CN111207645A - Momentum deflection-based explosion protection structure and method - Google Patents
Momentum deflection-based explosion protection structure and method Download PDFInfo
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- CN111207645A CN111207645A CN202010081956.4A CN202010081956A CN111207645A CN 111207645 A CN111207645 A CN 111207645A CN 202010081956 A CN202010081956 A CN 202010081956A CN 111207645 A CN111207645 A CN 111207645A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D5/00—Safety arrangements
- F42D5/04—Rendering explosive charges harmless, e.g. destroying ammunition; Rendering detonation of explosive charges harmless
- F42D5/045—Detonation-wave absorbing or damping means
Abstract
The invention discloses an explosion protection structure and method based on momentum deflection. The invention introduces the deflectable mass block into the conventional explosion-proof equipment, thereby introducing centripetal force in the explosion process, changing the momentum direction of the mass block and making the momentum harmless; meanwhile, the centripetal force can apply a downward acting force to the protective equipment to restrain the protective equipment from jumping upwards. The protection structure and the method are provided based on physical laws and material/structure mechanics analysis, and can effectively improve the safety of protection equipment and the reliability of fragment protection.
Description
Technical Field
The invention relates to the technical field of explosion protection, in particular to an explosion protection structure and method based on momentum deflection, which are suitable for police, military and public safety explosion protection.
Background
In recent years, explosive terrorist attacks occur internationally, and great threats are brought to the safety of lives and properties of people. In order to reduce the harm of explosives to surrounding personnel and facilities, it is common to construct explosion-proof retaining walls for shielding the explosion of bombs or to arrange explosion-proof containers for disposing suspected explosives in public places.
To improve the maneuverability of these explosion-proof equipment, the current structural design tends to be light weight. Although the light-structure-based explosion-proof equipment has the advantages of good maneuverability and high emergency response speed, the light-structure-based explosion-proof equipment has the following two defects: (1) the explosion-proof equipment can extract more kinetic energy under the action of explosive load due to mass reduction, the extraction of more kinetic energy is inherently favorable for weakening the explosive load, but some fragile explosion-proof structures can generate a plurality of high-speed flying fragments which cannot be lethal due to low density but still release impulse with potential secondary hazard to the surrounding environment; (2) the explosion-proof equipment is easy to jump upwards under the action of explosive load, so that a fragment protection notch is formed at the bottom of the equipment, and fragment leakage occurs; this risk is particularly evident when the explosive is located on the ground, and some explosion-proof equipment such as fiber composite-based explosion-proof enclosures mostly adopt an inner and outer enclosure design to deal with the problem of jumping, but the separated structure can slow down the emergency response speed.
Disclosure of Invention
In view of this, the present invention provides an explosion protection structure and method based on momentum deflection, which can reduce the secondary kinetic energy hazard while not inhibiting the momentum extraction effect, and can effectively inhibit the jump-flight phenomenon of the explosion-proof equipment.
The explosion protection structure based on momentum deflection comprises a plurality of mass blocks, wherein the mass blocks are arranged on the back explosion surface of a protection layer through tows.
Preferably, the mass block is a high molecular polymer with fragile materials packaged inside.
Preferably, the mass block is arranged in a fiber hollowed-out net bag, and the fiber hollowed-out net bag is connected with the tows.
Preferably, the friable material is a respective particulate material, liquid, or mixture thereof.
Preferably, the fragile material is one or a mixture of high molecular polymer particles, high molecular polymer foam, fine sand and inorganic salt powder; or a liquid or liquid mixture with a viscosity coefficient lower than 2MPa · s; or a mixture of the above materials.
Preferably, the tow is made of polymer fibers or carbon fibers.
Preferably, the mass blocks are uniformly arranged on the back explosion surface of the explosion-proof equipment.
Preferably, the number of the mass blocks distributed along the height direction of the protective layer is more than or equal to 5, and the number of the mass blocks distributed along the circumferential direction is more than or equal to 10.
Preferably, the total weight of the mass block accounts for 1/4-1/3 of the total weight of the protective structure.
Preferably, the anti-explosion device further comprises a high-wave-speed structural material layer, the high-wave-speed structural material layer is arranged on the back explosion surface of the anti-explosion layer or is inserted into the internal structure of the anti-explosion layer, one end of the filament bundle is connected with the mass block, and the other end of the filament bundle is connected with the high-wave-speed structural material layer.
The invention also provides an explosion protection method based on momentum deflection, wherein a plurality of mass blocks are arranged on the back explosion surface of the protection layer, and the mass blocks are connected with the back explosion surface of the protection layer through tows.
Preferably, the mass block is a high molecular polymer with fragile materials packaged inside.
Preferably, the mass block is wrapped by a hollow fiber net bag; the tows are connected with the hollow fiber net bag.
Preferably, the fragile material is one or a mixture of high molecular polymer particles, high molecular polymer foams, fine sand and inorganic salt powder; or a liquid or liquid mixture with a viscosity coefficient lower than 2MPa · s; or a mixture of the above materials.
Preferably, the total weight of the mass block accounts for 1/4-1/3 of the total weight of the protective structure.
Preferably, a high-wave-velocity structural material layer is arranged in the middle of the protective layer or on the back explosion surface, and the tows are fixed on the high-wave-velocity structural material layer.
Has the advantages that:
the invention introduces the deflectable mass block into the conventional explosion-proof equipment, thereby introducing centripetal force in the explosion process, changing the momentum direction of the mass block and making the momentum harmless; meanwhile, the centripetal force can apply a downward acting force to the protective equipment to restrain the protective equipment from jumping upwards. The protection structure and the method are provided based on physical laws and material/structure mechanics analysis, and can effectively improve the safety of protection equipment and the reliability of fragment protection.
Drawings
Fig. 1 is a schematic view of the protective structure of the present invention.
FIG. 2 is a schematic diagram of the principle of momentum deflection and fly-away suppression according to the protection method of the present invention.
Fig. 3 is a schematic diagram of a preferred structure of the mass block of the present embodiment.
The anti-explosion device comprises a 1- (anti-explosion device) main body structure, 2-mass blocks, 3-high-strength tows, 4-fragile materials, 5-high polymer and 6-high-strength fiber hollow net bags.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The invention provides an explosion protection structure and method based on momentum deflection, aiming at the problems that the existing explosion protection equipment with a light structure is fragile and flies upwards in the process of extracting kinetic energy.
As shown in fig. 1 and fig. 2, during explosion, the mass block obtains a translational momentum under the action of the shock wave, and under the constraint of the tow, on one hand, the translational momentum is converted into a rotational momentum to fly in a harmless direction; on the other hand, the centripetal force applied to the tows can generate downward acting force applied to the protective layer of the explosion-proof equipment, and the acting force can inhibit the explosion-proof equipment from flying.
In addition, according to the protection thought, the existing protection equipment can be improved and divided into a main body structure and a plurality of mass blocks; the mass block is arranged on the back explosion surface of the main body structure and is firmly connected with the main body structure through the tows, and the tows can provide centripetal force for the mass block and the main body structure. The main structure has basic explosion shock wave and fragment load weakening performance, can be designed according to the existing light protective layer structure, the mass blocks deviate from the momentum direction under the action of the centripetal force of the tows, so that the momentum is harmless, and meanwhile, the main structure is subjected to downward acting component force to avoid jumping. The high-strength fiber product can be selected as the filament bundle, the density is low, the strength is high, the centripetal force can be rapidly transmitted, the filament bundle cannot be easily broken, and even if the filament bundle is finally broken, secondary harm cannot be transmitted to the surrounding environment. The axial strength of the tows is generally equal to or more than 2 GPa.
The principle of the invention is as follows: under the action of explosive load, the mass blocks positioned on the back explosion surface can obtain translation speed and have a momentum extraction function, and under the unconstrained condition, the mass blocks can scatter around like other materials in an explosion-proof equipment structure, and secondary kinetic energy hazards still exist in the larger translation speed; however, due to the existence of the high-strength tows, the mass block immediately becomes (quasi) circular motion after obtaining the translation speed, and the circle center is the connection point of the high-strength tows and the main body structure. This transformation of the motion pattern causes the momentum extracted by the mass to deflect upwards, and this energy guidance makes part of the kinetic energy harmless, since there is often no personnel or facilities above it.
From another perspective, centripetal (centrifugal) forces in the direction of the high strength filament bundle are generated during the transition of the mass motion profile. As shown in FIG. 2, assume a certain mass block (mass m)i) The obtained tangential velocity is ViThe distance from the mass block to the connecting point of the high-strength tow and the main structure of the explosion-proof equipment is l, and the centripetal force is Fi＝miVi 2L, combined pulling force of masses ∑ FiWill be atThe body structure being acted upon at the body structure junction with its vertical downward component FdThe upward jump of the main structure of the explosion-proof equipment can be inhibited, and the threat of fragment leakage is reduced.
Wherein, the tie point of high strength silk bundle and major structure evenly arranges on the face of exploding on the back of the body of explosion-proof equipment, can ensure along the face of exploding on the back circumference evenly distributed that the major structure of explosion-proof equipment receives the effort that comes from the silk bundle and distribute evenly, guarantees that explosion-proof structure circumference atress is stable, avoids major structure to take place to overturn or local jump flies appears in one side, can make the silk bundle propagate whole structure to major structure's effort more fast along direction of height evenly distributed, suppresses the jump better and flies. The strength of the high-strength filament bundle is not lower than 2GPa, the length of the high-strength filament bundle is required to ensure that each mass block cannot touch the ground, and the upper mass block and the lower mass block cannot interfere with each other in the rotation process; therefore, the high-strength beams are in a pre-stretched state under the self weight of the mass blocks, when the anti-explosion equipment is used, the high-strength beams can quickly transmit centripetal force from the mass blocks to the connecting points, and meanwhile, the beams are not entangled together, so that the movement independence of each mass block is ensured. The total weight of the mass block accounts for 1/4-1/3 of the total weight of the explosion-proof structure so as to ensure that the momentum extraction process shares enough momentum for the main structure. The number of the mass blocks distributed along the height direction of the main body structure is more than or equal to 5, and the number of the mass blocks distributed along the circumferential direction is more than or equal to 10, so that the kinetic energy shortage caused by too large mass of a single mass block can be avoided.
In addition, in order to further inhibit secondary damage of the mass block, the mass block can adopt high molecular polymer encapsulated with fragile materials. Wherein the friable material can be various particulate materials, such as various polymeric particles (e.g., polystyrene foam particles, perlite particles, etc.), polymeric foam (e.g., polyurethane foam), fine sand, inorganic salt powder, etc., or a mixture of the above particulate materials, and the material density is not more than 1.5g/cm3(ii) a It can also be a liquid or a mixture of liquids, wherein the liquid has a density of not more than 1.5g/cm3The emulsion is non-toxic and non-flammable, the viscosity coefficient is lower than 2MPa & s, and the emulsion can be dispersed into very small liquid drops when flying; or a mixture of the above particulate material and a liquid. Polymer polymerThe compound can be selected from soft high molecular polymer with low density and low strength (strength is less than or equal to 5MPa, density is less than or equal to 1 g/cm)3) A material that is super elastic or more plastic, like a balloon, does not break immediately. When the strain of the high molecular polymer reaches the rupture value, the momentum extraction effect is often finished, and the high molecular polymer has low strength and small thickness, so that the high molecular polymer is easily decelerated by air in the crushing and scattering process, and therefore, the high molecular polymer does not have the killing property. The fragile materials are encapsulated in the polymer, (i) the polymer can enable the mass block to be in a good gathering state before explosion, and the fragile materials in the mass block can obtain more uniform speed at the beginning of the explosion so as to generate effective centripetal force, so that the motion direction of the mass block is deflected towards a harmless direction; (ii) after the explosion protection process is finished, the polymer with low strength can be cracked through multiple times of stress wave oscillation, and the internal fragile material can be broken into small particles scattered around without killing property.
The mass block can be wrapped by a high-strength fiber hollowed-out net bag, and the high-strength fiber hollowed-out net bag is firmly connected with the high-strength tows. The high molecular polymer on the outer surface of the mass block needs to meet the subsequent crushing function, so that the strength is not high (about MPa), and the connection part of the filament bundle and the mass block is easy to break prematurely. Therefore, the mass block is wrapped by the high-strength fiber hollowed-out net bag, the connection strength of the high-strength tows and the net bag is high enough, premature fracture cannot occur, and meanwhile, the hollowed-out design can ensure that the mass block can be scattered out of the hollowed-out part after subsequent crushing. The axial strength of the tows of the common fiber hollowed-out net bag is more than or equal to 2 GPa.
In addition, in order to ensure that the centripetal force is generated quickly enough, the action time is long enough and the amplitude is large enough, the tows can adopt high-performance polymer fibers or carbon fibers, such as commercial bulletproof fibers, which have high strength, high elastic modulus (more than or equal to 80GPa) and low density (less than or equal to 1.6 g/cm)3) Therefore, the wave velocity of the elastic wave is high. Because the high-strength centripetal wave has the characteristics of low density, high strength (GPa) and high axial wave speed, the high axial wave speed is favorable for quickly generating centripetal force, and the high strength isEnsuring that centripetal forces are not unloaded by breakage of the tow.
In order to further inhibit the jump flight, a high wave speed (the wave speed is more than or equal to 5000m/s) structural material layer can be added in the main structure of the explosion-proof equipment. The invention improves the explosion-proof layer of the explosion-proof equipment on the basis of utilizing the high-strength tows to generate enough and stable centripetal force (pulling force) to inhibit the jumping of the explosion-proof equipment, and adds a high-wave-speed structural material layer in the explosion-proof equipment, so that the explosion-proof tows are directly and firmly connected with the layer. The high-wave-speed structural material layer can be arranged on the back explosion surface of the explosion-proof layer and can also be inserted into the explosion-proof layer, so that other parts can be driven to bear force more conveniently. One end of the filament bundle is connected with the mass block, and the other end of the filament bundle penetrates through a small hole formed in the back explosion surface to be connected with the high-wave-speed structural material layer. Through this high wave speed structure material layer, the centripetal force (pulling force) that the silk bundle produced can propagate each part of explosion-proof equipment major structure at a high speed, and then can propagate on whole structure rapidly with the point force of high strength silk bundle effect on explosion-proof major structure for whole structure receives decurrent pulling force, and the structure jump that can restrain better like this flies.
The high-wave-speed structural material layer can be a structural-grade fiber-resin matrix composite board, the board has high-speed stress wave propagation characteristics, and downward pulling force provided by centripetal force of high-strength tows can be propagated to other parts of the main structure at high speed.
Example 1
As shown in fig. 1, the momentum deflection based explosion protection device of the present invention comprises a main structure 1 and a plurality of masses 2, which are firmly connected by a high strength tow 3, the masses being located on the backfire side of the main structure. It should be noted that the shape of the mass is not limited to spherical, and the mass has a plurality of distributions in the height direction, and the length of the high-strength filament bundle is shortened as much as possible to increase the centrifugal force.
FIG. 2 is a schematic diagram of the principle of momentum deflection and fly-back suppression (a mass block is selected) in the protection method of the present invention. When the explosion shock wave acts on the explosion-proof equipment, the mass block on the back explosion side can convert part of explosion energy into own translational momentum, so that the explosion shock can be weakenedA wave. Due to the existence of the high-strength tows, the translational motion of the mass block is quickly converted into the rotational motion under the traction of the mass block, so that on one hand, the momentum of the mass block can deflect towards the harmless direction (upper direction) of personnel and facilities, and the harm of secondary kinetic energy is reduced. On the other hand, the centripetal tension F formed by the high-strength filament bundle in the rotating motion process of the mass blockiWill act on the main structure of the explosion-proof equipment, with its vertical component FdDownward, upward jump of the body structure can thus be suppressed.
FIG. 3 illustrates a preferred material structure and constraint method of the proof mass of the present invention. The mass block 2 is specifically composed of a fragile material 4 and a high molecular polymer 5, and the fragile material is packaged in the high molecular polymer. Each mass block is wrapped by a high-strength fiber hollowed-out net bag 6, and the high-strength tows 3 and the high-strength fiber hollowed-out net bags can be firmly connected in a high-strength mode. The two functions shown in fig. 2 can be effectively realized by the structural design, and the secondary hazard can be further effectively reduced, so that the reliability and the safety of the structure are improved.
In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (16)
1. An explosion protection structure based on momentum deflection is characterized by comprising a plurality of mass blocks, wherein the mass blocks are arranged on the back explosion surface of a protection layer through tows.
2. The momentum deflection based blast protected structure of claim 1 wherein the mass is a high molecular polymer having a frangible material encapsulated therein.
3. The momentum deflection based explosion containment structure according to claim 2, wherein the mass is disposed within a fabric hollowed-out mesh bag, the fabric hollowed-out mesh bag being connected to the tow.
4. A momentum deflection based explosion protection structure according to claim 2 or 3, wherein the frangible material is a respective particulate material, a liquid or a mixture thereof.
5. The momentum deflection based explosion protection structure according to claim 4, wherein the friable material is one or a mixture of high molecular polymer particles, high molecular polymer foam, fine sand, inorganic salt powder; or a liquid or liquid mixture with a viscosity coefficient lower than 2MPa · s; or a mixture of the above materials.
6. The momentum deflection based explosion containment structure as claimed in claim 1, wherein the tows are made of polymer or carbon fibers.
7. A momentum deflection based explosion protection arrangement according to claim 1, wherein the masses are arranged uniformly on the backface of the explosion proof equipment.
8. Explosion protection structure based on momentum deflection according to claim 1 or 7, wherein the number of the mass blocks distributed along the height of the protection layer is greater than or equal to 5, and the number of the mass blocks distributed along the circumference is greater than or equal to 10.
9. The momentum deflection based blast protection structure according to claim 1, wherein the total weight of the mass is 1/4-1/3 of the total weight of the protection structure.
10. The momentum deflection based explosion containment structure according to claim 1, further comprising a layer of high wave velocity structural material disposed on the back blast side of the explosion proof layer or interspersed within the internal structure of the explosion proof layer, the tow having one end connected to the mass and the other end connected to the layer of high wave velocity structural material.
11. The explosion protection method based on momentum deflection is characterized in that a plurality of mass blocks are arranged on the back explosion surface of the protective layer and are connected with the back explosion surface of the protective layer through tows.
12. A momentum deflection based explosion protection method according to claim 11, wherein the mass is a high molecular polymer having a brittle material encapsulated therein.
13. The momentum deflection based explosion protection method according to claim 11, wherein the proof mass is wrapped with a hollow fiber mesh; the tows are connected with the hollow fiber net bag.
14. The momentum deflection based explosion protection method according to claim 11 or 12, wherein the friable material is one of or a mixture of high molecular polymer particles, high molecular polymer foam, fine sand, inorganic salt powder; or a liquid or liquid mixture with a viscosity coefficient lower than 2MPa · s; or a mixture of the above materials.
15. A momentum deflection based explosion protection method according to claim 11, wherein the total weight of the mass is 1/4 to 1/3 of the total weight of the protective structure.
16. A momentum deflection based explosion protection method according to claim 11, wherein a layer of high wave speed structural material is provided in the middle or on the back of the protection layer, and the tows are fixed on the layer of high wave speed structural material.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010081956.4A CN111207645A (en) | 2020-02-06 | 2020-02-06 | Momentum deflection-based explosion protection structure and method |
| CN202010996589.0A CN112161539B (en) | 2020-02-06 | 2020-09-21 | Momentum deflection-based explosion protection structure and method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010081956.4A CN111207645A (en) | 2020-02-06 | 2020-02-06 | Momentum deflection-based explosion protection structure and method |
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| CN202010996589.0A Active CN112161539B (en) | 2020-02-06 | 2020-09-21 | Momentum deflection-based explosion protection structure and method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2010019612A2 (en) * | 2008-08-11 | 2010-02-18 | Greenhill Antiballistics Corporation | Densely packed particle structure |
| CN204007366U (en) * | 2014-06-05 | 2014-12-10 | 马鞍山矿山研究院爆破工程有限责任公司 | A kind of flexibility is adjustable blasting flyrock protection network |
| CN208075694U (en) * | 2018-03-29 | 2018-11-09 | 武汉爆破有限公司 | The individual flying protective devices of explosion |
| CN209763901U (en) * | 2019-04-12 | 2019-12-10 | 何国兴 | Directional blasting flying stone protection network |
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| CN112161539B (en) | 2022-01-11 |
| CN112161539A (en) | 2021-01-01 |
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