Testing method with particle erosion firing for low and high velocities

Abstract

A test method for determining impact effects and abrasion effects of particles such as rain, hail, dust, ice, sand, and micrometeoroids at speeds above Mach, i.e., higher than the speed of sound. The test method includes the steps of placement of balls in capsules, firing the capsules with a rifle firing system, hitting of the fired capsules and/or the balls to a target inside a firing range, recording the impact effects during a firing with a recording system, determining a durability and a lifetime of a test sample of test samples by calculating a number of the balls hitting the target and a number of shots providing an effect.

Claims

1. A method for simulating impact effects and abrasion effects in an environment of a rain, a sand, a dust, an ice or micrometeoroids of different particle sizes at speeds above Mach or at speeds below Mach, comprising the process steps of: placement of balls in capsules, firing the capsules with a rifle firing system to obtain fired capsules, capturing the capsules using a spiked obstacle to test the effect of only the balls and eliminating impact effects of fired capsules, hitting of the balls to a target inside a firing range, recording the impact abrasion effects on the target during a firing with a recording system, and determining a durability and a lifetime of a test sample used as the target in the environment at speeds above Mach or below Mach by providing a number of the balls hitting the target and a number of fired capsules shots calculated to provide impact effects and abrasion effects equivalent to the rain, sand, dust, ice, or micrometeoroids of different particles sizes of the environment, and assessing the recorded impact abrasion effects on the target.

2. The method according to claim 1, further comprising the process step of testing the target by selecting the balls in different sizes.

3. The method according to claim 2, further comprising the process step of selecting the different sizes of the balls in a form of 0.5 mm and multiples of 0.5 mm.

4. The method according to claim 3, further comprising the process step of obtaining a mixture of 100% in total by mixing the balls of 0.5 mm and the multiples of 0.5 mm in different proportions.

5. The method according to claim 1, further comprising the process step of testing the target by selecting the balls in different sizes and various ratios.

6. The method according to claim 5, further comprising the process step of obtaining a mixture of 100% in total by mixing the balls of 0.5 mm and multiples of 0.5 mm in different proportions, and reproducing the test samples by using various ball sizes and mixing ratios.

7. The method according to claim 1, further comprising the process step of determining of a shot rate of the balls on the target depending on dimensions of a shot distribution cone.

8. The method according to claim 1, further comprising the process step of testing the target with a mounting bracket at different impact angles.

9. The method according to claim 8, further comprising the process step of protecting the mounting bracket from the shots with a protection shield.

10. The method according to claim 1, wherein the balls are produced from material selected from the group consisting of polyoxymethylene (POM) and silica.

11. The method according to claim 1, further comprising the process step of making the firing range suitable for environmental conditions of the environment desired to be tested by conditioning the fire range with a temperature, a humidity and a pressure.

12. The method according to claim 1, further comprising the process step of testing target materials in different shapes and forms, wherein the different shapes and forms comprise cube, pyramid and irregular shapes, apart from a spherical form depending on the effect of an abrasive material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGURE is the view of the shooting range in which the test method of the invention is carried out and the firing system.

REFERENCE NUMBERS

(2) 1. Rifle firing system 2. Balls 3. Shooting range 4. Target 5. Recording system 6. Mounting bracket 7. Shield 8. Shot distribution cone 9. Spiked obstacle

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) In this detailed description, the preferred structures of the test method of the invention are described only for a better understanding of the subject.

(4) The invention comprises the steps of placing the balls (2) made of materials with the closest density to water instead of the lead balls in the shotgun cartridge and firing this cartridge towards the sample to be tested at speeds close to or above Mach value. The number of balls in the cartridge varies depending on the size of the balls used. The sizes of the balls (2) can be adjusted to have mixtures of different diameters and desired proportions of various diameters according to droplet sizes and, if desired, droplet size distribution.

(5) In this test method, a special shotgun is used to accelerate the capsule and/or balls (2) above Mach speed. Depending on the test conditions, the material of the balls in the capsule can be selected or defined. For rain erosion testing, the material closest to the water density as much as possible can be selected. The balls produced from the selected material are inserted into the capsule. The capsules used in the tests are produced by replacing the lead balls in shotgun cartridges with balls made of materials closest to water properties. The number of balls (2) in the capsule varies depending on the dimensions used.

(6) Using information such as rainfall rate, rain velocity, etc., the raindrop size and raindrop size distribution per cubic meter can be approximately calculated. Using this calculation, it is possible to estimate how long the moving object will travel in the rain and the number and size of droplets that will hit the object during this time. Using these calculated values and the number and distribution of the balls in a capsule, the number of shots to be made to have an effect similar to the size and distribution of raindrops can be calculated. Using these calculations, the size and number of droplets that will hit the object and the number of shots simulating this effect can also be calculated. Tests for the durability and lifespan of the test sample can be performed by conducting shooting tests in accordance with the calculated number of shots.

(7) The test infrastructure, as shown in the FIGURE, consists of four main groups: rifle firing system (1), target (4), firing range (3) and recording system (5).

(8) The rifle firing system (1) comprises a special capsule structure for test conditions. In the special capsule structure, balls (2) suitable for planned tests are placed. The most suitable capsule structure according to the test parameters is also formed by using balls (2) with different diameters and various distribution ratios. The muzzle velocity can be adjusted according to the type and amount of gunpowder power and the distance to the target (4). The shot rate of the balls (2) on the target (4) can also be determined depending on the dimensions of the shot distribution cone (8).

(9) As a target (4), any real system or coupon matching the firing range (3) can be used. To test the target (4) at different angles of impact, it would be convenient to mount it with a mounting bracket (6) at different angles. The mounting bracket (6) is protected from shots by the protection shield-structure (7).

(10) To prevent environmental damage during tests, the tests were conducted at a ballistically protected firing range (3). According to the requirements of the test environmental conditions, the weather inside the range can be conditioned.

(11) By means of the recording system (5), impact effects during firings are recorded. The motion trajectory of the balls (2) during collision is recorded by the high-speed camera mounted outside the shot distribution cone (8).

(12) This test method is used to test the impact and abrasion effects of various particle sizes such as rain, dust, ice, micrometeoroids, etc., at high speeds. As an example, to test the erosive effect of rain erosion, delrin (POM—Polyoxymethylene) balls with a density of 1.4 g/cm.sup.3 and a diameter of 2 mm were selected among the materials closest to the density of water. Besides, balls made of materials such as silica are also selected. One capsule is filled with approximately 1000 delrin balls of 2 mm diameter. If desired, delrin balls with diameters of 0-10 mm in different proportions can be filled into the capsule. In assessing the impact of collisions, the sound propagation rate in the material can be taken into account in collisions at speeds above 1 Mach. Therefore, sound propagation rate can also be considered as a feature in material selection. This value is approximately 2400 m/s for delrin and 1500 m/s for water. The value of delrin is about 1.6 times that of water. This ratio can be evaluated as a safety coefficient. When its general properties are examined, delrin as a material is considered as a suitable material for balls to be used in tests.

(13) Capsules filled with delrin balls were fired at a speed of approximately 400 m/s (more than 1 Mach) at the target (4) object. This speed can be increased or decreased depending on the gunpowder and barrel size.

(14) The balls (2) in the cartridge are contained in a capsule. During the shot, the capsule moves with the balls inside at a high speed and hits the target. Since the shape, size and mass of the capsule are very different from the balls (2), the effects of the capsule and the balls are also very different. The balls in the capsule are in the form of 0.5 mm multiples such as 0.5 mm, 1 mm, 1.5 mm, and a mixture of various sizes and diameters can be obtained in a capsule. As an example, a 100% mixture can be obtained by mixing 30% of 0.5 mm diameter balls, 40% of 1 mm diameter balls, and 30% 1.5 mm diameter balls (2). Samples can be duplicated using different screen sizes and mixing ratios. In order to test the impact effect of only the balls (2), the impact of the capsule must be eliminated. Therefore, a structure is required to capture the capsule. To capture the capsule, a specially designed spiked obstacle (9) was used. Thus, only the balls (2) in the capsule are allowed to hit the target (4). Moreover, the balls can be tested in different shapes and forms (cube, pyramid, irregular shapes), apart from the spherical form, depending on which form of the material to be tested is desired to be tested according to the effect of the target (4) material.

(15) This test method can also be used to test the effects of sand, dust or other particles on the target (4) at low velocity and high speed (above 1 Mach). In this case, it is sufficient to fill the capsule with balls produced from the material closest to the technical specifications of these materials. For example, it is recommended to use silica material as the shot material for sand. Tests can be conducted by adjusting the size of the balls according to the size and other properties of the sand.

(16) Special measurement systems are also used for acoustic and pressure measurement in order to detect breaks and cracks that may occur on the target as a result of collision and to analyze the effects better. The firing range (3) can be conditioned according to environmental conditions such as temperature, humidity, pressure, etc., to be tested. In this way, tests can be performed under real environmental conditions.

(17) The testing method described by the invention is a method that allows the testing of impact and abrasion effects of rain, sand, dust, ice, and micrometeoroids of different particle sizes at high speeds above Mach, wherein; comprises the process steps of, placement of the balls (2) in the capsules, firing the said capsule with a rifle firing system (1), hitting of the fired capsule and/or balls (2) to the target (4) inside the firing range (3), recording the impact effects during firing with a recording system (5), determining the durability and lifetime of the test sample by calculating the number of balls hitting the target (4) and the number of shots providing this effect.

(18) In addition, it also includes the process steps of testing the target by selecting the balls in different sizes, testing the target (4) by selecting the balls in different sizes and various ratios, determining the hitting rate of the balls (2) depending on the size of the shot distribution cone (8), capturing the capsule to test the effect of only the balls (2) by using the spiked obstacle (9) and eliminating the impact, testing the target (4) with the mounting bracket (6) at different impact angles, protecting the said mounting bracket (6) from shots with the protection shield (7), conditioning the firing range (3) with temperature, humidity, pressure and making it suitable for the environmental conditions desired to be tested.