Rapid assessment method for damage effect of large fragment warhead

Abstract

The invention discloses a rapid assessment method for the damage effect of a large-scale fragment warhead, and relates to the technical field of assessment methods, and the key points of the technical scheme are that the method comprises the following steps: S1, constructing a static fragment ground power field according to different warhead model features, establishing target characteristic data according to different strike targets, constructing a database, and constructing a static fragment ground power field; basic data are provided for subsequent rapid damage analysis; s2, according to a normal kinetic energy criterion, establishing a judgment basis of damage of a single prefabricated fragment to a target according to three levels of damage levels of light, medium and heavy; s3, constructing a rapid damage algorithm of the fragment warhead to the target; and S4, based on the damage probability model of the fragments to different parts of the target, rapidly giving an evaluation conclusion of the damage effect of the warhead to the target part and the whole body. According to the technical scheme, the evaluation time of a traditional evaluation method can be shortened to the second level, and the related problem that in the prior art, it is difficult to guarantee the calculation precision and achieve rapid damage evaluation is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of evaluation methods, and more specifically, to a method for quickly evaluating the damage effect of a large-scale fragment warhead. Background Art

[0002] The fragmentation warhead relies on the explosion to form or drive a large number of fragments to fly at high speed, thereby achieving the purpose of destruction by colliding with the target.

[0003] Damage assessment is to analyze and predict the damage effect of the warhead in advance, so as to support the decision on the use of the warhead and improve the strike efficiency.

[0004] There are two main methods for damage assessment of fragment warheads:

[0005] (1) Empirical analysis: Relying on empirical formulas to perform simple calculations. This method is simple to calculate, but has low accuracy and is not applicable to complex damage scenarios;

[0006] (2) Numerical simulation: Numerical calculations are performed based on finite element / finite difference algorithms. This method has high calculation accuracy and meets the requirements of complex damage scenarios, but the amount of calculation is large and even with a high-performance computing platform, it cannot meet the requirements of rapid evaluation.

[0007] However, in the existing technical solutions, it is difficult to meet the requirements of both ensuring calculation accuracy and achieving rapid damage assessment. In view of this, the inventors propose a rapid assessment method for the damage effect of large-fragment warheads to solve the above-mentioned related problems. Summary of the invention

[0008] The purpose of the present invention is to provide a method for quickly evaluating the damage effect of a large-scale fragment warhead, which can ensure calculation accuracy and achieve rapid damage evaluation.

[0009] The above technical objectives of the present invention are achieved through the following technical solutions: A method for quickly evaluating the damage effect of a large-scale fragment warhead comprises the following steps:

[0010] S1: Construct static fragment ground power field according to different warhead model characteristics, establish target characteristic data according to different strike targets, build a database, and provide basic data for subsequent rapid damage analysis;

[0011] S2: According to the normal kinetic energy criterion, according to the three levels of damage: light, moderate and severe, a basis for judging the damage of a single prefabricated fragment to the target is established;

[0012] S3: Construct a fast damage algorithm for the fragmentation warhead to the target;

[0013] The specific steps of the fast damage algorithm are as follows:

[0014] S3.1: Read the position and velocity information data of all prefabricated fragments of the fragment warhead from the warhead power field database, and perform coordinate transformation on the position and velocity information data of all prefabricated fragments according to the spatial position and velocity vector of the fragment warhead when it is detonated.

[0015] S3.2: Calculate the flight motion of the fragments according to the following formula:

[0016]

[0017] Where m is the mass of the fragment, v is the velocity of the fragment, t is the time, C x is the air resistance coefficient, ρ is the local air density, and S is the windward area of ​​the fragments. Under normal circumstances, the flying speed of the fragments is between 1 and 3 Ma. At this time, for the spherical tungsten bead fragments, C x =0.97;

[0018] S3.3: Calculate the intersection parameters of the fragment and the target surface, which include the velocity of the fragment when it hits the target surface, the angle θ between the fragment velocity direction and the normal of the target surface impact point, and the component number N to which the target surface impact point belongs. k ;

[0019] S4: Based on the damage probability model of fragments to different target components, quickly give the evaluation conclusion of the damage effect of the warhead on the target components and the whole target;

[0020] Among them, according to the intersection parameters of the projectile and the target, the number of fragments hitting the target and the angle of kinetic penetration of each fragment are obtained, and the number of fragments that effectively penetrate the target is calculated.

[0021] The present invention is further configured as follows: in step S1, the construction of the static fragment ground force field is specifically:

[0022] The finite element model of the warhead shell and the warhead charge shell is constructed by Lagrangian method, the finite element model of the prefabricated fragment is constructed by discrete element method, and the finite element model of the warhead charge is constructed by Euler method;

[0023] The finite element software LS-DYNA is used to perform high-precision simulation calculations on the charge detonation and prefabricated fragment scattering process under the static explosion of the warhead, and the state parameters of all prefabricated fragments at the end of the driving effect of the charge explosion on the prefabricated fragments are obtained, that is, the warhead power field, including the spatial three-dimensional coordinate value (x i ′,y i ′,z i ′) and the component values ​​of velocity mass along three directions in the three-dimensional coordinate system of space (v′ xi ,v′yi ,v z ' i ), where i is the number of the prefabricated fragments; the warhead coordinate system is recorded as (o′x′y′z′), its origin o′ is located at the geometric center of the warhead, the symmetry axis of the warhead coincides with the z′ axis of the coordinate system, and the front end of the warhead faces the negative direction of the z′ axis.

[0024] The present invention is further configured as follows: in step S1, the warhead model characteristics include warhead size, charge power, and prefabricated fragment type.

[0025] The present invention is further configured as follows: in step S1, the target characteristic data is constructed, specifically:

[0026] According to the specific target being hit, target characteristic data is established, and the target characteristic data includes: three-dimensional geometric shape (IGS format), spatial position coordinates and orientation vector. The target coordinate system is denoted as (oxyz); its origin o is located at the geometric center of the target, and the target orientation (such as the direction of the front of the vehicle) coincides with the positive direction of the x-axis.

[0027] The present invention is further configured such that the targets to be attacked include personnel, vehicles and aircraft.

[0028] The present invention is further configured as follows: in step S2, the specific steps of establishing the basis for judging the damage of a single prefabricated fragment to a target are as follows:

[0029] S2.1: Conduct high-speed impact tests of fragments on pre-divided target areas to obtain the damage level of the target area under different typical impact speeds and impact angles.

[0030] S2.2: Based on the test results, a finite element simulation model identical to the test conditions is established and the model parameters are corrected. Based on the corrected simulation model, a high-throughput simulation is performed on the test conditions not covered by the test to obtain detailed information on the damage levels of fragments to the target area at various impact speeds and impact angles.

[0031] S2.3: Based on the test and simulation results, and in accordance with the normal kinetic energy criterion, a basis for determining the damage caused by fragments at different normal impact velocities on the target area is established.

[0032] The present invention is further configured as follows: in step S3.1, the coordinate transformation steps are as follows:

[0033] S3.1.1: Decompose the terminal velocity of the warhead at the time of detonation along the coordinate axis in the target coordinate system (oxyz) into: v 0x ,v 0y ,v 0z ; Read the velocity component v′ of each fragment from the warhead force field databasexi ,v′ yi ,v z ' i , transform the fragment velocity component from the warhead coordinate system to the target coordinate system, the fragment velocity component v in the target coordinate system (oxyz) xi ,v yi ,v zi Respectively expressed as:

[0034]

[0035] Among them, v 0x ,v 0y ,v 0z v is the decomposed velocity of the final velocity along the coordinate axis in the target coordinate system (oxyz); xi ,v yi ,v zi is the velocity component of the fragment in the target coordinate system (oxyz), i = 1, 2, 3, ..., indicating the number of the prefabricated fragment;

[0036] S3.1.2: Transform the spatial coordinates of all fragments; the warhead does not rotate in the static explosion force field. According to the set projectile-target intersection condition, the position component x of the warhead geometric center in the target coordinate system (oxyz) is 0i ,y 0i ,z 0i is a known quantity; the position component (x i ′,y i ′,z i ′), transform the fragment position component from the warhead coordinate system to the target coordinate system. At this time, the fragment position component x in the target coordinate system (oxyz) is i ,y i ,z i Respectively expressed as:

[0037]

[0038] Among them, x i ,y i and z i is the position component of the fragment in the target coordinate system (oxyz), i = 1, 2, 3, ..., indicating the number of the prefabricated fragment; x 0i ,y 0i and z 0i is the position component of the warhead geometric center in the target coordinate system (oxyz); i ′、y i ′ and z i ′ is the position component of the fragments in the warhead force field database;

[0039] Before detonation, the warhead is an axisymmetric geometric body. The overall spatial posture is described by a rectangular coordinate system (o′x′y′z′) with z′ as the axis. The relationship of its motion trajectory relative to the ground is described by an absolute coordinate system (oxyz). Therefore, with the target position as the coordinate origin, a rectangular coordinate system (oxyz) fixed on the ground is established, with the z axis perpendicular to the ground and pointing upward; then, with the center of mass of the warhead as the origin, a rectangular coordinate system (o′x′y′z′) of the warhead is established, with z′ coinciding with the axis of the warhead and pointing to the rear of the warhead.

[0040] S3.1.3: The cylindrical coordinate system of the warhead is converted to a rectangular coordinate system by:

[0041] Warhead cylindrical coordinates Converted to the rectangular coordinate system (o′x′y′z′), the calculation formula is:

[0042]

[0043] Where: ρ is the radius of the cylindrical circle where any fragment M is located, is the angle between OM and the x-axis, x′, y′, z′ are the coordinate parameters of the rectangular coordinate system. This formula can convert the position coordinates of any fragment M from the warhead cylindrical coordinate system to Convert to the warhead rectangular coordinate system (x′y′z′);

[0044] The conversion formula of warhead rectangular coordinates to target rectangular coordinates is:

[0045]

[0046] Among them: x, y, z are the coordinate parameters of the target rectangular coordinate system; α is the angle between the line between the warhead and the target and the x-axis of the target coordinate system; H is the vertical distance between the warhead and the ground when it explodes, that is, the explosion height;

[0047] Through the above transformation method, combined with the fragment flight equation, the distribution of the fragment force field at any time during the dynamic flight process can be quickly obtained.

[0048] The present invention is further configured as follows: in step S4, the damage probability model is specifically:

[0049] Calculate the damage level of a single component area based on the intersection parameters of each fragment with the target surface;

[0050] Among them, when each fragment is scattered, it can be assumed that the damage effect of each fragment on the target is an independent event, and the probability superposition problem between fragments satisfies the independent random event operation law; assuming that n fragments hit the same component, the probability of causing different levels of damage is: (p1A ,p 1B ,p 1C ), (p 2A ,p 2B ,p 2C )···(p nA ,p nB ,p nC ), where A, B and C represent severe, moderate and mild damage respectively; when n fragments hit the same component, the probability of causing different levels of damage to the component is calculated by the pairwise superposition method;

[0051] The damage between the various components of the target is also regarded as independent probabilistic events, so the superposition calculation of the damage probability of the entire target also adopts the pairwise superposition calculation method.

[0052] In summary, the present invention has the following beneficial effects:

[0053] 1. The numerical simulation model is constructed by using discrete element method, Euler method and Lagrangian method. The number of simulated fragments is large, the system is large, the calculation accuracy is high, and the model is established by combining experiments and simulations. The simulation results and evaluation conclusions are more realistic and reliable;

[0054] 2. Use high-performance computers to pre-calculate and build a static force field database that can be applied to various types of fragmentation warheads. The coordinate transformation calculation method can be used for different strike conditions, meeting the needs of complex damage scenarios, and can reduce the evaluation time of traditional evaluation methods from hours to seconds, thereby ensuring calculation accuracy and achieving rapid damage assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a model of a rapid assessment method for a large-scale fragment warhead in an embodiment of the present invention;

[0056] Figure 2 It is a fragmentation warhead model constructed in an embodiment of the present invention;

[0057] Figure 3 2 is a schematic diagram of a warhead coordinate system in an embodiment of the present invention;

[0058] Figure 4 is a schematic diagram of target characteristic data in an embodiment of the present invention;

[0059] Figure 5 is a damage probability criterion established according to the target in the embodiment of the present invention;

[0060] Figure 6 is a schematic diagram of a warhead coordinate system and a target coordinate system in an embodiment of the present invention;

[0061] Figure 7It is a schematic diagram of the cylindrical coordinate system and the rectangular coordinate system of the warhead in an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] The following is combined with Figure 1-3 The present invention is described in further detail.

[0064] Embodiment: A method for rapidly evaluating the damage effect of a large fragment warhead, such as Figure 1 As shown, the following steps are included:

[0065] S1: Construct static fragment ground power field according to different warhead model characteristics, establish target characteristic data according to different strike targets, build a database, and provide basic data for subsequent rapid damage analysis;

[0066] The finite element model of large fragment warhead is established based on discrete element method, Euler method and Lagrangian method. The geometric model is as follows: Figure 2 As shown, 1 is the warhead shell, 2 is the prefabricated fragment, 3 is the warhead charge shell, 4 is the warhead charge, and 5 is the detonation point. Among them, the warhead shell 1 and the warhead charge shell 2 are constructed with the Lagrangian method to construct the finite element model, the prefabricated fragment 2 is constructed with the discrete element method to construct the finite element model, and the warhead charge 4 is constructed with the Euler method to construct the finite element model. The total mass of the warhead can reach tons, and the number of prefabricated fragments filled inside can reach more than 100,000.

[0067] When the warhead is in action, the warhead charge 4 begins to detonate from the detonation point 5. After the detonation, high-temperature and high-pressure gas products are generated, which drive the warhead charge shell 2 to expand outward, push the prefabricated fragments 2 to move outward, and cause the warhead shell 1 to rupture rapidly. A large number of prefabricated fragments continue to accelerate around under the action of the explosion products. After a period of time, the explosion products cause the temperature and pressure to drop due to the rapid expansion, and they cannot continue to do work on the prefabricated fragments. The prefabricated fragments continue to move under the action of inertia, air resistance and gravity until they hit the target and strike the target.

[0068] Due to the large volume of the warhead and the large number of prefabricated fillings inside, it takes a lot of time to simulate the explosion of the charge and the scattering process of the prefabricated fragments using the finite element method. The present invention uses the finite element software LS-DYNA to perform high-precision simulation calculations on the explosion of the charge and the scattering process of the prefabricated fragments under the static explosion of the warhead, and obtains the state parameters of all prefabricated fragments when the charge explosion drives the prefabricated fragments, that is, the warhead power field, including the spatial three-dimensional coordinate value (x i ′,y i ′,z i ′, i = 1, 2, 3 ..., indicating the number of prefabricated fragments) and the component values ​​of velocity mass along three directions in the three-dimensional coordinate system of space (v′ xi ,v′ yi ,v z ' i , i = 1, 2, 3 ..., indicating the number of prefabricated fragments); the warhead coordinate system is recorded as (o'x'y'z'), such as Figure 3 , its origin o′ is located at the geometric center of the warhead, the symmetry axis of the warhead coincides with the z′ axis of the coordinate system, and the front end of the warhead faces the negative direction of the z′ axis.

[0069] According to the specific targets to be attacked, such as vehicles, personnel, aircraft, etc., target characteristic data is established, including: three-dimensional geometric shape (IGS format), spatial position coordinates and orientation vector, such as Figure 4 The target coordinate system is denoted as (oxyz); its origin o is located at the geometric center of the target, and the target orientation (such as the direction of the vehicle head) coincides with the positive direction of the x-axis.

[0070] The warhead power field and target characteristic data constitute a database, providing basic data for subsequent rapid damage analysis.

[0071] S2: According to the normal kinetic energy criterion, according to the three levels of damage: light, moderate and severe, a basis for judging the damage of a single prefabricated fragment to the target is established;

[0072] The damage judgment basis of a single prefabricated fragment to the target is constructed based on the kinetic energy criterion. Usually, the damage effect caused by the fragment hitting different positions on the target surface is different. Therefore, the target needs to be divided into a certain number of component areas N k (k=1,2,3…), and establish damage judgment criteria according to the three levels of damage: mild, moderate and severe.

[0073] First, a high-speed impact test of fragments on a pre-divided target area is carried out to obtain the damage level of the target area under different typical impact speeds and impact angles.

[0074] Secondly, based on the test results, a finite element simulation calculation model identical to the test conditions was established and the model parameters were calibrated. Based on the calibrated simulation model, a large-throughput simulation calculation was carried out on the test conditions not covered by the test to obtain detailed information on the damage level of fragments to the target area at various impact speeds and impact angles.

[0075] Finally, based on the comprehensive test and simulation results and in accordance with the normal kinetic energy criterion, a basis for judging the damage of fragments at different normal impact velocities on the target area is established.

[0076] The damage judgment basis established is as follows: Figure 5 As shown in the figure. p represents the damage probability, and its value range is [0,1]; v1, v2, and v3 represent the normal velocity of the fragments to the target area under three different working conditions.

[0077] S3: Construct a fast damage algorithm for the fragmentation warhead to the target;

[0078] The rapid damage algorithm of the fragmentation warhead to the target is divided into the following steps:

[0079] (1) Reading the position and velocity information data of all prefabricated fragments of the fragment warhead from the warhead power field database, and performing coordinate transformation on the position and velocity information data of all prefabricated fragments according to the spatial position and velocity vector of the fragment warhead when it is detonated.

[0080] First, the terminal velocity of the warhead at detonation is decomposed along the coordinate axis in the target coordinate system (oxyz), that is, decomposed into: v 0x ,v 0y ,v 0z The velocity component v′ of each fragment is read from the warhead force field database. xi ,v′ yi ,v z ' i (i=1,2,3……, represents the number of prefabricated fragments), convert the fragment velocity component from the warhead coordinate system to the target coordinate system, the fragment velocity component v in the target coordinate system (oxyz) xi ,v yi ,v zi Respectively expressed as:

[0081]

[0082] Secondly, the spatial positions of all fragments are transformed. According to the set projectile-target intersection condition, the position component x of the warhead geometric center in the target coordinate system (oxyz) is 0i ,y 0i ,z 0i is a known quantity. The position component (x i′,y i ′,z i ′, i = 1, 2, 3, ..., indicating the number of prefabricated fragments), the fragment position component is converted from the warhead coordinate system to the target coordinate system, and the fragment position component x in the target coordinate system (oxyz) is i ,y i ,z i Respectively expressed as:

[0083]

[0084] Before detonation, the warhead is an axisymmetric geometric body, and its overall spatial posture is described by a rectangular coordinate system (o′x′y′z′) with z′ as the axis, and its motion trajectory relative to the ground is described by an absolute coordinate system (oxyz). Therefore, with the target position as the coordinate origin, a rectangular coordinate system (oxyz) fixed on the ground is established, with the z axis perpendicular to the ground and pointing upward; then, with the center of mass of the warhead as the origin, a rectangular coordinate system (o′x′y′z′) of the warhead is established, with z′ coinciding with the axis of the warhead and pointing to the rear of the warhead.

[0085] The relative relationship between the two coordinate systems allows oxz and o′x′z′ to be in the same projection plane, then the y and y′ axes are two parallel lines perpendicular to the projection plane, such as Figure 5 shown.

[0086] Figure 6 In the figure, the vertical projection point of the warhead on the ground is o", the vertical distance between the warhead and the ground is the explosion height H = o′o", and o is the target point.

[0087] like Figure 7 As shown in the figure, the warhead cylindrical coordinates (ρ, φ, z) are converted into the rectangular coordinate system (o′x′y′z′), and the calculation formula is:

[0088]

[0089] The conversion formula of warhead rectangular coordinates to target rectangular coordinates is:

[0090]

[0091] Through the above transformation method, combined with the fragment flight equation, the distribution of the fragment force field at any time during the dynamic flight process can be quickly obtained.

[0092] (2) Calculate the flying motion of fragments according to the following formula:

[0093]

[0094] m is the mass of the fragment, v is the velocity of the fragment, t is the time, C xis the air resistance coefficient, ρ is the local air density, and S is the windward area of ​​the fragments. In general, the flying speed of fragments is between 1 and 3 Ma.

[0095] (3) Calculate the intersection parameters between the fragments and the target surface, including the velocity of the fragments when they hit the target surface (f indicates that the fragment hits the target surface, i is the fragment number), the angle θ between the fragment velocity direction and the normal of the target surface impact point, and the component number N to which the target surface impact point belongs k .

[0096] S4: Based on the damage probability model of fragments to different target components, quickly give the evaluation conclusion of the damage effect of the warhead on the target components and the whole target;

[0097] (1) Based on the intersection parameters of each fragment and the target surface, the damage level of a single component area is calculated. Since the fragments have almost no influence on each other during the scattering process and the scattering trajectories of the fragments do not overlap, the probability of hitting the same position of the target is almost zero. When each fragment is scattered, it can be assumed that the damage effect of each fragment on the target is an independent event. Then the probability superposition problem between the fragments satisfies the independent random event operation law. Assuming that n fragments hit the same component, the probability of causing different levels of damage is: (p 1A ,p 1B ,p 1C ), (p 2A ,p 2B ,p 2C )···(p nA ,p nB ,p nC ), A, B, and C represent severe, moderate, and slight damage respectively.

[0098] The analysis of the superimposed damage effects of each situation can be roughly divided into two types:

[0099] The first is the superposition of two same types of damage effects. Taking AA superposition as an example, since the effects of the fragments are independent of each other, it can be judged that the damage level is still A.

[0100] Another situation is the superposition of two different levels of damage effects. Taking AB superposition as an example, since one fragment has achieved the A-level damage effect, the target has already reached the highest level of damage. Therefore, no matter what damage effect the other fragments cause, it will not change the final judgment result.

[0101] Take two fragments hitting the same component as an example, the damage probability after superposition is:

[0102] p 12A =p 1A p2A +p 1A p 2B +p 1A p 2C +p 1B p 2A +p 1C p 2A

[0103] p 12B =p 1B p 2B +p 1B p 2C +p 1C p 2B

[0104] p 12C =p 1C p 2C

[0105] To further simplify the calculation and facilitate understanding, for the case where n fragments hit a component, the probability of the component being damaged at different levels can be calculated by superposition of two fragments:

[0106]

[0107] This is the fragmentation of a single component N k The damage probability assessment is as follows: 1,2…nA ,p 1,2…nB ,p 1,2…nC ) is denoted as p k The damage between the various components of the target can also be regarded as independent probabilistic events. Therefore, the damage probability of the entire target is calculated by superposition, using the same calculation method as when multiple fragments hit the same component.

[0108] (2) Based on the projectile-target intersection parameters, the number of fragments that hit the target and the angle of kinetic penetration of each fragment can be obtained, thereby giving the number of fragments that effectively penetrate the target.

[0109] Based on the ray detection method, the ray refers to an infinitely long line that a single fragment launches in three-dimensional space from the coordinate point after detonation along the speed direction. On the trajectory of the ray, once a collision occurs with the added target model, the emission will stop and the collision point information will be returned. The collision point information includes the collision target type, collision speed and collision point coordinates.

[0110] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A method for rapidly evaluating the damage effect of a large-scale fragment warhead, characterized in that: The following steps are involved: S1: Construct static fragmentation ground power field according to different warhead model characteristics, establish target characteristic data according to different strike targets, build a database, and provide basic data for subsequent rapid damage analysis; S2: According to the normal kinetic energy criterion, according to the three levels of damage: light, moderate and severe, a basis for judging the damage of a single prefabricated fragment to the target is established; S3: Construct a fast damage algorithm for the fragmentation warhead to the target; The specific steps of the fast damage algorithm are as follows: S3.1: Read the position and velocity information data of all prefabricated fragments of the fragment warhead from the warhead power field database, and perform coordinate transformation on the position and velocity information data of all prefabricated fragments according to the spatial position and velocity vector of the fragment warhead when it is detonated. S3.2: Calculate the flight motion of the fragments according to the following formula: Where m is the mass of the fragment, v is the velocity of the fragment, t is the time, C x is the air resistance coefficient, ρ is the local air density, and S is the windward area of ​​the fragments. Under normal circumstances, the flying speed of the fragments is between 1 and 3 Ma. At this time, for the spherical tungsten bead fragments, C x =0.97; S3.3: Calculate the intersection parameters of the fragment and the target surface, which include the velocity of the fragment when it hits the target surface, the angle θ between the fragment velocity direction and the normal of the target surface impact point, and the component number N to which the target surface impact point belongs. k ; S4: Based on the damage probability model of fragments to different target components, quickly give the evaluation conclusion of the damage effect of the warhead on the target components and the whole target; Among them, according to the intersection parameters of the projectile and the target, the number of fragments hitting the target and the angle of kinetic penetration of each fragment are obtained, and the number of fragments that effectively penetrate the target is calculated.

2. A method for rapidly evaluating the damage effect of a large-scale fragment warhead according to claim 1, characterized in that: In step S1, the construction of the static fragment ground force field is specifically as follows: The finite element model of the warhead shell and the warhead charge shell is constructed by Lagrangian method, the finite element model of the prefabricated fragment is constructed by discrete element method, and the finite element model of the warhead charge is constructed by Euler method; The finite element software LS-DYNA is used to perform high-precision simulation calculations on the charge detonation and prefabricated fragment scattering process under the static explosion of the warhead, and the state parameters of all prefabricated fragments at the end of the driving effect of the charge explosion on the prefabricated fragments are obtained, that is, the warhead power field, including the spatial three-dimensional coordinate value (x i ′,y i ′,z i ′) and the component values ​​of velocity mass along three directions in the three-dimensional coordinate system of space (v′ xi ,v′ yi ,v z ' i ), where i is the number of the prefabricated fragments; the warhead coordinate system is recorded as (o′x′y′z′), its origin o′ is located at the geometric center of the warhead, the symmetry axis of the warhead coincides with the z′ axis of the coordinate system, and the front end of the warhead faces the negative direction of the z′ axis.

3. A method for rapidly evaluating the damage effect of a large-scale fragment warhead according to claim 1, characterized in that: In step S1, the warhead model characteristics include warhead size, charge power, and prefabricated fragment type.

4. A method for rapidly evaluating the damage effect of a large-scale fragment warhead according to claim 1, characterized in that: In step S1, the target characteristic data is constructed, specifically: According to the specific target being hit, target characteristic data is established, and the target characteristic data includes: three-dimensional geometric shape, spatial position coordinates and orientation vector, and the target coordinate system is recorded as (oxyz); its origin o is located at the geometric center of the target, and the target orientation coincides with the positive direction of the x-axis.

5. A method for rapidly evaluating the damage effect of a large-scale fragment warhead according to claim 4, characterized in that: The targets mentioned included personnel, vehicles and aircraft.

6. A method for rapid assessment of damage effects of large-scale fragment warheads according to claim 1, characterized in that: In step S2, the specific steps of establishing the basis for judging whether a single prefabricated fragment damages a target are as follows: S2.1: Conduct high-speed impact tests of fragments on pre-divided target areas to obtain the damage levels of the target areas at different typical impact speeds and impact angles; S2.2: Based on the test results, establish a finite element simulation model that is the same as the test conditions and calibrate the model parameters; based on the calibrated simulation model, carry out high-throughput simulation calculations for test conditions not covered by the test to obtain detailed information on the damage levels of fragments to the target area at various impact speeds and impact angles; S2.3: Based on the test and simulation results, and in accordance with the normal kinetic energy criterion, a basis for judging the damage of fragments corresponding to different normal impact velocities on the target area is established.

7. A method for rapidly evaluating the damage effect of a large-scale fragment warhead according to claim 1, characterized in that: In step S3.1, the specific steps of the coordinate transformation are as follows: S3.1.1: Decompose the terminal velocity of the warhead at the time of detonation along the coordinate axis in the target coordinate system (oxyz) into: v 0x ,v 0y ,v 0z ; Read the velocity component v′ of each fragment from the warhead force field database xi ,v′ yi ,v z ' i , transform the fragment velocity component from the warhead coordinate system to the target coordinate system, the fragment velocity component v in the target coordinate system (oxyz) xi ,v yi ,v zi Respectively expressed as: Among them, v 0x ,v 0y ,v 0z v is the decomposed velocity of the final velocity along the coordinate axis in the target coordinate system (oxyz); xi ,v yi ,v zi is the velocity component of the fragment in the target coordinate system (oxyz), i = 1, 2, 3, ..., indicating the number of the prefabricated fragment; S3.1.2: Transform the spatial coordinates of all fragments; the warhead does not rotate in the static explosion force field. According to the set projectile-target intersection condition, the position component x of the warhead geometric center in the target coordinate system (oxyz) is 0i ,y 0i ,z 0i is a known quantity; the position component (x i ′,y i ′,z i ′), transform the fragment position component from the warhead coordinate system to the target coordinate system. At this time, the fragment position component x in the target coordinate system (oxyz) is i ,y i ,z i Respectively expressed as: Among them, x i ,y i and z i is the position component of the fragment in the target coordinate system (oxyz), i = 1, 2, 3, ..., indicating the number of the prefabricated fragment; x 0i ,y 0i and z 0i is the position component of the warhead geometric center in the target coordinate system (oxyz); i ′、y i ′ and z i ′ is the position component of the fragments in the warhead force field database; Before detonation, the warhead is an axisymmetric geometric body. The overall spatial posture is described by a rectangular coordinate system (o′x′y′z′) with z′ as the axis. The relationship of its motion trajectory relative to the ground is described by an absolute coordinate system (oxyz). Therefore, with the target position as the coordinate origin, a rectangular coordinate system (oxyz) fixed on the ground is established, with the z axis perpendicular to the ground and pointing upward; then, with the center of mass of the warhead as the origin, a rectangular coordinate system (o′x′y′z′) of the warhead is established, with z′ coinciding with the axis of the warhead and pointing to the rear of the warhead. S3.1.3: The cylindrical coordinate system of the warhead is converted to a rectangular coordinate system by: Warhead cylindrical coordinates Converted to the rectangular coordinate system (o′x′y′z′), the calculation formula is: Where: ρ is the radius of the cylindrical circle where any fragment M is located, is the angle between OM and the x-axis, x′, y′, z′ are the coordinate parameters of the rectangular coordinate system. This formula can convert the position coordinates of any fragment M from the warhead cylindrical coordinate system to Convert to the warhead rectangular coordinate system (x′y′z′); The conversion formula of warhead rectangular coordinates to target rectangular coordinates is: Among them: x, y, z are the coordinate parameters of the target rectangular coordinate system; α is the angle between the line between the warhead and the target and the x-axis of the target coordinate system; H is the vertical distance between the warhead and the ground when it explodes, that is, the explosion height; Through the above transformation method, combined with the fragment flight equation, the distribution of the fragment force field at any time during the dynamic flight process can be quickly obtained.

8. The method for rapid assessment of damage effects of large-scale fragment warheads according to claim 1, characterized in that: In step S4, the damage probability model is specifically: Calculate the damage level of a single component area based on the intersection parameters of each fragment with the target surface; Among them, when each fragment is scattered, it can be assumed that the damage effect of each fragment on the target is an independent event, and the probability superposition problem between fragments satisfies the independent random event operation law; assuming that n fragments hit the same component, the probability of causing different levels of damage is: (p 1A ,p 1B ,p 1C ), (p 2A ,p 2B ,p 2C )···(p nA ,p nB ,p nC ), where A, B and C represent severe, moderate and mild damage respectively; when n fragments hit the same component, the probability of causing different levels of damage to the component is calculated by the pairwise superposition method; The damage between the various components of the target is also regarded as independent probabilistic events, and the superposition calculation of the damage probability of the entire target also adopts the pairwise superposition calculation method.

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