glued by component glue, finally, the PE plates at the head-to-tail joint can be punched at present, and then, a high-strength fiber rope is adopted for connection; as shown in fig. 6 and 7. And after the explosion-proof capability strength is checked, the safety of the structure is confirmed.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.