WO2021259342A1 - Prestress constrained block and composite armor structure - Google Patents

Abstract

A prestress constrained block and a composite armor structure. The prestress constrained block comprises a filling platform body (11) and a constraint ring (12). The filling platform body (11) has a cross section of the same shape as that of an inner ring of the constraint ring (12), and is fixedly embedded in the inner ring of the constraint ring (12), an outer side wall of the filling platform body (11) and an inner ring wall of the constraint ring (12) being wedged tightly by means of the fit of conical surfaces or polygonal pyramid surfaces. The composite armor structure comprises at least one layer of armor plates. The armor plates comprise several prestress constrained blocks. For the prestress constrained blocks, several separate constrain rings that are spliced are used or a constraint ring with an integrated honeycomb structure is used. The prestress constrained block can apply a radial prestress to fragile materials such as ceramics, concrete or glass in a room temperature condition, and can adjust and control the magnitude of the prestress; and the prestress constrained block is suitable for applying prestress to components of various sizes and is easier to assemble, and damaged or broken components can be easily replaced, so that the prestress constrained block is applied to a plurality of protection fields such as armed helicopters, armored vehicles, ships, tanks, aircraft warehouses and missile-well covers.

Description

Prestressed restraint block and composite armor structure Technical field

The invention belongs to armor technology, and specifically relates to a prestressed restraint block and a composite armor structure.

Background technique

The anti-penetration performance of composite armor using ceramic materials mainly depends on the ceramic's compressive strength and hardness, crushing characteristics, fragment flow friction and particle abrasion; the high compressive strength of ceramics improves the anti-penetration performance to a certain extent; ceramics Energy absorption in the surface area of the crushing zone is an important factor for ceramic anti-penetration; for thick and strictly constrained ceramic blocks, the flow friction of ceramic fragments is the most important factor for anti-penetration. Studies have shown that after the ceramic target is laterally constrained, when the projectile penetrates the constrained ceramic, the confinement ring will exert a constraining force on the ceramic target plate, which can effectively curb the crack propagation of the ceramic material, thereby improving the resistance of the ceramic material. Penetration performance. With the deepening of research, more and more people have begun to study the effect of applying internal stress to ceramics in advance on the anti-penetration performance of ceramic materials.

Prestressing the ceramic material of the composite armor can effectively inhibit the initiation and propagation of cracks in the target body. Even if fracture occurs inside the ceramic under high-speed impact, the ceramic fragments are still squeezed relatively tightly, and there are only cracks without expansion, so that there is a large penetration resistance inside the broken ceramic area. The reverse movement of the ceramic particles and the projectile will have an abrasion effect on the quality of the projectile, and make the energy dissipation mechanism such as mutual friction play a role, effectively improving the anti-penetration performance of the ceramic.

technical problem

At present, scholars at home and abroad mainly apply prestressing methods to ceramics: mechanical extrusion and hot packing. The mechanical extrusion method presses on the side of the ceramic material to form a transverse compression prestress on the inside of the ceramic material; hot packing The method is to fix the constrained structure of the ceramic material and the metal material at high temperature, and then the overall temperature is lowered, and the metal compression ceramic with a larger thermal expansion coefficient and faster shrinkage is applied to prestress, such as a constraint disclosed in the Chinese patent application with application number 201810777211.4 Ceramic-metal composite bulletproof armor plate and preparation method thereof.

Both heat and cold shrinkage or mechanical pressure can be used to generate prestress inside the ceramic. In the pre-stress test of composite armor, a stable pre-stress is required and the pre-stress size can be adjusted. Under the limitation of actual test conditions, the heat treatment of the hot charging method will have an adverse effect on the strength of the metal. The temperature is controlled to adjust the internal pre-stress of the ceramic The method of stress magnitude is difficult to achieve the long rod impact test, so the mechanical extrusion method is mostly used in the test, and the mechanical pressure device requires uniform lateral pressure from the periphery of the ceramic material, and the assembly size between the ceramic material and the restraint structure The machining accuracy is high, and multiple surfaces are pressurized at the same time. The equipment structure is relatively complicated, but it is difficult to apply in actual engineering and is only limited to research.

Technical solutions

The technical problem solved by the present invention is to provide a prestressed restraint block and a composite armor structure that can be quickly assembled in a room temperature environment in view of the above-mentioned problems existing in the mechanical extrusion method and the hot charging method of applying prestress to the existing composite armor .

The present invention adopts the following technical solutions to achieve:

The pre-stressed constraining block includes a filling platform 11 and a constraining ring 12. The filling platform 11 has a cross section of the same shape as the inner ring of the constraining ring 12, and is fixedly embedded in the inner ring of the constraining ring 12. The filling platform The outer side wall of the body 11 and the inner ring wall of the constraining ring 12 are wedged tightly through taper fit;

The outer side wall of the filling platform 11 and the inner wall of the confinement ring 12 are respectively matched conical surfaces or matched polygonal pyramid surfaces.

In the prestressed restraint block in the above solution, the diameters of the large end and the small end of the outer side wall of the filling platform 11 are respectively d ₁ and d ₂ , and the diameters of the large end and the small end of the inner wall of the confinement ring 12 are respectively R ₁ and R ₂ satisfy R ₂ ≦d ₂ ≦R ₁ ≦d ₁ , and the heights of the filling platform 11 and the confinement ring 12 are h1 and h2, respectively, where h1≦h2.

In the prestressed restraint block in the above solution, the inclination angle α of the cone surface of the outer side wall of the filling platform 11 ranges from 1° to 10°, preferably 3° to 6°. The range of β is 1°~10°, preferably 3°~6°. There is an angular difference Δα between the outer side wall of the filling table body 11 and the inner wall of the confinement ring 12, Δα=α-β, the value of Δα The range is 0°~0.5°, preferably 0°~0.2°.

In the prestressed constraining block in the above solution, the diameter-to-thickness ratio d ₁ /h ₁ of the filling table body 11 is 0.5-40, preferably 3-12.

In the prestressed constraining block in the above solution, the filling platform 11 is a frustum with a conical surface or an outer side wall of a polygonal pyramid surface,

Or, the cylinder or prism of the first reducing ring 14 is fixed externally, and the outer side wall of the first reducing ring 14 is a conical surface or a polygonal pyramid surface.

In the prestressed constraining block in the above solution, the constraining ring 12 is a reduced-diameter ring body with an inner ring wall of a conical surface or a polygonal pyramid surface,

Or a cylindrical ring or a prismatic ring in which the second reducing ring 13 is fixed and embedded, and the inner wall of the second reducing ring 13 is a conical surface or a polygonal pyramid surface.

In the prestressed constraining block in the above solution, the filling platform 11 has a layered structure and includes at least two layers of fixed and stacked filling blocks.

In the prestressed constraining block in the above solution, the outer surface of the filling platform body 11 is wrapped with a wrapping layer 17.

In the prestressed restraining block in the above solution, the small end of the inner wall of the restraining ring 12 or the second reducing ring 13 is provided with a bottom plate structure, and the bottom plate structure is a restraining groove bottom plate 16 integrally structured with the restraining ring 12, Or the cushion is mounted on the cushion layer 15 at the small end of the filling platform 11.

In the prestressed restraint block in the above solution, the filling platform 11 is made of ceramic, concrete or glass material, and the restraining ring 12 is made of metal or fiber reinforced composite material.

In the prestressed constraining block of the present invention, the inner wall of the constraining ring 12 is provided with a clamping groove 18, and the clamping groove 18 is equipped with a wedge for the filling platform 11 to axially limit the constraining ring 12 Snap ring 19.

The present invention also discloses a composite armored structure, including at least one layer of armor plate, the armor plate includes a plurality of the above-mentioned prestressed restraint blocks of the present invention, the prestressed restraint blocks are spliced by a plurality of split restraint rings 12, or A confinement ring 12 with an integrated honeycomb structure is adopted.

The composite armor structure in the above solution also includes a cover plate 2 and a back plate 3 respectively attached to cover both sides of the composite armor.

Beneficial effect

The present invention has the following beneficial effects:

The present invention presses the filling platform body made of ceramic, concrete or glass into the inner ring of the confinement ring made of metal or fiber reinforced composite material to obtain the prestressed constraining block, wherein the confinement ring and the filling platform body are matched by a cone Wedge tightening, according to the hoop restraint principle, the inner ring of the confinement ring and the filling platform are wedge tightly tightened through the tapered surface to have a self-tightening function. The generated radial hoop force increases with the increase of vertical pressure, so that the strength of the filling platform becomes larger, and the elastic restoring force of the confinement ring exerts a lateral prestress on the filling platform, which increases the resistance of the restraining block. Thorough and anti-explosive shock performance.

The prestressed constraining block of the present invention can very simply apply radial prestress to brittle materials such as ceramics, concrete or glass at room temperature. The prestress can be filled with the depth of the inner ring of the constrained ring or the filling of the table body by the wedge of the table body. The taper inclination angle between the wedge and the constraining ring is controlled, which is suitable for prestressing of various sizes of filling platform components.

Since the prestressed constraining block of the present invention does not need to change the relative size of the components by heating like the hot charging method, it can also be applied to the fiber reinforced composite material confinement ring, concrete material or glass material filling table body which is difficult to apply to the hot charging method. In the present invention.

A single prestressed restraint block is assembled into a larger area composite armor structure, which can be assembled into a single-layer protective armor plate, or a single-layer protective armor plate can be misplaced and stacked into a multi-layer protective armor plate to reduce weak points and further increase the protective effect. The confinement ring can be made into an integral structure to increase the integrity of the confinement ring and the bending resistance of the armor plate.

In the process of installing the filling table body into the confinement ring, since the outer diameter of the small end of the filling table body has a larger tolerance than the large port diameter of the inner ring of the confinement ring, the prestressed restraint block of the present invention is more tolerant than the hot-fitting method. It is easier to assemble, the size of the table body and the confinement ring components has a larger tolerance range, and it is more environmentally friendly. Damaged or damaged components are easy to replace. In armed helicopters, armored vehicles, ships, tanks, aircraft caverns and missile manhole covers, etc. A variety of protection fields have broader application prospects. The prestressing method of the present invention is not only applied to protective materials such as armor, but also to brittle material components such as ceramic mirrors, lenses, transparent windows, etc. of aviation and aerospace devices. The prestressing of these components is improved by applying prestress through the confinement ring. Strength and reduce structural weight.

The present invention will be further described below in conjunction with the drawings and specific embodiments.

Description of the drawings

Fig. 1 is a schematic diagram of the assembly of the circular cross-section pre-stressed restraint block in the first embodiment.

Figure 2 is a schematic diagram of the assembly of the pre-stressed restraint block with a regular hexagonal cross-section in the first embodiment.

Fig. 3 is an anatomical view of the filling table body and the constraining ring in the first embodiment.

Fig. 4 is a schematic diagram of pre-stress application during the assembly process of the filling table body and the confinement ring in the first embodiment.

Figures 5a, 5b, and 5c are respectively schematic diagrams of prestressing application during the assembly process of the three filling platform bodies and the confinement ring in the second embodiment.

Fig. 6 is a schematic diagram of prestressing application during the assembly process of the filling table body and the confinement ring in the third embodiment.

Figures 7a and 7b are schematic diagrams of prestressing application during the two assembly processes of the filling platform body and the confinement ring in the fourth embodiment.

Fig. 8 is a schematic diagram of prestressing application during the assembly process of the filling table body and the confinement ring in the fifth embodiment.

Fig. 9 is a schematic diagram of prestressing application during the assembly process of the filling table body and the confinement ring in the sixth embodiment.

Fig. 10 is a schematic diagram of prestressing application during the assembly process of the filling platform body and the confinement ring in the seventh embodiment.

Figures 11a, 11b and 11c are schematic diagrams of assembling composite armor in the eighth embodiment.

Figures 12a, 12b and 12c are schematic cross-sectional views of three types of cover plates of the composite armor in the ninth embodiment.

13a, 13b, and 13c are schematic cross-sectional views of three types of back plates of composite armor in the ninth embodiment.

14a, 14b, 14c, 14d, and 14e are schematic cross-sectional views of five types of composite armor in the ninth embodiment.

Fig. 15 is a sectional dimension drawing of the frustum and the axis of the confinement ring planned in the first embodiment.

Fig. 16 is a 1/4 finite element model diagram of the planned size in the first embodiment.

Fig. 17 is the prestress-depression depth relation curve of the prestress restraint block in the prestress simulation process in the first embodiment.

FIG. 18 is a damage cloud diagram of the filling table body during the penetration simulation process of the prestressed restraint block in the first embodiment.

Figure 19 is the penetration depth-prestress relationship curve of the filled platform body in the penetration simulation process of the prestressed restraint block in the first embodiment

Numbers in the figure: 1-prestressed restraint block; 11-filled platform body; 111-first filled block; 112-second filled block; 113-sandwich; 12-confined ring; 121-conjoined constrained ring; 13-section Second reducing ring; 14-first reducing ring; 15-cushion layer; 16-constraint groove bottom plate; 17-wrapping layer; 18-slot; 19-snap ring;

2-cover plate; 21-first protective surface layer; 22-accommodating layer; 23-second protective surface layer;

3-back plate; 31-collision layer; 32-energy-absorbing layer; 33-resistance layer.

Embodiments of the present invention

Example one

Referring to Figures 1-4, the prestressed constraining block 1 shown in the figure includes a filling platform 11 and a confinement ring 12. The filling platform 11 has a cross section of the same shape as the inner ring of the confinement ring 12, as shown in Figure 1 as a circular cross section. As with the regular hexagonal section in Figure 2, the filling platform 11 is fixedly embedded in the inner ring of the confinement ring 12, and the outer side wall of the filling platform 11 and the inner ring wall of the confinement ring 12 are wedged tightly with each other through a taper fit. , Using the hoop restraint principle, when the filling platform 11 is pressed into the inner ring of the constraining ring 12, the elastic restoring force of the constraining ring 12 reacts to the filling platform 11, and the filling platform is moved from the outer side wall of the filling platform 11 The body 11 is prestressed by extrusion.

The filling platform 11 and the constraining ring 12 in this embodiment are both integral structures, and the two are wedge tightly with a conical surface. The filling platform 11 in FIG. For the platform structure, the inner wall of the confinement ring 12 is also a section of conical surface. The cross section of the filling platform 11 in Fig. 2 is a regular hexagon, and its outer side wall is a section of a hexagonal pyramidal reducing ring. The inner wall of the confinement ring 12 is also a section of a hexagonal pyramid. Spliced into a continuous armor layer, other polygonal pyramid surfaces can also be used in practical applications, including but not limited to triangles, quadrilaterals, and pentagons.

For details, referring to Fig. 3, in order to ensure that the filling platform 11 is press-fitted into the confinement ring 12 to generate extrusion prestress, the size between the filling platform 11 and the confinement ring 12 should meet the following conditions:

Regarding the cross-sectional dimensions of the filling platform 11 and the constraining ring 12, the outer side wall of the filling platform 11 is a tapered surface, that is, the filling platform 11 is set to a large end and a small end at both ends in the axial direction. The diameter of the large end is d ₁ , the diameter of the small end of the filling station body 11 is d ₂ , d ₁ >d ₂ , and the diameter referred to here is the outer diameter of the cross section of the filling station body 11 in Fig. 1 and the filling station in Fig. 2 The diameter of the circumscribed circle of the regular hexagon of the cross-section of the body 11; similarly, the inner wall of the constraining ring 12 is a tapered surface, and the large end and the small end are respectively set at the two axial ends of the inner ring wall of the constraining ring 12. The diameter of the large end is R ₁ , the diameter of the small end of the confinement ring 12 is R ₂ , R ₁ > R ₂ , and the diameter referred to here is the inner circle diameter of the inner wall of the inner ring wall of the confinement ring 12 in Fig. 1 and the confinement ring in Fig. 2 12 The diameter of the circumscribed circle of the regular hexagon of the inner ring wall cross section, preferably, R ₂ <d ₂ <R ₁ ≤ d ₁ .

For the size of the taper inclination angle between the filling platform 11 and the confinement ring 12, the taper angle α of the outer side wall of the filling platform 11 ranges from 1° to 10°, preferably 3° to 6°. The cone inclination angle β ranges from 1° to 10°, preferably 3° to 6°. The cone inclination angle referred to here is the conical generatrix and vertical direction of the outer wall of the filling platform 11 and the inner wall of the confinement ring 12 in Fig. 1 2 or the angle between the outer wall of the filling platform 11 and the inner wall of the constraining ring 12 in the vertical direction.

Regarding the axial dimensions of the filling platform 11 and the confinement ring 12, the axial heights of the filling platform 11 and the confinement ring 12 are h ₁ and h ₂ , respectively, where h ₁ ≤ _{h 2} .

The assembly method of prestressed restraint block and the basic principle of prestress are as follows:

The assembly diagram of the circular prestressed constraining block and the hexagonal prestressed constraining block are shown in Figures 1 and 2, respectively. The filling platform 11 with a circular cross section or the filling platform 11 with a hexagonal cross section is placed in the corresponding constraint. In the inner ring of the ring 12, in order to facilitate pressure, the large end of the inner ring of the confinement ring 12 is generally opened upward, and the small end of the filling platform 11 is pressed into the inner ring of the constraining ring 12 downward, and then the filling platform 11 is pressed along A downward pushing force is applied in the height direction, and the elastic restoring force of the confinement ring 12 squeezes the pre-stressed filling platform 11 inward, and applies a pre-compression stress in its radial direction. Larger, the greater the radial pre-compression stress applied by the constraining ring 12 to the filling platform 11, and the pre-stressed constraining block is obtained after the filling platform is pressed into a predetermined position. The filling platform 11 can be pressed in by jack, hydraulic press or bolt fastening. In order to reduce the pressing resistance, temporary lubricant can be applied to the contact cone surface of the two, and the lubricant can be removed after being pressed into a predetermined position. The radial prestress of the filling platform 11 can be designed to adjust the included angle between the conical generatrix or pyramid ridge line of the external side wall of the platform and the height of the filling platform, as well as the depression depth of the filling platform. When the included angle is constant, the restraining ring 12 does not yield. Or before failure, the greater the depression depth of the filling platform 11, the greater the prestress. The table body and the confinement ring can be bonded with an adhesive to prevent slippage, or they can be in direct contact, and the friction between the two can be stabilized.

The filling table body 11 may be made of ceramic, concrete or glass material, and the confinement ring 12 is made of metal or fiber reinforced composite material, and the fiber reinforced composite material includes fiber reinforced metal matrix composite material or fiber reinforced polymer.

For the prestressed constraining block of the filling platform 11 made of concrete, the confinement ring 12 can be used as a template for pouring and molding of the filling platform 11. Before the concrete is poured, the inner side of the confinement ring 12 should be painted with isolation oil or arranged isolation Membrane, the bottom of the confinement ring 12 retains the press-in space after the concrete is formed. When the concrete reaches the strength, the bottom of the confinement ring is supported or fixed, and the filling platform 11 is further pressed into the confinement ring 12, so that the filling platform 11 generates a radial pre-tension. stress.

With reference to Figure 4, during the assembly process of the filling table body 11 and the confinement ring 12, the diameter d2 of the small end of the bottom surface of the filling table body 11<the large end opening diameter R1 at the top of the inner ring of the confinement ring 12, so that the table body can be fitted into the confinement ring . The diameter-to-thickness ratio or the diameter-to-height ratio d ₁ /h ₁ of the filling table body 11 is 0.5-40, preferably 3-12. The ring wall of the confinement ring 12 may have a variable thickness or a uniform thickness, that is, the top wall thickness t1 of the confinement ring 12 ≤ the bottom wall thickness t2. The wall thickness and yield strength of the confinement ring 12 are determined according to the prestress that needs to be applied to the filling table body 11. The greater the potential for constrained prestress that can be provided. Affected by the inconsistency of the diameter of the upper and lower cross-sections of the filling platform 11 and the inconsistency of the wall thickness in the height direction of the confinement ring 12, the prestress of the filling platform 11 is uneven in the height direction. The outer wall cone clamp of the filling platform 11 can be adjusted by design. The slight difference between the angle α and the angle β of the conical surface of the inner ring wall of the confinement ring 12 is used to adjust the upper and lower prestress changes. In the process of pressing the filling platform 11 into the confinement ring 12, the prestress of the prestressed constraining block gradually increases from top to bottom, and the angle difference Δα between α and β is appropriately adjusted to reduce the upper and lower prestress of the platform. Difference, the value range of Δα is 0°~0.5°, preferably 0°~0.2°. When α=β, the filling platform 11 is put into the confinement ring 12, and the contact surface of the outer side wall of the filling platform 11 and the inner wall of the constraining block 12 are attached. Put the filling platform 11 into the confinement ring 12. The contact stress between the outer side wall of the filling platform 11 and the inner ring wall of the confinement ring 12 is very small. The difference is h3, and the height difference between the bottom surface of the platform and the bottom surface of the confinement ring is h4.

Specifically, the filling table body 11 in FIG. 1 is a truncated cone body, and the inner wall of the confinement ring 12 is a truncated cone cavity. The material of the filling table body 11 is one of ceramics, concrete or glass, and the material of the confinement ring 12 is steel, aluminum alloy, titanium alloy or fiber reinforced polymer material. The assembly method is: place the confinement ring 12 on the platform, apply epoxy resin, glass glue or vacancies on the inner wall of the confinement ring 12 and the outer side wall of the filling platform 11, and then put the filling platform 11 into the confinement ring 12 In the circle, before the thrust is applied, there is no contact force between the two contact surfaces. A jack or a press is used to apply thrust to the upper surface of the round-table filling platform, and the filling platform 11 is pressed down on the inner ring of the confinement ring 12 to obtain the pre-stressed constraining block 1. Due to the gap between the filling platform 11 and the confinement ring 12, The elastic restoring force of the confinement ring 12 squeezes the pre-tensioned filling platform 11 and applies a pre-compression stress in its radial direction.

Specifically, the filling table body 11 in FIG. 2 is a regular hexagonal pyramid frustum body, and the inner wall of the confinement ring 12 is a regular hexagonal pyramid frustum cavity. The material of the filling table body 11 is one of ceramics, concrete or glass, and the material of the confinement ring 12 is steel, aluminum alloy, titanium alloy or fiber reinforced polymer material. The assembly method is as follows: place the confinement ring 12 on the platform, apply epoxy resin, glass glue or vacancies on the inner wall of the confinement ring 12 and the outer side wall of the filling platform 11, and then put the filling platform 11 into the confinement ring The big end of 12 is open. Before thrust is applied, there is no contact force between the two contact surfaces. A jack or a press is used to apply a vertical downward thrust to the upper surface of the filling platform 11, and the filling platform 11 is pushed down on the inner ring of the confinement ring 12 to obtain the prestressed restraint block 1. Due to the difference between the filling platform 11 and the confinement ring 12, the elastic restoring force of the confinement ring 12 squeezes the pre-tensioning the filling platform 11 and applies a pre-compression stress in its radial direction.

Example two

In this embodiment, at least one of the filling platform 11 and the confinement ring 12 adopts a combined structure. The filling platform 11 can be a combined platform, which is composed of a first reducing ring 14 and a cylinder or prism, and the column is embedded in the first reducing ring 14; the constraining ring 12 can be a combined ring structure, consisting of The second reducing ring 13 is constituted by a cylindrical ring or prismatic ring of equal cross section, and the second reducing ring 13 is embedded and fixed in the cylindrical ring or prismatic ring of equal cross section. The axial cross-sections of the first reducing ring 14 and the second reducing ring 13 are both wedge-shaped cross-sections, and the outer side wall of the first reducing ring 14 and the inner wall of the second reducing ring 13 enclose a conical surface or a pyramid surface.

Referring to Figure 5a, the filling table body 11 in the figure adopts the same truncated cone or pyramid body as in the first embodiment, and the constraining ring 12 adopts a cylindrical ring or prismatic ring in which the second reducing ring 13 is fixed and embedded inside, and the second The inner wall of the reducing ring 13 is the conical surface or the inner wall of the polygonal pyramid surface of the constraining ring 12.

Referring to Figure 5b, the filling platform 11 in the figure adopts a cylindrical or prism body that is externally fixed and fitted with the first reducing ring 14, and the outer side wall of the first reducing ring 14, that is, the filling platform 11 is a conical surface or a polygonal pyramid On the outer side wall, the confinement ring 12 adopts the same integral reducing ring body with a conical surface or a polygonal pyramid surface inner ring wall as in the first embodiment.

Referring to Figure 5c, the filling platform 11 in the figure adopts a cylindrical or prism body that is externally fixed and fitted with the first reducing ring 14, and the outer side wall of the first reducing ring 14, that is, the filling platform 11 is a conical surface or a polygonal pyramid On the outer side wall, the constraining ring 12 adopts a cylindrical ring or a prismatic ring in which the second reducing ring 13 is fixed and embedded inside. The inner wall of the second reducing ring 13 is the conical or polygonal pyramid surface of the constraining ring 12.

In this embodiment, the second reducing ring 13 is used to adjust the inclination angle of the inner wall of the equal cross-section confinement ring 12, and the first reducing ring 14 is used to adjust the inclination angle of the outer side surface of the equal cross-section filling table body 11. The ring turns the equal cross-section confinement ring and the equal cross-section filling block into a combined confinement ring and a combined filling platform respectively, and the dimensions of the formed combined confinement ring and combined filling platform refer to Embodiment 1. The reducing ring is fixed with the table body or the constraining ring by means of nesting, welding or adhesive bonding. The material of the reducing ring can be made of elastic-plastic materials such as metal with better toughness and greater rigidity, or fiber-reinforced polymer, such as aluminum alloy and low-strength steel, which produces an appropriate amount of compression deformation during the extrusion process, so that the filling block and The restraint ring fits better.

Example three

Referring to FIG. 6, on the basis of the first embodiment, in this embodiment, a wrapping layer 17 is wrapped on the outer surface of the filling platform body 11. In the embodiment, before the filling table body 11 is pressed into the confinement ring 12, a thinner layer of metal is wrapped on its outer surface, such as a metal material such as a molten aluminum alloy or iron alloy, or a fiber-reinforced polymer material is pasted and wrapped on its surface. Such as carbon fiber, glass fiber, Kevlar fiber or ultra-high molecular weight polyethylene fiber-reinforced epoxy resin, fiber-reinforced phenolic resin and other polymer materials to form the packing layer 17 that fills the table body 11, and then fill the packing layer 17 with the packing layer 17 The table body 11 is pressed into the inner ring of the confinement ring 12. By wrapping a flexible material on the outside of the filling platform 11 to form the wrapping layer 17, the ability of the filling platform 11 to resist multiple blows can be increased, and the material of the filling platform 11 can be prevented from splashing after being impacted and causing secondary damage.

Embodiment four

As shown in Figures 7a and 7b, the filling platform 11 in this embodiment uses multiple layers of filling materials. The filling platform 11 includes a first filling block 111, an interlayer 113, and a second The filling block 112, the first filling block 111 and the second filling block 112 are made of the same material of the filling platform, and there is an interlayer or gap between the two filling blocks.

When assembling, the method shown in Fig. 7a can be used. The second filler block 112 below is pressed into the inner ring of the confinement ring 12, and then the interlayer 113 is arranged or missing on the surface, and then the first filler block 111 is pressed into it. Obtain the pre-stressed constraining block 1; it is also possible to use the method shown in Figure 7b. First, the first filling block 111, the interlayer 113, and the second filling block 112 are mounted and glued in order to form an integral filling platform body 11, and then the filling platform The body 11 is integrally pressed into the inner ring of the confinement ring 12. The material of the interlayer 113 can be at least one of foamed metal, metal layer, graphite retention layer, rubber, polymer porous material, resin binder, or air layer, and the foamed metal is preferably foamed aluminum.

The filling table body with a multi-layer filling block structure can reduce the impact damage range and damage degree of the filling block. In actual applications, two or more multi-layer filling blocks can be used to fill according to the armor thickness. The material of the filling block can be ceramic or concrete. , At least one of glass and metal materials, and the surface layer on the outside is preferably a ceramic material.

In this embodiment, the surface of the filling platform 11 using multiple layers of filling materials can also be provided with a wrapping layer 17 on the entire surface of the filling platform 11 in the manner of the fourth embodiment.

In addition, when the filling platform body 11 adopts a polygonal pyramid structure, in order to reduce the damage range, the pyramid body can be assembled from a plurality of small prisms in a plane arrangement to form a large pyramid filling platform body, and the combined large prism body The pre-stress is applied by inserting and squeezing into the restraining ring 12. The upper surface or the lower surface of the filling table body 11 may be flat, or may be provided as spherical crown-shaped protrusions, or pyramid-shaped protrusions, or other stacking methods.

Embodiment five

The confinement ring 12 is provided with a bottom plate structure. As shown in Figure 8, the height of the confinement ring 12 in this embodiment is greater than the thickness of the filling platform 11, and the bottom of the confinement ring 12 in the first embodiment or the second A cushion layer 15 is provided at the opening at the small end of the bottom of the reducing ring 13. Before the filling table body 11 is pressed into the inner ring of the constraining ring 12, the energy-absorbing cushion layer 15 is filled at the bottom of the inner ring of the constraining ring 12, and then pressed into the filling table. The body 11 is prestressed. The cushion layer 15 can be made of porous material or foamed metal, such as foamed aluminum, or a polymer material such as rubber as a cushioning material.

Example Six

As shown in Figure 9, the bottom structure of the confinement ring 12 in this embodiment is different from that of the fifth embodiment. The confinement ring 12 in this embodiment is a confinement groove bottom plate 16 integrated with the confinement ring 12, that is, the confinement groove bottom plate 16 and The outer wall of the confinement ring 12 is an integral structure. The bottom small end of the confinement ring 12 is sealed by the confinement groove bottom plate 16 to form a groove-shaped confinement ring. Before the filling table 11 is pressed into the confinement ring 12, the confinement groove bottom plate 16 Fill the upper surface of a thinner foam aluminum cushion layer, and then press into the filling table body 11, the foam aluminum cushion layer makes the bottom surface of the filling table body 11 and the constraining groove bottom plate 16 more closely fit. The constraining groove bottom plate 16 increases the bending rigidity of the prestressed constraining block to a certain extent, and plays the role of an armor back plate to a certain extent.

Example Seven

As shown in Figure 10, the constraining ring 12 in this embodiment is provided with a ring of clamping grooves 18 inside the large end of the inner ring wall, and the filling table 11 is pressed into the inner ring of the constraining ring 12. A snap ring 19 is installed in the groove 18 of the ring 12 to axially limit the filling platform 11. In the axial direction, because the size of the large end of the filling platform 11 is much larger than the opening of the small end of the inner ring of the constraining ring 12, it is tightly wedge The rear filling platform 11 cannot escape from the small end of the confinement ring 12. Assembling a snap ring 19 on the inner wall of the large end of the confinement ring 12 can effectively prevent the filling platform 11 from moving away from the large end of the confinement ring 12 when it is impacted. Slide out.

The snap ring 19 adopts an elastic opening snap ring that is easy to install. When the filling table body 11 is damaged, by taking out the snap ring 19, the damaged filling table body 11 is pushed back from the small end of the inner ring of the restraining ring to the large port, and replaced The new filling platform 11 can quickly repair damaged or destroyed armored structures.

Since the inner wall of the large end of the confinement ring 12 is processed with a groove, after the snap ring 19 is assembled, the surface of the filling table body 11 will be lower than the top surface of the confinement ring 12, and a metal plate, epoxy resin or polyurea can be further used. Material filling and leveling.

This embodiment can be applied to the prestressed constraining blocks in the first to sixth embodiments, and the corresponding circular split snap ring or polygonal bayonet snap ring can be selected according to the transverse cross-sectional shape of the filling platform and the constraining ring.

Example eight

This example discloses a specific implementation of the composite armor structure of the present invention. As shown in FIG. 11a, the composite armor structure includes a layer of armor plate formed by splicing a plurality of prestressed restraining blocks 1. In this example The prestressed constraining block 1 adopts a filling platform 11 and a constraining ring 12 with a regular hexagon in cross section, and spreads and spreads in the transverse direction to form a continuous armor plate. The confinement ring 12 is made of high-strength steel, and the regular hexagonal filling table body 11 is made of any one or more of ceramic, concrete or glass.

Fig. 11b discloses a composite armor structure including two layers of armor plates in Fig. 11a. The prestressed restraint blocks 11 between the armor plates are misaligned. The prestressed constrained blocks 11 separated by dislocation are used to compensate for the prestress of the single-layer composite armored structure. The weakened areas of protection at the joints of the stress-constrained blocks increase the protective effect of the composite armor structure. In practical applications, different layers of armor plates can be stacked according to the protection requirements and the overall thickness of the armor.

In the armor plates in Figure 11a and Figure 11b, the spliced prestressed restraint blocks 1 are all separate restraint rings, that is, all the restraint rings 12 and the filling platform 11 are assembled into a single prestressed restraint block 11. , All the prestressed restraint blocks 11 are spliced and laid. Fig. 11c discloses another way of paving the armor plate, that is, all the confinement rings 12 of the prestressed constraining block 1 adopt an integrated honeycomb structure, and all the confinement rings 12 are connected into an integral conjoined confinement ring 121, which can be welded Fix them together or directly process all the hexagonal inner walls of the confinement ring 12 on a whole plate structure to form a honeycomb plate structure, and then assemble all the filling table bodies 11 into the inner ring of the corresponding confinement ring one by one. The conjoined confinement ring 121 of the structure increases the integrity of the armor plate.

Example 9

This example discloses a further specific implementation of the composite armor structure of the present invention. On the basis of Example 7, this example covers the cover plate 2 and the back plate 3 on both sides of the armor plate, respectively. The cover plate 2 is used for the appearance of the outer side of the armor and improves the protective effect of the armor to a certain extent, and the back plate 3 increases the impact resistance of the inner side of the armor.

The installation method of the cover plate 2 or the back plate 3 can be combined with the pre-stressed restraint block 1 of the armor plate by an adhesive, or the cover plate 2 or the back plate 3 and the armor plate can be anchored by bolts, wherein the bolts can pass through the cover plate. The plate 2 or the reserved hole of the back plate 3 is anchored.

The cover plate 2 is divided into a single-layer, double-layer or multi-layer composite board. Specifically, as shown in Figures 12a, 12b and 12c, the optional cover plate 2 in this embodiment is divided into three forms: a single-layer protective layer, a protective surface layer + a holding layer, and a two-layer protective layer + a holding layer.

The cover plate 2 of the single-layer protective surface layer is shown in FIG. 12a. The first protective surface layer 21 is preferably made of metal materials such as steel plates, aluminum alloys, titanium alloys, or polymer materials or fiber-reinforced polymer materials, such as polyurea. Coating, polycarbonate coating, and the composite armor structure in FIG. 14a and FIG. 14c are all directly attached to the first protective surface layer 21 as the cover plate 2 on the outer surface of the armor plate.

The cover 2 of the double-layer structure of the protective surface layer + the containment layer is shown in FIG. Materials, such as polyurea coating and polycarbonate coating, the retaining layer 22 is made of graphite material, which is attached to the prestressed constraining block. The composite armor structures in Figure 14b, Figure 14d and Figure 14e are all pasted on the outer surface of the armor plate. Combining the cover plate 2 in Fig. 12b, from the distal end to the proximal end of the prestressed restraint block, the cover plate 2 is attached to the outer side of the armor plate in the order of the first protective surface layer of the steel plate + the graphite holding layer.

The three-layer structure cover plate 2 of three forms of two-layer protective layer + storage layer is shown in Figure 12c. The first protective layer 21 is preferably made of metal materials such as steel plate, aluminum alloy, titanium alloy, or polymer material. Or fiber-reinforced polymer materials, such as polyurea coating or polycarbonate coating, the retaining layer 22 is made of graphite material, which is attached to the prestressed constraining block, and the second protective surface layer 23 is made of copper alloy material from the prestressed constraining block. From the distal end to the proximal end, the cover plate 2 of the three-layer structure is attached to the outer side of the armor plate in the order of a steel plate first protective surface layer + a copper plate second protective surface layer + a graphite holding layer.

The backplane 3 is divided into a single-layer, double-layer or multi-layer composite board, including at least one layer of a collision layer 31, an energy absorption layer 32, and a resistance layer 33, as shown in FIGS. 13a, 13b, and 13c. The backplane 3 in Figure 13a has a single-layer resistance layer 33 structure. The resistance layer 33 uses one or more of metal materials such as steel plates, aluminum alloys, and titanium alloys, or uses polymer materials or fiber-reinforced polymer materials. The composite armor structure in 14a and 14b is directly attached to the resistance layer 33 as the back plate 3 on the inner surface of the armor plate.

The backplane 3 in Figure 13b has a double-layer structure of an energy absorbing layer 32 + a resistance layer 33. The resistance layer 33 is made of one or more of metal materials such as steel plates, aluminum alloys, titanium alloys, or polymer materials or fibers. Reinforced polymer material, the energy-absorbing layer 32 is made of one or more of foamed metal and rubber. The composite armor structure in Figure 14c and Figure 14d is attached to the double-layer backplane 3 in Figure 13b on the inner surface of the armor plate. , The energy-absorbing layer 32 is arranged close to the armor plate.

The back plate 3 in Figure 13c is a three-layer structure of collision layer 31 + energy absorption layer 32 + resistance layer 33. The resistance layer 33 is made of one or more of metal materials such as steel plate, aluminum alloy, titanium alloy, or polymer. Material or fiber-reinforced polymer material, the energy absorbing layer 32 is made of one or more of foamed metal and rubber, and the collision layer 31 is made of one or more of metal materials such as steel plate, aluminum alloy, titanium alloy, or Using polymer materials or fiber-reinforced polymer materials, the composite armor structure in FIG. 14e is attached to the three-layer backplane 3 in FIG. 13c on the inner surface of the armor plate, and the collision layer 31 is arranged close to the armor plate.

The armor plate spliced by the prestressed restraint block 1 can be used alone as armor, but in order to obtain a better protective effect, the cover plate 2 and the back plate 3 are installed on its surface, and the cover plate 2 is attached to the two surfaces of the prestressed restraint block It is preferable to install one side close to the large end of the filling platform, and install the back plate 3 on the other side. The cover plate 2 and the back plate 3 and the pre-stressed restraint block can be bonded by a resin adhesive, or anchored by bolts.

The above are only a few specific embodiments of the present invention, but the design concept of the present invention is not limited to this. Any insubstantial modification of the present invention using this concept should be an act that violates the protection scope of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

The following is an experimental verification of the pre-stress application and anti-penetration effect simulation of the pre-stress restraint block in the first embodiment:

(1) Finite element model

A specific size of the filling table body and the confinement ring in the first embodiment is drawn as shown in FIG. The height h1 of the filling platform is 40mm, and the height h2 of the confinement ring 12 is 50mm; the generatrix of the filling platform 11 and the generatrix of the inner wall of the confinement ring 12 are both straight lines, and the angle between the generatrix of the filling platform 11 and the height α=3°, the angle β=3° between the generatrix of the inner wall of the confinement ring 12 and the height. _{The diameter d 1} of the large end of the top surface of the filling platform 11 is 100mm, and the diameter d _{2 of the small end of the bottom surface is 95.8mm; the inner diameter R 1} of the large end of the inner ring wall of the confinement ring 12 is 100mm, and the inner diameter R ₂ of the small end of the bottom surface is 94.8mm ; The difference between the outer diameter of the small end of the bottom surface of the filling platform 11 and the inner diameter of the small end of the bottom surface of the confinement ring 12 is 1mm, because the height of the confinement ring is greater than the height of the filling platform, and the inclination of the inner wall of the confinement ring and the outer side of the filling platform The wall inclination is the same. As the filling platform is pressed down into the confinement ring until the small ends of the two are flush, the outer diameter of the large end of the top surface of the filling platform 11 and the inner wall of the confinement ring 12 will be the same as the small end. The surplus difference; the outer diameter of the confinement ring 12 is 110mm, the top wall thickness of the confinement ring 12 is 5mm, and the bottom wall thickness is 7.6mm. The material of the filling table body 11 is one of ceramics, concrete or glass, and the material of the confinement ring 12 is steel, aluminum alloy, titanium alloy or fiber reinforced polymer material.

The explicit finite element program LS-DYNA is used for the prestressed restraint block to establish a three-dimensional numerical model of the concrete circular table pressing into the steel restraining ring to impose prestress and bullet penetration. The finite element model and mesh division of the prestressed constraining block are established according to the geometric dimensions of the filling platform and the confinement ring. As shown in Figure 16, the model is composed of a circular constraining ring, a round table, a bullet, a backing plate and a thrust block, with 8 knots The point solid hexahedral element (*SECTION_SOLID) is modeled. According to the symmetry condition, only a 1/4 model that is symmetrical along the zy plane and the zx plane is established. The average size of the truncated cone unit and the confinement ring unit is about 1.25mm, the total number of concrete truncated cone units is 49152, and the total number of confinement ring units is 10240. The average grid size of the bullet is 1.25mm and it is divided into 300 units. The boundary condition of the backing plate is fixed, and surface contact (keyword *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE) is adopted between the confinement ring, round table, backing plate, and thrust block. The static friction coefficient between the two is 0.08, and the dynamic friction coefficient is 0.06. The contact between the bullet and the concrete is realized with the keyword *CONTACT_ERODING_SURFACE_TO_SURFACE.

(2) Concrete material model

The concrete material adopts the HJC model, the concrete density is 2400kg/m ³ , the strength is 170MPa, and the specific parameters are shown in Table 1. In order to avoid element distortion, cause hourglass effect, and affect the stability of calculation, the *MAT_ADD_EROSION erosion failure criterion is introduced, and the maximum principal strain is used to control the failure of the element. When the maximum principal strain of an element of the target body exceeds the strain value during the simulation process, the element is considered to be invalid and deleted, and the failure strain is set to 0.1.

To

To

Table 1 Concrete HJC constitutive model parameters

(3) Steel material model

The material of the confinement ring and the flat-headed bullet adopts the *MAT_PLASTIC_KINEMATIC material model. The main parameters of the material model are shown in Table 2.

Table 2 Steel material parameters

(4) Loading system

The loading system and test process are divided into two stages. The first stage pushes down the round table to apply pre-stress simulation test, and then the second stage conducts anti-penetration simulation test. In the first stage, the keyword *BOUNDARY_PRESCRIBED_MOTION_SET is used to give the thrust block displacement to push the concrete circular platform to the specified depth of the steel ring, the loading rate is 200mm/s, the stability is 10ms, and the corresponding restart file is generated. The bullet does not move in the first phase. After the first phase is over, use the full restart function in LS-DYNA to perform the second phase simulation. Use the keyword *CHANGE_VELOCITY_GENERATION to assign the bullet speed, and use the keyword *STRESS_ INITIALIZATION to move the previous The stress state of each component in the process is transferred to the corresponding component in the restart process. The bullet is a flat-headed bullet with a diameter of 7.62mm, a length of 20mm, and an initial velocity of 600m/s.

(4) Prestress simulation results and analysis

After the filled platform of concrete material is pushed down by 10mm, the prestress-depression depth relationship curve of the center element of the filled platform is shown in Figure 17. With the increase of the depression depth, the internal stress of the truncated cone gradually increases, and the downward pressure When the depth is 10 mm, the average radial stress of the truncated cone axis unit reaches 169 MPa. Therefore, it can be proved that the present invention can adjust the prestress by pressing down depth or displacement, and can apply sufficient prestress.

(5) Analysis of penetration simulation results

The pushing depth of the filling table body in the inner ring of the confinement ring is from 0 to 10mm, and the pushing down displacement is divided into 10 levels. With the increase of the depression depth, the radial prestress of the round table gradually increases. Under a positive impact, the damage cloud diagram of the filled platform concrete cylindrome at various levels of depression depth is shown in Figure 18. Combining the relationship curve between the penetration depth of the concrete cylindrome and the prestress shown in Figure 19, it can be seen that with the prestress As the stress increases, the penetration depth gradually decreases. When the depression depth is 7mm, that is, when the prestress applied to the center of the filling platform is 119MPa, the penetration depth of the filling platform decreases by 37.5%, and the anti-penetration performance reaches the best. With the further increase of the prestress, its anti-penetration performance will decrease. Therefore, the use of the prestressed restraint block of the present invention to apply a reasonable prestress value can greatly improve the anti-penetration performance of the composite armor component.

Claims (13)

1. A prestressed constraining block, characterized in that it comprises a filling platform (11) and a confinement ring (12). The filling platform (11) has the same cross-section as the inner ring of the confinement ring (12) and is fixed Embedded in the inner ring of the constraining ring (12), the outer side wall of the filling platform (11) and the inner ring wall of the constraining ring (12) are wedged tightly through taper fit;

   The outer side wall of the filling platform (11) and the inner ring wall of the confinement ring (12) are respectively matched conical surfaces or matched polygonal pyramid surfaces.
2. The prestressed restraint block according to claim 1, wherein the diameters of the large end and the small end of the outer side wall of the filling platform (11) are d ₁ and d ₂ respectively, and the large end of the inner wall of the restraining ring (12) The diameters of and the small end are R ₁ and R _{2 respectively} , satisfying R ₂ ＜d ₂ ＜R ₁ ≤d ₁ , the heights of the filling platform (11) and the confinement ring (12) are h1 and h2, respectively, where h1≤ h2.
3. The prestressed restraint block according to claim 1, wherein the inclination angle α of the cone surface of the outer side wall of the filling platform (11) ranges from 1° to 10°, preferably 3° to 6°, and the confinement ring (12) The tapered surface inclination angle β of the ring wall ranges from 1° to 10°, preferably 3° to 6°. There is an angle difference Δα between the outer side wall of the filling platform (11) and the inner ring wall of the confinement ring (12), Δα=α-β, and the value range of Δα is 0°~0.5°, preferably 0°~0.2°.
4. The prestressed restraint block according to claim 2, wherein the diameter-to-thickness ratio d ₁ /h ₁ of the filling table body (11) is 0.5-40, preferably 3-12.
5. The prestressed constraining block according to claim 1, wherein the filling platform (11) is a frustum with a conical surface or an outer side wall of a polygonal pyramid surface,

   Or, the cylinder or prism of the first reducing ring (14) is externally fixed, and the outer side wall of the first reducing ring (14) is a conical surface or a polygonal pyramid surface.
6. The prestressed restraint block according to claim 5, wherein the restraint ring (12) is a reduced-diameter ring body with an inner ring wall of a conical surface or a polygonal pyramid surface,

   Or a cylindrical ring or a prismatic ring in which the second reducing ring (13) is fixed and embedded inside, and the inner wall of the second reducing ring (13) is a conical surface or a polygonal pyramid surface.
7. The prestressed restraint block according to claim 5, wherein the filling platform body (11) is a layered structure and includes at least two fixed and stacked filling blocks.
8. The prestressed restraint block according to claim 5 or 7, wherein the outer surface of the filling platform (11) is wrapped with a wrapping layer (17).
9. The prestressed restraint block according to claim 6, wherein the small end of the inner ring wall of the restraining ring (12) or the second reducing ring (13) is provided with a bottom plate structure, and the bottom plate structure is connected with the restraining ring (12) The constraining groove bottom plate (16) of an integral structure, or the cushion layer (15) installed on the small end of the filling platform body (11).
10. The pre-stressed restraint block according to any one of claims 5-9, the inner wall of the restraint ring (12) is provided with a clamping groove (18), and the clamping groove (18) is assembled for tightening The filling platform (11) is axially limited by a snap ring (19) in the confinement ring (12).
11. The prestressed restraint block according to claim 1, wherein the filling platform (11) is made of ceramic, concrete or glass material, and the restraining ring (12) is made of metal or fiber-reinforced composite material.
12. The composite armor structure is characterized in that it includes at least one layer of armor plate, the armor plate includes a plurality of prestressed restraint blocks in claims 1-11, and the prestressed restraint blocks are spliced by a plurality of separate restraining rings (12). , Or use a confinement ring (12) with an integrated honeycomb structure.
13. The composite armor structure according to claim 12, further comprising a cover plate (2) and a back plate (3) which are respectively attached to cover both sides of the composite armor.