Test bomb design method for accelerating wear degradation

Abstract

The invention provides a test projectile design method for accelerating wear degradation, and relates to the field of test projectile design, the test projectile design method comprises a barrel (10) and a test projectile (20), and the outer wall of the test projectile (20) is designed to be of a multi-projectile-belt structure. The multi-band structure comprises a first band (21) and a plurality of follow-up bands (22), the first band (21) and the follow-up bands (22) are sequentially arranged on the outer ring of the test projectile (20) in the direction from a launching opening of the barrel (10) to a filling part of the test projectile (20), the width of the first band (21) is larger than that of the follow-up bands (22), and the sizes of the follow-up bands (22) are consistent. And chip accumulating grooves are formed between the first bullet belt (21) and the subsequent bullet belt (22) closest to the first bullet belt (21) and between the multiple adjacent subsequent bullet belts (22). According to the test bomb designed by the method, when the bomb is fired at a single time, series firing of extrusion friction of multiple sections of bomb belts can be achieved, barrel abrasion is accelerated, the end-of-life cycle of a barrel is shortened, and the simulation test efficiency and the accuracy of test data are improved.

Description

Technical Field

[0001] The invention relates to the technical field of test projectile design, and in particular to a test projectile design method for accelerated wear and degradation. Background Art

[0002] Artillery systems are more common suppression weapons on modern battlefields and are also the main fire assault force among conventional weapons. During the firing process, the artillery barrel will be eroded and worn due to the high temperature and high-pressure gas generated by the combustion of the propellant and the intense friction between the projectile, the belt and the inner wall of the barrel. First, the aging of the barrel is accelerated and the service life of the barrel is seriously shortened. Second, the wear and tear seriously affects the accuracy of the subsequent projectile firing, resulting in the inability to accurately hit the target. Third, it is prone to safety hazards such as barrel damage and explosion. In order to study the degree of barrel wear and ablation, the conventional method is to use live ammunition simulated shooting to conduct continuous and multiple shooting tests on the barrel, and then dissect the barrel after the accumulated damage has reached the end of its life, so as to analyze the degree of barrel wear and ablation and complete the evaluation of barrel materials, etc.; however, due to the long service life of the existing barrels, which are usually measured in thousands of projectiles, the required test cycle is long, time-consuming and labor-intensive, and the target shooting test requires a lot of manpower and material resources, increases test consumables, and causes a lot of unnecessary waste, that is, the cost of obtaining analysis samples by the existing traditional continuous and multiple simulated shooting test method is high, the accumulated data is limited, and there are certain errors in the accumulated data of the traditional simulated shooting test (due to the long test cycle and the inevitable interference of environmental factors during the test, the early target shooting test and the later target shooting test cannot be carried out under the same conditions, and test errors are prone to occur), and the error accumulation greatly affects the accuracy of the subsequent analysis of the barrel damage mechanism. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide a method for designing a test bullet with accelerated wear and degradation. The test bullet designed by this method can realize the serial firing of multiple sections of bullet belts squeezing into friction during a single firing of the projectile, thereby accelerating the wear of the barrel, shortening the end-of-life cycle of the barrel, and improving the data acquisition efficiency. At the same time, it can also effectively avoid errors caused by differences in environmental factors under long-term tests.

[0004] The purpose of the present invention is achieved through the following technical solutions: A method for designing a test projectile for accelerated wear and degradation comprises a barrel and a test projectile, wherein the outer wall of the test projectile is designed as a multi-band structure, the multi-band structure comprises a first band and a plurality of subsequent bands which are sequentially arranged on the outer circle of the test projectile from the barrel firing port to the test projectile loading part, the first band and the subsequent bands are coaxially arranged with the test projectile, the width of the first band is greater than the width of the subsequent bands and the sizes of the plurality of subsequent bands are consistent, the outer circles of the side surfaces of the first band and the plurality of subsequent bands close to the barrel firing port are both arranged as inclined surfaces with a conical longitudinal section, and chip storage grooves are provided between the first band and the subsequent band closest to it (i.e., the first band) and between the plurality of adjacent subsequent bands; the barrel is coaxially arranged with the test projectile and its inner wall is provided with rifling of a spiral structure, and the inner diameter of the barrel is greater than the outer wall of the test projectile (excluding the band).

[0005] Based on further optimization of the above solution, the first and subsequent belts are integrally formed with the test projectiles and are made of the same material.

[0006] Based on further optimization of the above solution, the number of subsequent elastic bands is 2 to 10.

[0007] Based on further optimization of the above scheme, the width of the first bullet belt is 6-8 mm, the angle of the slope is 30-40°, the height of the first bullet belt (i.e. the distance between the outer wall of the first bullet belt and the outer circle of the projectile) is 0.6-1.0 mm, and the forced extrusion amount of the first bullet belt (forced extrusion amount = 2x bullet belt height + projectile diameter - barrel positive line diameter) is 0.2-0.5 mm.

[0008] Based on further optimization of the above scheme, the distance between the tail of the first bullet belt and the front end (i.e., the striking end) of the test projectile is smaller than the distance between the center of mass of the test projectile and the front end of the test projectile.

[0009] Based on further optimization of the above scheme, the width of the subsequent elastic belt is 1 to 3 mm, and the height and angle of the inclined surface of the subsequent elastic belt are consistent with those of the first elastic belt (that is, the forced extrusion amount of the subsequent elastic belt is consistent with the forced extrusion amount of the first elastic belt).

[0010] Based on further optimization of the above solution, the distance between the bottom of the chip storage groove and the outer wall of the test projectile is 0 to 0.03 mm.

[0011] Based on further optimization of the above scheme, the distance between the first elastic belt and the subsequent elastic belt closest to it (i.e., the first elastic belt), and the distance between multiple subsequent elastic belts, i.e., the width D of the chip storage groove is calculated by vt Curve and v-l The curve is obtained, specifically: First, get the fixed frequency when multiple projectiles are fired continuously f, and obtain the time interval between two consecutive shots t :

[0012] Then, according to the corresponding vt Curve and v-l Curve, get the speed of the projectile launched at the corresponding moment v ; Finally, the width D is obtained by the time interval t and the speed v: .

[0013] Based on further optimization of the above scheme, the vt Curve and v-l The curve is obtained by pre-simulating shooting, specifically: According to the basic equation of interior ballistics, that is: Shape function:

[0014] Burning rate equation:

[0015] Projectile motion equation:

[0016] Projectile velocity and travel equation:

[0017] The basic equation of interior ballistics:

[0018] Where: p Indicates the pressure in the chamber; S Indicates the cross-sectional area of ​​the barrel; It indicates the reduced diameter length of the free volume of the chamber; It means the chamber volume is reduced in diameter; l Indicates the travel of the projectile; f It indicates the power of gunpowder; Indicates the charge amount; Z Indicates the relative thickness of the gunpowder that has burned; v Indicates the speed of the projectile; Indicates the percentage of gunpowder burned; m Indicates the mass of the projectile; represents the adiabatic coefficient; represents the secondary work coefficient; Indicates the density of gunpowder; Indicates the remaining amount of gunpowder; I k Indicates the total impulse of pressure; n Indicates the combustion index; , , Indicates the shape characteristic of gunpowder; The burning rate equation in the basic equation of internal ballistics is simplified so that the burning index n=1. At the same time, continuous and uninterrupted projectile shooting is performed to obtain the internal ballistic equation of each projectile: Among them, the first projectile:

[0019] Where: k represents the adiabatic index; It indicates the flow coefficient of the barrel mouth; Indicates the gas pressure at the barrel mouth; Indicates the gas density at the barrel mouth; L Indicates the barrel length; A.C represents a constant; Burning rate equation:

[0020] Projectile velocity and travel equation:

[0021] Projectile motion equation:

[0022] Where: R x represents the compensation coefficient, ,in, The crowding coefficient, which represents the linear relationship, is obtained based on experimental data; l x represents the formation threshold of initial motion; Second round: Starting from the second round, the travel of each projectile in the barrel is changing, that is, the projectile travel l The trend of change is gradually increasing. At this time, the bullet motion equation has changed:

[0023]

[0024] Where: l d Indicates the length of a single projectile; The projectile travel of the third bullet increases by two projectile lengths, and the bullet motion equation changes. By analogy (i.e., the projectile travel of the fourth bullet increases by three projectile lengths, and the projectile travel of the fifth bullet increases by four projectile lengths), the projectile's length in the barrel is obtained. vt Curve and v-l Curve (where v-l The curve is a nonlinear continuous curve).

[0025] The following are the technical effects of the solution of the present invention: The present application adopts a multi-belt structural design of a first belt and multiple subsequent belts. Compared with the structural design of a single belt, it causes greater wear and impact on the barrel, thereby effectively increasing the damage coefficient of the barrel and achieving the purpose of accelerating the end of the barrel life with a smaller number of shootings. First, it reduces time consumption, improves the efficiency of simulation tests, reduces the number of test bullets used, and reduces test costs. Second, it ensures to the maximum extent that the test is carried out in the same environment, improves the accuracy of the simulation test results, and avoids the influence of external environmental factors on the simulation test. At the same time, the present application adopts a multi-belt structure design of a specific first belt and multiple subsequent belts, that is, by limiting the width, height, forced extrusion amount and distance between the first belt and the subsequent belts, etc., it can not only increase the number of belts set on the same test projectile, but also ensure that each belt can effectively wear the inner wall of the barrel (if the distance between the latter belt and the previous belt is too close, the latter belt is in the wear shadow area of ​​the previous belt, that is, the wear path of the latter belt is consistent with that of the previous belt, and the latter belt runs on the wear of the previous belt, resulting in the latter belt being unable to effectively wear the barrel; if the distance between the latter belt and the previous belt is too far, although the latter belt can be separated from the wear path of the previous belt and form independent wear, the length of the projectile is limited, resulting in a small number of arranged belts, less wear superposition, and a large number of projectiles are still required for testing), thereby increasing the wear amount of the same projectile on the barrel and accelerating the wear degradation test of the barrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the test bomb designed in the embodiment of the present invention.

[0027] Among them, 10, barrel; 20, test projectiles; 21, first belt; 22, subsequent belts. DETAILED DESCRIPTION

[0028] 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 described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0029] Embodiment 1: A method for designing a test projectile with accelerated wear degradation, referring to Figure 1 As shown: it includes a barrel 10 and a test projectile 20, wherein the outer wall of the test projectile 20 is designed as a multi-band structure, and the multi-band structure includes a first band 21 and a plurality of subsequent bands 22 arranged in sequence on the outer circle of the test projectile 20 from the launch port of the barrel 10 to the loading part of the test projectile 20, and the number of the subsequent bands 22 is 2 to 10 (such as Figure 1As shown, in this embodiment, the number of subsequent bands 22 is 4), the first band 21 and the subsequent bands 22 are integrally formed with the test projectile 20 and are made of the same material, and the first band 21 and the subsequent bands 22 are coaxially arranged with the test projectile 20. The width of the first band 21 is greater than the width of the subsequent bands 22 and the sizes of the multiple subsequent bands 22 are consistent. The width M of the first band 21 is 6-8 mm (preferably 7 mm), the height H of the first band 21 (i.e., the distance between the outer wall of the first band 21 and the outer circle of the projectile) is 0.6-1.0 mm (preferably 0.8 mm), and the forced extrusion amount 2J of the first band 21 (forced extrusion amount = 2x band height + projectile diameter - barrel positive line diameter) is 0.2-0.5 mm (preferably 0.35 mm). The distance between the tail of the first band 21 and the front end (i.e., the striking end) of the test projectile 20 is less than the distance between the center of mass of the test projectile 20 and the front end of the test projectile 20 (i.e., the first band 21 is located at the front end of the center of mass of the test projectile 20). The barrel 10 is coaxially arranged with the test projectile 20 and its (i.e., the barrel 10) inner wall is provided with rifling of a spiral structure, and the inner diameter of the barrel 10 is greater than the outer wall of the test projectile 20 (excluding the band, and the band includes the first band 21 and the subsequent band 22).

[0030] The width N of the subsequent ammunition belt 22 is 1 to 3 mm (preferably 2 mm), and the height and angle of the slope of the subsequent ammunition belt 22 are consistent with those of the first ammunition belt 21 (that is, the forced extrusion amount of the subsequent ammunition belt 22 is consistent with the forced extrusion amount of the first ammunition belt 21). The outer circle of the side surface of the first ammunition belt 21 and multiple subsequent ammunition belts 22 close to the barrel firing port 10 is set as a tapered slope with a slope angle of 30 to 40° (preferably 35°). A chip storage groove is provided between the first ammunition belt 21 and the subsequent ammunition belt 22 closest to it (that is, the first ammunition belt 21), and between multiple adjacent subsequent ammunition belts 22. The distance between the bottom of the chip storage groove and the outer wall of the test projectile 20 (that is, the thickness of the chip storage groove) is 0 to 0.03 mm (preferably 0.01 mm).

[0031] The distance between the first elastic belt 21 and the subsequent elastic belt 22 closest to it (i.e., the first elastic belt 21), and between multiple subsequent elastic belts 22, i.e., the width D of the chip storage groove is vt Curve and v-l The curve is obtained, specifically: First, get the fixed frequency when multiple projectiles are fired continuously f (The projectile used here is a traditional single-belt projectile), and the time interval between two consecutive shots is obtained t : .

[0032] Then, according to the corresponding vt Curve and v-lCurve, get the speed of the projectile launched at the corresponding moment v ; in, vt Curve and v-l The curve is obtained by pre-simulating shooting (the projectiles used in the simulated shooting are also traditional single-belt projectiles), specifically: According to the basic equation of interior ballistics, that is: Shape function:

[0033] Burning rate equation:

[0034] Projectile motion equation:

[0035] Projectile velocity and travel equation:

[0036] The basic equation of interior ballistics is:

[0037] Where: p Indicates the pressure in the chamber; S Indicates the cross-sectional area of ​​the barrel; It indicates the reduced diameter length of the free volume of the chamber; It means the chamber volume is reduced in diameter; l Indicates the travel of the projectile; f It indicates the power of gunpowder; Indicates the charge amount; Z Indicates the relative thickness of the gunpowder that has burned; v Indicates the speed of the projectile; Indicates the percentage of gunpowder burned; m Indicates the mass of the projectile; represents the adiabatic coefficient; represents the secondary work coefficient; Indicates the density of gunpowder; Indicates the remaining amount of gunpowder; I k Indicates the total impulse of pressure; n Indicates the combustion index; , , Indicates the shape characteristic of gunpowder; The burning rate equation in the basic equation of internal ballistics is simplified so that the burning index n=1. At the same time, continuous and uninterrupted projectile shooting is performed to obtain the internal ballistic equation of each projectile: Among them, the first projectile:

[0038] Where: k represents the adiabatic index; It indicates the flow coefficient of the barrel mouth; Indicates the gas pressure at the barrel mouth; Indicates the gas density at the barrel mouth; L Indicates the barrel length; A.C represents a constant (obtained from actual test data); Burning rate equation:

[0039] Projectile velocity and travel equation:

[0040] Projectile motion equation:

[0041] Where: R x represents the compensation coefficient, ,in, The crowding coefficient, which represents the linear relationship, is obtained based on experimental data; l x Indicates the formation threshold of initial motion (this threshold is obtained based on actual experimental data and is generally not equal to 0); Second round: Starting from the second round, the travel of each projectile in the barrel is changing, that is, the projectile travel l The trend of change is gradually increasing. At this time, the bullet motion equation has changed:

[0042]

[0043] Where: l d Indicates the length of a single projectile; The projectile travel of the third bullet increases by two projectile lengths, and the bullet motion equation changes. By analogy (i.e., the projectile travel of the fourth bullet increases by three projectile lengths, and the projectile travel of the fifth bullet increases by four projectile lengths), the projectile's length in the barrel is obtained. vt Curve and v-l Curve (where v-l The curve is a nonlinear continuous curve).

[0044] Finally, the width D is obtained by the time interval t and the speed v: .

[0045] Embodiment 2: As another preferred embodiment of the present application, in order to facilitate the smooth extrusion of the test projectile 20 into the inner cavity of the barrel 10 and avoid the violent friction between the test projectile 20 and the extrusion end of the inner wall of the barrel 10, thereby affecting the subsequent friction loss of the barrel 10, on the basis of the scheme of Example 1, the barrel 10 is located at the end of the extrusion end of the test projectile 20 (i.e. Figure 1 The inner cavity of the right end portion (as shown in the figure) is arranged as a conical cavity with a diameter gradually decreasing from right to left, the conical cavity is arranged coaxially with the barrel 10 and the maximum diameter of the conical cavity is consistent with the outer diameter of the first bullet belt 21, and the length of the conical cavity is not greater than the width of the first bullet belt 21.

Claims

1. A method for designing a test projectile for accelerated wear degradation, characterized in that: It comprises a barrel and a test projectile, wherein the outer wall of the test projectile is designed as a multi-band structure, the multi-band structure comprises a first band and a plurality of subsequent bands which are sequentially arranged on the outer circle of the test projectile from the barrel firing port to the test projectile loading part, the first band and the subsequent bands are coaxially arranged with the test projectile, the width of the first band is greater than the width of the subsequent bands and the sizes of the plurality of subsequent bands are consistent, the outer circles of the side surfaces of the first band and the plurality of subsequent bands close to the barrel firing port are both arranged as inclined surfaces with a conical longitudinal section, and chip storage grooves are provided between the first band and the nearest subsequent band and between the plurality of adjacent subsequent bands; the barrel is coaxially arranged with the test projectile and its inner wall is provided with rifling of a spiral structure, and the inner diameter of the barrel is greater than the outer wall of the test projectile.

2. The method for designing a test bullet for accelerated wear degradation according to claim 1, characterized in that: The number of the subsequent elastic belts is 2 to 10.

3. A method for designing a test bullet for accelerated wear degradation according to claim 1 or 2, characterized in that: The width of the first elastic band is 6-8 mm, the angle of the inclined surface is 30-40°, the height of the first elastic band is 0.6-1.0 mm, and the forced extrusion amount of the first elastic band is 0.2-0.5 mm.

4. A method for designing a test bullet for accelerated wear degradation according to claim 1 or 3, characterized in that: The width of the subsequent elastic belt is 1 to 3 mm, and the height and angle of the inclined surface of the subsequent elastic belt are consistent with those of the first elastic belt.

5. The method for designing a test bullet for accelerated wear degradation according to claim 4, characterized in that: The distance between the first elastic belt and the subsequent elastic belt closest to it, and the distance between multiple subsequent elastic belts, that is, the width D of the chip storage groove is vt Curve and v-l The curve is obtained, specifically: First, get the fixed frequency when multiple projectiles are fired continuously f , and obtain the time interval between two consecutive shots t : Then, according to the corresponding vt Curve and v-l Curve, get the speed of the projectile launched at the corresponding moment v ; Finally, the width D is obtained by the time interval t and the speed v: 。 6. The method for designing a test bullet for accelerated wear degradation according to claim 5, characterized in that: Said vt Curve and v-l The curve is obtained by pre-simulating shooting, specifically: According to the basic equation of interior ballistics, that is: Shape function: Burning rate equation: Projectile motion equation: Projectile velocity and travel equation: The basic equation of interior ballistics is: Where: p Indicates the pressure in the chamber; S Indicates the cross-sectional area of ​​the barrel; It indicates the reduced diameter length of the free volume of the chamber; It means the chamber volume is reduced in diameter; l Indicates the travel of the projectile; f It indicates the power of gunpowder; Indicates the charge amount; Z Indicates the relative thickness of the gunpowder that has burned; v Indicates the speed of the projectile; Indicates the percentage of gunpowder burned; m Indicates the mass of the projectile; represents the adiabatic coefficient; represents the secondary work coefficient; Indicates the density of gunpowder; Indicates the remaining amount of gunpowder; I k Indicates the total impulse of pressure; n Indicates the combustion index; , , Indicates the shape characteristic of gunpowder; The burning rate equation in the basic equation of internal ballistics is simplified so that the burning index n=1. At the same time, continuous and uninterrupted projectile shooting is performed to obtain the internal ballistic equation of each projectile: Among them, the first projectile: Where: k represents the adiabatic index; It indicates the flow coefficient of the barrel mouth; Indicates the gas pressure at the barrel mouth; Indicates the gas density at the barrel mouth; L Indicates the barrel length; A.C represents a constant; Burning rate equation: Projectile velocity and travel equation: Projectile motion equation: Where: R x represents the compensation coefficient, ,in, The crowding coefficient, which represents the linear relationship, is obtained based on experimental data; l x represents the formation threshold of initial motion; Second round: Starting from the second round, the travel of each projectile in the barrel is changing, that is, the projectile travel l The trend of change is gradually increasing. At this time, the bullet motion equation has changed: Where: l d Indicates the length of a single projectile; The projectile travel of the third bullet increases by two projectile lengths, and the bullet motion equation changes. By analogy, the projectile's travel in the barrel is obtained. vt Curve and v-l curve.

Images