Embedded visual transparent protection structure resistant to multiple impacts

Abstract

This invention relates to an embedded, transparent protective structure resistant to repeated impacts. It comprises a transparent ceramic curved armor plate, a transparent fiber-reinforced skeleton, a polycarbonate curved backplate, an epoxy resin coating, and an STF shear-thickening coating. The polycarbonate curved backplate has a central groove with a concave bottom. Each polygonal unit of the transparent fiber-reinforced skeleton contains a transparent ceramic curved armor plate. The gaps between the transparent ceramic curved armor plates and the transparent fiber-reinforced skeleton are filled with the STF shear-thickening coating. The bottom of the overall structure formed by the transparent ceramic curved armor plates, the transparent fiber-reinforced skeleton, and the STF shear-thickening coating is a convex curved surface, and the upper part of the overall structure is also a convex curved surface coated with an epoxy resin coating. This invention uses segmented, interlocking fibers in the armor plates to inhibit the propagation of crack damage, ensuring that the protective capabilities and visibility of other areas are not affected after an impact. Combined with the function of the curved structure, the overall structure is embedded in the curved backplate, forming an embedded structure.

Description

Technical Field

[0001] This invention belongs to the field of protection, specifically relating to an embedded, transparent protective structure that can withstand multiple impacts. Background Technology

[0002] Currently, most existing transparent protective structures adopt a traditional laminated structure design of "planar hard ceramic layer + glass layer + polymer curved backing plate," relying primarily on the impact resistance of a single or a few planar ceramic sheets. However, this design reveals numerous insurmountable technical shortcomings when facing repeated impact threats. Firstly, traditional transparent protective structures lack effective damage tolerance design. Even if a single impact does not cause complete penetration, it will still cause internal damage such as material damage, structural cracking, and interface debonding within the composite structure. This damage severely weakens the protective structure's resistance to subsequent impacts, making it highly susceptible to failure to function effectively upon a second hit, thus failing to meet the requirement of "maintaining reliable protection against subsequent secondary threats after withstanding an initial effective hit." Secondly, the lack of a crack suppression structure in monolithic structures means that cracks can easily propagate rapidly after impact damage to the ceramic sheet, blurring the visible elements and failing to meet the visualization requirements. In addition, while the requirements for transparent protective equipment in civilian applications are becoming increasingly complex, lightweight design is also required. Therefore, it is necessary to break through the traditional single-layer design. The traditional laminated structure design is limited by the limitations of traditional process technology. As process technology is gradually optimized, the planar design adopted should be improved.

[0003] To improve protective performance, some technologies have attempted to introduce fiber composite materials as interlayers, but these remain at the level of optimizing traditional laminated structures, failing to overcome the inherent limitations of planar structures. Furthermore, simply increasing the number of composite structures significantly increases their cost. Therefore, employing a segmented ceramic sheet combined with a structure possessing strong crack suppression capabilities can greatly satisfy the requirement for resistance to multiple impacts. Furthermore, segmenting the ceramic sheet also significantly reduces overall damage to the visible unit. Simultaneously, to ensure lightweight requirements, this embedded structure design concept provides important inspiration for improving protective performance. The coordination between various structures also abandons the traditional planar design, using curved surfaces to tightly fit each structure, while locally thickening the main protective units to increase protective capabilities. Existing transparent composite protective structures neither incorporate this design concept to enhance resistance to multiple impacts nor lack supporting designs that can synergistically suppress crack propagation and protect the core support structure for multiple uses, resulting in their inability to meet high-end protection requirements in key indicators such as structural stability and residual protective performance. Summary of the Invention

[0004] The purpose of this invention is to provide an embedded, visible, transparent protective structure and its preparation method that can withstand multiple impacts. Through multi-structure collaborative design, it achieves a high protection threshold, strong crack suppression capability, and efficient energy dissipation effect.

[0005] The technical solution to achieve the purpose of this invention is: an embedded, transparent protective structure resistant to multiple impacts, comprising a transparent ceramic curved armor plate, a transparent fiber-reinforced skeleton, a polycarbonate curved backplate, an epoxy resin coating, and an STF shear-thickening coating.

[0006] The polycarbonate curved backplate has a central groove with a concave bottom surface. The transparent fiber reinforced skeleton is formed by an array of polygonal units. The bottom of the transparent fiber reinforced skeleton is bonded to the concave bottom surface of the central groove of the polycarbonate curved backplate. Each polygonal unit of the transparent fiber reinforced skeleton has a transparent ceramic curved plate. The gap between the transparent ceramic curved plate and the transparent fiber reinforced skeleton is uniform in width and filled with an STF shear thickening coating. The bottom of the whole formed by the transparent ceramic curved plate, the transparent fiber reinforced skeleton and the STF shear thickening coating is an outwardly convex curved surface that matches the concave surface of the central groove. The upper part of the whole is an outwardly convex curved surface with the same curvature as the bottom outwardly convex curved surface. The upper surface of the polycarbonate curved backplate with the transparent ceramic curved plate, the transparent fiber reinforced skeleton and the STF shear thickening coating is coated with an epoxy resin coating.

[0007] Furthermore, the polygonal units of the transparent ceramic curved armor plates and the transparent fiber reinforced skeleton are all hexagonal, and multiple hexagonal transparent ceramic curved armor plates are symmetrically arranged around the central armor plate.

[0008] Furthermore, the transparent ceramic curved armor plate is made of alumina transparent ceramic blank, the transparent fiber reinforced skeleton is made of continuous glass fiber and resin-based composite material, the polycarbonate curved back plate is made of PC sheet, the bottom of the transparent fiber reinforced skeleton and the bottom of the central groove of the polycarbonate curved back plate are bonded with polyurethane adhesive, and the epoxy resin coating is made of transparent epoxy resin.

[0009] Furthermore, the distance R1 from the center of the hexagon to the vertex of the hexagon in the transparent ceramic curved armor plate satisfies the following formula:

[0010] ,

[0011] In the formula, r is the radius of the crushing zone generated under threat.

[0012] Furthermore, the minimum number of units in the transparent ceramic curved armor plate. Determined according to the following formula:

[0013] ,

[0014] V(n) is the ratio of the remaining effective window area after n effective hits; u is the residual light transmittance of some failed units; n is the expected number of effective hits to withstand;

[0015] Maximum number of units in transparent ceramic curved armor plates according to Sure, Determined according to the following formula:

[0016] K 实际 =K max -1,

[0017] .

[0018] Furthermore, the thickness of the transparent fiber reinforced skeleton The calculation method is as follows:

[0019] ,

[0020] ,

[0021] ,

[0022] .

[0023] Furthermore, the gap width between the transparent ceramic curved armor plate and the transparent fiber-reinforced skeleton, i.e. the thickness D of the STF shear-thickening coating, satisfies the following formula:

[0024] ,

[0025] ,

[0026] Where λ is the characteristic wavelength of the impact pulse, t is the duration of the fragment impact, ranging from 10 to 50 μs, and c is the sound velocity of the STF, ranging from 1000 to 1500 m / s.

[0027] Furthermore, the radii of curvature of the concave bottom surface of the polycarbonate curved backplate center groove and the convex surfaces on both sides of the transparent fiber reinforced skeleton... The calculation formula is as follows:

[0028] ,

[0029] x is the horizontal distance from the impact point P to the vertex of the curved surface, α is the initial incident angle of the fragment, and k is the deflection efficiency coefficient, which ranges from 0.5 to 0.8.

[0030] ,

[0031] β is the angle between the ejection direction of the fragment and the vertical direction, expressed as follows:

[0032] ,

[0033] The angle between the exit direction and the normal and the local incident angle. Satisfy the following formula:

[0034] ,

[0035] The expression is:

[0036] ,

[0037] Let P be the angle between the surface normal at point P and the vertical direction.

[0038] A method for fabricating the above-mentioned embedded, visible, transparent protective structure includes the following steps:

[0039] Processing of transparent ceramic curved nail plates: A diamond wire saw is used to cut the transparent alumina ceramic blank. A curved surface grinding mold is designed, and a CNC curved surface grinding machine is used to process the curved surface of the cut ceramic blank. First, rough grinding is used to remove excess material, and then fine grinding is used to ensure the accuracy of the curved surface. The front and back sides of the nail plate are polished to remove burrs.

[0040] Transparent fiber reinforced skeleton processing: Pre-treated continuous glass fiber is mixed with epoxy resin in a certain proportion, and after molding, it is naturally cooled to room temperature for demolding. Diamond grinding wheel is used to trim the edges to ensure that the size matches the gap between the armor pieces. At the same time, the surface is finely polished to obtain the transparent fiber reinforced skeleton.

[0041] Processing of polycarbonate curved back panel: Cut the PC sheet and process the concave curved groove in the center area of ​​the PC sheet. First rough milling, then fine milling to ensure that it matches the convex curved surface of the shell and fiber. Then polish the groove surface and the upper surface of the PC curved back panel. Then wipe it with alcohol to remove oil, dry it with hot air for later use, and obtain the polycarbonate curved back panel.

[0042] Adhesive assembly of each structure: Apply polyurethane adhesive evenly to the surface of the groove of the polycarbonate curved back plate, place the transparent fiber reinforced skeleton in the groove of the curved back plate, and then place the transparent ceramic curved armor plate in the center of the hexagonal unit of the transparent fiber reinforced skeleton, and wait for the bottom adhesive to dry.

[0043] STF shear thickening liquid is poured into the reserved gap between the transparent ceramic curved armor plate and the transparent fiber reinforced skeleton. After the thickening liquid has seeped into the reserved gap, the excess liquid that overflows is removed with a scraper.

[0044] After the STF shear thickener has cured and stabilized, a 2mm epoxy resin layer is applied to the upper surface of the overall structure.

[0045] Compared with the prior art, the significant advantages of this invention are:

[0046] (1) Excellent resistance to multiple impacts, ensuring continuous protective performance: The present invention adopts a structural design of segmented armor plate groups combined with fiber composite materials between the armor plates to form multiple relatively independent protective units. At the same time, STF shear thickening is added to the contact surface between the armor plates and the fibers. When encountering the first impact, the supporting fibers and STF shear thickening fluid can work together to inhibit crack propagation and restrain fragments from splashing, preventing single-point damage from spreading to the whole; even if some armor plates are damaged, the remaining intact armor plates can still maintain effective protection, ensuring reliable impact resistance under multiple continuous impacts, meeting the core requirement of "continuously resisting secondary threats after the first hit" in practical applications.

[0047] (2) Full-cycle visualization guarantee to ensure continuous observation: The present invention guarantees full-cycle visualization through two major designs: First, it uses high light transmittance materials to ensure excellent light transmittance before impact, providing a clear field of view for the visual system; Second, it relies on the segmented structure and crack suppression design, so that a single impact will only cause local damage to the armor plate, while the remaining intact area will still maintain light transmittance integrity, filling the gap in the existing technology in "post-impact visualization guarantee".

[0048] (3) High efficiency in crack and stress suppression, improving structural stability: The present invention coats the contact surface between the ceramic sheet and the supporting fiber composite material with STF shear thickening. This material can quickly achieve shear thickening under impact load, which can not only effectively suppress crack propagation and block shear stress transmission, but also protect the supporting fiber composite material, preventing it from structural failure under multiple impacts, and ensuring the long-term stability and reliability of the overall structure after multiple uses.

[0049] (4) Design models of three core protective structures, namely ceramic sheet, fiber and STF shear coating, have been established, which can be changed according to different materials and impact conditions.

[0050] (5) Optimized energy dissipation path to improve single impact resistance: The armor plate of this invention adopts a gradient thickness of "thick in the center and thin at the edge" and an outward convex curved surface design, which can actively guide the deflection and slippage of fragments, change the impact posture of fragments, and disperse the concentrated impact kinetic energy to a larger area; at the same time, the synergistic effect of the supporting fiber and the curved back plate can further absorb and dissipate the remaining kinetic energy, greatly improve the resistance to single high kinetic energy impacts, and reduce the damage degree of the first hit.

[0051] (6) Embedded structure design to enhance connection reliability and anti-peeling ability: The present invention adopts an embedded adaptation bonding design of "plate-fiber-curved back plate" and an overall coverage of epoxy resin coating, which not only improves the connection tightness between the various structures, but also enhances the overall rigidity; under impact load, it can effectively avoid interlayer peeling, further ensuring the structural integrity and the stability of protective performance. Attached Figure Description

[0052] Figure 1 This is a three-dimensional schematic diagram of the overall protective structure of the present invention.

[0053] Figure 2 This is a schematic diagram of the overall protective structure of the present invention; wherein (a) is a top view and (b) is a cross-sectional view of (a) along the AA direction.

[0054] Figure 3 This is a schematic diagram of the axle assembly of the present invention; wherein (a) is a top view and (b) is a cross-sectional view of (a) along the BB direction.

[0055] Figure 4 This is a schematic diagram of the STF shear-thickening coating of the present invention.

[0056] Figure 5 This is a schematic diagram of the fiber-reinforced bone structure of the present invention; wherein (a) is a top view and (b) is a cross-sectional view of (a) along the CC direction.

[0057] Figure 6 This is a schematic diagram of the curved back plate of the present invention; where (a) is a top view and (b) is a sectional view along the DD direction of (a).

[0058] Explanation of reference numerals in the attached figures:

[0059] 1- Transparent ceramic curved armor plate, 2- Transparent fiber reinforced skeleton, 3- Polycarbonate curved backplate, 4- Epoxy resin coating, 5- STF shear thickening coating. Detailed Implementation

[0060] This invention discloses an embedded, transparent protective structure design capable of withstanding multiple impacts. Through multi-structure collaborative design, it achieves a high protection threshold, strong crack suppression capability, and efficient energy dissipation, making it widely applicable in protective observation windows in financial institutions, data centers, transportation, and other fields. The structure features an embedded composite design, comprising, from top to bottom, an epoxy resin coating, a transparent ceramic curved armor plate assembly, transparent fiber, and a polycarbonate curved backplate. Each structure is tightly fitted through curved surface adaptation and bonding processes, forming a multi-level collaborative protection system.

[0061] An embedded, transparent protective structure resistant to multiple impacts includes a transparent ceramic curved armor plate 1, a transparent fiber-reinforced skeleton 2, a polycarbonate curved backplate 3, an epoxy resin coating 4, and an STF shear-thickening coating 5. The overall structure is an embedded composite protective structure, with each component sequentially fitted and aligned from top to bottom to form a multi-level synergistic protective system. The transparent ceramic curved armor plates are symmetrically arranged around the central armor plate. The transparent fiber composite material is a honeycomb-shaped glass fiber composite material embedded in the gaps between the armor plates and bonded to the polycarbonate curved backplate with a polyurethane adhesive layer. The upper surface of the transparent fiber composite material is an outwardly convex curved surface with the same radius as the armor plate's curvature. The polycarbonate curved backplate, made of impact-resistant polycarbonate, is placed at the bottom of the protective structure. Its central area has a concave curved groove that precisely matches the lower outwardly convex curved surface of the transparent ceramic curved armor plate assembly and the transparent fibers. The epoxy resin coating is a uniform, thin-film transparent material structure covering the surface of the transparent ceramic curved armor plate assembly, while the STF shear-thickening coating covers the sides of the fiber structure. The specific designs of each core structure are as follows:

[0062] The core protection and observation unit is a transparent ceramic curved armor plate assembly. Therefore, the area of ​​the circular crushing zone of the ceramic essentially covers a hexagon. Other structures limit the propagation of radial force cracks, circumferential cracks, and other cracks. The core structure is designed as follows: First, the area of ​​the inscribed circle of the hexagonal unit (R1 is the distance from the center of the hexagon to its vertex) is:

[0063]

[0064] The formula for the area of ​​the circular crushing zone is:

[0065]

[0066] By establishing the equation for equal area and deriving the design formula, and setting (1.1) = (1.2), we get:

[0067]

[0068] This formula is the mathematical core of the design size standard of this invention. As long as the radius r of the crushing zone generated by the ceramic protective unit under a specific threat is determined, the size of the hexagon of the armor plate unit required to achieve "damage localization" can be directly calculated, and the propagation of cracks can be suppressed with minimal material cost.

[0069] Furthermore, based on the equation for the ratio of remaining effective window area, the minimum number of units N required to satisfy the design objective is obtained, assuming that each strike hits a completely new area and causes one complete failure plus two partial failures:

[0070]

[0071] in:

[0072] V(n): The ratio of the remaining effective window area after n effective hits. In this structural design, V(3) ≥ 60%;

[0073] u: Residual transmittance of partially failed units, which is related to material properties, and is taken as u=0.3;

[0074] n: Expected number of effective hits to withstand;

[0075] Therefore:

[0076]

[0077] Since the armor plate array needs to be embedded within the entire curved backplate (L1=100mm, L2=110mm, where L1 and L2 are the length and width of the curved backplate), the following geometric conditions must be met, where K is the number of turns around the central armor plate:

[0078]

[0079] Additionally, space needs to be reserved for other structures, therefore K is chosen. 实际 =K max -1, K 实际 In the actual structural design, K represents the number of rings around the central armor plate. In this design, K... 实际 =2.

[0080] This patent addresses the typical damage range caused by common small-mass fragments impacting transparent ceramics. The radius of the crushing zone is 5~10mm. When r=6.66mm, the circular crushing zone basically covers the hexagonal unit without significantly exceeding the boundary, achieving the optimal balance between material utilization and crack suppression.

[0081] To suppress the impact of cracks on other elements after impact, a fiber structure is used. Suppressing crack propagation essentially means that the energy released for crack propagation in ceramics must not exceed the energy absorbed by the fibers. Therefore, the fiber thickness (G) is obtained using the following correlation formula. 动态断裂能 =60J / m 2 l 裂纹长度 =6.66mm, τ 剪切屈服强度 =78Mpa, γ 最大工程剪切应变 =0.20、A 有效接触面积 =38.45mm 2 ):

[0083]

[0084]

[0085]

[0086]

[0087] In addition, considering practical engineering applications, a safety factor, h, is adopted. 实际 =K∙h 纤维厚度 Taking K=3, the material used for the armor plate in this patent is AlON transparent ceramic, so the final calculated fiber thickness h≥1.996, rounded to h=2mm.

[0088] Since the compressive stress wave generated by the impact will attenuate as it propagates in the material, the thickness of the STF coating must ensure that the stress wave can interact sufficiently within the STF coating during the impact duration, so as to fully activate it and exert its maximum effectiveness.

[0089] In order for the STF layer to effectively interact with the shock wave and generate a significant wave impedance gradient effect, the STF coating thickness D should be no less than λ / 15 to λ / 20, where λ is the characteristic wavelength of the shock pulse. Given that the fragment impact duration t is approximately 10~50 μs and the sound velocity c of the STF is approximately 1000-1500 m / s, according to...

[0090]

[0091] The theoretical reference thickness range can be calculated to be 0.5mm-5mm. Considering the need for lightweighting, D=0.5mm is selected.

[0092] To further enhance the attitude control of debris and the dissipation of energy, the traditional planar structure is abandoned in favor of a convex curved surface design. The curved surface shape can effectively guide the deflection and slippage of debris, reduce local impact pressure, and improve energy dissipation efficiency.

[0093] Assume the panel is a uniform sphere with a radius of curvature of R2, as follows: Figure 5 As shown, R2 is the designed target. First, the fragment impacts a point P on the curved surface with an initial incident angle α (the angle between the fragment and the vertical direction). The horizontal distance from this point to the vertex (center) of the surface is x. The angle ∅ between the surface normal at point P and the vertical direction is approximately:

[0094]

[0095] The angle between the debris velocity direction and the normal (i.e., the local angle of incidence) is:

[0096]

[0097] After a fragment impacts a curved surface, its ejection direction changes due to material interactions. The angle between the ejection direction and the normal, and the angle of incidence, can be expressed as follows:

[0098]

[0099] Where k is the deflection efficiency coefficient, which reflects the energy loss of non-ideal reflection, and is usually taken as 0.5~0.8.

[0100] The angle β between the ejection direction of the fragment and the vertical direction can be expressed as:

[0101]

[0102] To simplify the model, assume α > φ, and that α and φ are on the same side. According to the deflection angle expression:

[0103]

[0104] The formula for the radius of curvature is derived from the above formula as follows (x=55mm, α=6.5°=0.1134rad, ∆θ=0.13°, k=0.5):

[0105]

[0106] Complete overall design and layout of the structure.

[0107] Based on the above-mentioned invention, the specific implementation method of this structure is as follows: it is carried out strictly in accordance with the process of "material pretreatment → component processing → assembly and bonding → coating preparation → finished product inspection" to ensure that the accuracy of each step meets the design requirements:

[0108] For material pretreatment and selection, high-transmittance alumina transparent ceramic blanks are selected for transparent ceramic materials to ensure both protective performance and light transmission requirements. Continuous glass fiber and resin-based composite materials are selected for transparent fiber composites, and the fiber volume fraction is controlled to ensure the strength and transparency of the fiber layer. The polycarbonate curved backing plate uses impact-resistant PC sheets, high-toughness polyurethane adhesive is used for bonding, and two-component transparent epoxy resin is used for the epoxy resin coating to ensure bonding strength and coating transparency.

[0109] The processing of transparent ceramic curved armor plates involves precision cutting of the alumina transparent ceramic blank using a diamond wire saw according to the design dimensions of the armor plate assembly. A dedicated curved surface grinding mold is designed based on a curved surface radius of 505.67mm. A CNC curved surface grinding machine is used to process the curved surface of the cut ceramic blank. First, rough grinding removes excess material, followed by fine grinding to ensure surface accuracy. Both sides of the armor plate are polished to remove burrs and reduce stress concentration.

[0110] Transparent fiber processing involves designing a molding die for the fiber interlocking structure based on the gap size of the nail plates and the radius of curvature of 505.67mm. The pre-treated continuous glass fiber is mixed with the epoxy resin matrix in the design ratio. After molding, the mixture is naturally cooled to room temperature for demolding. A diamond grinding wheel is used to trim the fiber edges to ensure that the fiber size is precisely matched with the gap of the nail plates. At the same time, the fiber surface is finely polished.

[0111] The polycarbonate curved back panel is processed by using a CNC panel cutting machine to cut the PC sheet into a basic size of 110×100mm. A milling cutter is designed based on a concave curved surface radius of 505.67mm. A CNC milling machine is used to process the concave curved groove in the center area of ​​the PC sheet. Rough milling is performed first, followed by fine milling to ensure a perfect fit with the convex curved surfaces of the sheet metal and fibers. Then, the groove surface and the upper surface of the PC curved back panel are polished to improve the roughness of the bonding surface. Finally, the oil is removed by wiping with alcohol and dried with hot air for later use.

[0112] For the bonding and assembly of each structure, a dedicated positioning fixture was designed. Positioning was performed according to the bottom-up assembly sequence (PC curved backplate → fiber → ceramic nail plate assembly) to ensure center alignment and precise surface fitting of each structure. First, the curved backplate was bonded to the fiber interlocking layer. Polyurethane adhesive was evenly applied to the groove surface of the PC curved backplate, with a thickness of 0.3-0.5mm. The fiber interlocking layer was then precisely placed within the groove of the curved backplate. Finally, the nail plate was placed in the center of the fiber hexagonal structure, and the underlying adhesive was allowed to dry.

[0113] After the adhesive layer connecting the ceramic armor plate assembly and the fiber structure to the backplate has dried and fixed, STF shear thickening liquid can be poured directly into the reserved gap between the ceramic armor plate assembly and the fiber structure. After the thickening liquid has seeped into the reserved gap, use a scraper to remove the excess liquid. After the STF shear thickening liquid has cured and stabilized, cover the upper surface of the overall structure with a 2mm epoxy resin layer, ensuring that the coating is uniform during the application process.

Claims

1. A multi-impact resistant, embedded, visibly transparent protective structure, characterized in that, It includes a transparent ceramic curved armor plate (1), a transparent fiber reinforced skeleton (2), a polycarbonate curved back plate (3), an epoxy resin coating (4), and an STF shear thickening coating (5). The polycarbonate curved backplate (3) has a central groove with a concave bottom surface. The transparent fiber reinforced skeleton (2) is formed by an array of polygonal units. The bottom of the transparent fiber reinforced skeleton (2) and the concave bottom surface of the central groove of the polycarbonate curved backplate (3) are bonded together. Each polygonal unit of the transparent fiber reinforced skeleton (2) has a transparent ceramic curved plate (1). The gap between the transparent ceramic curved plate (1) and the transparent fiber reinforced skeleton (2) is uniform in width and filled with STF shear thickening coating (5). The bottom of the whole formed by the transparent ceramic curved plate (1), the transparent fiber reinforced skeleton (2) and the STF shear thickening coating (5) is an outward convex surface that matches the concave surface of the central groove. The upper part of the whole is an outward convex surface with the same curvature as the bottom outward convex surface. The upper surface of the polycarbonate curved backplate (3) with the transparent ceramic curved plate (1), the transparent fiber reinforced skeleton (2) and the STF shear thickening coating (5) is coated with epoxy resin coating (4).

2. The embedded see-through shield structure of claim 1, wherein, The polygonal units of the transparent ceramic curved armor plate (1) and the transparent fiber reinforced skeleton (2) are both hexagonal, and multiple hexagonal transparent ceramic curved armor plates are symmetrically arranged around the central armor plate.

3. The embedded see-through shield structure of claim 2, wherein, The transparent ceramic curved shell (1) is made of alumina transparent ceramic blank, the transparent fiber reinforced skeleton (2) is made of continuous glass fiber and resin-based composite material, the polycarbonate curved back plate (3) is made of PC sheet, the bottom of the transparent fiber reinforced skeleton (2) and the bottom of the central groove of the polycarbonate curved back plate (3) are bonded with polyurethane adhesive, and the epoxy resin coating (4) is made of transparent epoxy resin.

4. The embedded see-through shield structure of claim 3, wherein, The distance R1 from the center of the hexagon to the vertex of the hexagon in the transparent ceramic curved armor plate (1) satisfies the following formula: ， In the formula, r is the radius of the crushing zone generated under threat.

5. The embedded visible transparent protective structure according to claim 4, characterized in that, Minimum number of transparent ceramic curved nail plate (1) Determined according to the following formula: ， V(n) is the ratio of the remaining effective window area after n effective hits; u is the residual light transmittance of some failed units; n is the expected number of effective hits to withstand; Maximum number of units of a transparent ceramic curved nail plate (1) According to Determined, According to the following formula: K 实际 =K max -1, 。 6. The embedded visible transparent protective structure according to claim 5, characterized in that, Thickness of the transparent fiber reinforced skeleton (2) The calculation method is as follows: ， ， ， 。 7. The embedded visible transparent protective structure according to claim 6, characterized in that, The gap width between the transparent ceramic curved armor plate (1) and the transparent fiber-reinforced skeleton (2), i.e. the thickness D of the STF shear-thickening coating (5), satisfies the following formula: ， ， Where λ is the characteristic wavelength of the impact pulse, t is the duration of the fragment impact, ranging from 10 to 50 μs, and c is the sound velocity of the STF, ranging from 1000 to 1500 m / s.

8. The embedded visible transparent protective structure according to claim 7, characterized in that, The concave curved surface at the bottom of the central groove of the polycarbonate curved backplate (3) and the radius of curvature of the convex curved surfaces on both sides of the transparent fiber reinforced skeleton (2) The calculation formula is as follows: ， x is the horizontal distance from the impact point P to the vertex of the curved surface, α is the initial incident angle of the fragment, and k is the deflection efficiency coefficient, which ranges from 0.5 to 0.

8. ， β is the angle between the ejection direction of the fragment and the vertical direction, expressed as follows: ， The angle between the exit direction and the normal and the local incident angle. Satisfy the following formula: ， The expression is: ， Let P be the angle between the surface normal at point P and the vertical direction.

9. A method for preparing the embedded visible transparent protective structure according to any one of claims 1-8, characterized in that, Includes the following steps: Processing of transparent ceramic curved nail plates: A diamond wire saw is used to cut the transparent alumina ceramic blank. A curved surface grinding mold is designed, and a CNC curved surface grinding machine is used to process the curved surface of the cut ceramic blank. First, rough grinding is used to remove excess material, and then fine grinding is used to ensure the accuracy of the curved surface. The front and back sides of the nail plate are polished to remove burrs. Transparent fiber reinforced skeleton processing: Pre-treated continuous glass fiber is mixed with epoxy resin in a certain proportion, and after molding, it is naturally cooled to room temperature for demolding. Diamond grinding wheel is used to trim the edges to ensure that the size matches the gap between the armor pieces. At the same time, the surface is finely polished to obtain the transparent fiber reinforced skeleton. Processing of polycarbonate curved back panel: Cut the PC sheet and process the concave curved groove in the center area of ​​the PC sheet. First rough milling, then fine milling to ensure that it matches the convex curved surface of the shell and fiber. Then polish the groove surface and the upper surface of the PC curved back panel. Then wipe it with alcohol to remove oil, dry it with hot air for later use, and obtain the polycarbonate curved back panel. Adhesive assembly of each structure: Apply polyurethane adhesive evenly to the surface of the groove of the polycarbonate curved back plate, place the transparent fiber reinforced skeleton in the groove of the curved back plate, and then place the transparent ceramic curved armor plate in the center of the hexagonal unit of the transparent fiber reinforced skeleton, and wait for the bottom adhesive to dry. STF shear thickening liquid is poured into the reserved gap between the transparent ceramic curved armor plate and the transparent fiber reinforced skeleton. After the thickening liquid has seeped into the reserved gap, the excess liquid that overflows is removed with a scraper. After the STF shear thickener has cured and stabilized, a 2mm epoxy resin layer is applied to the upper surface of the overall structure.

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