Light bionic bulletproof helmet

Abstract

The invention provides a light bionic bulletproof helmet, and relates to the field of bulletproof equipment, and a negative Poisson's ratio microstructure layer is formed by a plurality of microstructure surfaces which are mutually crossed; the microstructure surface comprises a plurality of microstructure rows, and each microstructure row comprises a plurality of microstructure units; the microstructure unit comprises an outer arrow module and an inner arrow module, the bottom edges of the outer arrow module and the inner arrow module are inner concave edges, and the three vertex angles of the outer arrow module are connected to the three vertex angles of the inner arrow module respectively to form an inner and outer double-layer nested structure; the outer composite material layer is firstly in contact with the bullet, so that the kinetic energy of the bullet is greatly reduced; the middle negative Poisson's ratio microstructure layer buffers and absorbs kinetic energy of bullets continuously entering the helmet, reduces vibration change of the whole helmet, slowly releases stress transmitted by the outer composite material layer, and greatly reduces impact caused by blunt impact; the inner composite material layer consumes the residual kinetic energy of the bullet; and the bullet-proof and blunt-trauma-proof shock-insulation shell has good bullet-proof, blunt-trauma-proof and shock-insulation performance, and has a better protection effect on non-penetration wounds of bullets.

Description

Technical Field

[0001] The invention relates to the field of bulletproof equipment, and further to a lightweight bionic bulletproof helmet. Background Art

[0002] In modern warfare, bulletproof helmets are one of the main protective equipment for individual soldiers, and their use has significantly reduced battlefield casualties. With the increasing demand for anti-terrorism and urban warfare, bulletproof helmets must not only avoid penetrating injuries caused by puncture and bullet penetration, but also avoid the impact of non-penetrating injuries on combatants.

[0003] like Figure 1 As shown, in the prior art, a small concave impact-resistant bionic bulletproof helmet is provided, which is sequentially placed from the outer layer to the inner layer with a hard impact-resistant layer 01, a soft energy-absorbing layer 02, a composite layer 03 and an inner lining layer 04, and the layers are connected by bonding. The outermost layer uses hard ceramics to buffer most of the impact energy of the bullet. When the soft energy-absorbing layer is impacted, it absorbs the impact energy through large deformation in the middle and small deformation on the outside. The composite layer uses flexible materials to absorb the impact energy through large deformation, and the inner lining layer uses shape memory polymer fibers. When impacted, the temperature rise changes so that it bulges outward near the impact point, so that the impact stress spreads to the surroundings to reduce the impact on the head. However, the hard impact-resistant layer of the device uses ceramics or light alloys, and bullets can easily penetrate ceramics or light alloys, increasing the impact pressure of the remaining layers and reducing the overall bulletproof performance of the helmet. At the same time, the bonding between the layers makes the helmet structure prone to dislocation when resisting impact, making the structure easy to collapse, and the bulletproof process is extremely unstable. In addition, the lightweight space of the helmet poses a challenge to the multi-layer structure design.

[0004] For those skilled in the art, how to provide better protection against non-penetrating bullet injuries is a technical problem that needs to be solved at present. Summary of the invention

[0005] The core of the present invention is to provide a lightweight bionic bulletproof helmet, which is provided with an outer composite material layer, a negative Poisson's ratio microstructure layer, and an inner composite material layer. The middle negative Poisson's ratio microstructure layer is used to buffer and absorb the kinetic energy of the bullet and reduce the vibration change of the helmet as a whole, and the stress transmitted by the outer composite material layer is slowly released, which greatly reduces the impact caused by blunt impact, and has a better protective effect on non-penetrating bullet injuries. The specific scheme is as follows:

[0006] A lightweight bionic bulletproof helmet, comprising an outer composite material layer, a negative Poisson's ratio microstructure layer, and an inner composite material layer, which are stacked and fixed in sequence from the outside to the inside; the negative Poisson's ratio microstructure layer comprises a plurality of microstructure surfaces, and the plurality of microstructure surfaces intersect each other to form a negative Poisson's ratio spatial microstructure;

[0007] The microstructure surface includes a plurality of stacked and fixedly arranged microstructure rows, each of which includes a plurality of fixedly connected microstructure units, the microstructure units include an outer arrow module and an inner arrow module, the bottom edges of the outer arrow module and the inner arrow module are inner concave edges, and the three vertices of the outer arrow module are respectively connected to the three vertices of the inner arrow module to form an inner and outer nesting;

[0008] The bottom angles of two adjacent outer arrow modules in each of the microstructure rows are relatively fixed, and the top angle of the outer arrow module of the lower layer in the two adjacent microstructure rows is fixed to the inward concave point of the bottom edge of the outer arrow module of the upper layer, or fixed to the bottom angle of the outer arrow module of the upper layer.

[0009] Optionally, the negative Poisson's ratio microstructure layer is formed by microstructure surfaces intersecting each other perpendicularly.

[0010] Optionally, the side edges of the outer arrow module and the inner arrow module are straight edges, and the bottom edge is an obtuse angle formed by the two straight edges.

[0011] Optionally, the outer arrow module and the inner arrow module are of similar appearance.

[0012] Optionally, each of the inner arrow modules includes two "Y"-shaped combination parts, and each of the combination parts includes two forks and a connecting rod that converge at one point;

[0013] A plurality of the outer arrow modules constituting one of the microstructure rows include a first single arrow truss and a second single arrow truss both in a wavy shape, wherein the first single arrow truss and the second single arrow truss, the first single arrow truss and the inner arrow module, and the second single arrow truss and the inner arrow module are fixed to each other;

[0014] The forked ends corresponding to the two combined parts are in contact and fit with each other; the angle formed by the contact between the first single-arrow truss and the second single-arrow truss can be matched and engaged with the end of the connecting rod.

[0015] Optionally, a plug-in column is provided at the end of the fork, and a plurality of the plug-in columns distributed symmetrically in the center can be plugged and locked with the correspondingly provided plug holes of the first single-arrow truss;

[0016] The first single-arrow truss and the second single-arrow truss are locked by inserting blocks and inserting holes.

[0017] Optionally, there is a gap of 1-2 mm between the outer composite material layer and the negative Poisson's ratio microstructure layer, and between the inner composite material layer and the negative Poisson's ratio microstructure layer.

[0018] Optionally, among the microstructure surfaces constituting the negative Poisson's ratio microstructure layer, a microstructure surface with a large porosity is arranged innerward, and a microstructure surface with a small porosity is arranged outerward.

[0019] Optionally, there is a porosity difference between different regions of the microstructure surface, and the porosity at different positions of the microstructure surface is inversely proportional to the bullet distribution probability.

[0020] Optionally, the outer composite material layer and the inner composite material layer are formed by stacking a plurality of composite material layers, an angle exists between two adjacent composite material layers, and the plurality of composite material layers are sequentially distributed in a spiral in the same direction of rotation;

[0021] The composite material layer is a non-woven fabric formed by compression, and is cured with resin after being stacked.

[0022] Optionally, the outer surface of the outer composite material layer is sprayed with ceramic material and super-tough protective material;

[0023] The protective materials include boron carbide, silicon carbide and aluminum oxide.

[0024] Optionally, the negative Poisson's ratio microstructure layer uses any one or more of aluminum alloy, titanium alloy or magnesium alloy as a base material.

[0025] The invention provides a lightweight bionic bulletproof helmet, which comprises an outer composite material layer, a negative Poisson's ratio microstructure layer and an inner composite material layer which are stacked and fixedly arranged in sequence from the outside to the inside; the negative Poisson's ratio microstructure layer is formed by a plurality of microstructure surfaces intersecting each other to form a negative Poisson's ratio spatial microstructure; the microstructure surface comprises a plurality of stacked and fixedly arranged microstructure rows, and each microstructure row comprises a plurality of fixedly connected microstructure units; the microstructure unit comprises an outer arrow module and an inner arrow module, the bottom edges of the outer arrow module and the inner arrow module are inner concave edges, the three vertex corners of the outer arrow module are respectively connected to the three vertex corners of the inner arrow module to form an inner and outer double-layer nested structure, and the bottom angles of two adjacent outer arrow modules in each microstructure row are opposite to each other. For fixation, the top corner of the outer arrow module in the lower layer of two adjacent microstructure rows is fixed to the inward concave pole of the bottom edge of the upper outer arrow module; through the mutual cooperation between the outer composite material layer, the negative Poisson's ratio microstructure layer and the inner composite material layer, the outer composite material layer first contacts the bullet, greatly reducing the kinetic energy of the bullet; the middle negative Poisson's ratio microstructure layer buffers and absorbs the kinetic energy of the bullet that continues to enter and reduces the overall vibration change of the helmet, slowly releases the stress transmitted by the outer composite material layer, and greatly reduces the impact caused by blunt impact; the inner composite material layer consumes the remaining kinetic energy of the bullet; it has good bulletproof, blunt injury protection and shock isolation properties, and has a better protective effect on non-penetrating bullet injuries. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a cross-sectional schematic diagram of an existing bulletproof structure;

[0028] Figure 2 A schematic diagram of a lightweight bionic bulletproof helmet made into a helmet according to the present invention;

[0029] Figure 3 (a) is a schematic diagram of one of the microstructured surfaces of the outer composite material layer of the present invention;

[0030] Figure 3 (b) is a schematic diagram of the density changes of three representative microstructure units in a microstructure surface;

[0031] Figure 3 (c) is another schematic structural diagram of one of the microstructured surfaces of the outer composite material layer of the present invention;

[0032] Figure 4 (a) is a schematic diagram of a microstructure unit of the present invention;

[0033] Figure 4 (b) is a schematic diagram of the outer arrow module;

[0034] Figure 4 (c) is a schematic diagram of the inner arrow module;

[0035] Figure 4 (d) is a schematic diagram showing the decomposition of the inner arrow module into two "Y"-shaped assembly parts;

[0036] Figure 4 (e) is a schematic diagram of the outer arrow module being decomposed into a first single-arrow truss and a second single-arrow truss;

[0037] Figure 5 (a) is a schematic diagram of a first embodiment of a microstructure unit of the present invention;

[0038] Figure 5 (b) is a schematic diagram of a second embodiment of the microstructure unit of the present invention;

[0039] Figure 5 (c) is a schematic diagram of a third embodiment of the microstructure unit of the present invention;

[0040] Figure 5 (d) is a schematic diagram of a fourth embodiment of the microstructure unit of the present invention;

[0041] Figure 5 (e) is a schematic diagram of a fifth embodiment of the microstructure unit of the present invention;

[0042] Figure 5 (f) is a schematic diagram of a sixth embodiment of the microstructure unit of the present invention;

[0043] Figure 6 (a) (d) are three-dimensional schematic diagrams of microstructure assembly of an embodiment of a negative Poisson's ratio microstructure layer of the present invention;

[0044] Figure 6 (b) is a schematic diagram of a “Y”-shaped assembly, a first single-arrow truss, and a second single-arrow truss;

[0045] Figure 6 (c) is a schematic diagram of the assembly of the negative Poisson's ratio microstructure layer of the present invention;

[0046] Figure 6 (e) is a schematic diagram of the three-dimensional assembly of four "Y"-shaped combination parts;

[0047] Figure 7 (a) is a schematic diagram of the woodpecker skull structure;

[0048] Figure 7 (b) is a schematic diagram of a helmet;

[0049] Figure 7 (c) Figure 7 (b) Cross-sectional view along the A direction;

[0050] Figure 7 (d) Figure 7 (b) Cross-sectional view along the B direction;

[0051] Figure 7 (e) Figure 7 (b) Cross-section along the C direction;

[0052] Figure 8 (a) is a schematic diagram of the fibrous bone structure of the peacock mantis shrimp's claw;

[0053] Figure 8 (b) is a schematic diagram of the arrangement of several double-arrow-shaped three-dimensional micro-cell arrays of the bionic peacock mantis shrimp;

[0054] Fig. 9 (a) is a schematic diagram of a beetle;

[0055] Fig. 9 (b) is the cross-sectional structure of the beetle elytra skeleton;

[0056] Fig. 9 (c) is an example of the detailed interlayer arrangement of the cross-section of the beetle elytra skeleton structure;

[0057] Fig. 9 (d) is a schematic diagram of the spiral laminated structure of the beetle elytra skeleton;

[0058] Fig.10 The stress-time comparison diagram of the nested triangle negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure;

[0059] Fig.11 It is a comparison diagram of specific energy absorption between the nested triangle negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure;

[0060] Fig.12 The specific energy absorption-time comparison diagram of the nested triangle negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure at an impact speed of 40 m / s;

[0061] Fig.13 The specific energy absorption-time comparison diagram of the nested triangle negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure at an impact speed of 60 m / s;

[0062] Fig.14 The specific energy absorption-time comparison diagram of the nested triangle negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure at an impact speed of 90 m / s;

[0063] Fig.15 Design a flow chart for multi-scale collaborative optimization based on function-oriented design.

[0064] The figure includes:

[0065] Hard impact-resistant layer 01, soft energy-absorbing layer 02, composite layer 03 and lining layer 04;

[0066] Outer composite material layer 1, negative Poisson's ratio microstructure layer 2, outer arrow module 21, first single arrow truss 211, second single arrow truss 212, inner arrow module 22, fork 221, connecting rod 222, plug-in column 223, inner composite material layer 3. DETAILED DESCRIPTION

[0067] In order to enable those skilled in the art to better understand the technical solution of the present invention, the lightweight bionic bulletproof helmet of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0068] The present invention provides a lightweight bionic bulletproof helmet, comprising an outer composite material layer 1, a negative Poisson's ratio microstructure layer 2, and an inner composite material layer 3 which are sequentially stacked and fixed from the outside to the inside; Figure 2 The figure shows a structural schematic diagram of the lightweight bionic bulletproof helmet. The outer composite material layer 1, the negative Poisson's ratio microstructure layer 2, and the inner composite material layer 3 are arranged from the outside to the inside in sequence, and all have a certain thickness.

[0069] The negative Poisson's ratio microstructure layer 2 includes a plurality of microstructure surfaces, which are three-dimensionally intersected to form a negative Poisson's ratio spatial microstructure. Each microstructure surface includes a plurality of stacked fixedly arranged microstructure rows, and each microstructure row includes a plurality of fixedly connected microstructure units. Figure 3 As shown in (a), A represents a portion of the microstructure surface cut off, B represents a microstructure row in the microstructure surface, and C represents a microstructure unit in the microstructure row; a row of several microstructure units C are arranged along the X-axis and connected to each other on the left and right to form a microstructure row B, and a row of several microstructure rows B are arranged side by side and connected to each other on the top and bottom to form a microstructure surface A. Figure 3 The microstructure surface shown is in a flat unfolded state. When it is made into a structure with a curved surface such as a helmet, spatial bending, distortion and deformation will occur.

[0070] Combination Figure 4 As shown, the microstructure unit includes an outer arrow module 21 and an inner arrow module 22. The bottom edges of the outer arrow module 21 and the inner arrow module 22 are concave edges. It should be noted that, in combination with Figure 5 As shown, the bottom edges of the outer arrow module 21 and the inner arrow module 22 can be in the form of a broken line formed by straight lines, or in the form of a smooth curve, but the overall trend is that the bottom edges are concave inward. The broken line can be formed by two straight lines forming an angle, or by three straight lines forming two angles; the outer arrow module 21 and the inner arrow module 22 both have three vertices, the upper one is called the top angle, and the lower two are called the bottom angles. Each microstructure unit is an axisymmetric structure, the outer arrow module 21 is axisymmetric, and the inner arrow module 22 is symmetrical.

[0071] The three vertex corners of the outer arrow module 21 are connected one-to-one to the three vertex corners of the inner arrow module 22 to form a double-layer inside-outside nested structure, and the outer arrow module 21 surrounds the inner arrow module 22; there is a certain distance between the three vertex corners of the inner arrow module 22 and the three vertex corners of the outer arrow module 21, and they do not overlap with each other.

[0072] Combination Figure 3 As shown in (a)(c), the bottom angles of two adjacent outer arrow modules 21 in each microstructure row are relatively fixed, and the two bottom angles of an outer arrow module 21 (except the left and right ends) are respectively connected to the other two outer arrow modules 21 on the left and right. Through the mutual connection and coordination between the outer arrow modules 21, multiple microstructure units are connected end to end to form a microstructure row, and a microstructure row includes multiple microstructure units.

[0073] Two adjacent microstructure rows have two relative connection forms, combined with Figure 3As shown in (a), the top corner of the outer arrow module 21 of the lower layer in two adjacent microstructure rows is fixed to the inward concave pole of the bottom edge of the upper outer arrow module 21; Figure 3 As shown in (c), the top corner of the outer arrow module 21 of the lower layer in two adjacent microstructure rows is fixed to the bottom corner of the outer arrow module 21 of the upper layer. Figure 3 (a) In the structure shown, the microstructure units in the upper and lower microstructure rows are aligned vertically. Figure 3 (c) In the structure shown, the microstructure units in the upper and lower adjacent microstructure rows are staggered and spaced one by one, so that the microstructure units in the odd-numbered microstructure rows are directly opposite to each other, and the microstructure units in the even-numbered microstructure rows are directly opposite to each other. Figure 3 (a) with Figure 3 (c) Compared with the two structures, Figure 3 The microstructure units of (a) are more densely distributed. Figure 3 The microstructure units of (c) are more sparsely distributed. Figure 3 (c) equivalent to Figure 3 (a) Move rightward (and slightly downward) by 1 / 2 the width of the microstructure unit. In addition, the displacement size can also be other values ​​between 0 and 1 / 2.

[0074] When different microstructure surfaces intersect to form a three-dimensional negative Poisson's ratio microstructure layer 2, the microstructure rows should be matched one by one to form a cross-section to form a regularly distributed spatial array structure.

[0075] The structural composition of the negative Poisson's ratio microstructure layer 2 has a negative Poisson's ratio characteristic. The negative Poisson's ratio effect means that when stretched, the material expands laterally within the elastic range; when compressed, the material shrinks laterally instead; the negative Poisson's ratio characteristic cannot generally be produced by solid materials themselves, and requires the help of special microstructure design to make the product as a whole exhibit negative Poisson's ratio characteristics when subjected to force. The truss structure filled with the negative Poisson's ratio microstructure and the "compression-contraction" gathering and gathering characteristics of the overall structure during the impact process will effectively block the advancement of the bullet and change its direction of movement, becoming an effective barrier to reduce its impact speed.

[0076] Negative Poisson's ratio microstructures have the characteristics of "compression-contraction" negative Poisson's ratio and porous medium characteristics. When it is subjected to axial compression load, the material gathers toward the center, the instantaneous density and instantaneous elastic modulus increase, and the structural stiffness also increases, resulting in a typical "platform area" and "platform stress enhancement area"; the porous medium characteristics provide it with a large amount of buffer deformation space and a more stable and efficient energy absorption process during the compression process, and it has great potential in load bearing and collision energy absorption. At the same time, when the negative Poisson's ratio microstructure is subjected to bullet impact or explosion load, the material flows and gathers toward the load center action area, which can enhance the energy absorption and seismic isolation capabilities of the structure.

[0077] The outer layer of the lightweight bionic bulletproof helmet of the present invention is a composite material layer, which can reduce the impact kinetic energy of bullets; the middle layer is a negative Poisson's ratio microstructure layer, which absorbs the kinetic energy of the bullets that continue to penetrate, and releases the stress transmitted by the outer composite material layer, reduces the vibration of the helmet as a whole, and protects against blunt injuries; the inner layer is a composite material layer, which consumes the remaining kinetic energy of the bullet. The combination of the three-layer structure is used to exert the bulletproof performance, and the negative Poisson's ratio microstructure layer is mainly used to enhance the protective effect against non-penetrating injuries of bullets.

[0078] Based on the above scheme, combined with Figure 6 As shown, in a specific embodiment, the negative Poisson's ratio microstructure layer 2 is formed by mutually perpendicularly crossing microstructure surfaces, that is, a number of microstructure surfaces are parallel to the XZ plane, and a number of microstructure surfaces are parallel to the YZ plane, and these mutually perpendicular microstructure surfaces are mutually crossed to form a spatial microstructure of the negative Poisson's ratio microstructure layer 2. In addition to the mutually perpendicular crossing form, the three microstructure surfaces can also be formed in a cross-shaped form with an interval of 120 degrees, and these specific solutions should also be included in the protection scope of the present invention.

[0079] In a specific embodiment, Figure 5 (a) shows a structure in which the sides of the outer arrow module 21 and the inner arrow module 22 are straight sides, and the bottom side is an obtuse angle formed by the two straight sides. The outer arrow module 21 and the inner arrow module 22 are similar in appearance, that is, the outer arrow module 21 and the inner arrow module 22 have the same appearance and the size is proportional.

[0080] The above form is only used as a specific solution, such as Figure 5 (b), wherein the two side edges of the inner arrow module 22 are convex curves, and the bottom edge is an obtuse angle formed by two straight edges. Figure 5 (c) The two sides of the outer arrow module 21 are curved lines that bulge outward, and the bottom side is an obtuse angle formed by two straight sides. Figure 5 (d) The two sides of the inner arrow module 22 and the two sides of the outer arrow module 21 are both convex curves, and the bottom edges are both obtuse angles formed by two straight edges. Figure 5(e) Both sides of the inner arrow module 22 and the outer arrow module 21 are straight edges, and the bottom edge is a three-fold line structure with three straight edges forming an angle. Figure 5 (f) Both sides of the inner arrow module 22 and both sides of the outer arrow module 21 are straight edges, and the bottom edges are arc-shaped curves. Figure 5 In the multiple embodiments shown, some have inner arrow modules 22 and outer arrow modules 21 with similar shapes, while others have different shapes, but both have an inwardly concave bottom edge and an upwardly protruding top angle, similar to the shape of an arrow.

[0081] Based on the above scheme, combined with Figure 4 (d) Figure 6 (e) Each inner arrow module 22 includes two "Y"-shaped combination parts, each combination part includes two forks 221 and a connecting rod 222 that converge at one point, and the two forks 221 and the connecting rod 222 are radially distributed. The ends of the forks 221 of the two combination parts constituting an inner arrow module 22 are connected one by one.

[0082] The design of the microstructure unit is based on the front claw of the peacock mantis shrimp, such as Figure 8 (a) The peacock mantis shrimp is a species of the genus Odontochelydae family of the order Stomatopoda. It is distributed in tropical waters of the Indian and Pacific Oceans. Its appearance is composed of bright red, blue, green and other colors. The front claw of the individual is well-developed and used for prey. It is light and impact-resistant. The front claw is the attack weapon of the peacock mantis shrimp. Under the microscopic structure (combined with Figure 8 (b) shows that the surface of the front rod presents a double-arrow-shaped microstructure array arrangement and forms a porous structure layer, in which the double-arrow-shaped microstructures are arranged layer by layer, and there is a gradient arrangement phenomenon in which the density of the top microstructure is greater than the density of the bottom microstructure. This structure increases the overall strength and stiffness, and can improve the protection ability of the front rod during attack, while reducing the mass of the front rod. When the rod is subjected to force, it transmits energy to the inside through the contact layer, and the energy is absorbed by each layer of different structural biological tissues and their irregular deformation. At the same time, the forces in all directions act on the innermost curved surface, which can be simplified to a very small plane force. Therefore, through structural similarity, load similarity and functional similarity, the protective structure of the front rod is imitated, and a negative Poisson's ratio microstructure layer that can be regarded as a microstructure unit cell array is established as the main buffer energy absorption structure. The negative Poisson's ratio microstructure layer can be any integer number of layers, and the guided design is carried out with reference to the lightweight space of the bionic bulletproof helmet and the specific design size of the microstructure, including the specific size of the microstructure, the porosity design of the microstructure, the number of layers of the microstructure, etc.

[0083] Combination Figure 4 (e) Figure 6(b), a plurality of outer-arrow modules 21 constituting a microstructure row include a first single-arrow truss 211 and a second single-arrow truss 212 both in a wavy shape, the first single-arrow truss 211 mainly constitutes the two side edges of the outer-arrow module 21, the second single-arrow truss 212 mainly constitutes the bottom edge of the outer-arrow module 21, the fluctuation amplitude of the first single-arrow truss 211 is greater than the fluctuation amplitude of the second single-arrow truss 212; the first single-arrow truss 211 and the second single-arrow truss 212 respectively have a plurality of undulating wave structures, constituting a plurality of outer-arrow modules 21. The outer-arrow module 21 in a microstructure row may be composed of a first single-arrow truss 211 and a second single-arrow truss 212, or may be composed of two or more segments.

[0084] The first single-arrow truss 211 and the second single-arrow truss 212, the first single-arrow truss 211 and the inner-arrow module 22, and the second single-arrow truss 212 and the inner-arrow module 22 are fixed to each other; Figure 6 (c) A plurality of spaced connection points are arranged between the first single-arrow truss 211 and the second single-arrow truss 212, and the connection points are located at the bottom corners of the outer arrow module 21; the connection points between the first single-arrow truss 211 and the inner arrow module 22 are located at the top corners of the outer arrow module 21; and the connection points between the second single-arrow truss 212 and the inner arrow module 22 are located at the angle formed by the contact between the first single-arrow truss 211 and the second single-arrow truss 212.

[0085] The ends of the forks 221 corresponding to the two "Y"-shaped combination parts that constitute the same inner arrow module 22 are in contact and fit with each other, connected and locked with each other; the angle formed by the contact between the first single-arrow truss 211 and the second single-arrow truss 212 can match and fit with the end of the connecting rod 222, and a wedge-shaped structure with reduced thickness is set at the end of the connecting rod 222, which can be inserted into the angle formed by the first single-arrow truss 211 and the second single-arrow truss 212 to achieve positioning.

[0086] Furthermore, the present invention provides a specific connection structure. The ends of the two forks 221 of the same combination part are respectively provided with plug-in posts 223. The fork 221 close to the first single-arrow truss 211 is used to match other plug-in posts 223 and the first single-arrow truss 211, and the plug-in posts 223 close to the second single-arrow truss 212 are used to match other plug-in posts 223. The multiple plug-in posts 223 distributed symmetrically in the center can be plugged and locked with the corresponding sockets of the first single-arrow truss 211; Figure 4 (d) Figure 6As shown in (b) and (e), the upper plug-in column 223 is in the shape of a square column. The four upper plug-in columns 223 are symmetrically distributed and contact each other, and are spliced ​​to form a larger columnar structure, which can be inserted into the sockets set on the first single-arrow truss 211. The sockets limit the circumferential position of the multiple upper plug-in columns 223, so that the multiple plug-in columns 223 are gathered together to form a spatial structure in which two inner-arrow modules 22 intersect each other, and the two inner-arrow modules 22 are formed by four combined parts. The four lower plug-in columns 223 are also symmetrically distributed, and the four plug-in columns 223 contact and lean against each other.

[0087] In order to achieve stable matching, the height of the two forks 221 on the same assembly is greater than the thickness of the fork 221 itself to provide a larger contact area. The width of the plug-in column 223 is half the width of the fork, and the plug-in column 223 protrudes from the end of the fork 221 to form a step angle, which is used to match other plug-in columns 223.

[0088] The first single-arrow truss 211 and the second single-arrow truss 212 are locked by inserting blocks and inserting holes. Figure 6 As shown in (c), the first single-arrow truss 211 and the second single-arrow truss 212 have a number of contact points arranged at intervals, that is, they are in contact at the two bottom corners of the outer arrow module 21, and the two bottom corners of the adjacent two outer arrow modules 21 that are close to each other share the same contact point. At the contact point positions of the first single-arrow truss 211 and the second single-arrow truss 212, one of them is provided with an insert block, and the other is provided with a plug hole, and a fixed connection is achieved by mutual insertion to form an assembly structure of interlocking assembly. Interlocking assembly refers to a concave-convex combination connection method used on two components, and the convex part bites with the concave part to play a connecting role.

[0089] It should be noted that the inner-arrow module 22 and the outer-arrow module 21 provided above are connected to each other in the form of an interlocking assembly, and the first single-arrow truss 211 and the second single-arrow truss 212 constituting the outer-arrow module 21 are in the form of an interlocking assembly. This is only a specific embodiment. Laser welding, adhesive fixation and other connection forms, or 3D printing integrated molding can also be used. These specific implementations should be included in the scope of protection of the present invention.

[0090] Combination Figure 7 (a) The layered structure design of the lightweight bionic bulletproof helmet is based on the layered structure of the woodpecker skull. It is designed as a "sandwich" structure of an outer composite material layer, a negative Poisson's ratio microstructure layer, and an inner composite material layer. The energy absorption, buffering and other performance preferences of each structural layer are designed according to the function orientation to meet the performance requirements of the bulletproof helmet device.

[0091] Woodpeckers are a general term for animals of the Picidae family. Woodpeckers can continuously impact tree trunks at a speed of 6 to 7 m / s and an acceleration of 1000 g without suffering any damage to their heads and brains. This is mainly due to the three-layer protective device on their heads. The outermost layer is the woodpecker's skull. The inner structure of the skull is loose and filled with air, which can effectively reduce the transmission speed of the shock wave and play a role in shock resistance. At the same time, the outside of the brain is a tough outer meninges. Furthermore, because the woodpecker's head floats in the cerebrospinal fluid, it directly limits the impact from being transmitted to the brain.

[0092] The present invention is based on the principle of cerebrospinal fluid suspension and imitates the woodpecker's head to establish Figure 7 (b) shows the overall structure of the bionic bulletproof helmet. The bionic bulletproof helmet is arranged from the outer layer to the inner layer. The outermost layer imitates the outermost skull structure of the woodpecker's head, which is the outer composite material layer 1; the second layer imitates the loose and porous structure of the inner skull of the woodpecker's head, which is the negative Poisson's ratio microstructure layer 2; the third layer imitates the outer meningeal structure of the woodpecker's head, which is the inner composite material layer 3. The outer composite material layer is one side of the helmet shell, the negative Poisson's ratio microstructure layer 2 is the inner lining layer of the helmet, and the inner composite material layer 3 is one side of the helmet buffer layer.

[0093] On the basis of the above scheme and its mutual combination, among the several microstructure surfaces constituting the negative Poisson's ratio microstructure layer 2, several microstructure surfaces with large porosity are arranged inside (close to the head), and several microstructure surfaces with small porosity are arranged outside (away from the head). The "large" and "small" probabilities referred to here refer only to the comparison between several microstructure surfaces close to the inner layer and several microstructure surfaces close to the outer layer (not including the microstructure surfaces in the middle area), and the porosity of the inner layer close to the head is greater than that of the outer layer. Under the condition of microstructures with the same configuration, large porosity is easier to deform and more comfortable, while small porosity has stronger defense performance against external impact. Therefore, the porosity of the microstructure units distributed close to the outside is smaller and the solid density is higher; the porosity of the microstructure units distributed close to the inside is larger and the solid density is lower. However, it does not mean that the porosity of the outer layer is the position with the smallest porosity of the entire negative Poisson's ratio microstructure layer 2.

[0094] The porosity distribution of the middle layer between the inner layer and the outer layer of the negative Poisson's ratio microstructure layer 2 can be linearly or nonlinearly changed according to a certain coefficient, and the porosity from the outer side of the middle layer to the inner side of the middle layer can also increase first and then decrease from the outside to the inside, or decrease first and then increase from the outside to the inside. The present invention provides an arrangement of the negative Poisson's ratio microstructure layer 2, in which the porosity of each microstructure row of the negative Poisson's ratio microstructure layer 2 gradually increases from the outside to the inside; combined with Figure 3As shown in (a) and (b), in the thickness direction of the surface in the Z-axis direction, the upper side is the outer side and the lower side is the inner side (close to the head), the porosity of each microstructure row of the negative Poisson's ratio microstructure layer 2 changes gradually, the porosity on the outer side is small, and the density of the corresponding solid structure is higher, and the porosity on the inner side is large, and the density of the corresponding solid structure is lower. The high density on the outer side provides stronger resistance to bullet impact, and the low density on the inner side has more space to provide stronger deformation buffering performance; while ensuring the impact resistance, the wearing comfort is improved.

[0095] Specifically, the porosity of the outer arrow modules 21 in each different microstructure row is equal, that is, the structural size of each outer arrow module 21 remains equal to ensure sufficient impact resistance; the porosity of the inner arrow modules 22 in each different microstructure row gradually increases from the outside to the inside, and the change in porosity is reflected in the size change of the inner arrow module 22. Figure 3 As shown in (a) and (b), the outer inner-arrow module 22 is thicker, and the inner-arrow module 22 is thinner, providing better cushioning performance.

[0096] In a specific embodiment, different regions of the microstructure surface have different porosities, and the porosities at different positions of the microstructure surface are inversely proportional to the probability of bullet distribution; each microstructure unit constituting the same microstructure row has different porosities; different regions of the helmet have different probabilities of being impacted by bullets. Figure 2 As shown in the figure, under certain combat conditions, the probability of the top area ② being hit by bullets is low, and a larger porosity is set in the area with a low probability of being hit by bullets, which has a lower solid structure density; the probability of the front area ① and the rear area ③ being hit by bullets is high, and a smaller porosity is set in the area with a high probability of being hit by bullets, which has a higher solid structure density. On the basis of ensuring sufficient protection performance, the weight of the entire helmet can be reduced by reducing the density of the local area.

[0097] Combination Figure 7(c)(d)(e), Section A is a cross-sectional view of the helmet from the front, and the negative Poisson's ratio microstructure of the structure shown has a gradient k1 from top to bottom, and has the same gradient k2 from left to right and from right to left; Section B is a cross-sectional view of the helmet from the left, and has a gradient k1 from top to bottom, and a gradient k3 from back to front; Section C is a cross-sectional view of the helmet from the top, and has a gradient k3 from back to front, and has the same gradient k2 from left to right and from right to left. The above-mentioned gradients k1, k2, and k3 can be the same or different gradient values, and the density of the three gradually decreases in the direction indicated by the arrows. The corresponding bionic helmet has a gradient arrangement in each cross section, which can provide full-domain and all-round bullet impact protection. As shown in cross sections A, B, and C, there are gaps between the negative Poisson's ratio microstructure layer 2 and the outer composite material layer 1, and between the negative Poisson's ratio microstructure layer 2 and the inner composite material layer 3, respectively. The gap size is 1 to 2 mm, providing the negative Poisson's ratio microstructure layer with the space required for the cerebrospinal fluid suspension theory, so that the negative Poisson's ratio microstructure layer has the moving space required for floating, and at the same time provides the sliding and damping required for the multi-directional impact protection system MIPS, thereby improving the cushioning and shock absorption performance of the helmet.

[0098] The outer composite material layer 1 and the inner composite material layer 3 are formed by stacking several composite material layers, and there is an angle between two adjacent composite material layers; the composite material layer is a pressed and formed non-woven fabric, which is cured with resin after stacking. The fiber directions between the layers are staggered and overlapped, so that the bullet impact is diffused in multiple directions and the damage resistance of the composite material is improved. The outer composite material layer and the inner composite material layer are bonded with a special thermoplastic resin to press the composite material layer into a UD non-woven fabric, and then laminated to form a soft bulletproof chip, and the composite material is woven into a woven fabric, and then laminated and cured with resin to improve the integrity of the composite material layer. At the same time, the three-dimensional weaving structure is introduced to further improve the structural three-dimensionality of the woven fabric material and improve the impact resistance of the material.

[0099] When the composite material layers are stacked, a fiber angle is formed between two adjacent fiber layers, and the angles between the layers can be equal or different. The dynamic mechanical properties of the composite material layer when subjected to impact are related to the number of fiber layers, the order of plying, and the ply angle.

[0100] The present invention provides a specific example here, in which each composite material layer of the outer composite material layer 1 and the inner composite material layer 3 is arranged in a spiral arrangement in the same direction, and the spiral arrangement adopts the concept of bionics. Compared with composite materials of other arrangement forms, the composite material of spiral arrangement has better comprehensive performance. According to from inside to outside or from outside to inside, each composite material layer rotates a certain angle in turn, and from the perspective of each stacked layer, the fiber direction forms a spiral laminated structure. The spiral lamination design diffuses the bullet impact in multiple directions and improves the damage resistance of the composite material. The material ratio and resin ratio are designed by function-oriented design to have high strength and high hardness, while fiber breakage absorbs the kinetic energy of the bullet and passivates the bullet impact. Between the layers, on the basis of the bionic beetle elytra composite material structure sample and the negative Poisson's ratio microstructure sample with the best protection performance design, the composite material layer and the negative Poisson's ratio microstructure layer are pressed by a fixed mold machine, and integrated molding is performed to avoid the dislocation of the structural layer when it is impacted by a bullet, effectively improving the integrity and lightness of the lightweight bionic bulletproof helmet, and improving its overall bulletproofness.

[0101] The spiral design of the outer composite material layer 1 and the inner composite material layer 3 refers to the elytra structure of a beetle. Fig. 9 (a) is a complete demonstration of a beetle. Beetles are a general term for insects of the order Coleoptera in the class Insecta. The beetle has a hard outer shell on the outside of its body. The hind wings are membranous and the forewings are keratinous. The thick and hard forewings serve as elytra, which can protect the hind wings while protecting the body. The strength and stiffness of the elytra skeleton are greatly improved through the interlayer spiral arrangement and compression. Under the microstructure, the cross-sectional structure of the beetle elytra skeleton is obtained as follows: Fig. 9 As shown in (b), the skeleton structure of the beetle elytra has clear order and stratification, with multiple layers overlapping. Fig. 9 (c) shows a detailed example of the interlayer arrangement of the cross-section of the beetle elytra skeleton structure. In this microstructure, the inclination angles between different layers are different, that is, the arrangement angles vary. Finally, the beetle elytra skeleton structure is simplified to a composite structure formed by interlayer combination and compression. Further, the layers are arranged in a spiral shape with a certain variable angle between them, as shown in Fig. Fig. 9 As shown in (d), the spiral laminated structure of the beetle elytra skeleton is imitated, and the function-oriented design is introduced to mix different matrix materials and resins between layers to obtain composite materials with stiffness orientation or toughness orientation.

[0102] The outer composite material layer and the inner composite material layer adopt the same design method. Based on the skeleton structure of beetle elytra, through spiral lamination design, different matrix materials such as aramid III, aramid II, UHMWPED and other fiber composite material ratios, resin and fiber ratios, and the use of nanomaterials, graphene, carbon nanotubes, alumina fibers and nano-aramid fibers are used. The overall stiffness and toughness of the composite material are designed according to the different needs of the inner and outer layers. The outer composite material layer needs to greatly reduce the speed of the bullet and reduce the initial kinetic energy of the bullet when entering the negative Poisson's ratio microstructure layer, while the inner composite material layer needs to avoid the penetration of the bullet and the slow release of blunt impact. The interlayer spiral arrangement is to arrange the next layer after the rotation angle. Compared with the upper layer, the spiral angle can be 5°, 10°, 15° and other degrees. The fiber breakage can absorb the energy of the bullet impact, and the angle between the layers is different, which effectively avoids the direct penetration of the bullet and reduces the possibility of the bullet directly shooting into the resin part. The spiral arrangement of the fiber increases the overall damage resistance.

[0103] The outer surface of the outer composite material layer 1 is sprayed with ceramic material and super-tough protective material to improve the overall rigidity and toughness of the helmet and increase the ability to resist bullet loss. The protective materials include boron carbide, silicon carbide and aluminum oxide, etc., and can be coated with one or more layers.

[0104] The negative Poisson's ratio microstructure layer 2 uses any one or more of aluminum alloy, titanium alloy or magnesium alloy as the base material. Negative Poisson's ratio microstructures are rich in variety and have great designability. They have "compression-contraction" mechanical properties when responding to impact, and their strength and stiffness are greatly enhanced. Based on the double-arrow-shaped fibrous bone structure of the claw of the peacock mantis shrimp, this paper designs a three-dimensional geometric porous model of a negative Poisson's ratio microstructure. At the same time, the structure is strengthened and designed, and a nested triangular negative Poisson's ratio microstructure is designed. The nested triangular negative Poisson's ratio microstructure has excellent negative Poisson's ratio characteristics. When impacted by a bullet, there is an obvious "compression-contraction" characteristic. The material gathers toward the bullet impact point, the stiffness and strength increase, and the microstructure absorbs the bullet impact energy and reduces the bullet speed; the gradient coefficients of the negative Poisson's ratio microstructure are set to different levels of positive and negative. Based on the protective performance requirements of the bulletproof helmet, the variable density gradient distribution coefficient of the negative Poisson's ratio microstructure is coordinated and matched, so that the negative Poisson's ratio microstructure layer takes into account both strength and buffering energy absorption characteristics; the porous characteristics give it a large amount of buffering deformation space, which further reduces the weight of the bulletproof helmet, provides sliding and damping of the Multi-directional Impact Protection System (MIPS), and improves the energy absorption characteristics, seismic performance and blunt injury protection performance of the bulletproof helmet.

[0105] In the lightweight bionic bulletproof helmet of the present invention, the outer layer is an outer composite material layer, and first contacts with the bullet. By designing its function-oriented structure to be biased towards high strength and hardness, the kinetic energy of the bullet is greatly reduced; the middle layer is a negative Poisson's ratio microstructure layer, and the nested triangular negative Poisson's ratio microstructure designed by gradient density buffers and absorbs the kinetic energy of the bullet that continues to enter and reduces the vibration change of the helmet as a whole, slowly releases the stress transmitted by the outer composite material layer, and greatly reduces the impact caused by blunt impact; the inner side is a composite material layer with a directional design biased towards toughness, which consumes the remaining kinetic energy of the bullet. Through the mutual cooperation between the outer composite material layer, the negative Poisson's ratio microstructure layer, and the inner composite material layer, the bionic bulletproof helmet designed by the present invention has good bulletproof, blunt injury prevention and shock isolation performance.

[0106] See also Fig.15 The function-oriented collaborative optimization design theory refers to the process of taking function as the dominant factor of design and achieving the design goal through the collaborative optimization of multiple demand objectives. In the design process, the different functional requirements of the new concept structure are integrated to achieve the optimal design solution. Secondly, the parameter model of each integrated requirement is constructed and its influencing factors are decomposed to complete the integrated design of materials and structures, including the multiple influences of model parameters and material parameters. After the function-oriented design is completed, the physical object is manufactured and assembled, and the design results are verified by physical experiments in accordance with national standards. If the verification is successful, the optimal structural components required after the function-oriented design are obtained. The function-oriented collaborative optimization design theory can unify the design process, unify the structural design and material design in the design process, realize the unification of the optimal material distribution and structural distribution of the function orientation, and reduce the cost of physical manufacturing, which greatly reduces the time required for design.

[0107] The present invention adopts a multi-scale collaborative optimization design method based on function-oriented design, taking into account the mutual influence and restriction relationship of lightweight, blunt injury resistance, high strength and toughness, seismic isolation performance and resistance to multiple injuries of the lightweight bionic bulletproof helmet structure, based on the protection mechanism of each layer in the three-layer structure of the woodpecker head combined with the different functional requirements of the three-layer structure of the bulletproof helmet, the design goal of each layer in the three-layer structure of the lightweight bionic bulletproof helmet is obtained, and secondly, guided by the design goal, the composite material layer with a spiral laminated structure and the negative Poisson's ratio microstructure layer with a variable density gradient, which are highly designable, are modeled and multi-objective numerically optimized to complete the integrated design of materials and structures, and finally a lightweight bionic bulletproof helmet with lightweight, blunt injury resistance, high strength and toughness, seismic isolation and resistance to multiple injuries is developed.

[0108] See also Fig.10 , Fig.11, which are the compression simulation comparison diagram and specific energy absorption comparison diagram of the nested triangular negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure. The 9x9 modeled nested triangular negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure were compressed at a rigid wall constant speed of 1mm / ms, and finally the stress-time curve was obtained, where the solid line is the nested triangular negative Poisson's ratio microstructure and the dotted line is the traditional double-arrow negative Poisson's ratio microstructure. In the figure, the dotted line enters the stress platform at a similar time as the solid line, but the nested triangular negative Poisson's ratio microstructure has a higher platform stress area. At the same time, in the further compression process, the stress enhancement speed of the nested triangular negative Poisson's ratio microstructure is significantly accelerated, and it enters the dense area faster, which can have a faster stiffness change for rapid protection against the impact of bullets. The nested triangular negative Poisson's ratio microstructure improves the stiffness change speed of the helmet when responding to external impact. Fig.10 (a)(b) show the schematic diagram of the change of the traditional double-arrow negative Poisson's ratio microstructure and the schematic diagram of the change of the nested triangle negative Poisson's ratio microstructure under 20s compression time. The arrows of the nested triangle negative Poisson's ratio microstructure have overlapped, and the stiffness strength has been greatly enhanced, which provides reliable protection against bullet penetration and improves the overall stiffness performance of the helmet. Fig.11 Shown is a comparison diagram of the specific energy absorption and time of the nested triangular negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure. It shows that under the same compression time, the slope of the nested triangular negative Poisson's ratio microstructure curve is larger, and the specific energy absorption is correspondingly larger, with greater strength stiffness and superior collision energy absorption characteristics.

[0109] See also Fig.12 , Fig.13 , Fig.14 , which shows the specific energy absorption-time comparison of the nested triangular negative Poisson's ratio microstructure and the traditional double-arrow negative Poisson's ratio microstructure at impact speeds of 40m / s, 60m / s and 90m / s respectively. Fig.12 Time ratio energy absorption comparison chart and Fig.12 (a)(b) Schematic diagrams of the deformation modes of the two microstructures at the same time. Compared with the traditional double-arrow negative Poisson's ratio microstructure layer, the nested triangular negative Poisson's ratio microstructure layer of the present invention shows a significant upward trend in specific energy absorption during the impact process. Its enhanced "compression-contraction" negative Poisson's ratio characteristics cause the stiffness strength of the microstructure layer to change dramatically during the impact process, and it can respond quickly to external impacts for protection, presenting an overall "contraction" deformation mode. The traditional double-arrow negative Poisson's ratio microstructure layer has a lower density at the same time, and its overall stiffness strength is lower than the nested triangular negative Poisson's ratio microstructure, and it also has a delay in responding to external impacts. Similarly, Fig.13 (a)(b) and Fig.14 (a)(b) have the same deformation mode trend, Fig.13 and Fig.14The specific energy absorption-time comparison has the same trend of change. The nested triangular negative Poisson's ratio microstructures all show stronger compactness at the same time, have higher strength and stiffness, and react faster to external changes, and have excellent energy absorption characteristics in low-speed, medium-speed, and high-speed impacts. Therefore, the specific energy absorption of the nested triangular negative Poisson's ratio microstructure designed by the present invention is higher than that of the traditional double-arrow negative Poisson's ratio microstructure, and has excellent collision energy absorption characteristics.

[0110] Based on the above content, the technical solution method of the present invention has the following advantages:

[0111] 1) The present invention provides a multi-scale collaborative optimization design method based on function-oriented design, which takes function as the dominant factor, achieves the design goal through collaborative optimization, unifies the design process, unifies structural design and material design in the design process, and realizes the unification of function-oriented optimal material distribution and structural distribution.

[0112] 2) Based on the hierarchical gradient structure of the woodpecker skull, the bionic bulletproof helmet is designed with a "sandwich" structure consisting of an outer composite material layer, a negative Poisson's ratio microstructure layer, and an inner composite material layer. The woodpecker skull structure can directly limit the impact from being transmitted directly to the brain, effectively protecting against blunt injuries.

[0113] 3) Based on the double-arrow-shaped fiber-bone structure of the claw of the peacock mantis shrimp, a three-dimensional geometric porous model of a negative Poisson's ratio microstructure is designed using the principle of bionics. The compression-contraction characteristics and porous medium characteristics of the negative Poisson's ratio microstructure provide a large amount of buffer deformation space during the compression process, and the material gathers toward the center, the structural stiffness is improved, and the energy absorption process is stable and efficient, providing the sliding and damping of MIPS, while reducing the weight of the helmet and improving the shock resistance and energy absorption characteristics.

[0114] 4) Using the principle of bionics, based on the fiber spiral laminated structure of the beetle elytra skeleton structure, a composite material layer with multiple material ratios is designed. The toughness, specific energy absorption, lightweight and damage resistance of the composite material layer structure can be designed according to the matrix material parameters, spiral laying angle and laying layer number.

[0115] 5) The negative Poisson's ratio microstructure layer and the composite material layer designed in the present invention can absorb the kinetic energy of the bullet, greatly reduce the penetration of the bullet, and diffuse the blunt impact of the bullet.

[0116] 6) The materials of each layer used in the present invention are all relatively lightweight materials, which are suitable for the lightweight space requirements of the helmet. Compared with the traditional ones, they are lighter and have stronger bulletproof capabilities, thereby improving the mobility and survivability of combatants.

[0117] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lightweight bionic bulletproof helmet, characterized in that: It comprises an outer composite material layer (1), a negative Poisson's ratio microstructure layer (2), and an inner composite material layer (3) which are stacked and fixed in sequence from the outside to the inside; the negative Poisson's ratio microstructure layer (2) comprises a plurality of microstructure surfaces, and the plurality of microstructure surfaces intersect each other to form a negative Poisson's ratio spatial microstructure; The microstructure surface comprises a plurality of stacked and fixedly arranged microstructure rows, each of the microstructure rows comprising a plurality of fixedly connected microstructure units, the microstructure units comprising an outer arrow module (21) and an inner arrow module (22), the bottom edges of the outer arrow module (21) and the inner arrow module (22) being inner concave edges, and the three vertices of the outer arrow module (21) being respectively connected to the three vertices of the inner arrow module (22) to form an inner and outer nesting; The bottom angles of two adjacent outer arrow modules (21) in each of the microstructure rows are relatively fixed, and the top angle of the outer arrow module (21) of the lower layer in the two adjacent microstructure rows is fixed to the inwardly concave point of the bottom edge of the outer arrow module (21) of the upper layer, or is fixed to the bottom angle of the outer arrow module (21) of the upper layer.

2. The lightweight bionic bulletproof helmet according to claim 1, characterized in that: The negative Poisson's ratio microstructure layer (2) is formed by microstructure surfaces intersecting each other perpendicularly.

3. The lightweight bionic bulletproof helmet according to claim 2, characterized in that: The side edges of both the outer arrow module (21) and the inner arrow module (22) are straight edges, and the bottom edge is an obtuse angle formed by the two straight edges.

4. The lightweight bionic bulletproof helmet according to claim 2, characterized in that: The outer arrow module (21) and the inner arrow module (22) have similar appearances.

5. The lightweight bionic bulletproof helmet according to any one of claims 1 to 4, characterized in that: Each of the inner arrow modules (22) comprises two "Y"-shaped combined parts, each of the combined parts comprises two forks (221) converging at one point and a connecting rod (222); A plurality of the outer arrow modules (21) constituting one microstructure row comprise a first single arrow truss (211) and a second single arrow truss (212) both of which are wavy in shape; the first single arrow truss (211) and the second single arrow truss (212), the first single arrow truss (211) and the inner arrow module (22), and the second single arrow truss (212) and the inner arrow module (22) are fixed to each other; The ends of the forks (221) corresponding to the two combined parts are in contact with each other; and the angle formed by the contact between the first single-arrow truss (211) and the second single-arrow truss (212) can be matched and engaged with the end of the connecting rod (222).

6. The lightweight bionic bulletproof helmet according to claim 5, characterized in that: A plug-in column (223) is provided at the end of the fork (221), and a plurality of the plug-in columns (223) distributed symmetrically around the center can be plugged and locked with correspondingly provided plug holes of the first single-arrow truss (211); The first single-arrow truss (211) and the second single-arrow truss (212) are locked by means of an insert block and an insert hole.

7. The lightweight bionic bulletproof helmet according to claim 1, characterized in that: There is a gap of 1 to 2 mm between the outer composite material layer (1) and the negative Poisson's ratio microstructure layer (2), and between the inner composite material layer (3) and the negative Poisson's ratio microstructure layer (2).

8. The lightweight bionic bulletproof helmet according to any one of claims 1 to 4, characterized in that: Among the microstructure surfaces constituting the negative Poisson's ratio microstructure layer (2), a microstructure surface with a large porosity is arranged innerward, and a microstructure surface with a small porosity is arranged outerward.

9. The lightweight bionic bulletproof helmet according to any one of claims 1 to 4, characterized in that: There is a porosity difference in different areas of the microstructure surface, and the porosity at different positions of the microstructure surface is inversely proportional to the bullet distribution probability.

10. The lightweight bionic bulletproof helmet according to any one of claims 1 to 4, characterized in that: The outer composite material layer (1) and the inner composite material layer (3) are formed by stacking a plurality of composite material layers, an angle exists between two adjacent composite material layers, and the plurality of composite material layers are sequentially distributed in a spiral in the same direction of rotation; The composite material layer is a non-woven fabric formed by compression, and is cured with resin after being stacked.

11. The lightweight bionic bulletproof helmet according to claim 10, characterized in that: The outer surface of the outer composite material layer (1) is sprayed with ceramic material and super-tough protective material; The protective materials include boron carbide, silicon carbide and aluminum oxide.

12. The lightweight bionic bulletproof helmet according to any one of claims 1 to 4, characterized in that: The negative Poisson's ratio microstructure layer (2) uses any one or more of aluminum alloy, titanium alloy or magnesium alloy as a base material.

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