CN110671972A - Explosion-proof layer structure and manufacturing method thereof - Google Patents

Explosion-proof layer structure and manufacturing method thereof Download PDF

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Publication number
CN110671972A
CN110671972A CN201911019623.2A CN201911019623A CN110671972A CN 110671972 A CN110671972 A CN 110671972A CN 201911019623 A CN201911019623 A CN 201911019623A CN 110671972 A CN110671972 A CN 110671972A
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CN
China
Prior art keywords
cell
cell wall
explosion
layer structure
proof layer
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CN201911019623.2A
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Chinese (zh)
Inventor
袁梦琦
郭亚鑫
钱新明
卫禹辰
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Beijing University of Technology
Beijing Institute of Technology BIT
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Beijing University of Technology
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Priority to CN201911019623.2A priority Critical patent/CN110671972A/en
Publication of CN110671972A publication Critical patent/CN110671972A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41—WEAPONS
    • F41H—ARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL
    • F41H1/00—Personal protection gear
    • F41H1/02—Armoured or projectile- or missile-resistant garments; Composite protection fabrics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
    • B32B3/10—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material
    • B32B3/12—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/558—Impact strength, toughness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2571/00—Protective equipment
    • B32B2571/02—Protective equipment defensive, e.g. armour plates, anti-ballistic clothing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0058—Kind of property studied
    • G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
    • G01N2203/0075—Strain-stress relations or elastic constants
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/026—Specifications of the specimen
    • G01N2203/0262—Shape of the specimen
    • G01N2203/0278—Thin specimens
    • G01N2203/0282—Two dimensional, e.g. tapes, webs, sheets, strips, disks or membranes

Abstract

The invention relates to the technical field of protective equipment and discloses an explosion-proof layer structure and a manufacturing method thereof, wherein the explosion-proof layer structure comprises a plurality of cells which are connected in a layered and staggered manner, the cells extend along the axial direction, the cells comprise two first cell walls which are parallel and opposite and two second cell wall groups, one end of each second cell wall group is connected with one end of one first cell wall, and the other end of each second cell wall group is connected with the same end of the other first cell wall; each group of second cell wall groups comprises two second cell walls which are arranged in an inwards concave included angle; two second cell walls are connected through a first transition section, and at least one second cell wall is connected to the first cell wall through a second transition section to form a negative Poisson's ratio honeycomb structure. This explosion-proof layer structure can make rigidity, shear modulus, fracture toughness, the indentation resistance of whole explosion-proof structure show the reinforcing through setting up the changeover portion, can not take place the big deformation in the twinkling of an eye and lead to wholly collapsing, can effectually exert the energy-absorbing effect of slowly-releasing when resisting the impact.

Description

Explosion-proof layer structure and manufacturing method thereof
Technical Field
The invention relates to the technical field of protective equipment, in particular to an explosion-proof layer structure and a manufacturing method thereof.
Background
The public safety is a foundation stone for national safety and social stability, is a basic guarantee for the peaceful and happy industry of people, is a major strategic problem for constructing a harmonious society, and is also a major public welfare problem related to the national civilians. The production safety is an important component for guaranteeing the public safety of cities. With the rapid development of economic society, human body protection technology in safety production gradually becomes a research hotspot. In recent years, a large number of casualties of emergency rescue personnel are caused by dangerous chemical explosion accidents, and in the dangerous chemical explosion accidents, the probability of death and injury of the emergency rescue personnel are respectively 1.2 multiplied by 10 of the rescue actions such as fire-fighting rescue, social rescue and the like7Power and 3.4X 107And (4) doubling. One important reason for disastrous casualties of emergency rescuers is that the emergency rescuers are not equipped with special explosion-proof clothes at present in dangerous chemical explosion accidents, so that the injuries to human bodies caused by shock waves, fragments and high temperature generated by explosion cannot be effectively resisted.
The existing explosion-proof clothes mainly comprise hard clothes and soft clothes. The current hard protective layer is mainly made of high-strength alloy, can protect the damage of high-speed fragments, overpressure and high temperature generated by explosion to human bodies, but is heavy, generally weighs 30-50 kg, and has great influence and limitation on the action and wearing comfort of a wearer; the soft explosion-proof clothes protective material is mainly formed by stacking high-performance fibers, the average weight is 7kg, and the comprehensive protective effect is weak. The national institute of justice states that in the national standard of protective clothing (NIJ 115), the protective clothing is designed in such a way that "proper protection and wearability are life saving", that is, after the requirement of protective performance is met, the wearability is an important factor influencing the wearing frequency, and the requirement of avoiding improper damage caused by low wearing frequency is met. Although the existing explosion-proof clothes can provide effective protection for police officers, the existing explosion-proof clothes are limited by the traditional design concept and the manufacturing process, have higher weight, poorer flexibility and extremely poor heat and moisture permeability, and are easy to cause larger consumption on the physical strength of equipment personnel. Experiments show that under the condition of low activity of a person wearing heavy protective clothing, the skin temperature and the internal temperature of the surface of the person can be greatly increased within 30min, the heat production quantity of the body is increased by 3-4 times compared with that of the person in a static state at normal temperature, and if the person is light, the person is in heatstroke and dizzy, and if the person is heavy, the person is in vague consciousness and endangers life. The above reasons all result in the inefficient wearing of explosion-proof garments. Therefore, the shock wave protective clothing which is safe, light, flexible and high in cost performance needs to be researched, the dressing rate of the protective clothing of emergency rescue personnel is integrally improved, and the life safety of the emergency rescue personnel is guaranteed.
Disclosure of Invention
The embodiment of the invention provides an explosion-proof layer structure and a manufacturing method thereof, which are used for solving the problems of high cost, heavy weight and poor explosion-proof performance of the conventional explosion-proof clothes and improving the usability of protective equipment.
The embodiment of the invention provides an explosion-proof layer structure, which comprises a plurality of cells connected in a layered and staggered manner, wherein the cells extend along an axial direction, each cell comprises two parallel and opposite first cell walls and two groups of second cell wall groups, one end of each second cell wall group is connected to one end of one first cell wall, and the other end of each second cell wall group is connected to the same end of the other first cell wall; each group of second cell wall groups comprises two second cell walls which are arranged in an inwards concave included angle; two second cell walls are connected through a first transition section, and at least one second cell wall is connected to the first cell wall through a second transition section to form a negative Poisson's ratio honeycomb structure.
Wherein both of said second cell walls are connected to said first cell wall by a second transition having a length equal to the length of said first transition; the three cells are adjacent to each other to form a cell group, the second cell wall at the upper right part of the first cell is connected with the second cell wall at the lower left part of the second cell, and the second cell wall at the lower right part of the first cell is connected with the second cell wall at the upper left part of the third cell.
Wherein the first cell wall of the lower part of the second cell and the first cell wall of the upper part of the third cell in the cell group are merged into one first cell wall.
Wherein both of the second cell walls are connected to the first cell wall by a second transition section, the length of the first transition section being equal to the sum of the lengths of the two second transition sections.
Wherein the shape of the first transition section in one set of the second cell wall sets is complementary to the shape of the two second transition sections in the other set of the second cell wall sets.
Wherein the length of the first cell wall is between 2.5mm and 5 mm.
Wherein the included angle between the first cell wall and the second cell wall is between 60 and 75 degrees.
The explosion-proof substrate is composed of a plurality of cells connected in a layered and staggered manner, and super energy-absorbing plates are fixedly connected to the top surface and the bottom surface of the explosion-proof substrate.
The first transition section and the second transition section are straight line sections, broken line sections or wavy line sections.
The embodiment of the invention also provides a method for manufacturing the explosion-proof layer structure, which comprises the following steps:
and based on the three-dimensional model of the explosion-proof layer structure, titanium alloy powder is used as a raw material, and the three-dimensional model is processed and formed by adopting a 3D printing technology.
The explosion-proof layer structure comprises a plurality of layered and staggered connected cells, the cells extend along the axial direction, the cross sections of the cells are improved concave hexagons, and one group of concave angles and at least one group of outer convex angles of the existing concave hexagons are arranged as transition sections to form a negative Poisson ratio honeycomb structure. Through setting up the changeover portion, rigidity, shear modulus, fracture toughness, the indentation resistance that can make whole explosion-proof structure are showing and are strengthening, can not take place big deformation in the twinkling of an eye and lead to whole collapse, can effectually exert the energy-absorbing effect of slowly-releasing when resisting the impact. When the cell is loaded in the longitudinal direction, the cell shrinks in the transverse direction; when the cell element bears a tensile load in the longitudinal direction, the cell element can generate an expansion phenomenon in the transverse direction, and the negative Poisson ratio effect can be effectively exerted. This explosion-proof layer structure is with the help of the excellent performance that negative poisson ratio structure shows in the aspect of the antiknock of impact, combine the lightweight advantage of honeycomb type structure, and utilize the changeover portion to strengthen the rigidity and the shock resistance of structure, not only have good energy-absorbing characteristic in the aspect of protecting against shock wave, and the fragment that produces in the explosion-proof process has good resistance ability, the multilayer of explosion-proof clothes in the manufacturing process is avoided compound, the travelling comfort of protective equipment has been improved, the flexibility, the production technology has been simplified, and the production cost is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a schematic structural view of an explosion-proof layer structure in an embodiment of the invention;
FIG. 2 is a schematic cross-sectional view of the blast-resistant substrate of FIG. 1;
figure 3 is a schematic diagram of a cell according to an embodiment of the present invention;
figure 4 is a schematic cross-sectional view of the cell of figure 3;
fig. 5 is a cell set consisting of three cells of fig. 3;
fig. 6 is another cell set consisting of three cells of fig. 3;
FIG. 7 is an enlarged cross-sectional view of an explosion-proof substrate composed of a plurality of cell groups of FIG. 6;
fig. 8 is an enlarged cross-sectional view of another blast-resistant substrate made up of a plurality of cells of fig. 3;
figure 9 is a schematic cross-sectional view of another cell in an embodiment of the invention;
fig. 10 is an enlarged cross-sectional view of an explosion-proof substrate made up of a plurality of cells of fig. 9;
figure 11 is a schematic cross-sectional view of yet another cell in an embodiment of the present invention;
FIG. 12 is a schematic structural view of yet another explosion-proof layer structure in an embodiment of the invention;
FIG. 13 is a graph comparing the results of impact resistance tests of the explosion proof layer structure of the embodiment of the present invention and the prior art explosion proof layer structure;
description of reference numerals:
1: a cell element; 11: a first cell; 12: a second cell;
13: a third cell; 2: a first cell wall; 3: a second cell wall group;
4: a second cell wall; 51: a first transition section; 52: a second transition section;
10: an explosion-proof substrate; 20: super energy-absorbing board.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the embodiments of the present invention, it should be noted that the terms "first" and "second" are used for the sake of clarity in describing the numbering of the components of the product and do not represent any substantial difference, unless explicitly stated or limited otherwise. The directions of "up", "down", "left" and "right" are all based on the directions shown in the attached drawings. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations.
It is to be understood that, unless otherwise expressly specified or limited, the term "coupled" is used broadly, and may, for example, refer to directly coupled devices or indirectly coupled devices through intervening media. Specific meanings of the above terms in the embodiments of the invention will be understood to those of ordinary skill in the art in specific cases.
As shown in fig. 1 to 10, an explosion-proof layer structure according to an embodiment of the present invention includes a plurality of cells 1 connected in a layered and staggered manner, wherein the cells 1 extend along an axial direction. The cell 1 comprises two parallel first cell walls 2 and two second cell wall groups 3, one end of each second cell wall group 3 is connected to one end of one first cell wall 2, and the other end of each second cell wall group 3 is connected to the same end of the other first cell wall 2, namely, the end on the same side corresponding to one end of the previous first cell wall 2. Specifically, the upper end of the second cell wall group 3 on the left side is connected to the left end of the first cell wall 2 on the upper part, and the lower end of the second cell wall group 3 on the left side is connected to the left end of the first cell wall 2 on the lower part; the upper end of the second cell wall group 3 on the right side is connected to the right end of the first cell wall 2 on the upper portion, and the lower end of the second cell wall group 3 on the right side is connected to the right end of the first cell wall 2 on the lower portion.
Each group of second cell wall groups 3 comprises two second cell walls 4 which are arranged in an inwards concave included angle; two second cell walls 4 are connected by a first transition section 51, and at least one second cell wall 4 is connected to the first cell wall 2 by a second transition section 52 to form a negative poisson's ratio honeycomb structure.
As shown in fig. 1 to 2, the cells 1 adjacent to each other in the top and bottom direction are adjacent to each other via the first cell walls 2, and the two cells 1 adjacent to each other in the left and right direction are adjacent to each other via the second cell walls 4. As shown in fig. 3, each cell 1 extends in a long stripe shape in the axial direction.
In particular, as shown in fig. 4, it is possible for both second walls 4 to be connected to the first wall 2 by a second transition 52. Taking the left second cell wall group 3 as an example, the upper end of the upper left second cell wall 4 is connected to the left end of the upper first cell wall 2 through the second transition section 52, and the lower end of the lower left second cell wall 4 is also connected to the left end of the lower first cell wall 2 through the second transition section 52.
As shown in fig. 9, it is also possible for one of the second cell walls 4 to be connected to one of the first cell walls 2 by a second transition 52, the other second cell wall 4 being connected directly to the other first cell wall 2. Also taking the left second cell wall group 3 as an example, the upper end of the left upper second cell wall 4 is connected to the left end of the upper first cell wall 2 through a second transition section 52, and the lower end of the left lower second cell wall 4 is directly connected to the left end of the lower first cell wall 2. The length of the second cell wall 4 and the angle between it and the first cell wall 2 are the same in this embodiment.
The cross section of the cell 1 in this embodiment is optimized on the basis of a concave hexagon, and the strength of the cell 1 is improved by setting one group of concave angles and one group of external convex angles (or two groups of external convex angles) of the existing concave hexagon as transition sections.
More specifically, through quasi-static mechanics experiments and dynamic mechanics experiments, the differences of mechanical response characteristics and energy absorption characteristics of the concave honeycomb structure with the negative Poisson's ratio effect and the traditional regular hexagonal honeycomb structure and quadrilateral structure are compared.
In the quasi-static loading process by using the electronic universal testing machine, the loading rate is 3mm/min, and the rated loading strain rate is 0.005s-1. The concave hexagonal honeycomb structure has unique negative Poisson ratio effect, and the compression modulus, yield strength and surface ratio energy absorption are all higher than those of the regular quadrilateral honeycomb structure and the regular hexagonal honeycomb structure, so that the concave hexagonal honeycomb structure has the strongest deformation resistance and the optimal energy absorption effect under the quasi-static loading action.
At a strain rate of 700s each-1，1000s-1And 1300s-1In the dynamic compression load loading process of the Hopkinson pressure bar, the concave hexagonal honeycomb structure has unique negative Poisson's ratio effect, and the dynamic yield strength and the surface ratio energy absorption are higher than those of a regular quadrilateral honeycomb structure and a regular hexagonal honeycomb structure, so that the concave hexagonal honeycomb structure has the strongest deformation resistance and the optimal energy absorption effect under the dynamic loading action.
In the shock wave loading process with the incident pressure of 200kPa, compared with a regular hexagonal honeycomb structure and a regular quadrilateral honeycomb structure, the concave hexagonal honeycomb structure has the most excellent shock wave attenuation characteristic due to the specific negative Poisson's ratio effect, the attenuation effect is improved by 20.11 percent compared with the regular hexagonal structure and 10.15 percent compared with the regular quadrilateral structure, and the result is consistent with the conclusion of quasi-static compression mechanics experiments and dynamic compression mechanics experiments. Therefore, compared with the traditional positive poisson ratio material, the negative poisson ratio material (also called as an auxetic material) shrinks in the vertical force-bearing direction when being subjected to compressive load; when the tension load is applied, the expansion is generated in the vertical force-bearing direction. The negative poisson's ratio effect can obviously enhance many mechanical properties of the material, such as shear modulus, fracture toughness, indentation resistance and the like.
In this embodiment, the cell 1 of the negative poisson ratio honeycomb structure is adopted as an optimized concave hexagonal structure, and six corners of the hexagon are subjected to transition optimization. As shown in fig. 13, the solid line shows the experimental results of the cell 1 of the concave hexagonal structure including the transition section in the present embodiment, and the dotted line shows the experimental results of the cell of the conventional concave hexagonal structure without the transition section. The result shows that the impact resistance of the explosion-proof structure layer in the embodiment is improved by 30 to 45 percent compared with the original structure.
Under the condition of strong load loading (shock wave impact), the traditional concave hexagonal anti-explosion structure can be obviously deformed in a very short time, the whole thickness of the light anti-explosion structure is small, and the anti-explosion structure tends to a compaction state instantly due to the large deformation condition in a short time, so that the shock can not be effectively resisted. In the process of resisting impact, the optimized cell 1 with the concave hexagonal structure can obviously enhance the rigidity, shear modulus, fracture toughness and indentation resistance of the whole anti-explosion structure due to the existence of the transition section, cannot cause large deformation instantly to cause whole collapse, and can effectively exert the slow-release energy-absorbing effect when resisting impact. When the cell 1 is subjected to a compressive load in the longitudinal direction, the cell 1 is contracted in the transverse direction; when the cell 1 is subjected to a tensile load in the longitudinal direction, the cell 1 can generate an expansion phenomenon in the transverse direction, and can effectively exert a negative poisson ratio effect.
The embodiment provides an explosion-proof layer structure, which comprises a plurality of cells connected in a layered and staggered manner, wherein the cells extend along the axial direction, the cross sections of the cells are modified concave hexagons, and a group of concave angles and at least one group of external convex angles of the existing concave hexagons are arranged as transition sections so as to form a negative Poisson ratio honeycomb structure. Through setting up the changeover portion, rigidity, shear modulus, fracture toughness, the indentation resistance that can make whole explosion-proof structure are showing and are strengthening, can not take place big deformation in the twinkling of an eye and lead to whole collapse, can effectually exert the energy-absorbing effect of slowly-releasing when resisting the impact. When the cell is loaded in the longitudinal direction, the cell shrinks in the transverse direction; when the cell element bears a tensile load in the longitudinal direction, the cell element can generate an expansion phenomenon in the transverse direction, and the negative Poisson ratio effect can be effectively exerted. This explosion-proof layer structure is with the help of the excellent performance that negative poisson ratio structure shows in the aspect of the antiknock of impact, combine the lightweight advantage of honeycomb type structure, and utilize the changeover portion to strengthen the rigidity and the shock resistance of structure, not only have good energy-absorbing characteristic in the aspect of protecting against shock wave, and the fragment that produces in the explosion-proof process has good resistance ability, the multilayer of explosion-proof clothes in the manufacturing process is avoided compound, the travelling comfort of protective equipment has been improved, the flexibility, the production technology has been simplified, and the production cost is reduced.
Further, as shown in fig. 4 to 5, two second cell walls 4 are connected to the first cell wall 2 by a second transition section 52, and the length of the second transition section 52 is equal to the length of the first transition section 51. The three cells 1 are adjacent to each other to form a cell group, the second cell wall 4 at the upper right of the first cell 11 is connected to the second cell wall 4 at the lower left of the second cell 12, and the second cell wall 4 at the lower right of the first cell 11 is connected to the second cell wall 4 at the upper left of the third cell 13.
The cell set in this embodiment includes both a transition and two sharp corners, one of which is formed between the first wall 2 of the upper portion of the first cell 11 and the second wall 4 of the upper left portion of the second cell 12, and the other of which is formed between the first wall 2 of the lower portion of the first cell 11 and the second wall 4 of the lower left portion of the third cell 13. The transition section can be used for enhancing the rigidity and the impact resistance of the structure, and the sharp corner can be used for improving the deformation characteristic and the energy absorption characteristic of the structure, so that the impact resistance and the energy absorption characteristic can be considered simultaneously, and the structure is flexible and rigid.
Further, as shown in fig. 6 to 7, the first cell wall 2 of the lower portion of the second cell 12 and the first cell wall 2 of the upper portion of the third cell 13 in the cell group are merged into one first cell wall 2. By integrating two first cell walls 2, the presence of redundant edges can be reduced, further reducing the weight of the structure.
As shown in fig. 7, a plurality of cell groups may be cyclically connected in the horizontal direction to form a cell layer, i.e., the right portion of the second cell 12 and the right portion of the third cell 13 are connected to the first cell 11 of the cell group on the right side. The two upper and lower cell layers may be connected in a repeated cycle in the longitudinal direction, i.e., the lower first cell wall 2 of the third cell 13 is connected to the upper first cell wall 2 of the lower second cell 12. The gaps between the upper and lower cell layers naturally form a plurality of sharp corners.
In addition, by adjusting the lengths of the first transition section 51 and the second transition section 52, another form of the explosion-proof substrate 10 can also be composed. As shown in fig. 8, the two second cell walls 4 are each connected to the first cell wall 2 by a second transition 52, the length of the first transition 51 being equal to the sum of the lengths of the two second transitions 52.
Specifically, the length of the upper second transition section 52 is L1, the length of the lower second transition section 52 is L2, the length of the first transition section 51 is L3, and L3 is L1+ L2, where L1 and L2 may be equal or different. That is, the first transition 51 at the right of the first cell 11 coincides with the second transition 52 at the lower left of the second cell and the second transition 52 at the upper left of the third cell, and the first cell wall 2 at the lower of the second cell 12 coincides with the first cell wall 2 at the upper of the third cell 13. The explosion-proof substrate 10 formed by the cell 1 in the embodiment does not have sharp corners and is completely a transition section, so that the rigidity and the impact resistance are strongest and the explosion-proof substrate is not easy to deform.
Further, as shown in fig. 8, the shape of the first transition section 51 in one set of the second cell wall group 3 is complementary to the shape of the two second transition sections 52 in the other set of the second cell wall group 3. Specifically, the shape of the first transition section 51 in the left second cell wall group 3 is complementary to the shape of the spliced lower second transition section 52 and upper second transition section 52 in the right second cell wall group 3, that is, the two transition sections are just butted into a whole. Similarly, the shape of the first transition section 51 in the second cell wall group 3 on the right side is complementary to the shape of the second transition section 52 on the lower side and the second transition section 52 on the upper side in the second cell wall group 3 on the left side after splicing. As shown in fig. 8, the first transition 51 at the right of the first cell 11 is directly connected to the junction of the second transition 52 at the lower left of the second cell 12 and the second transition 52 at the upper left of the third cell 13.
As shown in fig. 9 to 10, the upper second cell wall 4 of the left second cell wall group 3 is connected to the upper first cell wall 2 via a second transition section 52, and the lower second cell wall 4 is directly connected to the lower first cell wall 2. The cell 1 in this embodiment comprises a transition section and a pointed structure. Therefore, the explosion-proof substrate 10 formed by alternately connecting the cells 1 in the present embodiment can also achieve both impact resistance and energy absorption characteristics.
Further, the length of the first cell wall 2 is between 2.5mm and 5 mm. In particular, the length of the first cell wall 2 is greater than or equal to 2.5mm and less than 5 mm. In a particular embodiment, the length of the first cell wall 2 is equal to 3.4 mm. Specifically, in the quasi-static loading process by using the electronic universal testing machine, the loading rate is 3mm/min, and the rated loading strain rate is 0.005s-1The compression modulus, yield strength and energy absorption value of the concave honeycomb structure with the size of 2.575mm in the quasi-static compression process are all higher than those of the concave honeycomb structure with the size of 3.40mm, but the surface density of the concave honeycomb structure with the size of 2.575mm is much higher than that of the concave honeycomb structure with the size of 3.40mm, and although the surface density of the concave honeycomb structure with the size of 5.05mm is minimum, the mechanical property and the energy absorption effect of the concave honeycomb structure are also the worst, so that the surface ratio of the concave honeycomb structure with the size of 3.40mm is the largest in energy absorption. At a strain rate of 700s each-1，1000s-1And 1300s-1In the dynamic compression load loading process of the Hopkinson pressure bar, the concave honeycomb structure with the size of 3.40mm absorbs energy with the largest surface ratio. In the shock wave loading process with the incident pressure of 200kPa, the concave honeycomb structure with the size of 3.40mm has the highest shock wave attenuation efficiency, and meets the requirements of protective equipment on light weight and high strength of the protective structure.
Further, the included angle between the first cell wall 2 and the second cell wall 4 is between 60 ° and 75 °. Specifically, in the quasi-static loading process by using the electronic universal testing machine, the loading rate is 3mm/min, and the rated loading strain rate is 0.005s-1Compression modulus and yield strength of concave honeycomb structure with included angle of 60 degreesThe degree is maximum, the area ratio energy absorption is maximum, and the energy absorption effect is optimal. At a strain rate of 700s each-1，1000s-1And 1300s-1In the dynamic compression load loading process of the Hopkinson pressure bar, the dynamic yield strength of the concave honeycomb structure with the included angle of 60 degrees is obviously higher than that of the concave honeycomb structure with the included angle of 67.5 degrees and 75 degrees, and the anti-deformation performance is the strongest under the quasi-static loading action. In the range of 0-5% of strain value, the concave honeycomb structure with the included angle of 60 degrees absorbs most energy, the area ratio absorbs most energy, and the energy absorption effect is optimal. In the shock wave loading process with the incident pressure of 200kPa, the attenuation effect of the concave honeycomb structure with the included angle of 60 degrees on the shock wave is respectively improved by 14.47 percent and 5.49 percent compared with the concave honeycomb structure with the included angles of 75 degrees and 67.5 degrees, and the concave honeycomb structure has the most excellent energy absorption effect and shock wave attenuation characteristic.
Further, the material of the cell 1 is titanium alloy. The titanium alloy has good heat insulation performance and high strength and low density, and can effectively reduce the quality of the protective layer. Specifically, a typical thermoplastic titanium alloy powder, powder type TC4(Ti6Al4V), may be used. In the quasi-static loading process by using the electronic universal testing machine, the loading rate is 3mm/min, and the rated loading strain rate is 0.005s-1The compression modulus and the yield strength of the concave honeycomb structure processed by the titanium alloy powder are the highest, and the surface ratio energy absorption is the highest, so that the deformation resistance is the strongest under the action of quasi-static loading, the energy absorption effect is the best, the surface density of the concave honeycomb structure processed by the titanium alloy powder is the smallest, the titanium alloy powder is used as a processing raw material, the technology is mature in the field of metal 3D printing, and the honeycomb protection structure can meet the requirements of light weight and high strength. At a strain rate of 700s each-1，1000s-1And 1300s-1In the dynamic compression load loading process of the Hopkinson pressure bar, the dynamic yield strength and the surface ratio of the concave honeycomb structure processed by the titanium alloy powder absorb energy to the maximum extent, which shows that the concave honeycomb structure has the strongest deformation resistance and the optimal energy absorption effect under the action of dynamic loading. In the shock wave loading process with the incident pressure of 200kPa, the concave honeycomb structure processed by titanium alloy powder resists deformation under the shock wave loading actionThe performance is strongest, and the energy absorption effect is optimal.
Further, as shown in fig. 12, the explosion-proof substrate 10 is formed by a plurality of cells 1 connected in a layered and staggered manner, and the super energy absorbing plate 20 is fixedly connected to both the top surface and the bottom surface of the explosion-proof substrate 10. Specifically, the super Energy absorbing plate 20 is made of super Energy absorbing Materials (SDM), which is a novel polymer composite material, and the polymer material is used as a matrix, and a unique Energy Absorbing Elastomer (EAE) is blended into the SDM, so that the SDM has a particularly outstanding Energy absorbing and shock absorbing characteristic. The super energy-absorbing material inherits the excellent performance of the high-molecular elastomer matrix, and the energy-absorbing buffering and shock-absorbing damping performance of the base material is further improved through modification and reinforcement of the energy-absorbing elastomer. Wherein EAE is a novel polymer material with shear thickening property. The material is a viscous liquid in a normal state, is soft and easy to deform, and once the material is quickly and forcefully impacted, the flexible liquid can be instantly converted into a hard material to prevent external force from penetrating through the material, so that the effect of preventing sharp weapon from puncturing and even preventing bullet is achieved, and the material has the characteristic of strong energy absorption when meeting strong force.
The SDM material has shear thickening property in a normal state, free movement among molecules, flexibility and elasticity; when the shock absorber is impacted, the shock absorber instantaneously finishes the change, the intermolecular is contracted, the energy is absorbed in time, and the response is very quick; after the external force is removed, the original initial state can be recovered and can be repeatedly used. By compounding the front and back surfaces of the explosion-proof substrate 10 with the super energy-absorbing material (SDM), the super energy-absorbing material can show the functional characteristic of 'strong when meeting' when being impacted, so that the impact resistance of the compounded explosion-proof layer structure is greatly improved.
Further, as shown in fig. 4 to 11, the first transition section 51 and the second transition section 52 have the same shape, and are straight line segments, broken line segments or wavy line segments. In addition, the line segments may have other repetitive patterns.
Furthermore, the cell wall thickness of the cell 1 is 0.1mm to 0.3 mm. In a specific embodiment, the wall thickness of the first cell wall 2, the second cell wall 4 and the transition section 5 are all 0.2 mm.
In summary, the explosion-proof substrate 10 in the above embodiment enhances the rigidity of the structure by introducing the transition section, so that all sharp corners of the existing concave hexagonal structure can be completely replaced by the transition section, and meanwhile, the adjacent cells 1 are tightly connected without sharp corners. The anti-explosion substrate 10 has the strongest rigidity at the moment, but has poor deformation performance, can be used for an anti-explosion layer structure of a human body trunk part, and the anti-explosion layer structure of the part does not have the requirement of large deformation in the using process and has the highest requirement on impact resistance.
Secondly, all sharp corners of the existing concave hexagonal structure can be replaced by transition sections, and the sharp corners are formed between the adjacent cells 1 by forming cell groups. The explosion-proof substrate 10 has high rigidity and high deformability, and can be used for explosion-proof layer structures at four limbs of a human body, and the explosion-proof layer structures at the parts have the requirement of large deformation in the using process and have high requirement on impact resistance.
Thirdly, partial sharp corners of the existing concave hexagonal structure can be replaced by transition sections, namely, one cell 1 comprises both sharp corners and transition sections. The explosion-proof substrate 10 has high rigidity and high deformability, and can be used for explosion-proof layer structures at four limbs of a human body, and the explosion-proof layer structures at the parts have the requirement of large deformation in the using process and have high requirement on impact resistance.
Fig. 13 is a graph showing the comparison of the impact resistance test results between the explosion-proof layer structure of the present embodiment and the conventional explosion-proof layer structure without the transition section, and it is apparent from the graph that the impact resistance of the entire explosion-proof layer structure is improved due to the provision of the transition section.
The embodiment of the invention also provides a method for manufacturing the explosion-proof layer structure, which comprises the following steps: the three-dimensional model based on the explosion-proof layer structure takes titanium alloy powder as a raw material and is processed and formed by adopting a 3D printing technology. Specifically, a CAD model of the stab-resistant titanium alloy plate and the connection structure is drawn in drawing software SolidWorks, then the CAD model is stored as an STL format file and is imported into a printing operation system of equipment, parameters are set for processing, and the CAD model is processed and molded by using a 3D printing technology, namely Laser Sintering (LS for short). And after the laser sintering is finished, taking the workpiece and conveying the workpiece with residual temperature into an air box to remove the residual powder on the surface. 3D printing is used as a rapid prototyping technology, has the advantages which are not possessed by other traditional machining methods in the aspects of complex structure prototyping and machining efficiency, and finally converts a three-dimensional model into an entity by stacking materials layer by layer through the rapid prototyping technology.
It can be seen from the above embodiments that the present invention provides an explosion-proof layer structure and a method for manufacturing the same, wherein the explosion-proof layer structure includes a plurality of cells connected in a layered and staggered manner, the cells extend along an axial direction, the cross sections of the cells are modified concave hexagons, and a set of concave angles and at least a set of convex angles of the existing concave hexagons are provided as transition sections to form a negative poisson ratio honeycomb structure. Through setting up the changeover portion, rigidity, shear modulus, fracture toughness, the indentation resistance that can make whole explosion-proof structure are showing and are strengthening, can not take place big deformation in the twinkling of an eye and lead to whole collapse, can effectually exert the energy-absorbing effect of slowly-releasing when resisting the impact. When the cell is loaded in the longitudinal direction, the cell shrinks in the transverse direction; when the cell element bears a tensile load in the longitudinal direction, the cell element can generate an expansion phenomenon in the transverse direction, and the negative Poisson ratio effect can be effectively exerted. This explosion-proof layer structure is with the help of the excellent performance that negative poisson ratio structure shows in the aspect of the antiknock of impact, combine the lightweight advantage of honeycomb type structure, and utilize the changeover portion to strengthen the rigidity and the shock resistance of structure, not only have good energy-absorbing characteristic in the aspect of protecting against shock wave, and the fragment that produces in the explosion-proof process has good resistance ability, the multilayer of explosion-proof clothes in the manufacturing process is avoided compound, the travelling comfort of protective equipment has been improved, the flexibility, the production technology has been simplified, and the production cost is reduced.
Furthermore, the titanium alloy is adopted as the main material of the anti-explosion structure, has good heat insulation performance and high strength and low density, and can effectively reduce the quality of the protective layer. Compared with the traditional explosion-proof structure, the explosion-proof layer is lighter, and the mass of the explosion-proof layer is reduced by more than 70% compared with that of the traditional explosion-proof layer on the premise of excellent explosion-proof performance. In addition, the novel super energy absorption material (SDM) is compounded with the explosion-proof substrate, so that the explosion-proof performance is improved by more than 48%.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. An explosion-proof layer structure, comprising a plurality of cells connected in layers in a staggered manner, the cells extending in an axial direction, the cells comprising two parallel and opposite first cell walls and two sets of second cell walls, one end of each set of second cell walls being connected to one end of one of the first cell walls, and the other end of each set of second cell walls being connected to the same end of the other first cell wall;
each group of second cell wall groups comprises two second cell walls which are arranged in an inwards concave included angle; two second cell walls are connected through a first transition section, and at least one second cell wall is connected to the first cell wall through a second transition section to form a negative Poisson's ratio honeycomb structure.
2. An explosion-proof layer structure as claimed in claim 1, wherein both of the second cell walls are connected to the first cell wall by a second transition section having a length equal to the length of the first transition section; the three cells are adjacent to each other to form a cell group, the second cell wall at the upper right part of the first cell is connected with the second cell wall at the lower left part of the second cell, and the second cell wall at the lower right part of the first cell is connected with the second cell wall at the upper left part of the third cell.
3. The blast-resistant layer structure of claim 2, wherein the first cell wall of the lower portion of the second cell and the first cell wall of the upper portion of the third cell in the cell group are merged into one first cell wall.
4. An explosion-proof layer structure as claimed in claim 1, wherein both of the second cell walls are connected to the first cell wall by a second transition section, the length of the first transition section being equal to the sum of the lengths of the two second transition sections.
5. An explosion proof layer structure as claimed in claim 4 wherein the shape of the first transition section in one set of the second cell wall sets is complementary to the shape of two of the second transition sections in the other set of the second cell wall sets.
6. An explosion-proof layer structure as claimed in claim 1, wherein the length of the first cell wall is between 2.5mm and 5 mm.
7. An explosion proof layer structure as claimed in claim 1 wherein the angle between the first cell wall and the second cell wall is between 60 ° and 75 °.
8. The explosion-proof layer structure of claim 1, wherein a plurality of the cells connected in a layered and staggered manner form an explosion-proof substrate, and super energy-absorbing plates are fixedly connected to both the top surface and the bottom surface of the explosion-proof substrate.
9. An explosion proof layer structure as claimed in any one of claims 1 to 8 wherein the first and second transition sections are both straight, broken or wavy line segments.
10. A method of manufacturing an explosion proof layer structure as claimed in any one of claims 1 to 9, comprising:
and based on the three-dimensional model of the explosion-proof layer structure, titanium alloy powder is used as a raw material, and the three-dimensional model is processed and formed by adopting a 3D printing technology.
CN201911019623.2A 2019-10-24 2019-10-24 Explosion-proof layer structure and manufacturing method thereof Pending CN110671972A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112677920A (en) * 2020-12-16 2021-04-20 南京理工大学 Anti-explosion passenger leg protection device for military vehicle
CN114832359A (en) * 2022-01-17 2022-08-02 大连理工大学 Negative Poisson ratio skiing sport protector suitable for two seasons of summer and winter under multiple scenes
NL2029154A (en) * 2021-04-29 2022-09-19 Asociacion De Investig De La Industria Textil Aitex Protective vest

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112677920A (en) * 2020-12-16 2021-04-20 南京理工大学 Anti-explosion passenger leg protection device for military vehicle
CN112677920B (en) * 2020-12-16 2022-01-11 南京理工大学 Anti-explosion passenger leg protection device for military vehicle
NL2029154A (en) * 2021-04-29 2022-09-19 Asociacion De Investig De La Industria Textil Aitex Protective vest
CN114832359A (en) * 2022-01-17 2022-08-02 大连理工大学 Negative Poisson ratio skiing sport protector suitable for two seasons of summer and winter under multiple scenes
CN114832359B (en) * 2022-01-17 2023-09-19 大连理工大学 Negative poisson ratio skiing sports protective equipment suitable for multi-scene in summer and winter

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