Method and device for determining speed of projectile body penetrating multi-layer composite armor structure

Abstract

The invention relates to a method and device for determining the speed of a projectile body penetrating through a multi-layer composite armor structure, and belongs to the technical field of aggressive mechanics. The method for determining the speed of the projectile body penetrating through the multi-layer composite armor structure comprises the steps that the multi-layer composite armor structure is determined on the basis of the sequence that the projectile body penetrates through a multi-layer anti-projectile structure; calculating the residual speed of the projectile body after penetrating through the single-layer anti-missile structure according to the initial speed of the projectile body impacting the single-layer anti-missile structure and the penetration influence factors of the single-layer anti-missile structure in sequence; and according to each initial speed and each residual speed, constructing a ballistic velocity model of each layer of anti-missile structure, and based on the ballistic velocity model of each layer of anti-missile structure, constructing an overall ballistic velocity model of the multi-layer anti-missile structure, and based on the overall ballistic velocity model and the initial velocity of the multi-layer anti-missile structure impacted by the projectile body, calculating the projectile body velocity in the process of penetrating the multi-layer anti-missile structure by the projectile body. According to the invention, the residual velocity of the projectile body after penetrating through each layer of the multi-layer anti-missile structure can be accurately simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of penetration mechanics, and in particular, to a method and device for determining the velocity of a projectile penetrating a multi-layer composite armor structure. Background Art

[0002] For the performance evaluation of multi-layer anti-ballistic structures, experiments are generally used for testing. However, the experiments for testing the performance of multi-layer anti-ballistic structures are usually expensive and time-consuming; the performance of multi-layer anti-ballistic structures is mainly reflected in the velocity of the projectile after penetrating the multi-layer anti-ballistic structure and the effect of each anti-ballistic layer on reducing the velocity of the projectile. In high-speed penetration, the response time is short and the load amplitude is high, which is likely to cause serious damage to the testing equipment. Therefore, it is difficult to obtain a large amount of data during the experiment.

[0003] In the prior art, there has emerged a method of simulating and testing the performance of multi-layer anti-ballistic structures through numerical simulation technology. However, due to the complexity of the process of a projectile penetrating a multi-layer anti-ballistic structure and the complex correlation between each anti-ballistic layer, the simulation test requires high computing power and resources, and the multi-layer anti-ballistic structures will affect each other, resulting in inaccurate overall performance testing of the multi-layer anti-ballistic structure and being unable to accurately simulate the remaining velocity of the projectile after penetrating the multi-layer anti-ballistic structure.

[0004] It can be seen that the prior art has inaccurate overall performance testing of multi-layer anti-ballistic structures and is unable to accurately simulate the remaining velocity of the projectile after penetrating the multi-layer anti-ballistic structure. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and device for determining the velocity of a projectile penetrating a multi-layer composite armor structure to solve the problems that the prior art has inaccurate overall performance testing of multi-layer anti-ballistic structures and is unable to accurately simulate the remaining velocity of the projectile after penetrating the multi-layer anti-ballistic structure.

[0006] To solve the above problems, in a first aspect, the present invention provides a method for determining the velocity of a projectile penetrating a multi-layer composite armor structure, including: Based on the order of the projectile penetrating the multi-layer anti-ballistic structure, successively calculate the remaining velocity of the projectile after penetrating a single anti-ballistic layer according to the initial velocity of the projectile impacting the single anti-ballistic layer and the penetration influencing factors of the single anti-ballistic layer; Construct a ballistic velocity model for each anti-ballistic layer according to each initial velocity and each remaining velocity, and determine an overall ballistic velocity model for the multi-layer anti-ballistic structure based on the projectile velocities of each anti-ballistic layer.

[0007] In some possible implementation manners, when the single anti-ballistic layer is not the first anti-ballistic layer of the multi-layer anti-ballistic structure, the process of determining the initial velocity of the projectile impacting the single anti-ballistic layer includes: Calculate the first residual velocity of the projectile after penetrating the front anti - ballistic structure based on the first initial velocity of the projectile in the front anti - ballistic structure of the multi - layer anti - ballistic structure and the first penetration influencing factors of the front anti - ballistic structure; Take the first residual velocity as the second initial velocity of the projectile penetrating the rear anti - ballistic structure in the multi - layer anti - ballistic structure, and calculate the second residual velocity of the projectile after penetrating the rear anti - ballistic structure based on the second initial velocity and the second penetration influencing factors of the rear anti - ballistic structure, where the rear anti - ballistic structure is the layer of anti - ballistic structure behind the front anti - ballistic structure.

[0008] In some possible implementation manners, when the single - layer anti - ballistic structure is the first - layer anti - ballistic structure of the multi - layer anti - ballistic structure and the first - layer anti - ballistic structure is the front panel, calculating the residual velocity of the projectile after penetrating the single - layer anti - ballistic structure according to the initial velocity of the projectile impacting the single - layer anti - ballistic structure and the penetration influencing factors of the single - layer anti - ballistic structure includes: Obtain the initial velocity and initial length of the projectile, and determine the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel in combination with the penetration influencing factors of the front panel; Differentiate the momentum of the projectile and the front panel based on the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel to obtain the relationship between the residual velocity influencing factor and time; where the residual velocity influencing factor includes the remaining length of the projectile, the first penetration remaining mass of the projectile, the velocity of the projectile, and the thickness of the plugging block; Based on the relationship between the residual velocity influencing factor and time, and in combination with the energy loss formula and the law of conservation of momentum, determine the common residual velocity of the projectile and the plugging block after the projectile penetrates the front panel.

[0009] In some possible implementation manners, when the single - layer anti - ballistic structure is the rear anti - ballistic structure of the front panel and the single - layer anti - ballistic structure is the ceramic layer, calculating the residual velocity of the projectile after penetrating the single - layer anti - ballistic structure according to the initial velocity of the projectile impacting the single - layer anti - ballistic structure and the penetration influencing factors of the single - layer anti - ballistic structure includes: According to the common residual velocity of the projectile and the plugging block after the projectile penetrates the front panel, determine the diameter and semi - cone angle of the ceramic cone formed by the ceramic layer after the projectile is upset in combination with the elastic characteristics of the ceramic layer; Based on the diameter and semi - cone angle of the ceramic cone, calculate the common residual velocity of the projectile and the ceramic cone, the second penetration remaining mass of the projectile, and the mass of the ceramic cone in combination with the energy formula of the ceramic cone.

[0010] In some possible implementation manners, the calculating the common residual velocity of the projectile and the ceramic cone, the second penetration remaining mass of the projectile, and the mass of the ceramic cone based on the diameter and semi - cone angle of the ceramic cone and in combination with the energy formula of the ceramic cone includes: Determine that the energy dissipated by the erosion of the projectile penetrating the ceramic layer to form a ceramic cone is:

[0011] Among them, represents the dynamic yield strength of the projectile, is the erosion length of the projectile; Determine that the energy consumed by the upsetting deformation of the projectile is:

[0012] Among them, is the thickness of the petal body, and the value is about 0.1 - 0.25 , is the bending rotation angle of the petal body; Determine that the half - cone angle of the ceramic cone is

[0013] Among them, is the half - cone angle of the ceramic cone, is the common residual velocity of the projectile and the punching plug; Determine that the energy dissipated during the forming of the ceramic cone is:

[0014] Among them, is the shear strength of the ceramic, is the diameter of the ceramic cone; Based on the energy dissipated by the erosion of the projectile, the energy consumed by the upsetting deformation of the projectile, and the energy dissipated during the forming of the ceramic cone, combined with the energy conservation formula, determine the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone as:

[0015]

[0016]

[0017] Among them, is the common residual velocity of the projectile and the ceramic cone, is the second penetration residual mass of the projectile, is the mass of the ceramic cone.

[0018] In some possible implementation manners, when the single - layer anti - ballistic structure is the rear - layer anti - ballistic structure of the ceramic layer and the single - layer anti - ballistic structure is a polyethylene fiber composite layer, calculate the residual velocity of the projectile after penetrating the single - layer anti - ballistic structure according to the initial velocity of the projectile impacting the single - layer anti - ballistic structure and the penetration influencing factors of the single - layer anti - ballistic structure, including: Determine the dynamic compression force formula of the ceramic cone according to the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone; Integrate the dynamic compression force formula of the ceramic cone to obtain the shear force formula of the ceramic cone. Combine the dynamic compression force formula and the shear force formula of the ceramic cone, and determine the motion equations of the projectile and the ceramic cone according to the law of conservation of momentum; Based on the motion equations and combined with the thin film strain distribution theory, determine the thin film sub-layer model. Based on the thin film sub-layer model, determine the residual velocity of the projectile after penetrating the polyethylene fiber composite layer.

[0019] In some possible implementation manners, when the single-layer anti-ballistic structure is the rear anti-ballistic structure of the polyethylene fiber composite layer and the single-layer anti-ballistic structure is the rear panel layer, calculate the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure, including: According to the residual velocity of the projectile after penetrating the polyethylene fiber composite layer, combine the energy loss formula and the law of conservation of momentum to calculate the final residual velocity of the projectile after penetrating the rear panel.

[0020] In some possible implementation manners, the determining the residual velocity of the projectile after penetrating the polyethylene fiber composite layer based on the thin film sub-layer model includes: Based on the thin film sub-layer model, determine that the motion equation of the projectile is:

[0021]

[0022] Wherein, is the shear force for the projectile to penetrate the polyethylene fiber composite layer, is the inertial force for the projectile to penetrate the polyethylene fiber composite layer, is the projectile velocity.

[0023] In some possible implementation manners, construct the ballistic velocity model of each layer of anti-ballistic structure according to each initial velocity and each residual velocity, and determine the overall ballistic velocity model of the multi-layer anti-ballistic structure based on the projectile velocity of each layer of anti-ballistic structure, including: Determine the ballistic velocity model of the front panel according to the initial velocity of the projectile impacting the front panel and the residual velocity of the projectile after penetrating the front panel; Determine the ballistic velocity model of the ceramic layer according to the residual velocity of the projectile after penetrating the front panel and the residual velocity of the projectile after penetrating the ceramic layer; Determine the ballistic velocity model of the polyethylene fiber composite layer according to the residual velocity of the projectile after penetrating the ceramic layer and the residual velocity of the projectile after penetrating the polyethylene fiber composite layer; Determine the ballistic velocity model of the rear panel according to the residual velocity of the projectile after penetrating the polyethylene fiber composite layer and the residual velocity of the projectile after penetrating the rear panel; Determine the overall ballistic velocity model of the multi-layer anti-ballistic structure according to the ballistic velocity model of the front panel, the ballistic velocity model of the ceramic layer, the ballistic velocity model of the polyethylene fiber composite layer, and the projectile velocity of the rear panel.

[0024] In a second aspect, the present invention also provides a device for determining the velocity of a projectile penetrating a multi-layer composite armor structure, including: A projectile velocity calculation module, configured to sequentially calculate the remaining velocity of the projectile after penetrating a single-layer anti-ballistic structure based on the order of the projectile penetrating the multi-layer anti-ballistic structure, according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure; A model construction module, configured to construct the ballistic velocity model of each layer of the anti-ballistic structure according to each initial velocity and each remaining velocity, and determine the overall ballistic velocity model of the multi-layer anti-ballistic structure based on the projectile velocity of each layer of the anti-ballistic structure; A projectile velocity determination module, configured to calculate the projectile velocity during the process of the projectile penetrating the multi-layer anti-ballistic structure based on the overall ballistic velocity model and the initial velocity of the projectile impacting the multi-layer anti-ballistic structure.

[0025] The beneficial effects of the present invention are as follows: The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure provided by the present invention calculates the remaining velocity of the projectile after penetrating each layer of the anti-ballistic structure by sequentially calculating the initial velocity of the projectile impacting each layer of the anti-ballistic structure and the penetration influencing factors of this layer of the anti-ballistic structure according to the order of the projectile penetrating the multi-layer anti-ballistic structure. By combining this initial velocity and the remaining velocity, it is possible to construct the ballistic velocity model of a single-layer anti-ballistic structure according to the characteristics of each layer of the anti-ballistic structure. Moreover, since the ballistic velocity model of each layer of the anti-ballistic structure is calculated based on the initial velocity of the projectile impacting this layer of the anti-ballistic structure, the influence of the projectile penetrating the previous layer of the anti-ballistic structure on the initial velocity of the projectile penetrating the subsequent layer of the anti-ballistic structure is considered, that is, the mutual influence between multiple layers of the anti-ballistic structure is considered, which can ensure the accuracy of the ballistic velocity model. At the same time, according to the ballistic velocity models of each single-layer anti-ballistic structure, the overall ballistic velocity model of the multi-layer anti-ballistic structure can be constructed. Decomposing the overall ballistic model of the complex multi-layer anti-ballistic structure into the ballistic velocity models of multiple single-layer anti-ballistic structures reduces the difficulty of constructing the overall ballistic velocity model and ensures the accuracy at the same time, and can accurately simulate the remaining velocity of the projectile after penetrating each layer of the multi-layer anti-ballistic structure. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1Schematic flow chart of a method for determining the velocity of a projectile penetrating a multi-layer composite armor structure provided by an embodiment of the present invention; Figure 2 Schematic flow chart of an initial velocity determination method provided by an embodiment of the present invention; Figure 3 Schematic flow chart of a front panel penetration analysis method provided by an embodiment of the present invention; Figure 4 Schematic diagram of a projectile penetrating a metal front panel provided by an embodiment of the present invention; Figure 5 Schematic flow chart of a ceramic layer penetration analysis method provided by an embodiment of the present invention; Figure 6 Schematic diagram of a projectile penetrating a ceramic layer provided by an embodiment of the present invention; Figure 7 Schematic flow chart of a polyethylene fiber composite layer penetration analysis method provided by an embodiment of the present invention; Figure 8 Schematic diagram of the shear compression stage of a high-strength polyethylene laminate provided by an embodiment of the present invention; Figure 9 Schematic diagram of out-of-plane impact on a single-layer thin film sub-layer provided by an embodiment of the present invention; Figure 10 Schematic diagram of the bulging deformation of a high-strength polyethylene laminate provided by an embodiment of the present invention; Figure 11 Schematic diagram of a metal rear panel resisting penetration provided by an embodiment of the present invention; Figure 12 Schematic flow chart of an implementation method of S102 provided by an embodiment of the present invention; Figure 13 Schematic structural diagram of a device for determining the velocity of a projectile penetrating a multi-layer composite armor structure provided by an embodiment of the present invention. Detailed implementation manners

[0028] The following specifically describes the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0029] In the embodiments of the present invention, the descriptions such as "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Therefore, the technical features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0030] References to "embodiments" in this specification mean that the particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0031] A specific embodiment of the present invention, as Figure 1 shown, discloses a method for determining the velocity of a projectile penetrating a multi-layer composite armor structure, including: S101, based on the order in which the projectile penetrates the multi-layer anti-projectile structure, successively calculate the remaining velocity of the projectile after penetrating the single-layer anti-projectile structure according to the initial velocity of the projectile impacting the single-layer anti-projectile structure and the penetration influencing factors of the single-layer anti-projectile structure.

[0032] In the embodiments of the present invention, the multi-layer anti-projectile structure can be a bionic anti-projectile core layer composite armor structure, and the penetration of the projectile can be blocked by multiple materials that have a blocking effect on the projectile, such as bulletproof vests, bulletproof armors, bulletproof doors, etc. The overall ballistic velocity model of the multi-layer anti-projectile structure can accurately simulate the initial velocity and remaining velocity of the projectile penetrating each layer of the anti-projectile structure in the multi-layer anti-projectile structure, and can accurately ensure the accuracy of the performance test of the multi-layer anti-projectile structure.

[0033] Specifically, the initial velocity of the projectile impacting the single-layer anti-projectile structure refers to the velocity of the projectile when it contacts a certain layer of the anti-projectile structure in the multi-layer anti-projectile structure. Among them, this certain layer of the anti-projectile structure can be the first layer of the multi-layer anti-projectile structure or a non-first layer. When this certain layer of the anti-projectile structure is a non-first layer, the initial velocity of the projectile contacting this layer of the anti-projectile structure needs to be calculated in combination with the remaining velocity of the projectile after penetrating the previous layer of the anti-projectile structure, which will be described in detail later in the present invention.

[0034] It should be noted that the penetration influencing factors of the single-layer anti-projectile structure are related to the material properties of the single-layer anti-projectile structure. These penetration influencing factors will affect the shape, velocity, weight, etc. of the projectile when penetrating the single-layer anti-projectile structure. It is a complex process and needs to be calculated in combination with the specific materials of the single-layer anti-projectile structure. The anti-projectile structures of several materials will be described in detail in the subsequent embodiments of the present invention.

[0035] Specifically, calculating the remaining velocity of the projectile after penetrating the single-layer anti-projectile structure according to the initial velocity of the projectile impacting the single-layer anti-projectile structure and the penetration influencing factors of the single-layer anti-projectile structure can be calculated in combination with the mechanical formulas, energy formulas, etc. corresponding to each material, and finally determine the remaining velocity of the projectile after penetrating the single-layer anti-projectile structure, which will be described in detail in the subsequent embodiments of the present invention.

[0036] S102. Construct the ballistic velocity model of each layer of anti - ballistic structure according to each initial velocity and each remaining velocity, and determine the overall ballistic velocity model of the multi - layer anti - ballistic structure based on the projectile velocity of each layer of anti - ballistic structure.

[0037] In the embodiments of the present invention, the ballistic velocity model of each layer of anti - ballistic structure can calculate the remaining velocity of the projectile after penetrating this layer of anti - ballistic structure according to the initial velocity when the projectile impacts this layer of anti - ballistic structure. Based on this, the ballistic velocity model of each layer of anti - ballistic structure can be constructed according to each initial velocity and each remaining velocity in the foregoing embodiments, and then the overall ballistic velocity model of the multi - layer anti - ballistic structure can be determined based on the projectile velocity of each layer of anti - ballistic structure. The specific model construction method will be described in detail later in the present invention.

[0038] S103. Calculate the projectile velocity during the process of the projectile penetrating the multi - layer anti - ballistic structure based on the overall ballistic velocity model and the initial velocity of the projectile impacting the multi - layer anti - ballistic structure.

[0039] In the embodiments of the present invention, after determining the overall ballistic velocity model of the multi - layer anti - ballistic structure, when it is necessary to determine the projectile velocity during the process of the projectile penetrating the multi - layer ballistic structure subsequently, the initial velocity of the projectile impacting the first - layer anti - ballistic structure of the multi - layer anti - ballistic structure and the penetration influencing factors of each layer of anti - ballistic structure can be directly input into the overall ballistic velocity model of the multi - layer anti - ballistic structure, and the velocity response during the process of the projectile penetrating the entire multi - layer anti - ballistic structure can be obtained, and the initial velocity and remaining velocity of the projectile in each layer of anti - ballistic structure can be determined.

[0040] The method for determining the velocity of a projectile penetrating a multi - layer composite armor structure provided by the present invention calculates the remaining velocity of the projectile after penetrating each layer of anti - ballistic structure according to the order of the projectile penetrating the multi - layer anti - ballistic structure, based on the initial velocity of the projectile impacting each layer of anti - ballistic structure and the penetration influencing factors of this layer of anti - ballistic structure. By combining this initial velocity and the remaining velocity, the ballistic velocity model of a single - layer anti - ballistic structure can be constructed according to the characteristics of each layer of anti - ballistic structure. And because the ballistic velocity model of each layer of anti - ballistic structure is calculated according to the initial velocity when the projectile impacts this layer of anti - ballistic structure, the influence of the projectile after penetrating the previous layer of anti - ballistic structure on the initial velocity of the projectile penetrating the subsequent layer of anti - ballistic structure is considered, that is, the mutual influence between multi - layer anti - ballistic structures is considered, which can ensure the accuracy of the ballistic velocity model. At the same time, according to the ballistic velocity models of each single - layer anti - ballistic structure, the overall ballistic velocity model of the multi - layer anti - ballistic structure can be constructed, decomposing the overall ballistic model of the complex multi - layer anti - ballistic structure into the ballistic velocity models of multiple single - layer anti - ballistic structures, reducing the difficulty of constructing the overall ballistic velocity model, while ensuring the accuracy, and being able to accurately simulate the remaining velocity of the projectile after penetrating each layer of the multi - layer anti - ballistic structure.

[0041] In some embodiments of the present invention, such as Figure 2As shown, when the single-layer bulletproof structure is not the first-layer bulletproof structure of the multi-layer bulletproof structure, the process of determining the initial velocity of the bullet impacting the single-layer bulletproof structure includes: S201, calculating the first remaining velocity of the bullet after penetrating the front-layer bulletproof structure of the multi-layer bulletproof structure based on the first initial velocity of the bullet penetrating the front-layer bulletproof structure of the multi-layer bulletproof structure and the first penetration influencing factor of the front-layer bulletproof structure.

[0042] In the embodiments of the present invention, when the bullet impacts the first-layer bulletproof structure of the multi-layer bulletproof structure, its initial velocity can be directly calculated according to the measured value or calculated based on aerodynamics combined with the muzzle velocity of the bullet. When the bullet impacts the non-first-layer bulletproof structure of the multi-layer bulletproof structure, its initial velocity needs to be determined according to the first remaining velocity of the bullet after penetrating the front-layer bulletproof structure. Specifically, the first remaining velocity of the bullet after penetrating the front-layer bulletproof structure can be calculated based on the first initial velocity of the bullet penetrating the front-layer bulletproof structure of the multi-layer bulletproof structure and the first penetration influencing factor of the front-layer bulletproof structure. Since the material properties of each layer of the bulletproof structure may be different, the remaining velocity of the bullet after penetrating each layer of the bulletproof structure needs to be calculated in combination with the penetration influencing factor of that layer of the bulletproof structure. The specific calculation method will be described in detail later in the present invention.

[0043] S202, taking the first remaining velocity as the second initial velocity of the bullet penetrating the rear-layer bulletproof structure of the multi-layer bulletproof structure, and calculating the second remaining velocity of the bullet after penetrating the rear-layer bulletproof structure based on the second initial velocity and the second penetration influencing factor of the rear-layer bulletproof structure, where the rear-layer bulletproof structure is the layer of bulletproof structure behind the front-layer bulletproof structure.

[0044] In the embodiments of the present invention, for the rear-layer bulletproof structure that is the layer behind the front-layer bulletproof structure in the multi-layer bulletproof structure, the remaining velocity of the bullet after penetrating the front-layer bulletproof structure is taken as the initial velocity of the bullet impacting the rear-layer bulletproof structure, and the second remaining velocity of the bullet after penetrating the rear-layer bulletproof structure is calculated in combination with the second penetration influencing factor of the rear-layer bulletproof structure. Repeat this process until the calculation of all bulletproof structures is completed.

[0045] The embodiments of the present invention ensure the accuracy of the calculation of the remaining velocity of the bullet by taking the remaining velocity of the bullet after penetrating the front-layer bulletproof structure as the initial velocity of the bullet impacting the rear-layer bulletproof structure, fully considering the influence between each layer of the bulletproof structure.

[0046] In some embodiments of the present invention, as Figure 3 shown, when the single-layer bulletproof structure is the first-layer bulletproof structure of the multi-layer bulletproof structure and the first-layer bulletproof structure is the front panel, calculating the remaining velocity of the bullet after penetrating the single-layer bulletproof structure according to the initial velocity of the bullet impacting the single-layer bulletproof structure and the penetration influencing factor of the single-layer bulletproof structure includes: S301. Obtain the initial velocity and initial length of the projectile, and determine the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel in combination with the penetration influencing factors on the front panel.

[0047] In the embodiment of the present invention, the first anti - ballistic structure of the multi - layer anti - ballistic structure is generally the front panel, and its material is a metal material. When the projectile penetrates the metal front panel, large stresses are generated on the contact surface between the projectile and the target, causing erosion of both the projectile and the panel. At this time, the velocity of the projectile's tail is , and the interface velocity between the head of the projectile and the panel is . The back surface of the target plate also accelerates from rest to the velocity w, as shown in Figure 4 (a). Due to the velocity difference between the head and the tail, the reduction rate of the projectile length is , and the thickness reduction rate of the panel is . Assume that after the interface velocity between the projectile and the panel reaches an initial value, it remains constant throughout the penetration process. According to the theory, the magnitude of the interface velocity depends on the initial incident velocity of the projectile and the material properties of the projectile and the panel, as shown in formulas (1.1) and (1.2): (1.1) (1.2) Among them, is the plastic wave velocity in the metal panel, is the material density, is the dynamic yield strength. The subscripts and refer to the projectile and the metal panel respectively.

[0048] S302. Differentiate the momentum of the projectile and the front panel based on the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel to obtain the relationship between the remaining velocity influencing factor and time; among them, the remaining velocity influencing factor includes the remaining length of the projectile, the remaining mass of the first penetration of the projectile, the velocity of the projectile, and the thickness of the punching block.

[0049] In the embodiment of the present invention, during the penetration process of the projectile, the differential equations representing the momentum changes of the projectile and the metal panel are as shown in formulas (1.3) and (1.4): ; (1.3) ; (1.4) Among them, is the mass of the projectile, is the cross - sectional area of the projectile. For the metal panel, and The mass and cross-sectional area of the panel material in front of the projectile body.

[0050] Since the velocity at the tail of the projectile is higher than the interface velocity between the projectile and the panel, the length of the projectile will become shorter over time. Assuming that the cross-sectional area of the projectile remains constant during penetration, the relationship between the length of the projectile and time is shown in Equation (1.5): (1.5) The rate of change of the thickness of the metal panel with time is shown in Equation (1.6): (1.6) S303. Based on the relationship between the residual velocity influence factor and time, combined with the energy loss formula and the law of conservation of momentum, determine the common residual velocity of the projectile and the punching block after the projectile penetrates the front panel.

[0051] By simultaneously solving Equations (1.1) to (1.6), the remaining length of the projectile, the first penetration remaining mass of the projectile, the remaining velocity of the projectile, and the remaining thickness of the target plate at any moment can be obtained. When the incident velocity of the projectile is relatively low, the thickness of the metal panel will not be completely eroded. At this time, the rate of decrease of the panel thickness , the projectile still has velocity and mass , the remaining thickness of the panel is: (1.7) Among them, is the dynamic shear strength of the metal panel. In the current situation, the metal panel mainly undergoes shear punching failure, and the thickness of the punching block is the remaining thickness of the panel , as shown in Figure 4 (b), the diameter of the punching block is assumed to be equal to the diameter of the projectile, and the energy dissipation statistics of the panel shear punching are: (1.8) Among them, is the diameter of the projectile. According to the law of conservation of energy, it can be obtained that: (1.9) Among them, is the mass of the punching block of the panel. If the velocity or length of the projectile is zero, the theoretical model ends. Otherwise, the projectile will penetrate the front panel and jointly penetrate the ceramic layer with the punching block, where the common mass and remaining velocity of the projectile and the punching block are defined as and respectively. Through the above Equation (1.9), the common residual velocity of the projectile and the punching block after the projectile penetrates the front panel can be calculated.

[0052] In the embodiment of the present invention, when the first anti-ballistic structure of the multi-layer anti-ballistic structure is a front metal panel, the process of the projectile penetrating the front metal panel is analyzed. Finally, the common residual velocity of the projectile and the plugging block after penetrating the front panel is obtained. Through formula fitting, the energy loss during the single-body penetration process and the formation of the front panel plugging block are fully considered to ensure the accuracy of the calculation of the projectile residual velocity.

[0053] In some embodiments of the present invention, as Figure 5 shown, when the single-layer anti-ballistic structure is the rear anti-ballistic structure of the front panel and the single-layer anti-ballistic structure is a ceramic layer, the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure is calculated according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure, including: S501. According to the common residual velocity of the projectile and the plugging block after penetrating the front panel, and in combination with the elastic characteristics of the ceramic layer, determine the diameter and semi-cone angle of the ceramic cone formed by the ceramic layer after the projectile is upset.

[0054] Continuing from the foregoing embodiment, when the second anti-ballistic structure of the multi-layer anti-ballistic structure is a ceramic layer, after the projectile penetrates the metal front panel, the projectile and the plugging block jointly impact the ceramic layer, which is a very complex phenomenon, involving projectile erosion, upsetting, the formation of the ceramic cone, and the fragmentation of the ceramic layer, etc. Once the ceramic cone is formed, it jointly penetrates the next layer under the push of the projectile. Figure 6 The process of the projectile penetrating the ceramic layer to form a ceramic cone is given, and the energy dissipated by the projectile erosion is: (1.10) Among them, refers to the dynamic yield strength of the projectile, is the erosion length of the projectile, which is mainly related to the projectile velocity and the material properties of the projectile and the ceramic layer. Based on dimensionless analysis, can be expressed as: (1.11) Among them, is an empirical constant that can be determined through experiments, HEL is the Hugoniot elastic limit of the ceramic. For the constant , by comparing a large amount of experimental data with the prediction results of formula (1.11), a value of 0.06 is given. The projectile will undergo plastic deformation during the impact, and a petal body will form at the head. The energy consumed by the upset deformation of the projectile is: (1.12) Among them, is the thickness of the petal body, and the value is about 0.1 - 0.25 , is the bending and rotation angle of the petal body, approximately: 90°~150°; the petal body formed by bending is cut off during the subsequent penetration process, and the remaining part will form the head of the projectile after upsetting. The diameter of the projectile after upsetting is: .

[0055] The formation of the ceramic cone is mainly caused by shear failure, and the maximum shear force can be expressed as: (1.13) where is the shear strength of the ceramic, is the half-cone angle of the ceramic cone, and can be described as an expression of the projectile velocity: (1.14) The energy dissipated during the formation of the ceramic cone can be expressed as: (1.15) where is the diameter of the ceramic cone.

[0056] S502, based on the diameter of the ceramic cone and the half-cone angle of the ceramic cone, combines the energy formula of the ceramic cone to calculate the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone.

[0057] In the embodiment of the present invention, once the ceramic cone is formed, the projectile and the ceramic cone will act on the next layer of anti-ballistic structure at a common velocity. At this time, the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone are: (1.16) (1.17) (1.18) The embodiment of the present invention analyzes the process of forming a ceramic cone when the projectile penetrates the ceramic layer, and based on the energy loss formula and the law of conservation of momentum, finally determines the calculation formula for the common residual velocity of the projectile and the ceramic cone, ensuring the accuracy of the calculation of the residual velocity of the projectile after penetrating the ceramic layer.

[0058] In some embodiments of the present invention, as Figure 7 shown, when the single-layer anti-ballistic structure is the subsequent anti-ballistic structure of the ceramic layer and the single-layer anti-ballistic structure is a polyethylene fiber composite layer, the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure is calculated according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure, including: S701. Determine the dynamic compression force formula of the ceramic cone based on the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone.

[0059] In the embodiment of the present invention, after the ceramic layer forms a ceramic cone under the impact of the projectile, the projectile and the ceramic cone act on the high-strength polyethylene laminate as a community. According to the failure mechanism observed in the experiment, the anti-penetration process of the high-strength polyethylene laminate can be divided into two consecutive stages: the shear compression stage and the bulging deformation stage.

[0060] In the shear compression stage, the damage of the laminate mainly occurs near the impact area. At this time, the compression stress wave propagates along the thickness direction of the laminate. After reaching the back surface of the laminate, it will be reflected to form a tensile stress wave propagating towards the ceramic cone. According to the propagation process of the stress wave, the shear compression stage can be further divided into two sub-processes: the propagation of the compression stress wave and the propagation of the tensile stress wave, as Figure 8 shown.

[0061] Before the compression stress wave reaches the back surface of the high-strength polyethylene laminate, the laminate will not undergo overall displacement. A compression force will be generated between the ceramic cone and the laminate, causing the fiber layer in the impact area to be compressed. At this time, the velocity in the impact area is higher than that of the surrounding fiber materials, and this velocity gradient will cause shear forces to be generated at the edge of the impact area. In addition, according to the boundary consistency condition, the velocity at the contact interface between the ceramic cone and the high-strength polyethylene laminate is the same as the velocity of the ceramic cone, and the velocity of the fiber layer at the compression stress wave front is equal to zero. Therefore, inertial forces will be generated in the contact area, dissipating the kinetic energy of the ceramic cone and the projectile. According to the above analysis, the ceramic cone will be subjected to three forces during the penetration process. Specifically, the dynamic compression force is expressed as: (1.19) Where, is the dynamic compression stress of the high-strength polyethylene laminate, which can be expressed as: (1.20) Where, is the warhead shape factor, which is generally taken as 2 for a flat-nose projectile. and are the density and quasi-static compression strength of the high-strength polyethylene laminate respectively, is the common residual velocity of the projectile and the ceramic cone.

[0062] S702. Integrate the dynamic compression force formula of the ceramic cone to obtain the shear force formula of the ceramic cone. Combine the dynamic compression force formula and the shear force formula of the ceramic cone, and determine the motion equations of the projectile and the ceramic cone according to the law of conservation of momentum.

[0063] The shear stress applied to the ceramic cone is assumed to decrease linearly through the thickness of the laminate. The shear stress at the interface between the ceramic cone and the high-strength polyethylene laminate is determined by the dynamic shear strength of the laminate, while the shear stress is zero on the back of the laminate. Integrating the shear stress around the base of the ceramic cone through the thickness direction yields the shear force: (1.21) (1.22) (1.23) in, is the remaining thickness of the laminate, is the dynamic shear strength of the laminate, which can be described as the quasi-static shear strength , viscosity coefficient and shear strain rate expression.

[0064] The inertial force is generated by accelerating the laminate in the impact zone along the penetration path of the ceramic cone. The kinetic energy gained by this displaced portion of the laminate is assumed to be equal to the work done on the ceramic cone by the inertial force. It is assumed that the velocity of the material in the impact zone decreases linearly along the thickness of the laminate, and that the velocity is zero at the compression front. According to the law of conservation of momentum, we obtain: (1.24) in, is the velocity of the compression stress wave in the thickness direction of the laminate, is the compression modulus in the thickness direction of the laminate.

[0065] Combining equations (1.19), (1.21) and (1.24), the equations of motion for the projectile and the ceramic cone can be expressed as: (1.25) S703, determining a film sublayer model based on the equation of motion and film strain distribution theory, and determining a residual velocity of the projectile after penetrating the polyethylene fiber composite material layer based on the film sublayer model.

[0066] When the compressive stress wave reaches the back of the laminate, the reflected tensile stress wave propagates toward the projectile, and the penetration process enters the second sub-process. Assume that the ceramic cone is completely shattered, and the projectile comes into direct contact with the high-strength polyethylene laminate. Unlike the first sub-process, the dynamic compressive force is neglected in this case, and the only resistance components exerted on the projectile are shear force and inertia. The expression for shear force is similar to that of the first sub-process: (1.26) During the propagation of the reflected tensile stress wave, assuming that the velocity of the laminate in the impact area is consistent with the velocity of the projectile and uniformly distributed, the inertial force can be expressed as: (1.27) The equation of motion of the projectile is: (1.28) (1.29) The tensile stress wave velocity of the high-strength polyethylene laminate is , where is the tensile modulus in the fiber direction. Once the reflected tensile stress wave reaches the head of the projectile, it is considered that the shear compression stage ends. During the shear compression stage, the velocity reduction process of the projectile is mainly related to the mechanical parameters in the thickness direction of the laminate, such as the compression modulus , the compressive strength , the shear strength , etc. For the bionic laminate with a double-helix ply arrangement, each sub-layer of the laminate consists of orthogonal sub-layers with 0° / 90° ply, so the mechanical properties of the double-helix laminate in the thickness direction are the same as those of the orthogonal laminate. Therefore, in this stage, the influence of the laminate ply arrangement on the equation of motion of the projectile can be ignored.

[0067] For the bulging deformation stage, in this stage, the contact stress between the projectile and the high-strength polyethylene laminate is not sufficient to cause further local failure, and the remaining part of the laminate mainly fails due to tensile failure caused by bulging deformation. For this reason, a 2D membrane stretching model is used to describe the bulging deformation of the laminate. In this model, the laminate is considered to be composed of multiple thin film sub-layers, and the thickness of the remaining part of the laminate is , where represents the thickness of the sub-layer, and is the total number of sub-layers. In addition, due to the low matrix strength of the high-strength polyethylene laminate, delamination failure between sub-layers is not considered in the model.

[0068] The schematic diagram of a single thin film sub-layer subjected to out-of-plane impact by a flat-nose projectile is shown in Figure 9 . To describe the deformation of the thin film, a cylindrical coordinate system is established with the center of the projectile as the origin, and the undeformed thin film is located on the plane of . After being impacted by the projectile, the longitudinal wave propagates outward at a speed of , followed by a slower transverse wave . Among them, the longitudinal wave causes the material to flow towards the impact point and stretch the fibers in the plane, while the subsequent transverse wave causes the material to move laterally, generating a deformation cone (bulging deformation). According to the theory, the strain distribution in the thin film can be approximately expressed as: (1.30) Among them, is the wavefront position of the shear wave, denotes the ratio of the shear wave velocity to the longitudinal wave velocity, and can also be expressed as: (1.31) Among them, is the velocity of the projectile after the end of the shear compression stage. The maximum strain of the film usually appears at the edge position of the projectile and can be expressed as (1.32) Among them, is the ratio of the shear wavefront to the projectile radius .

[0069] The above single-layer film sublayer model only considers the case of orthogonal ply. For the bionic spiral laminate, each sublayer has a different ply angle in the plane. According to the Krenchel equivalent theory, the in-plane tensile equivalent modulus of the sublayer with a helix angle of can be expressed as: (1.33) Among them, is the equivalent factor, is the proportion of each fiber direction in the total fiber direction, and are the elastic moduli of the fiber and the matrix respectively, is the fiber volume fraction. Correspondingly, the equivalent tensile stress wave velocity in the sublayer plane is: .

[0070] Based on the single-layer film sublayer model, the bulging deformation stage of the high-strength polyethylene laminate composed of multiple film sublayers is as shown in Figure 10 . When the projectile impacts the laminate, there will be an instantaneous momentum exchange between the projectile and the target plate material in the directly impacted area. When the projectile penetrates to the i th sublayer, the mass of the laminate that exchanges momentum with the projectile is: (1.34) According to the law of conservation of momentum at the moment of impact, it can be defined that: (1.35) Among them, is the velocity of the projectile before impact, is the velocity of the projectile at the instant after impact. Define as the ratio of the remaining target plate mass to the projectile mass. When the projectile reaches the i th sublayer, the velocity of the projectile changes to: (1.36) The reaction force of the remaining intact sublayer on the projectile can be expressed as: (1.37) in, is the cone angle of the deformation cone, which is usually considered to be only related to the initial incident velocity of the projectile and remains unchanged during the bulge deformation process, and can be expressed as (1.38) Combining formulas (1.32), (1.37), and (1.38), we can obtain: (1.39) In addition, given that , and substituting it and formula (1.31) into formula (1.39), we can obtain: (1.40) According to Newton's second law, the projectile will i The equation of motion for the layer-sublayer is: (1.41) (1.42) Integrating both sides of formula (1.42), we can obtain: (1.43) Substituting equation (1.32) into (1.43), the membrane strain at the edge of the projectile can be expressed as the normalized shear wave front. Definition K For the i The strain magnification coefficient at the edge of the sub-layer body can be obtained: (1.44) when When the gauge factor reaches its maximum value, and accordingly, the maximum normalized deformed cone wavefront can be expressed as: (1.45) exist At membrane strain and reaction force However, The sublayer may arrive before the normalized shear wave Failure has already occurred. When the contact stress between the projectile and the sub-layer reaches the average indentation strength of the laminate When, The sublayer can fail directly without deformation. In this case, the normalized shear wave front 。To simulate the layer-by-layer failure mode of the laminate, it is assumed that the unfailed sub-layers have the same transverse wave front position, i.e., 。When the projectile penetrates the th sub-layer and contacts the layer sub-layer, the instantaneous velocity of the projectile can be expressed as: (1.46) If the transverse wave front of the th sub-layer reaches , but the maximum strain of the sub-layer does not exceed the failure strain , it is considered that the projectile is intercepted by the high-strength polyethylene laminate. Or, if the projectile penetrates all the remaining sub-layers and still has a certain kinetic energy, the projectile will continue to penetrate the metal rear panel.

[0071] In the embodiments of the present invention, by analyzing the complex process of the projectile penetrating the high-strength polyethylene laminate, and calculating the kinetic energy and morphology of the projectile and the ceramic layer according to the shear compression stage and the bulging deformation stage of the high-strength polyethylene laminate against penetration, the calculation formula for the remaining velocity of the projectile after penetrating the high-strength polyethylene laminate is finally determined, which can accurately calculate the remaining velocity of the projectile after penetrating the high-strength polyethylene laminate.

[0072] In some embodiments of the present invention, when the single-layer anti-ballistic structure is the rear-layer anti-ballistic structure of the polyethylene fiber composite layer and the single-layer anti-ballistic structure is the rear panel layer, the remaining velocity of the projectile after penetrating the single-layer anti-ballistic structure is calculated according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure, including: According to the remaining velocity of the projectile after penetrating the polyethylene fiber composite layer, combined with the energy loss formula and the law of conservation of momentum, the final remaining velocity of the projectile after penetrating the rear panel is calculated.

[0073] In the embodiments of the present invention, when the projectile penetrates the high-strength polyethylene laminate, it will impact the metal rear panel at a relatively low speed. For a relatively thin metal target plate, when the incident velocity of the projectile is close to the ballistic limit velocity, the target plate usually undergoes shear plugging failure. The diameter of the plug is considered to be equal to the diameter of the projectile, and the thickness is the same as the thickness of the target plate. According to the above analysis, the anti-penetration process of the metal rear panel can be divided into two stages: compression shear and plug ejection, as Figure 11 shown.

[0074] In the compression shear stage, the target plate material in the impact area forms a plug under the compression of the projectile. According to the law of conservation of momentum, the common velocity of the projectile and the plug is: (1.47) Wherein, is the mass of the plug, and the energy dissipation of the projectile during the compression process is: (1.48) During the compression stage, the contact pressure between the projectile and the target plate needs to meet two conditions: 1) The materials on both sides of the contact interface must be continuous, which also means that the material velocities in the impact area are the same; 2) The pressures on the projectile and the target plate must be equal. According to these two conditions, the pressure at the contact interface between the projectile and the target plate is: (1.49) where is the plastic wave velocity of the projectile. Substituting Equation (1.49) into (1.48), we can obtain: (1.50) Due to the relative movement between the plug and the target plate, a circumferential shear force will be generated on their contact surface , which increases the pressure between the projectile and the target plate. In addition, since the displacement of the plug is relatively small, the actual circumferential shear area can be approximated as the maximum area of the initial shear. Therefore, the normal pressure increment caused by the shear force is: (1.51) Combining Equations (1.50) and (1.51), the energy dissipation of the target plate during the compression-shear stage is: (1.52) When the circumferential shear strain at the contact interface between the plug and the target plate reaches the critical value, the plug will be pushed out of the target plate by the projectile. Integrating the shear force in the thickness direction of the target plate, the energy dissipation during the plug-pushing-out stage can be obtained as: (1.53) Combining Equations (1.52) and (1.53), and applying the law of conservation of energy, we can obtain: (1.54) where is the velocity of the projectile penetrating the high-strength polyethylene laminate, is the remaining velocity of the projectile penetrating the entire bionic anti-ballistic core layer composite armor structure. Based on this, the final remaining velocity of the projectile after penetrating the multi-layer anti-ballistic structure can be calculated. It can be seen that when the final remaining velocity of the projectile, the maximum incident velocity of the projectile is the ballistic limit velocity of the bionic anti-ballistic core layer composite armor structure.

[0075] In the embodiments of the present invention, by analyzing the process of the projectile impacting the rear panel and combining the energy loss formula and the law of conservation of momentum, a calculation formula for the final remaining velocity of the projectile after penetrating the entire multi-layer anti-ballistic structure is obtained, which can accurately calculate the final remaining velocity of the projectile after penetrating the entire multi-layer anti-ballistic structure.

[0076] In some embodiments of the present invention, as Figure 12 shown, a ballistic velocity model of each layer of the anti-ballistic structure is constructed according to each initial velocity and each remaining velocity, and an overall ballistic velocity model of the multi-layer anti-ballistic structure is determined based on the projectile velocity of each layer of the anti-ballistic structure, including: S1201, determining a ballistic velocity model of the front panel according to the initial velocity of the projectile impacting the front panel and the remaining velocity of the projectile after penetrating the front panel; S1202, determining a ballistic velocity model of the ceramic layer according to the remaining velocity of the projectile after penetrating the front panel and the remaining velocity of the projectile after penetrating the ceramic layer; S1203, determining a ballistic velocity model of the polyethylene fiber composite layer according to the remaining velocity of the projectile after penetrating the ceramic layer and the remaining velocity of the projectile after penetrating the polyethylene fiber composite layer; S1204, determining a ballistic velocity model of the rear panel according to the remaining velocity of the projectile after penetrating the polyethylene fiber composite layer and the remaining velocity of the projectile after penetrating the rear panel; S1205, determining an overall ballistic velocity model of the multi-layer anti-ballistic structure according to the ballistic velocity model of the front panel, the ballistic velocity model of the ceramic layer, the ballistic velocity model of the polyethylene fiber composite layer, and the projectile velocity of the rear panel.

[0077] In the embodiments of the present invention, according to the calculation formulas given in the previous embodiments, the ballistic velocity model of the front panel, the ballistic velocity model of the ceramic layer, the ballistic velocity model of the polyethylene fiber composite layer, and the ballistic velocity model of the rear panel can be determined respectively. By integrating the ballistic velocity models of these several single-layer anti-ballistic structures, the overall ballistic velocity model of the multi-layer anti-ballistic structure can be obtained.

[0078] In order to better implement the method for determining the velocity of a projectile penetrating a multi-layer composite armor structure in the embodiments of the present invention, correspondingly, based on the method for determining the velocity of a projectile penetrating a multi-layer composite armor structure, as Figure 13 shown, the embodiments of the present invention further provide a device for determining the velocity of a projectile penetrating a multi-layer composite armor structure. The device 1300 for determining the velocity of a projectile penetrating a multi-layer composite armor structure includes: A projectile velocity calculation module 1301, configured to sequentially calculate the remaining velocity of the projectile after penetrating a single-layer anti-ballistic structure according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure based on the order of the projectile penetrating the multi-layer anti-ballistic structure; The model construction module 1302 is configured to construct a ballistic velocity model of each layer of bulletproof structure according to each initial velocity and each remaining velocity, and determine an overall ballistic velocity model of the multi-layer bulletproof structure based on the bullet velocities of each layer of bulletproof structure; The bullet velocity determination module 1303 is configured to calculate the bullet velocity during the process of the bullet penetrating the multi-layer bulletproof structure based on the overall ballistic velocity model and the initial velocity of the bullet impacting the multi-layer bulletproof structure.

[0079] The velocity determination device 1300 for the bullet penetrating the multi-layer composite armor structure provided in the above embodiment can implement the technical solutions described in the above method embodiment for determining the velocity of the bullet penetrating the multi-layer composite armor structure. The specific implementation principles of the above modules or units can be referred to the corresponding content in the above method embodiment for determining the velocity of the bullet penetrating the multi-layer composite armor structure, which will not be elaborated here.

[0080] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for determining the velocity of a projectile penetrating a multi-layer composite armor structure, characterized in that, Including: Based on the order of the projectile penetrating multiple anti-ballistic structures, successively calculate the remaining velocity of the projectile after penetrating a single anti-ballistic structure according to the initial velocity of the projectile impacting the single anti-ballistic structure and the penetration influencing factors of the single anti-ballistic structure; Construct a ballistic velocity model for each anti-ballistic structure according to each of the initial velocities and each of the remaining velocities, and determine the overall ballistic velocity model of the multiple anti-ballistic structures based on the projectile velocities of each layer of the anti-ballistic structures; Calculate the projectile velocity during the process of the projectile penetrating the multiple anti-ballistic structures based on the overall ballistic velocity model and the initial velocity of the projectile impacting the multiple anti-ballistic structures.

2. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 1, wherein When the single anti-ballistic structure is not the first anti-ballistic structure of the multiple anti-ballistic structures, the determination process of the initial velocity of the projectile impacting the single anti-ballistic structure includes: Calculate the first remaining velocity of the projectile after penetrating the previous anti-ballistic structure based on the first initial velocity of the projectile penetrating the previous anti-ballistic structure in the multiple anti-ballistic structures and the first penetration influencing factors of the previous anti-ballistic structure; Take the first remaining velocity as the second initial velocity of the projectile penetrating the subsequent anti-ballistic structure in the multiple anti-ballistic structures, and calculate the second remaining velocity of the projectile after penetrating the subsequent anti-ballistic structure based on the second initial velocity and the second penetration influencing factors of the subsequent anti-ballistic structure, where the subsequent anti-ballistic structure is the next anti-ballistic structure after the previous anti-ballistic structure.

3. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 1, characterized in that, When the single anti-ballistic structure is the first anti-ballistic structure of the multiple anti-ballistic structures and the first anti-ballistic structure is the front panel, the calculation of the remaining velocity of the projectile after penetrating the single anti-ballistic structure according to the initial velocity of the projectile impacting the single anti-ballistic structure and the penetration influencing factors of the single anti-ballistic structure includes: Obtain the initial velocity and initial length of the projectile, and determine the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel in combination with the penetration influencing factors of the front panel; Perform differential processing on the momentum of the projectile and the front panel based on the reduction rate of the projectile, the thickness reduction rate of the front panel, and the interface velocity of the front panel to obtain the relationship between the remaining velocity influencing factor and time; where the remaining velocity influencing factor includes the remaining length of the projectile, the first remaining mass of the projectile after penetration, the projectile velocity, and the thickness of the plugging block; Based on the relationship between the remaining velocity influencing factor and time, determine the common remaining velocity of the projectile and the plugging block after the projectile penetrates the front panel in combination with the energy loss formula and the law of conservation of momentum.

4. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 3, characterized in that, When the single anti-ballistic structure is the subsequent anti-ballistic structure of the front panel and the single anti-ballistic structure is the ceramic layer, the calculation of the remaining velocity of the projectile after penetrating the single anti-ballistic structure according to the initial velocity of the projectile impacting the single anti-ballistic structure and the penetration influencing factors of the single anti-ballistic structure includes: According to the common remaining velocity of the projectile and the plugging block after the projectile penetrates the front panel, determine the diameter and semi-cone angle of the ceramic cone formed by the ceramic layer after the projectile is upset in combination with the elastic characteristics of the ceramic layer. Based on the diameter of the ceramic cone and the half-cone angle of the ceramic cone, combined with the energy formula of the ceramic cone, calculate the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone.

5. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 4, characterized in that, The calculating of the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone based on the diameter of the ceramic cone and the half-cone angle of the ceramic cone, combined with the energy formula of the ceramic cone, includes: Determine that the energy dissipated by the erosion of the projectile penetrating the ceramic layer to form a ceramic cone is: Among them, represents the dynamic yield strength of the projectile, is the erosion length of the projectile; Determine that the energy consumed by the upsetting deformation of the projectile is: Among them, is the petal body thickness, and the value ranges from about 0.1 to 0.25 , is the bending and rotating angle of the petal body; Determine that the semi-cone angle of the ceramic cone is Among them, is the half-cone angle of the ceramic cone, is the common residual velocity of the projectile and the punching block; Determine that the energy dissipated during the formation of the ceramic cone is: Among them, is the shear strength of the ceramic, is the diameter of the ceramic cone; Based on the energy dissipated by the erosion of the projectile, the energy consumed by the upsetting deformation of the projectile, and the energy dissipated during the formation of the ceramic cone, combined with the law of conservation of energy, determine the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone as: Among them, is the common residual velocity of the projectile and the ceramic cone, is the second penetration residual mass of the projectile, is the mass of the ceramic cone.

6. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 4, wherein, When the single-layer anti-ballistic structure is the rear anti-ballistic structure of the ceramic layer and the single-layer anti-ballistic structure is a polyethylene fiber composite layer, the calculating of the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure includes: Determine the dynamic compression force formula of the ceramic cone according to the common residual velocity of the projectile and the ceramic cone, the second penetration residual mass of the projectile, and the mass of the ceramic cone; Integrate the dynamic compression force formula of the ceramic cone to obtain the shear force formula of the ceramic cone. Combine the dynamic compression force formula and the shear force formula of the ceramic cone, and determine the motion equations of the projectile and the ceramic cone according to the law of conservation of momentum; Based on the motion equations, determine the thin film sub-layer model in combination with the thin film strain distribution theory, and based on the thin film sub-layer model, determine the residual velocity of the projectile after penetrating the polyethylene fiber composite layer.

7. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 6, characterized in that, The determining of the residual velocity of the projectile after penetrating the polyethylene fiber composite layer based on the thin film sub-layer model includes: Determine the motion equation of the projectile based on the thin film sub-layer model as: Among them, is the penetration shear force of the projectile through the polyethylene fiber composite layer, is the inertial force of the projectile through the polyethylene fiber composite layer, is the projectile velocity.

8. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 4, characterized in that, When the single-layer anti-ballistic structure is the rear anti-ballistic structure of the polyethylene fiber composite layer and the single-layer anti-ballistic structure is a rear panel layer, the calculating of the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influencing factors of the single-layer anti-ballistic structure includes: According to the residual velocity of the projectile after penetrating the polyethylene fiber composite layer, combined with the energy loss formula and the law of conservation of momentum, calculate the final residual velocity of the projectile after penetrating the rear panel.

9. The method for determining the velocity of a projectile penetrating a multi-layer composite armor structure according to claim 8, characterized in that, The constructing of the ballistic velocity model of each layer of anti-ballistic structure according to each of the initial velocities and each of the residual velocities, and determining the overall ballistic velocity model of the multi-layer anti-ballistic structure based on the projectile velocities of each layer of anti-ballistic structure includes: Determine the ballistic velocity model of the front panel according to the initial velocity of the projectile impacting the front panel and the residual velocity of the projectile after penetrating the front panel; Determine the ballistic velocity model of the ceramic layer according to the residual velocity of the projectile after penetrating the front panel and the residual velocity of the projectile after penetrating the ceramic layer; Determine the ballistic velocity model of the polyethylene fiber composite layer according to the residual velocity of the projectile after penetrating the ceramic layer and the residual velocity of the projectile after penetrating the polyethylene fiber composite layer; Determine the ballistic velocity model of the rear panel according to the residual velocity of the projectile after penetrating the polyethylene fiber composite layer and the residual velocity of the projectile after penetrating the rear panel; Determine the overall ballistic velocity model of the multi-layer anti-ballistic structure according to the ballistic velocity model of the front panel, the ballistic velocity model of the ceramic layer, the ballistic velocity model of the polyethylene fiber composite layer, and the projectile velocity of the rear panel.

10. A device for determining the velocity of a projectile penetrating a multi-layer composite armor structure, characterized in that, Including: A projectile velocity calculation module, configured to sequentially calculate the residual velocity of the projectile after penetrating the single-layer anti-ballistic structure according to the initial velocity of the projectile impacting the single-layer anti-ballistic structure and the penetration influence factors of the single-layer anti-ballistic structure based on the order of the projectile penetrating the multi-layer anti-ballistic structure; A model construction module, configured to construct the ballistic velocity model of each layer of the anti-ballistic structure according to each of the initial velocities and each of the residual velocities, and determine the overall ballistic velocity model of the multi-layer anti-ballistic structure based on the projectile velocities of each layer of the anti-ballistic structure; A projectile velocity determination module, configured to calculate the projectile velocity during the penetration of the multi-layer anti-ballistic structure based on the overall ballistic velocity model and the initial velocity of the projectile impacting the multi-layer anti-ballistic structure to determine the projectile velocity.

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