A rapid evaluation method for the penetration probability of a projectile penetrating a target plate

Abstract

The present invention relates to the field of composite material safety assessment, and in particular to a method for quickly assessing the penetration probability of a projectile penetrating a target plate, comprising the following steps: conducting a ballistic penetration test on the target plate, obtaining the probability of the projectile penetrating a target plate at different incident velocities V i The remaining velocity V after passing through the target plate r ; Process the ballistic penetration test data and fit the incident velocity-residual velocity relationship; Add the probability parameter δ to the incident velocity-residual velocity relationship and calculate the probability parameter δ for each penetration test j ; Determine the probability model of ballistic limit and establish the ballistic limit V BL The relationship between the penetration probability model of the projectile penetrating the target plate is established, which greatly reduces the number of projectile penetration tests on composite materials and greatly reduces the test investment cost. At the same time, it can also quickly determine the penetration probability of the projectile penetrating the target plate.

Description

Technical Field

[0001] The present invention relates to the field of composite material safety assessment, and particularly to a method for rapidly evaluating the penetration probability of a projectile penetrating a target plate. Background Art

[0002] Due to the discreteness of the anti-ballistic performance of the target plate, there is often a mixed velocity range for the ballistic limit when a projectile penetrates the target plate. Within this velocity range, the projectile may penetrate the target plate or may not. The ballistic limit V50 refers to the velocity at which the probability of the projectile penetrating the target is 50%. This velocity is an important index for measuring the ballistic performance of composite materials and is used as a standard for evaluating the protection performance in many fields.

[0003] With the development of science and technology, various new composite materials are continuously applied in major engineering facilities and equipment. The practical demand for evaluating the penetration probability of a projectile penetrating a target plate for various new composite materials is continuously increasing. However, the current method for obtaining the penetration probability of a projectile penetrating a target plate at different incident velocities requires a large number of tests to obtain the penetration probability curve of the material. The above method is not only costly but also takes a lot of time and cannot meet the need for evaluating the penetration probability of a projectile penetrating a target plate. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for rapidly evaluating the penetration probability of a projectile penetrating a target plate. This design method greatly reduces the number of projectile penetration tests for composite materials by establishing a penetration probability model for a projectile penetrating a target plate, greatly reduces the test input cost, and at the same time, can quickly determine the penetration probability of a projectile penetrating a target plate.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A method for rapidly evaluating the penetration probability of a projectile penetrating a target plate includes the following steps:

[0007] S1. Conduct a ballistic penetration test on the target plate to obtain the residual velocity V of the projectile after penetrating the target plate at different incident velocities V i ; r

[0008] S2. Process the ballistic penetration test data and fit to obtain the relationship between the incident velocity and the residual velocity;

[0009] S3. Add a probability parameter δ to the incident velocity-residual velocity relationship formula and calculate the probability parameter δ of each penetration test j ;

[0010] S4. Determine the probability model of the ballistic limit and establish the ballistic limit V BLRelationship with the probability parameter δ, and calculate the undetermined parameters in the ballistic limit probability model according to the statistical description information of δ;

[0011] S5. Determine the penetration probability function of the projectile penetrating the target plate, input the incident velocity of the projectile penetrating the target plate, and calculate the probability of the projectile penetrating the target plate.

[0012] Further, in step S2, the incident velocity V i - Residual velocity V r50 The relationship is V r50 = a(V i P - V BL50 P ) 1 / P , and determine the parameters a, P and the ballistic limit V BL50 value at 50% penetration probability by least squares fitting.

[0013] Further, in step S3, after adding the probability parameter δ, the V i - V r relationship formula becomes V r = a((V i ) P - (V BL50 ×δ) P ) 1 / P ; Substitute the V i , V r obtained from each penetration test in step S1 and the a, P and V BL50 obtained in step S2 into the formula δ = ((V i ) P - (V r / a) P ) 1 / P / V BL50 to calculate the probability parameter value δ j for each penetration test.

[0014] Further, in step S4, the ballistic limit probability model satisfies the normal distribution. Let the residual velocity V r = 0, then the incident velocity V i at this time is equal to the ballistic limit V BL , and the relationship between the ballistic limit and the probability parameter satisfies V BL = δV BL50 .

[0015] Further, in step S4, the probability model of the probability parameter satisfies δ j : N(μ, σ 2 ), and the probability model of the ballistic limit satisfies V BL(j) ~N(V BL50 μ, (VBL50 σ) 2 ) where μ and σ are the mean and standard deviation of the probability parameters obtained in step S3, with μ = 1,

[0016] Further, in step S5, the penetration probability of the projectile penetrating the target plate at the incident velocity V i is equal to the cumulative probability distribution of the ballistic limit V BL ( j) < V i .

[0017] Further, in step S5, the probability of the normal distribution function within the interval (μ - x, μ + x) is When the probability models of both the ballistic limit and the probability parameters in step S4 are selected as the normal distribution, the penetration probability of the projectile penetrating the target plate satisfies The probability model of the ballistic limit satisfies V BL(j) ~N(V BL50 μ, (V BL50 σ) 2 ), where x = V i - V BL50 , σ x = V BL50 σ, and the penetration probability of the projectile penetrating the target plate satisfies Substituting the ballistic limit V obtained in step S2 and the standard deviation σ obtained in step S4 into this BL50 formula, and inputting the incident velocity Vi, the penetration probability F(V i ) of the projectile penetrating the target plate at this velocity can be obtained.

[0018] The beneficial effects of the present invention are as follows: The rapid evaluation method for the penetration probability of a projectile penetrating a target plate provided by the present invention can significantly reduce the number of projectile penetration tests on composite materials by establishing a penetration probability model for the projectile penetrating the target plate, thereby greatly reducing the test input cost. At the same time, it can quickly determine the penetration probability of the projectile penetrating the target plate. Specifically, the rapid evaluation method for the penetration probability of a projectile penetrating a target plate provided by the present invention can conduct a ballistic penetration test on the target plate to obtain the residual velocity V i of the projectile after penetrating the target plate at different incident velocities V r , then process the ballistic penetration test data, fit to obtain the relationship between the incident velocity and the residual velocity, add the probability parameter δ to the incident velocity - residual velocity relationship formula, calculate the probability parameter δ j of each penetration test, etc., determine the probability model of the ballistic limit, establish the relationship between the ballistic limit V BL and the probability parameter δ, and finally calculate the projectile penetration probability of the target plate. Description of the Drawings

[0019] Figure 1 Flow chart of a rapid evaluation method for the penetration probability of a projectile penetrating a target board in an embodiment of the present invention;

[0020] Figure 2 Fitting result diagram of the incident velocity - residual velocity relationship obtained in an embodiment of the present invention;

[0021] Figure 3 Is the penetration probability diagram of the projectile penetrating the target board at different velocities obtained in an embodiment of the present invention. Specific implementation mode

[0022] Specific Example 1: The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. It should be noted that: in the present invention, if there is no special description, all the implementation manners and preferred implementation methods mentioned in this article can be combined with each other to form a new technical solution. In the present invention, if there is no special description, all the technical features and preferred features mentioned in this article can be combined with each other to form a new technical solution. The "range" disclosed in the present invention can be in the form of a lower limit and an upper limit, which can be one or more lower limits, and one or more upper limits respectively. Unless otherwise specified, the professional and scientific terms used in this article have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention.

[0023] As shown in the specification appendix of the present invention Figure 1 The purpose of the present invention is to provide a rapid evaluation method for the penetration probability of a projectile penetrating a target board. The evaluation method greatly reduces the number of penetration tests by establishing a penetration probability model of the projectile penetrating the target board, can reduce costs, and quickly determine the penetration probability of the projectile penetrating the target board. To achieve the above purpose, the present invention adopts the following technical methods: A rapid evaluation method for the penetration probability of a projectile penetrating a target board, including the following steps:

[0024] Step S1: Conduct a ballistic penetration test on the target board to obtain the residual velocity V i of the projectile after penetrating the target board at different incident velocities V r ;

[0025] Step S2: Process the incident velocity - residual velocity data obtained from the ballistic penetration test. The relationship between the incident velocity V i -residual velocity Vr 50 is V r50 = a(V i P-V BL50 P ) 1 / P , the parameters a, P and the ballistic limit V at 50% penetration probability in the formula are determined by least squares fitting BL50 value;

[0026] Step S3: Add the probability parameter δ to the incident velocity - residual velocity relationship formula, and calculate the probability parameter δ for each penetration test j . After adding the probability parameter δ, the V in step S2 i -V r relationship formula becomes V r = a((V i ) P -(V BL50 ×δ) P ) 1 / P ; Substitute the V i , V r obtained from each penetration test in step S1 and the a, P and V BL50 obtained in step S2 into the formula δ = ((V i ) P -(V r / a) P ) 1 / P / V BL50 to calculate the probability parameter value δ for each penetration test j ;

[0027] Step S4: Determine the probability model of the ballistic limit, establish the relationship between the ballistic limit V BL and the probability parameter δ, and calculate the undetermined parameters in the ballistic limit probability model according to the statistical description information of δ. Let the residual velocity V r = 0, then the incident velocity V i at this time is equal to the ballistic limit V BL , and the relationship between the ballistic limit V BL and the probability parameter δ can be obtained as V BL = δV BL50 ; The probability model of the ballistic limit is selected as the normal distribution, then the probability model of the probability parameter also satisfies the normal distribution; if the probability model of the probability parameter satisfies δ j : N(μ, σ 2 ), then the probability model of the ballistic limit satisfies V BL(j) ~N(V BL50 μ, (V BL50 σ) 2 ); μ and σ are the mean and standard deviation of the probability parameter obtained in step S3, where the mean μ = 1, and the standard deviation is obtained through Perform calculations; Step S5: Determine the penetration probability function of the projectile penetrating the target plate, input the incident velocity of the projectile penetrating the target plate, and calculate the probability of the projectile penetrating the target plate; The penetration probability of the projectile penetrating the target plate at the incident velocity of V i is equal to the ballistic limit V BL(j) <V i cumulative probability distribution; The probability of the normal distribution function in the interval (μ - x, μ + x) is Therefore, when the probability models of the ballistic limit and probability parameters in Step S4 both select the normal distribution, the penetration probability of the projectile penetrating the target plate satisfies For the probability model V of the ballistic limit BL(j) ~N(V BL50 μ, (V BL50 σ) 2 ), where x = V i -V BL50 , σ x =V BL50 σ, so the penetration probability of the projectile penetrating the target plate satisfies Substitute the ballistic limit V BL50 obtained in Step S2 and the standard deviation σ obtained in Step S4 into this formula, and input the incident velocity V i to obtain the penetration probability F(V i ) of the projectile penetrating the target plate at this velocity.

[0028] The following combines an example to elaborate in detail on the rapid evaluation method for the penetration probability of a projectile penetrating a target plate according to the present invention. The example is the analysis of the penetration probability of a projectile penetrating a target plate. The projectile is a cylindrical steel fragment with a Rockwell hardness of HRC30, and the target plate is a low-carbon steel plate with a Brinell hardness of 190 BHN. The target plate is relatively thin, and the ratio of the target plate thickness to the projectile length is 0.44.

[0029] The following are the specific operation steps:

[0030] Step S1: Set a certain incident velocity gradient, conduct a ballistic penetration test on the target plate, and obtain the remaining velocity of the projectile after penetrating the target plate; In this embodiment, the 6 groups of incident velocity - remaining velocity data obtained through the test are shown in Table 1 below:

[0031] Table 1 Test results of a cylindrical projectile fragment penetrating the target plate

[0032] Serial number Incident velocity (m / s) Remaining velocity (m / s) 1 1554.6 0 2 1684.0 449.2 3 1942.8 675.4 4 2347.1 945.8 5 2651.5 1073.9 6 3077.7 1428.2

[0033] Step S2: Process the incident velocity - remaining velocity data obtained in Step S1. The relationship between the incident velocity V i - remaining velocity V r50 is expressed by the formula V r50 =a(V i P -VBL50 P ) 1 / P Analyze it, and use the least squares method to fit and determine the parameters a, P, and the ballistic limit V at the 50% penetration probability in the formula BL50 value; The appendix of the specification Figure 2 is the fitting result of the incident velocity - residual velocity relationship, and determine V r50 = a(V i P - V BL50 P) 1 / P The parameters in it are a = 0.47927, P = 2.59938, V BL50 = 1554.6;

[0034] Step S3: Add the probability parameter δ to the incident velocity - residual velocity relationship formula, then the incident velocity - residual velocity relationship becomes V r = a((V i ) P - (V BL50 × δ) P ) 1 / P , and the probability parameter value δ = ((V i ) P - (V r / a) P ) 1 / P / V BL50 ; Substitute the parameters a = 0.47927, P = 2.59938, V BL50 = 1554.6 determined in step S2 into this formula, and input the six groups of incident velocities and residual velocities in Table 1 obtained in step S1 respectively to calculate the probability parameter value δ of each penetration test j ; The probability parameter value δ calculated in this embodiment j is shown in Table 2 below:

[0035] Table 2 Probability parameter values calculated in this embodiment

[0036] Serial number 1 2 3 4 5 6 <![CDATA[Probability parameter δ j > 1 0.985 1.004 1.022 1.144 0.751

[0037] Step S4: For the formula Vr = a((Vi)P - (VBL50 × δ)P)1 / P, let the residual velocity Vr = 0, then the incident velocity Vi at this time is equal to the ballistic limit VBL, and the relationship between the ballistic limit VBL and the probability parameter δ can be obtained as VBL = δVBL50; The probability model of the ballistic limit is selected as the normal distribution, then the probability model of the probability parameter also satisfies the normal distribution; If the probability model of the probability parameter satisfies the normal distribution Δj ~ N(μ, σ2), then the probability model of the ballistic limit satisfies the normal distribution VBL(j): N(VBL50μ, (VBL50σ)2); Statistical analysis of the probability parameter values obtained in step s3 can obtain the standard deviation of the probability parameter δ in this embodiment The probability model of the probability parameter satisfies the normal distribution δj: N(1, 0.1291992), and the probability model of the ballistic limit satisfies the normal distribution VBL(j) ~ N(1554.6, (1554.6 × 0.129199)2);

[0038] Step S5: Determine the penetration probability function of the projectile penetrating the target plate, input the incident velocity of the projectile penetrating the target plate, and calculate the probability of the projectile penetrating the target plate; the penetration probability of the projectile penetrating the target plate at the incident velocity of V i is equal to the cumulative probability distribution of the ballistic limit V BL(j) < V i When the probability models of the ballistic limit and the probability parameter in Step S4 both select the normal distribution, the penetration probability of the projectile penetrating the target plate satisfies Substitute the ballistic limit V BL50 = 1554.6 obtained in Step S2 and the standard deviation σ = 0.129199 obtained in Step S4 into this formula, and input any incident velocity V i to obtain the penetration probability of the projectile penetrating the target plate at this velocity At this time, input any incident velocity to calculate the penetration probability of the projectile at this velocity. As shown in the penetration probability diagram of the projectile penetrating the target plate at different velocities in the attached description of the present invention Figure 3 For example, as shown in the penetration probability diagram of the projectile penetrating the target plate at different velocities obtained in this embodiment, when inputting Vi = 1000 m / s, the penetration probability is 0.28%, when Vi = 1250 m / s, the penetration probability is 6.47%, when Vi = 1500 m / s, the penetration probability is 39.29%, when Vi = 1750 m / s, the penetration probability is 83.47%, when Vi = 2000 m / s, the penetration probability is 98.67%, and when Vi = 2250 m / s, the penetration probability is 99.97%; The above is only a preferred embodiment of the present invention, and it is not a limitation to the present invention in any form. Although the present invention has been disclosed as above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for quickly evaluating the penetration probability of a projectile penetrating a target plate, characterized in that: The steps include: S1. Conduct ballistic penetration test on the target plate to obtain the projectile at different incident speeds V i The remaining velocity V after passing through the target plate r ; S2. Processing the ballistic penetration test data and fitting the incident velocity-residual velocity relationship; S3. Add the probability parameter δ to the incident velocity-residual velocity relationship and calculate the probability parameter δ for each penetration test. j ; S4. Determine the probability model of the ballistic limit and establish the ballistic limit V BL The relationship between the probability parameter δ and the unknown parameters in the ballistic limit probability model is calculated based on the statistical description information of δ; S5, determining the penetration probability function of the projectile penetrating the target plate, inputting the incident velocity of the projectile penetrating the target plate, and calculating the probability of the projectile penetrating the target plate; In step S3, after adding the probability parameter δ, V in step S2 i -V r The relationship becomes V r =a((V i ) P -(V BL50 ×δ) P ) 1 / P ; The V obtained from each penetration test in step S1 i 、V r and a, P and V obtained in step S2 BL50 Substituting into the formula δ=((V i ) P -(V r / a) P ) 1 / P / V BL50 The probability parameter value δ of each penetration test can be calculated j ; Ballistic limit V at 50% penetration probability BL50 value; In step S5, the probability that the normal distribution function is in the interval (μ-x, μ+x) is When the probability models of the ballistic limit and probability parameters in step S4 are both normal distribution, the penetration probability of the projectile penetrating the target plate satisfies The probability model of ballistic limit satisfies V BL(j) ~N(V BL50 μ,(V BL50 σ) 2 ), where x = V i -V BL50 , σ x =V BL50 σ, the penetration probability of the projectile penetrating the target plate satisfies exist Substitute the ballistic limit V obtained in step S2 into the formula BL50 and the standard deviation σ obtained in step S4, input the incident velocity V i The penetration probability F(V i ).

2. A method for rapidly evaluating the probability of a projectile penetrating a target plate according to claim 1, characterized in that: In step S2, the incident speed V i - Remaining speed V r50 The relationship is V r50 =a(V i P -V BL50 P ) 1 / P , the parameters a, P and the ballistic limit V at 50% penetration probability are determined by least squares fitting BL50 value.

3. A method for rapidly evaluating the probability of a projectile penetrating a target plate according to claim 2, characterized in that: In step S4, the ballistic limit probability model satisfies the normal distribution, and the remaining velocity V r = 0, then the incident velocity V i Equal to the ballistic limit V BL , the relationship between the ballistic limit and the probability parameter satisfies V BL =δV BL50 .

4. A method for rapidly evaluating the probability of penetration of a projectile into a target plate according to claim 3, characterized in that: In step S4, the probability model of the probability parameter satisfies δ j ∶N(μ,σ 2 ), the probability model of ballistic limit satisfies V BL(j) ~N(V BL50 μ,(V BL50 σ) 2 ), μ and σ are the mean and standard deviation of the probability parameters obtained in step S3, where μ = 1, 5. A method for rapidly evaluating the probability of a projectile penetrating a target plate according to claim 4, characterized in that: In step S5, the projectile is i The penetration probability of the target plate at an incident speed of is equal to the ballistic limit V BL(j) <V i The cumulative probability distribution of .

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