A warhead dynamic explosive power field test verification method and device

Abstract

The present invention provides a method and apparatus for testing and verifying the dynamic explosive power field of a warhead. During a dynamic explosive test of a warhead, this method and apparatus uses an image acquisition device to capture images of the warhead's flight attitude at the explosion point, the shell fragment dispersion trajectory, the explosion point, and the moment of impact. Overpressure data during the explosion test is acquired through a shock wave overpressure testing system. After the explosion, fragment perforation of the target plate is acquired. Based on these images, the warhead's initial velocity, fragment velocity, and dispersion trajectory are calculated. The spatial distribution of fragment count is analyzed based on the fragment perforation of the target plate. Based on the overpressure data, the effects of warhead drop velocity and impact angle on the air shock wave specific impulse and overpressure peak are analyzed. The method and apparatus of the present invention can detect the distribution patterns of the fragment power field and shock wave power field during a dynamic explosive state, including fragment dispersion and shock wave distribution, and can provide important data support for the structural design, performance evaluation, and combat use of anti-personnel grenades.

Description

Technical Field

[0001] The present invention relates to the field of damage assessment technology, and in particular to a warhead dynamic explosion power field test verification method and device. Background Art

[0002] High-explosion grenades are artillery shells that rely on the fragments and shock waves generated by the explosion of explosives to kill or destroy targets. They are the most commonly used basic type of shells in modern artillery, and use the fragments and shock waves generated by the explosion of the projectile to kill or blast.

[0003] Acquiring the power field of a high-explosion grenade provides crucial support for its structural design, performance evaluation, and operational use. Currently, the power field of a high-explosion grenade is primarily determined through static testing. Based on static explosion tests, velocity vector synthesis is used to study the dispersion patterns of fragments after the explosion of a moving projectile. However, since the dispersion velocities of thousands of fragments are difficult to accurately determine through testing, the dynamic dispersion pattern of fragments cannot be accurately determined through static explosion testing combined with theoretical analysis. Static explosion tests also struggle to accurately reflect the impact of the terminal velocity on power field parameters such as the fragment dispersion pattern. Therefore, acquiring a high-explosion grenade power field that reflects the true terminal trajectory characteristics has become a pressing technical challenge for researchers in this field.

[0004] Among the many types of high-explosive grenades, large-caliber high-explosive grenades differ from precision-strike munitions in their low accuracy. This characteristic makes it difficult to accurately predict their impact points, as with precision-guided munitions. Therefore, deploying power test targets and sensors near these grenades allows for the measurement of the kinetic explosive power field, reflecting the actual trajectory and velocity of the projectile. Therefore, determining the dynamic explosive power field of large-caliber high-explosive grenades through simulation testing is a pressing technical challenge. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for testing and verifying the dynamic explosive power field of a warhead, thereby addressing the problem of studying the spatial distribution of fragments formed by continuous, dynamic, multi-projectile strikes driven by explosions and verifying the spatial distribution formula for fragments. The specific technical solution is as follows:

[0006] A warhead dynamic explosive power field test verification method, characterized in that the method comprises the following steps:

[0007] S1. Acquire relevant images and overpressure data during the warhead dynamic explosion process and target plate fragment penetration images after the dynamic explosion;

[0008] S2. Calculate the initial velocity of the warhead, the velocity of the fragments, and the trajectory of the fragments based on the images obtained during the dynamic explosion process;

[0009] S3. Analyze and process the fragment penetration image of the target plate to obtain the spatial distribution result of the number of fragments;

[0010] S4. Analyze the acquired overpressure data to obtain the results of the effects of the combat landing speed and landing angle on the air shock wave specific impulse and overpressure peak value.

[0011] Furthermore, step S1 specifically includes: conducting multiple dynamic explosion tests using a grenade warhead, obtaining images of the warhead explosion point flight posture, shell fragment scattering trajectory, explosion point and target impact moment during the dynamic explosion process, and simultaneously obtaining shock wave overpressure data, and obtaining fragment penetration images of the rectangular target plate after the dynamic explosion is completed.

[0012] Furthermore, step S2 specifically includes: setting the time when the fire light initially appears in the acquired dynamic explosion process image to 0ms, and obtaining the shell fire light duration from the image, and taking the size of the rectangular target plate in the image background as a reference benchmark, sequentially calculating the initial velocity of the warhead, the fragment velocity and the flying trajectory.

[0013] Furthermore, step S3 specifically includes: analyzing the fragment perforation image, using the sudden change of the grayscale value of the pixel edge of the pit area to segment the image, identify the target area and extract the area shape, using Image-Pro Plus and ImageJ image analysis software to distinguish the obtained pit contours, and classify and count the natural fragment perforations and prefabricated fragment perforations.

[0014] Furthermore, step S4 specifically includes: the shock wave overpressure data is a curve of the air shock wave overpressure at a certain point changing with time, and the peak overpressure Ap, positive pressure action time t+, and specific impulse i at different distances are obtained according to the curve, and the peak overpressure, positive pressure action time, and specific impulse test results at different distances are plotted.

[0015] The present invention also provides a warhead kinetic explosion power field test verification device for implementing the above-mentioned warhead kinetic explosion power field test verification method, the device comprising a test warhead, a rectangular target, a shock wave overpressure test unit, an image acquisition unit, and a host computer;

[0016] The test warhead is used for explosive driving;

[0017] The rectangular target is used to reflect the distribution of warhead fragments;

[0018] The shock wave overpressure test unit is used to obtain shock wave overpressure data of the air around the warhead explosion point;

[0019] The image acquisition unit is used to capture the instantaneous speed of the fragments penetrating the target, the evolution of the scattering trajectory, and the initial velocity and flight attitude of the warhead at the explosion point during the explosion driving process;

[0020] The host computer is used for image analysis and processing and overpressure data analysis and processing.

[0021] Furthermore, the test warhead is a 105mm grenade warhead, the firing state of the test warhead is flat shooting, and the detonation method is detonation by a center fuse at one end.

[0022] Furthermore, the rectangular targets are arranged on both sides and in front of the explosion point. The rectangular targets on the left and right sides are 10m away from the explosion point and both have an angle of 45° with the direction of the ballistic line. The rectangular target in front is 30m away from the explosion point.

[0023] Furthermore, the shock wave overpressure test system includes a shock wave overpressure tester and multiple sensors. The shock wave overpressure tester and sensors are respectively arranged on two straight lines in the emission direction and perpendicular to the emission direction. The sampling frequency of the sensor is 1MHz, the measuring range is 1.5Mpa, and the triggering mode is internal triggering.

[0024] Furthermore, the image acquisition system is a Fastemite nltimaAPX high-speed camera, and the shooting rate of the high-speed camera is set to 24,000 frames / s.

[0025] The present invention provides a method and device for verifying the dynamic explosive power field of a warhead, which has the following beneficial effects:

[0026] The present invention provides a warhead dynamic explosive power field test verification method and device that can detect the power field distribution law of the anti-personnel grenade in the dynamic explosive state, including the fragment power field and the shock wave power field, including the fragment scattering and shock wave distribution, etc., which can provide important data support for the structural design, performance evaluation and combat use of the anti-personnel grenade. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of a warhead dynamic explosive power field test verification method provided by the present invention;

[0028] Figure 2 Schematic diagram of the dynamic axial distribution of warhead fragments in Example 1 of the present invention;

[0029] Figure 3 The measured data of the shock wave overpressure and positive pressure action time in Example 1 of the present invention;

[0030] Figure 4 Schematic diagram of the measurement results of shock wave overpressure, positive pressure action time, and specific impulse in Example 1 of the present invention;

[0031] Figure 5 It is a schematic diagram of a warhead kinetic explosive force field test verification device provided by the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings provided by the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are all in a very simplified form and are not to exact scale. They are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connection" and "connected" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the description of the present invention, terms such as "up", "down", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inside", and "outside" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0035] Example 1: This example provides a method for testing and verifying the dynamic explosive power field of a warhead. Figure 1 As shown, the method includes the following steps:

[0036] S1. Obtain relevant images and overpressure data during the warhead dynamic explosion process and the target plate perforation status after the dynamic explosion;

[0037] S2. Calculate the initial velocity of the warhead, the velocity of the fragments, and the trajectory of the fragments based on the acquired images;

[0038] S3. Analyze and process the fragment penetration situation on the target plate to obtain the spatial distribution result of the number of fragments;

[0039] S4. Analyze the acquired overpressure data to obtain the results of the effects of the combat landing speed and landing angle on the air shock wave specific impulse and overpressure peak value.

[0040] The verification results of the above-mentioned method of the present invention can provide important data support for the structural design, performance evaluation and combat use of anti-personnel grenades. The following uses a 105mm grenade warhead as an example to specifically illustrate a warhead dynamic explosive power field test verification method provided by the present invention.

[0041] As a specific implementation of step S1 above, a 105mm grenade warhead was used to conduct a kinetic explosion and continuous strike test on a rectangular target. The warhead was launched in a flat-fire mode, detonated using a central fuze at one end, and the muzzle-to-blast point distance was 200m, with the explosion point at a height of 1.5m above the ground. The warhead was capable of continuous strikes, and the test was repeated multiple times. In this embodiment, three kinetic explosion tests were conducted. During each explosion, images of the warhead's explosion point flight posture, the shell fragment dispersion trajectory, the explosion point, and the moment of impact were captured. Overpressure data of the air shock wave was also captured. After the explosion, images of the fragment penetration of the rectangular target plate were obtained.

[0042] As a specific implementation of step S2 above: Since explosives produce a noticeable flash after detonation, which first intensifies and then gradually weakens over time, the initial flash time in the image is set to 0ms, and the shell flash duration is obtained from the image. Since each high-speed image in the figure is scaled to the same ratio, the size of the rectangular target plate in the background can be used as a reference to sequentially calculate the initial warhead velocity, fragment velocity, and dispersion trajectory.

[0043] In this example, the warhead flew parallel to the ground at the detonation point, forming a 45° angle with the rectangular target plate. Initial velocities at the detonation point were measured in three tests, measuring 540 m / s, 563 m / s, and 523 m / s, respectively. The fireball and fragments began to separate 1.394 ms after detonation, and the fragments then began to move ahead of the fireball. Fragment data within this angle was collected using a witness plate. It can be seen that after the detonation, a bright spot appeared on the target plate at 30.8 ms. Then, by 38.4 ms, the fragments gradually spread from the center of the target plate to both sides, increasing in velocity. This indicates that the warhead fragment dispersion velocity increases from the detonation end to the center of the detonation to the tail end, then decreases. The calculation is carried out according to the law of fragment motion. It is assumed that the horizontal flight trajectory of the fragment is a straight line. The influence of air lift and body gravity is ignored. Only the air resistance is considered. The initial velocity of the fragment is calculated by reverse calculation from the velocity of the speed measuring point. The obviously smaller value of the fragment velocity obtained by the error of the shooting frame is removed to obtain the initial velocity. The fragment velocities measured in the three tests are compared to obtain the spatial distribution results of the velocity and the dispersion angle under the dynamic explosion condition of the warhead. The axial penetration velocity distribution of the fragment within the target plate coverage angle is obtained and fitted. The dynamic axial distribution results of the fragment after fitting are shown as follows: Figure 2 shown.

[0044] As a specific implementation of step S3 above: After multiple consecutive strike tests, analyze the fragment perforation image of the target plate on one side of the trajectory. Using the sudden change in pixel grayscale values ​​at the edge of the crater area, the image is segmented, the target region is identified, and the region shape is extracted. IPP (Image-Pro Plus) and ImageJ image analysis software are used to distinguish the obtained crater contours, and natural and prefabricated fragment perforations are classified and counted. Image-Pro is used to process the target plate to generate a fragment perforation grayscale bitmap. Prefabricated fragment perforations are divided and counted using pre-drawn area lines on the target plate. Each vertical line represents one degree. The target impacts under three consecutive dynamic strikes are counted separately. The resulting spatial distribution of fragment counts generally conforms to the normal distribution curve for static fragment dispersion.

[0045] As a specific embodiment of step S4 above: In an aerial explosion test, for a period of time before the air shock wave generated by the explosion reaches the free-field sensor, the ambient pressure of the sensor is the initial air pressure p0. When the air shock wave reaches the sensor, the pressure rapidly rises to p, and then the overpressure slowly decays to the initial air pressure. Δp = p - p0 is called the air shock wave overpressure. The pressure measured by the sensor in the present invention is the air shock wave overpressure Δp. When the sensor measures pressure at a distance R, a curve showing the air shock wave overpressure at that point is measured after the shock wave passes through the pressure sensor. Furthermore, parameters describing the explosion air shock wave include the peak (peak or trough) pressure of the air shock wave and the propagation velocity. The wave arrival time, peak pressure, and the duration of the positive pressure action of the shock wave can be used to quantify the instantaneous energy release of the explosive. The positive pressure action time t+ is a characteristic parameter of the explosion air shock wave and is one of the important parameters that influence the magnitude of the destructive effect on the target. When the air shock wave reaches the pressure sensor, the pressure suddenly rises to a peak value, which is usually called the air shock wave peak overpressure. Then, within the time t+, the pressure slowly decays to the ambient pressure. The part of the time history in which the pressure is greater than the initial ambient pressure is called the positive pressure action time t+.

[0046] In this embodiment, the shock wave overpressure variation curve obtained in the experiment decays rapidly in the initial stage, then decays slowly, and then a small amplitude shock wave follows closely behind the positive pressure area or the negative pressure area. It is comprehensively judged that the small amplitude shock wave that appears is a secondary shock wave; the peak overpressure Ap, positive pressure action time t+, and specific impulse i at different distances measured in this embodiment are shown in FIG. Figure 3 As shown in the figure, the peak overpressure, positive pressure action time and specific impulse test curves at different distances can be obtained accordingly. Figure 4 shown.

[0047] The experimental curves show that the peak overpressure, positive pressure duration, and specific impulse of the air shock wave at different blast heights and angles exhibit a certain pattern. When the shock wave overpressure sensor is tested up to 4 meters from the overpressure test distance, the peak overpressure decay rate of the second sample is faster than that of the other two. After 4 meters, the decay rate of the second sample's peak overpressure is similar to that of the other two. At 2 meters from the explosion center, a secondary shock wave appears behind the negative pressure zone. At 5 meters, secondary shock waves appear behind the positive pressure zones (Y1 and Y2), indicating that the arrival time of the secondary shock wave is related to the overpressure amplitude and the test distance. When the specific impulse is tested up to 3.5 meters from the explosion center, the second sample's shock wave specific impulse decay rate is faster than that of the other two. After 3.5 meters, the decay rate of the second sample's shock wave specific impulse is similar to that of the other two. This is primarily due to the different locations of the explosion points. As the drop angle at the explosion point increases and the drop height decreases, the measured positive pressure duration increases gradually from 2 to 5 meters, with a comparable increase (57.2%). In the near field (2-4 meters), the air shock wave specific impulse and peak overpressure drop driven by the dynamic explosion significantly decrease, primarily due to the drop velocity. The experimental results show that the warhead drop velocity has the greatest influence on the overpressure specific impulse, the drop angle has the greatest influence on the overpressure peak, and the drop angle and explosion height have the greatest influence on the positive pressure duration. Optimal damage conditions exist for increasing the overpressure peak and specific impulse by appropriately increasing the warhead's drop angle, drop height, and drop velocity.

[0048] Example 2: This example provides a warhead dynamic explosive power field test verification device, see Figure 5 As shown, the device includes a test warhead 1, a rectangular target plate 2, a shock wave overpressure test unit 3, an image acquisition unit 4, and a host computer.

[0049] As a specific implementation of the test warhead 1, the test warhead is a 105mm grenade warhead, the shell wall thickness of which is 20mm, and an injection-molded tungsten ball cap is installed at one end of the shell. The tungsten ball has a diameter of 3.3mm and a mass of 1.56kg. The tungsten ball cap shell and the wind cap are fixed by a threaded connection. The firing state of the warhead is flat shooting, and the detonation method is detonation by a center fuse at one end.

[0050] As a specific embodiment of the rectangular target plate 2, the rectangular targets can be arranged on both sides and in front of the explosion point. The target width of a single target plate is 1m and the target height is 3m. The rectangular targets on the left and right sides are 10m away from the explosion point radius, and both have an angle of 45° with the direction of the ballistic line. The target plate on the left side of the ballistic line has a size of 6m*3m and a recovery angle of 65°. The target plate on the right side has a size of 5m*3m and a recovery angle P of 49°. The rectangular target in front of the explosion point is 30m away from the explosion point and has a size of 13m*3m. At the same time, in order to clearly obtain the number of holes formed by prefabricated fragments on the rectangular target, so as to realize the conversion between size and fragments in the later stage and then obtain the corresponding fragment spatial distribution, the target plate can be spray-painted in advance, so that the holes formed by prefabricated fragments and natural fragments on the target plate can be clearly distinguished in the later stage.

[0051] Preferably, the target plate of the rectangular target is a Q235 steel target with a thickness of 3 mm.

[0052] As a specific embodiment of the shock wave overpressure test unit 3, the shock wave overpressure test unit includes a shock wave overpressure tester and sensors, which are arranged in the emission direction and two straight lines perpendicular to the emission direction, respectively, at 2 meters, 3 meters, 4 meters, and 5 meters away from the explosion point, for a total of 8 overpressure test points. The angle between the two rows of sensors is 90°, the sensor sampling frequency is 1MHz, the range is 1.5Mpa, and the trigger mode is internal triggering. For the sensor layout diagram, see Figure 5 shown.

[0053] As a specific implementation of the image acquisition unit 4, the image acquisition unit can use a high-speed camera. A high-speed camera is placed 50m away from the explosion point. A Fastemite nltimaAPX high-speed camera can be selected. During the test, the shooting rate is set to 24,000 frames / s to capture the initial velocity and flight posture of the warhead at the explosion point during the explosion drive process, as well as the instantaneous velocity of the fragments penetrating the target and the evolution of the flying trajectory.

[0054] As a specific implementation of the host computer, the host computer includes image processing software and overpressure testing software. The image processing software can analyze and process the images obtained during the dynamic explosion process and the target plate perforation images. The overpressure testing software can analyze and process the overpressure data to obtain corresponding test verification results.

[0055] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention in accordance with the above disclosure are within the scope of protection of the claims.

Claims

1. A warhead dynamic explosive power field test verification method, characterized in that: The method comprises the following steps: S1. Acquire relevant images and overpressure data during the warhead dynamic explosion process and target plate fragment penetration images after the dynamic explosion; S2. Calculate the initial velocity of the warhead, the velocity of the fragments, and the trajectory of the fragments based on the images obtained during the dynamic explosion process; S3. Analyze and process the fragment penetration image of the target plate to obtain the spatial distribution result of the number of fragments; S4. Analyze the acquired overpressure data to obtain the effects of the combat drop velocity and landing angle on the air shock wave specific impulse and overpressure peak value; Step S1 specifically includes: performing multiple dynamic explosion tests using a grenade warhead, obtaining images of the warhead's flight posture at the explosion point, the scattering trajectory of shell fragments, the explosion point, and the moment of impact during the dynamic explosion, and simultaneously obtaining shock wave overpressure data; and obtaining an image of the fragment penetration of the rectangular target plate after the dynamic explosion is completed; The step S4 specifically includes: the shock wave overpressure data is a curve of the air shock wave overpressure at a certain point changing with time, and the peak overpressure Ap, positive pressure action time t+, and specific impulse i at different distances are obtained according to the curve, and the peak overpressure, positive pressure action time, and specific impulse test results at different distances are plotted.

2. The warhead dynamic explosive power field test verification method according to claim 1, characterized in that: The step S2 specifically includes: setting the time when the fire light initially appears in the acquired dynamic explosion process image to 0ms, obtaining the shell fire light duration from the image, and using the size of the rectangular target plate in the image background as a reference benchmark to sequentially calculate the warhead initial velocity, fragment velocity, and flying trajectory.

3. The warhead dynamic explosive power field test verification method according to claim 1, characterized in that: The step S3 specifically includes: analyzing the fragment perforation image, using the sudden change in the grayscale value of the pixel at the edge of the pit area to segment the image, identify the target area, and extract the area shape, using Image-Pro Plus and ImageJ image analysis software to distinguish the obtained pit contours, and classify and count the natural fragment perforations and prefabricated fragment perforations.

4. A warhead kinetic explosion power field test verification device, used in the warhead kinetic explosion power field test verification method according to any one of claims 1 to 3, characterized in that: The device includes a test warhead, a rectangular target, a shock wave overpressure test unit, an image acquisition unit, and a host computer; The test warhead is used for explosive driving; The rectangular target is used to reflect the distribution of warhead fragments; The shock wave overpressure test unit is used to obtain shock wave overpressure data of the air around the warhead explosion point; The image acquisition unit is used to capture the instantaneous speed of the fragments penetrating the target, the evolution of the scattering trajectory, and the initial velocity and flight attitude of the warhead at the explosion point during the explosion driving process; The host computer is used for image analysis and processing and overpressure data analysis and processing.

5. The warhead dynamic explosive power field test verification device according to claim 4, characterized in that: The test warhead is a 105mm grenade warhead, the firing state of the test warhead is flat shooting, and the detonation method is detonation by a center fuse at one end.

6. The warhead dynamic explosive force field test and verification device according to claim 4, characterized in that: The rectangular targets are arranged on both sides and in front of the explosion point. The rectangular targets on the left and right sides are 10m away from the explosion point and both have an angle of 45° with the direction of the ballistic line. The rectangular target in front is 30m away from the explosion point.

7. The warhead dynamic explosive power field test verification device according to claim 4, characterized in that: The shock wave overpressure test unit includes a shock wave overpressure tester and multiple sensors. The shock wave overpressure tester and sensors are respectively arranged in the emission direction and two straight lines perpendicular to the emission direction. The sampling frequency of the sensor is 1MHz, the measuring range is 1.5Mpa, and the triggering mode is internal triggering.

8. The warhead dynamic explosive force field test verification device according to claim 4, characterized in that: The image acquisition system is a Fastemite nltima APX high-speed camera, and the shooting rate of the high-speed camera is set to 24,000 frames / s.

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