Flexible explosion-proof protective armor and design method thereof

Abstract

The present invention discloses a flexible explosion-proof armor and a design method thereof. The design method comprises: constructing a simulation model of the flexible explosion-proof armor. The flexible explosion-proof armor comprises the following structure: an armored sandwich layer in contact with the ship's hull, a composite material layer located outside the armored sandwich layer, and a polyurea coating located outside the composite material layer. The armored sandwich layer is composed of several stacked armored units, each of which includes a composite material layer and a foamed aluminum layer. The composite material layer is formed of a carbon fiber-reinforced aluminum alloy composite material. The present invention can design and calculate different dimensional parameters of flexible explosion-proof armor with a sandwich structure, facilitating improvements in the armor's explosion and impact resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of ship explosion-proof and impact-resistant structural design, and in particular to the technical field of flexible explosion-proof armor design. Background Art

[0002] Missiles, bombs, and large warheads can have a significant destructive effect on ship structures. Ship design typically incorporates armor protection in key compartments and areas to enhance their blast and impact resistance. Lightweight, high-energy-absorbing sandwich structures, as a form of protective armor, are widely used in the field of blast and impact resistance for ship structures. This sandwich armor utilizes carbon fiber-reinforced aluminum alloy composites for the upper and lower panels, and aluminum foam as the core material to absorb blast waves and enhance the strength of the sandwich panels. A thick polyurea coating is sprayed onto the surface of the sandwich panels to further enhance their impact resistance.

[0003] When this naval sandwich-structured flexible explosion-proof armor is applied to a naval vessel, its explosion and impact resistance are analyzed and discussed through its energy absorption rate and surface density absorption energy under explosive loads. When a warhead explodes in mid-air, it produces high-temperature, high-pressure gas detonation products, which rapidly diffuse through the air through the sphere and strongly squeeze the surrounding air, generating a shock wave and a large number of high-speed fragments. Under the combined load of airburst shock waves and high-speed fragments, the armor's failure mode is extremely complex, making experimental research extremely difficult, and it is difficult to obtain accurate experimental conclusions and design a protective structure with excellent resistance to combined damage. Summary of the Invention

[0004] The object of the present invention is to provide a design method for flexible explosion-proof protective armor, by which protective armor with excellent resistance to fragment damage can be directly obtained without the need for complex experimental research.

[0005] The technical solutions of the present invention are as follows:

[0006] A design method for flexible explosion-proof protective armor, comprising:

[0007] S1 builds a simulation model of flexible explosion-proof protective armor;

[0008] S2 calculates the optimal thickness of the composite material layer and the foam aluminum layer in the flexible explosion-proof protective armor based on the target energy absorption rate and surface density absorption energy of the expected design of the flexible explosion-proof protective armor;

[0009] S3: simulating the explosion resistance of a simulation model of a flexible explosion-proof protective armor using the optimal thickness values ​​of the composite material layer and the foamed aluminum layer under fragment load impact, comparing the simulated energy absorption rate and surface density absorption energy of the flexible explosion-proof protective armor with the target energy absorption rate and surface density absorption energy of the expected design; if the error between the two is within 10%, it is considered that the optimal thickness values ​​of the composite material layer and the foamed aluminum layer meet the design requirements;

[0010] The flexible explosion-proof armor comprises an armored interlayer in contact with the ship's hull, a composite material layer outside the armored interlayer, and a polyurea coating outside the composite material layer. The armored interlayer is composed of a plurality of stacked armored units, each of which includes a composite material layer and a foam aluminum layer.

[0011] Wherein, the composite material layer is formed by carbon fiber reinforced aluminum alloy composite material.

[0012] According to some preferred embodiments of the present invention, S2 includes:

[0013] S21 obtains the mass and static initial velocity of the fragments produced by the warhead explosion;

[0014] S22 obtains the residual velocity of the fragments after they pass through the flexible explosion-proof armor based on the target energy absorption rate of the flexible explosion-proof armor;

[0015] S23 calculates the surface density based on the number of layers, thickness, and density of different materials, and uses the surface density absorption energy to characterize the energy absorption capacity of the flexible explosion-proof armor;

[0016] S24 obtains the optimal single-layer thickness value of the composite material layer and the foam aluminum layer based on the relationship between the surface density absorption energy and the number and density of different material layers.

[0017] According to some preferred embodiments of the present invention, the S21 includes:

[0018] The mass of the fragments is obtained by the following calculation model:

[0019] m=2μ

[0020]

[0021] Where m represents the average mass of the fragments produced by the warhead destruction, μ is 1 / 2 of the average mass of the fragments, which can characterize the projectile fragmentation characteristics related to the projectile structure, material and explosive properties, A is a constant related to the physical properties of the explosive and projectile metal, which can be obtained by substituting the warhead explosion test results into formula (1), d1 is the average inner diameter of the projectile shell, t0 is the average wall thickness of the projectile shell, W is the explosive charge mass, and M is the shell mass;

[0022] The static initial velocity is obtained by the following calculation model:

[0023]

[0024] Among them, v0 represents the static initial velocity of the fragments produced by the warhead destruction, is the Gurney coefficient, and β is the ammunition explosion load coefficient.

[0025] According to some preferred embodiments of the present invention, the S22 includes:

[0026] The initial kinetic energy of the fragments is obtained through the following calculation model:

[0027]

[0028] The energy absorption rate of the flexible explosion-proof protective armor is obtained by the following calculation model:

[0029]

[0030] The residual velocity of the fragments passing through the flexible explosion-proof protective armor is obtained by the following calculation model:

[0031]

[0032] Among them, E0 is the initial kinetic energy of the fragment, E a is the energy absorbed by the flexible explosion-proof protective armor, η is the target energy absorption rate of the flexible explosion-proof armor, v0 is the static initial velocity, v r is the residual velocity of the fragments, m represents the average mass of the fragments, A is a constant related to the physical properties of the explosive and the projectile metal, d1 is the average inner diameter of the projectile casing, t0 is the average wall thickness of the projectile casing, W is the mass of the explosive charge, and M is the casing mass.

[0033] According to some preferred embodiments of the present invention, S23 includes:

[0034] The surface density is calculated according to the following formula:

[0035]

[0036] Obtain the surface density absorption energy E α The calculation model is as follows:

[0037]

[0038] Where d represents the surface density, h i and ρ i are the thickness and density of the i-th layer material, a is the total number of composite material layers, b is the total number of foam aluminum layers, v0 is the static initial velocity, vr is the residual speed.

[0039] According to some preferred embodiments of the present invention, the surface density absorption energy E α The calculation model is as follows:

[0040] b=a-1(8)

[0041] h b =nh a (9)

[0042] h=h0+ah a +bh b (10)

[0043]

[0044] Wherein, h0 and ρ0 are the thickness and density of the polyurea coating, respectively, and h a and ρ a are the thickness and density of the composite material layer, h b and ρ b are the thickness and density of the foam aluminum layer, h is the total thickness of the flexible explosion-proof armor, and n is the multiple of the foam aluminum layer thickness relative to the composite material layer thickness.

[0045] According to some preferred embodiments of the present invention, the S24 includes:

[0046] The optimal single layer thickness values ​​of the composite material layer and the foam aluminum layer are obtained by the following calculation model:

[0047]

[0048] Where A is a constant related to the physical properties of explosives and projectile metal, d1 is the average inner diameter of the projectile shell, t0 is the average wall thickness of the projectile shell, W is the mass of the explosive charge, and M is the mass of the shell. is the Gurney coefficient, β is the ammunition explosion load coefficient, η is the energy absorption rate of the flexible anti-explosion armor, E α is the surface density absorption energy, h is the total thickness of the flexible explosion-proof armor, a is the total number of layers of the composite material, n is the multiple of the thickness of the foam aluminum layer relative to the thickness of the composite material layer, ρ0, ρ a and ρ b are the densities of polyurea coating, composite material layer and foam aluminum layer, respectively.

[0049] According to the above design method, flexible explosion-proof protective armor can be obtained.

[0050] In the design method provided by the present invention, in the constructed armor structure, the carbon fiber reinforced aluminum alloy composite material has good impact resistance, the foamed aluminum has good buffering and energy absorption effect, and the polyurea coating is an elastomeric coating with strong applicability, impact resistance, and excellent explosion-proof performance. By staggering the carbon fiber reinforced aluminum alloy composite material and the foamed aluminum and coating the upper panel with a layer of polyurea coating, good explosion-proof performance can be obtained; and the optimal single-layer thickness of the carbon fiber reinforced aluminum alloy composite material and the foamed aluminum can be determined based on the target energy absorption rate and surface density absorption energy of the expected design of the flexible explosion-proof protective armor, the total thickness of the flexible explosion-proof protective armor, the number of foamed aluminum layers and composite material layers, the density and thickness multiples thereof, and warhead explosion-related parameters.

[0051] The design method of the present invention can design and calculate the thickness of different single layers of materials of the sandwich structure flexible explosion-proof protective armor based on the target energy absorption rate and surface density absorption energy of the expected design of the flexible explosion-proof protective armor, the total thickness of the flexible explosion-proof protective armor, the number of foam aluminum layers and composite material layers, the density and thickness multiples thereof, and warhead explosion-related parameters, thereby providing convenience for improving the explosion and impact resistance of the armor. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of a specific implementation flow of the design method of the present invention;

[0053] Figure 2 It is a schematic diagram of a specific implementation structure of the flexible explosion-proof protective armor of the present invention. DETAILED DESCRIPTION

[0054] The present invention is described in detail below with reference to the embodiments and accompanying drawings. However, it should be understood that the embodiments and accompanying drawings are merely exemplary descriptions of the present invention and do not constitute any limitation on the scope of protection of the present invention. All reasonable variations and combinations within the scope of the inventive concept of the present invention fall within the scope of protection of the present invention.

[0055] Refer to the attached Figure 1 The design method implementation process shown includes:

[0056] S1 builds a simulation model of flexible explosion-proof protective armor;

[0057] In some embodiments, the flexible explosion-proof protective armor has the following Figure 2 The structure shown has a total thickness of h, a length and a width of P and Q respectively, and includes an armored interlayer in contact with the hull, a composite material layer located outside the armored interlayer, and a polyurea coating 1 with a thickness of h0 located outside the composite material layer. The armored interlayer is composed of several stacked armored units, each of which includes a thickness of h a The composite material layers 2 and 1 have a thickness of h bThe foam aluminum layer 3, wherein the composite material is a carbon fiber reinforced aluminum alloy composite material.

[0058] S2 calculates the optimal single-layer thickness of the carbon fiber aluminum alloy composite material and the foam aluminum layer based on the target energy absorption rate and surface density absorption energy of the expected design of the flexible anti-blast protective armor;

[0059] In some embodiments, the calculating comprises:

[0060] S21 obtains the mass and static initial velocity of the fragments produced by the warhead explosion.

[0061] The fragment mass is obtained through the following calculation model:

[0062] m=2μ

[0063]

[0064] Where m represents the average mass of the fragments produced by the warhead destruction, μ is 1 / 2 of the average mass of the fragments, which can characterize the projectile fragmentation characteristics related to the projectile structure, material and explosive properties, A is a constant related to the physical properties of the explosive and projectile metal, which can be obtained by substituting the warhead explosion test results into formula (1), d1 is the average inner diameter of the projectile shell, t0 is the average wall thickness of the projectile shell, W is the explosive charge mass, and M is the shell mass.

[0065] The static initial velocity is obtained by the following calculation model:

[0066]

[0067]

[0068] Among them, v0 represents the initial velocity of the fragments produced by the warhead destruction, is the Gurney coefficient, and β is the ammunition explosion load coefficient.

[0069] S22 obtains the residual speed of the fragments after passing through the flexible explosion-proof armor based on the target energy absorption rate of the flexible explosion-proof armor.

[0070] Furthermore, the remaining speed is obtained by the following calculation model:

[0071] Initial kinetic energy of fragments:

[0072]

[0073] Energy absorption rate of flexible explosion-proof armor:

[0074]

[0075] The residual speed of fragments passing through flexible explosion-proof armor:

[0076]

[0077] Among them, E0 is the initial kinetic energy of the fragment, E a is the energy absorbed by the flexible explosion-proof armor, v r is the residual velocity of the fragment.

[0078] S23 calculates the surface density based on the number of layers, thickness, and density of different materials, and uses the surface density absorption energy to characterize the energy absorption capacity of the flexible explosion-proof armor.

[0079] Furthermore, the surface density calculation formula is as follows:

[0080]

[0081] Where d is the surface density, h is i and ρ i are the thickness and density of the i-th layer material, a is the total number of carbon fiber aluminum alloy composite layers, and b is the total number of foam aluminum layers.

[0082] Surface density absorption energy E α The calculation model is as follows:

[0083]

[0084] In some specific embodiments, the number of aluminum foam layers is set to be one layer less than the number of carbon fiber aluminum alloy composite layers, and the thickness of the aluminum foam layer is set to n times the thickness of the carbon fiber aluminum alloy composite layer, then the surface density absorption energy E α The calculation model is simplified as follows:

[0085] b=a-1(8)

[0086] h b =nh a (9)

[0087] h=h0+ah a +bh b (10)

[0088]

[0089] Where h0 and ρ0 are the thickness and density of the polyurea coating, respectively, and h a and ρ a are the thickness and density of the carbon fiber aluminum alloy composite material layer, h b and ρ b are the thickness and density of the foam aluminum layer, h is the total thickness of the flexible explosion-proof armor, and n is the multiple of the foam aluminum layer thickness relative to the composite material layer thickness.

[0090] S24 obtains the optimal single-layer thickness value of the carbon fiber aluminum alloy composite material and the foam aluminum layer, that is, the optimal design parameters, based on the relationship between the surface density absorption energy and the number of layers and densities of different materials.

[0091] Furthermore, the optimal single-layer thickness of the carbon fiber aluminum alloy composite material and the foam aluminum layer is obtained through the following calculation model:

[0092]

[0093] S3 simulates the explosion resistance performance of the simulation model of the flexible explosion-resistant protective armor under the impact of fragment load, and compares it with the expected design target;

[0094] In some embodiments, the simulation comprises:

[0095] S31 obtains the energy absorption rate and surface density absorption energy of the flexible explosion-proof armor simulation model.

[0096] Among them, the energy absorption rate η′ is obtained by the following calculation model:

[0097]

[0098] Among them, v0′ is the initial velocity of the fragments set by the simulation, which is equal to v0, and v r ′ is the residual velocity of the fragments obtained by simulation.

[0099] Surface density absorption energy E α The calculation model is as follows:

[0100]

[0101] Wherein, m is the average mass of the fragments described in S21, and d is the surface density of the flexible explosion-proof armor described in S23.

[0102] S32 simulates the energy absorption rate η′ and surface density absorption energy E of the flexible explosion-proof armor α ′ and the target energy absorption rate η and surface density absorption energy E of the expected design α Comparison is performed. If the error between the two is within 10%, the flexible explosion-proof protective armor prepared using the optimal design parameters is considered to meet the design requirements. Otherwise, the flexible explosion-proof protective armor is redesigned by changing the total thickness h of the flexible explosion-proof protective armor, the total number a of carbon fiber aluminum alloy composite material layers, and the multiple n of the foam aluminum layer thickness relative to the composite material layer thickness. The steps S23, S24, S31, and S32 are repeated until the error between the simulated and expected flexible explosion-proof protective armor energy absorption rate and areal density absorption energy meets the requirements.

[0103] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A design method for flexible explosion-proof protective armor, characterized in that: It includes: S1 builds a simulation model of flexible explosion-proof protective armor; S2 calculates the optimal thickness of the composite material layer and the foam aluminum layer in the flexible explosion-proof protective armor based on the target energy absorption rate and surface density absorption energy of the expected design of the flexible explosion-proof protective armor; S3: simulating the explosion resistance of a simulation model of a flexible explosion-proof protective armor using the optimal thickness values ​​of the composite material layer and the foamed aluminum layer under fragment load impact, comparing the simulated energy absorption rate and surface density absorption energy of the flexible explosion-proof protective armor with the target energy absorption rate and surface density absorption energy of the expected design; if the error between the two is within 10%, it is considered that the optimal thickness values ​​of the composite material layer and the foamed aluminum layer meet the design requirements; The flexible explosion-proof armor comprises an armored interlayer in contact with the ship's hull, a composite material layer outside the armored interlayer, and a polyurea coating outside the composite material layer. The armored interlayer is composed of a plurality of stacked armored units, each of which includes a composite material layer and a foam aluminum layer. Wherein, the composite material layer is formed by carbon fiber reinforced aluminum alloy composite material; the surface density absorption energy E α The calculation model is as follows: b=a-1(8) h b =nh a (9) h=h0+ah a +b b (10) Where h0 and ρ0 are the thickness and density of the polyurea coating, respectively, and h a and ρ a are the thickness and density of the carbon fiber aluminum alloy composite material layer, h b and ρ b are the thickness and density of the foam aluminum layer, h is the total thickness of the flexible explosion-proof armor, and n is the multiple of the foam aluminum layer thickness relative to the composite material layer thickness; The S2 includes: S21 obtains the mass and static initial velocity of the fragments produced by the warhead explosion; S22 obtains the residual velocity of the fragments after they pass through the flexible explosion-proof armor based on the target energy absorption rate of the flexible explosion-proof armor; S23 calculates the surface density based on the number of layers, thickness, and density of different materials, and uses the surface density absorption energy to characterize the energy absorption capacity of the flexible explosion-proof armor; S24 obtains the optimal single layer thickness of the composite material layer and the foam aluminum layer based on the relationship between the surface density absorption energy and the number of layers and density of different materials; The optimal single layer thickness of the composite material layer and the foam aluminum layer is obtained by the following calculation model: Where A is a constant related to the physical properties of explosives and projectile metal, d1 is the average inner diameter of the projectile shell, t0 is the average wall thickness of the projectile shell, W is the mass of the explosive charge, and M is the mass of the shell. is the Gurney coefficient, β is the ammunition explosion load coefficient, η is the energy absorption rate of the flexible anti-explosion armor, E α is the surface density absorption energy, h is the total thickness of the flexible explosion-proof armor, a is the total number of layers of the composite material, n is the multiple of the thickness of the foam aluminum layer relative to the thickness of the composite material layer, ρ0, ρ a and ρ b are the densities of polyurea coating, composite material layer and foam aluminum layer, respectively.

2. The design method according to claim 1, characterized in that: The S21 includes: The mass of the fragments is obtained by the following calculation model: m=2μ Where m represents the average mass of fragments produced by warhead destruction, μ is 1 / 2 of the average mass of fragments, A is a constant related to the physical properties of explosives and projectile metal, which can be obtained by substituting the warhead explosion test results into formula (1), d1 is the average inner diameter of the projectile shell, t0 is the average wall thickness of the projectile shell, W is the explosive charge mass, and M is the shell mass; The static initial velocity is obtained by the following calculation model: Among them, v0 represents the static initial velocity of the fragments produced by the warhead destruction, is the Gurney coefficient, and β is the ammunition explosion load coefficient.

3. The design method according to claim 1, characterized in that: The S22 includes: The initial kinetic energy of the fragments is obtained through the following calculation model: The energy absorption rate of the flexible explosion-proof protective armor is obtained by the following calculation model: The residual velocity of the fragments passing through the flexible explosion-proof protective armor is obtained by the following calculation model: Among them, E0 is the initial kinetic energy of the fragment, E a is the energy absorbed by the flexible explosion-proof protective armor, η is the target energy absorption rate of the flexible explosion-proof armor, v0 is the static initial velocity, v r is the residual velocity of the fragments, m represents the average mass of the fragments, A is a constant related to the physical properties of the explosive and the projectile metal, d1 is the average inner diameter of the projectile casing, t0 is the average wall thickness of the projectile casing, W is the mass of the explosive charge, and M is the casing mass.

4. The design method according to claim 1, characterized in that: The S23 includes: The surface density is calculated according to the following formula: Obtain the surface density absorption energy E α The calculation model is as follows: Where d represents the surface density, h i and ρ i are the thickness and density of the i-th layer material, a is the total number of composite material layers, b is the total number of foam aluminum layers, v0 is the static initial velocity, v r is the residual speed.

5. The flexible explosion-proof protective armor prepared according to the design method according to any one of claims 1 to 4.

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