Test apparatus and method for characterizing ignition growth under explosive impact

Abstract

This invention provides an experimental apparatus and method for characterizing ignition growth under explosive impact, comprising a base, two impact pins, and an impact pin sleeve. The impact pin sleeve includes a cylindrical body fitted into a countersunk hole. A radially outwardly extending growth conductor is disposed on one side of the sleeve, secured within a positioning slot, with its radial end extending beyond the base. A through ignition hole is axially formed at the center of the sleeve. Two coaxially arranged impact pins are installed in the ignition hole, with an explosive sample placed between them. An explosive sample filling groove is formed on the top surface of the growth conductor, its radially outer end closed, and its radially inner end connected to the ignition hole. A through probe mounting hole is formed on the sidewall of the growth conductor near its radially outer end. This apparatus can evaluate whether growth and propagation occur after ignition under explosive impact.

Description

Technical Field

[0001] This invention belongs to the field of explosives technology and relates to the measurement of explosive performance parameters. Specifically, it relates to a test device and method suitable for characterizing ignition growth under the impact of explosives. Background Technology

[0002] Explosives are flammable and explosive hazardous materials, and are metastable energetic materials. Achieving a balance between explosive power and safety through rational formulation design is the eternal pursuit of explosive formulation designers. The United States pioneered the Low Vulnerability Concept (LOVA) in the 1970s. Under the premise of ensuring combat capability, the design must minimize the response of munitions to unexpected stimuli, and reduce potential personnel and property losses to a minimum. Explosives can undergo rapid chemical reactions under certain external conditions, leading to combustion or explosion. The energy causing explosive explosions includes heat, mechanical forces, shock waves, and detonation waves. In most cases, the reaction of explosives after unexpected stimuli is mainly combustion and thermal decomposition. The intensity and severity of the reaction depend on whether the explosive continues to grow and propagate after ignition. Therefore, more and more researchers hope to obtain information on the propagation and growth of explosives after ignition, in order to more accurately predict the safety of explosives. Impact is the most common form of stimulation for explosives during storage and use. Whether an explosive ignites and grows after an impact is of great significance to the safety of explosive use, the design of protective measures, and the reduction of the severity of accidents.

[0003] Currently, the main experimental devices used to study the ignition of explosives under impact are the Castells drop weight apparatus and the Federal Bureau of Materials (BAM) impact sensitivity tester. However, these devices have the following problems:

[0004] First, the impact sensitivity tester can only evaluate whether ignition occurs under the impact of explosives, but cannot evaluate whether growth occurs after ignition under the impact of explosives.

[0005] Second, DDT-type test devices are used to evaluate whether an explosive that has already started burning will turn into a detonation, but they are not suitable for evaluating the growth propagation after ignition under the impact of an explosive.

[0006] Impact is the most common form of stimulation for explosives during storage and use. In recent years, accidents have occurred frequently in the explosives industry, which faces a severe safety situation. In order to accurately predict the safety performance of explosives after ignition under impact, it is urgent to develop a test device suitable for the ignition growth of explosives under impact. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a test apparatus and method suitable for characterizing ignition growth under explosive impact, thereby solving the technical problem that existing test apparatuses cannot evaluate whether growth occurs after ignition under explosive impact.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] An experimental apparatus suitable for characterizing ignition growth under explosive impact includes a base, two impact pins and an impact pin sleeve.

[0010] The base includes a base body, on the top surface of which is machined a countersunk hole for mounting a striker sleeve. A radially penetrating positioning slot is provided on one side wall of the countersunk hole for mounting the striker sleeve, and the top of the positioning slot is open.

[0011] The aforementioned striking pin sleeve includes a cylindrical sleeve body, which is fitted into the striking pin sleeve mounting countersunk hole; a radially outwardly extending growth conductor is provided on one side of the sleeve body, which is fitted into the positioning slot, and the radial end of the growth conductor extends out of the base; a through ignition hole is provided in the central axis of the sleeve body.

[0012] The ignition hole is equipped with two coaxially arranged striking pins, and the space between the two striking pins is used to place the explosive sample.

[0013] The top surface of the growth conductor is provided with an explosive sample filling groove. The outer radial end of the explosive sample filling groove is closed, and the inner radial end of the explosive sample filling groove is connected to the ignition hole. The bottom of the explosive sample filling groove is flush with the upper surface of one impact pin, and the upper surface of the other impact pin extends out of the ignition hole.

[0014] The growth conductor has a through probe mounting hole on the side wall near the radial outer end. The probe mounting hole passes through the explosive sample filling groove, and the central axis of the probe mounting hole is perpendicular to the long axis of the explosive sample filling groove.

[0015] The present invention also has the following technical features:

[0016] A probe is installed in the probe mounting hole, with both ends of the probe extending out of the probe mounting hole; both ends of the probe are connected to the detector via signal cables.

[0017] The striking post is a solid cylindrical structure.

[0018] The explosive sample filling groove is rectangular in shape.

[0019] The probe in question is an electrical probe.

[0020] The probe is made of high-strength enameled wire or nickel-chromium alloy wire with a diameter of 0.04-0.07 mm.

[0021] The detector is an oscilloscope or a data logger.

[0022] The present invention also protects a test method for characterizing ignition growth under explosive impact, the method employing the test apparatus described above for characterizing ignition growth under explosive impact.

[0023] The method includes the following steps:

[0024] Step 1: Place the sleeve of the impact sleeve into the impact sleeve mounting countersunk hole of the base, and the growth conductor of the impact sleeve is locked in the positioning slot.

[0025] Step 2: Insert the probe into the probe mounting hole, with both ends extending 0.5mm beyond the probe mounting hole, and then fix it with glue.

[0026] Step 3: Place a striker into the ignition hole and push the striker into contact with the base.

[0027] Step 4: Weigh 50mg to 100mg of explosive sample and place it on the upper surface of the impact post. Spread the explosive sample evenly on the upper surface of the impact post so that all upper surfaces of the impact post are covered with explosive sample.

[0028] Step 5: Place another striking post on the surface of the explosive sample through the ignition hole and rotate it 1 to 2 times.

[0029] Step 6: Fill the explosive sample filling groove with explosive samples in a natural stacking state. The height of the explosive sample is about 2 / 3 of the height of the explosive sample filling groove.

[0030] Step 7: Place the test device for characterizing ignition growth under explosive impact into the positioning sleeve below the impact sensitivity tester.

[0031] Step 8: Connect the signal cable between the probe and the detector. The detector is triggered and the voltage signal change is measured using the on-off method. Select a hammer of the same mass according to the impact sensitivity result of the explosive sample and raise the hammer to the corresponding position.

[0032] Step nine: Put the detector into a test-ready state, release the hammer, and strike the impact column.

[0033] Step 10: If there is an explosion sound, light, or smoke, it indicates that the explosive sample has exploded. If there is no explosion sound, light, or smoke, it indicates that the explosive sample has not exploded. Repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. If no explosion sound, light, or smoke is observed after 25 tests, increase the drop hammer height and repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. Continue the test at this height.

[0034] Step 11: When the explosive sample explodes, if the probe is destroyed and the detector collects a signal, it indicates that the explosive sample will grow and propagate after ignition; otherwise, the explosive sample will not grow and propagate after ignition.

[0035] Step 12: Continue repeating steps 1 through 11 for a total of 25 shots.

[0036] Step thirteen: Based on the results of the 25 tests obtained in step twelve, calculate the probability P of the explosive sample growing and propagating after ignition according to P = n1 × 100% / 25; the magnitude of probability P represents the likelihood of the explosive growing after ignition under impact.

[0037] In the formula:

[0038] n1 represents the number of shots that caused post-growth and propagation in a sample of 25 explosives.

[0039] Compared with the prior art, the present invention has the following technical effects:

[0040] (I) Existing impact sensitivity testing devices can only determine whether an explosive sample ignites, but cannot determine whether the explosive sample continues to grow and propagate after ignition. The device of the present invention can evaluate whether growth and propagation occur after ignition under the impact of an explosive.

[0041] (II) The device of the present invention uses an electric probe to detect the on / off signal generated after the explosive sample ignites and grows under impact, thereby determining whether the explosive sample has ignited and grown, providing a new research method for studying the safety of ignition growth under impact.

[0042] (III) The device of the present invention, combined with the falling weight tester, can expand the application range of the impact sensitivity test device. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the test apparatus of the present invention.

[0044] Figure 2 for Figure 1 A schematic diagram of the AA section structure.

[0045] Figure 3 This is a top view of the base structure.

[0046] Figure 4 for Figure 2 A schematic diagram of the BB section structure.

[0047] Figure 5 This is a side view of the base structure.

[0048] Figure 6 This is a front view structural diagram of the striking post.

[0049] Figure 7 This is a top view of the structure of the striking column.

[0050] Figure 8 This is a top view of the impact sleeve structure.

[0051] Figure 9 for Figure 8 A schematic diagram of the CC section structure.

[0052] Figure 10 This is a side view of the striking post sleeve.

[0053] Figure 11 This is a schematic diagram of the probe's frontal structure.

[0054] Figure 12 This is a top view of the probe's structure.

[0055] Figure 13 This is a typical output signal diagram of the test apparatus of the present invention.

[0056] The meanings of the labels in the diagram are as follows: 1-base, 2-impact pin, 3-impact pin sleeve, 4-probe, 5-detector.

[0057] 101-Base body, 102-Sunk hole for mounting the strike pin sleeve, 103-Positioning bayonet.

[0058] 301-Shell body, 302-Growth conductor, 303-Ignition hole, 304-Explosive sample filling groove, 305-Probe mounting hole.

[0059] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0060] It should be noted that, unless otherwise specified, all components, equipment, and materials in this invention are based on components, equipment, and materials known in the prior art. For example, the impact sensitivity tester uses a commonly used impact sensitivity tester. The impact sensitivity tester is a loading device, preferably using the GJB772A method 601.1 impact sensitivity tester, and the loading device needs to have protective measures capable of withstanding at least 20g of TNT explosion.

[0061] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0062] Example 1:

[0063] This embodiment provides an experimental apparatus suitable for characterizing ignition growth under explosive impact, such as... Figure 1 and Figure 2 As shown, it includes a base 1, two striking pins 2 and a striking pin sleeve 3.

[0064] like Figures 3 to 5 As shown, the base 1 includes a base body 101. A countersunk hole 102 for mounting a striker sleeve is machined on the top surface of the base body 101. A radially penetrating positioning slot 103 is provided on the side wall of one side of the countersunk hole 102. The top of the positioning slot 103 is open.

[0065] like Figures 8 to 10 As shown, the striker sleeve 3 includes a cylindrical sleeve 301, which is fitted into the striker sleeve mounting countersunk hole 102; a radially outwardly extending growth conductor 302 is provided on one side of the sleeve 301, which is snapped into the positioning slot 103, and the radial end of the growth conductor 302 extends out of the base 1; a through ignition hole 303 is provided in the central axial direction of the sleeve 301;

[0066] like Figure 2 As shown, two coaxially arranged striking pins 2 are installed in the ignition hole 303, and the space between the two striking pins 2 is used to place the explosive sample.

[0067] like Figures 8 to 10 As shown, an explosive sample filling groove 304 is provided on the top surface of the growth conductor 302. The outer radial end of the explosive sample filling groove 304 is closed, and the inner radial end of the explosive sample filling groove 304 is connected to the ignition hole 303. The bottom of the explosive sample filling groove 304 is flush with the upper surface of one striking post 2, and the upper surface of the other striking post 2 extends out of the ignition hole 303.

[0068] like Figure 1 , Figures 8 to 10As shown, a through probe mounting hole 305 is provided on the side wall of the growth conductor 302 near the radial outer end. The probe mounting hole 305 passes through the explosive sample filling groove 304, and the central axis of the probe mounting hole 305 is perpendicular to the long axis of the explosive sample filling groove 304.

[0069] In this embodiment, the preferred materials for the components, unless otherwise specified, are all high-grade high-carbon tool steel T10A. For example, the base 1, the striking pin 2, and the striking pin sleeve 3 are machined from high-grade high-carbon tool steel T10A and heat-treated to achieve a hardness of HRC60-65.

[0070] In this embodiment, the preferred dimensions of the base 101 are φ50×25mm, and the dimensions of the countersunk hole 102 for mounting the striker sleeve are φ40×10mm.

[0071] As a preferred embodiment of this invention, such as Figures 6 to 7 As shown, the striking post 2 is a solid cylindrical structure. In this embodiment, the striking post 2 preferably has a diameter of 10mm and a height of 10mm.

[0072] In this preferred embodiment, the ignition hole 303 has a diameter of 10 mm, the explosive sample filling groove 304 has a size of 25×5×6 mm, and the probe mounting hole 305 has a diameter of 0.5 mm.

[0073] In this preferred embodiment, the tolerances between the striking pin 2 and the ignition hole 303, and between the striking pin sleeve mounting countersunk hole 102 and the sleeve body 301, conform to the requirements of GJB 772A method 601.1.

[0074] As a preferred embodiment of this invention, such as Figure 8 and Figure 9 As shown, the explosive sample filling groove 304 is a rectangular groove.

[0075] As a preferred embodiment of this invention, such as Figure 1 As shown, a probe 4 is installed in the probe mounting hole 305, and both ends of the probe 4 extend out of the probe mounting hole 305; the two ends of the probe 4 are connected to the detector 5 through signal cables.

[0076] As a preferred embodiment of this invention, such as Figure 11 and Figure 12 As shown, probe 4 is an electrical probe. Further, probe 4 is made of 0.04-0.07mm high-strength enameled wire or nickel-chromium alloy wire. Preferably, in this embodiment, probe 4 is made of 0.05mm high-strength enameled wire.

[0077] As a preferred embodiment of this invention, such as Figure 1As shown, detector 5 is an oscilloscope or a data logger. In this embodiment, detector 5 is preferably a Tektronix oscilloscope.

[0078] Example 2:

[0079] This embodiment provides a test method for characterizing ignition growth under explosive impact, which uses the test apparatus described above for characterizing ignition growth under explosive impact.

[0080] The method includes the following steps:

[0081] Step 1: Place the sleeve 301 of the striking pin sleeve 3 into the striking pin sleeve mounting countersunk hole 102 of the base 1, and the growth conductor 302 of the striking pin sleeve 3 is locked in the positioning slot 103.

[0082] Step 2: Insert probe 4 into probe mounting hole 305. The two ends of probe mounting hole 305 extend 0.5mm beyond probe mounting hole 305, and then fix it with glue.

[0083] Step 3: Place a striking pin 2 into the ignition hole 303 and gently push the striking pin 2 to contact the base 1.

[0084] Step 4: Weigh 50mg to 100mg of explosive sample and place it on the upper surface of the impact post 2. Spread the explosive sample evenly on the upper surface of the impact post, so that all upper surfaces of the impact post 2 are covered with explosive sample.

[0085] Step 5: Place another striking post 2 on the surface of the explosive sample through the ignition hole 303 and gently rotate it 1 to 2 times.

[0086] Step 6: Fill the explosive sample filling groove 304 with explosive samples in a natural stacking state, with the height of the explosive sample being approximately 2 / 3 of the height of the explosive sample filling groove 304.

[0087] Step 7: Place the test apparatus suitable for characterizing ignition growth under explosive impact into the positioning sleeve below the impact sensitivity tester.

[0088] Step 8: Connect the signal cable between probe 4 and detector 5. Detector 5 is triggered and the voltage signal change is measured using the on-off method (the external contact signal is a 1V constant voltage source). Select a hammer of the same mass according to the impact sensitivity result (H50) of the explosive sample, and raise the hammer to the corresponding position (H50).

[0089] Step nine: Put detector 5 into the test state, release the hammer, and strike the impact column 2.

[0090] Step 10: If there is an explosion sound, light, or smoke, it indicates that the explosive sample has exploded. If there is no explosion sound, light, or smoke, it indicates that the explosive sample has not exploded. Repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. If no explosion sound, light, or smoke is observed after 25 tests, appropriately increase the drop hammer height and repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. Continue the test at this height.

[0091] Step 11: When the explosive sample explodes, if probe 4 is destroyed, detector 5 will collect the following data: Figure 6 The signal shown indicates that the explosive sample will grow and propagate after ignition; otherwise, the explosive sample will not grow and propagate after ignition.

[0092] Step 12: Continue repeating steps 1 through 11 for a total of 25 shots.

[0093] Step thirteen: Based on the results of the 25 tests obtained in step twelve, calculate the probability P of the explosive sample growing and propagating after ignition according to P = n1 × 100% / 25; the magnitude of probability P represents the likelihood of the explosive growing after ignition under impact.

[0094] In the formula:

[0095] n1 represents the number of shots that caused post-growth and propagation in a sample of 25 explosives.

Claims

1. A test method suitable for characterizing ignition growth under explosive impact, characterized in that, The method employs a test device suitable for characterizing ignition growth under explosive impact; the test device suitable for characterizing ignition growth under explosive impact includes a base (1), two impact pins (2) and an impact pin sleeve (3). The base (1) includes a base body (101), and a countersunk hole (102) for mounting a striker sleeve is machined on the top surface of the base body (101). A radially penetrating positioning slot (103) is provided on the side wall of one side of the countersunk hole (102), and the top of the positioning slot (103) is open. The striker sleeve (3) includes a cylindrical sleeve (301) which is fitted into the striker sleeve mounting countersunk hole (102); a radially outward extending growth conductor (302) is provided on one side of the sleeve (301), the growth conductor (302) is fitted into the positioning slot (103), and the radial end of the growth conductor (302) extends out of the base (1); a through ignition hole (303) is provided in the central axis of the sleeve (301). The ignition hole (303) is equipped with two coaxially arranged striking pins (2), and the space between the two striking pins (2) is used to place the explosive sample; The growth conductor (302) has an explosive sample filling groove (304) on its top surface. The outer radial end of the explosive sample filling groove (304) is closed, and the inner radial end of the explosive sample filling groove (304) is connected to the ignition hole (303). The bottom of the explosive sample filling groove (304) is flush with the upper surface of one striking post (2), and the upper surface of the other striking post (2) extends out of the ignition hole (303). The growth conductor (302) has a through probe mounting hole (305) on the side wall near the radial outer end. The probe mounting hole (305) passes through the explosive sample filling groove (304), and the central axis of the probe mounting hole (305) is perpendicular to the long axis of the explosive sample filling groove (304). A probe (4) is installed in the probe mounting hole (305), and both ends of the probe (4) extend out of the probe mounting hole (305); the two ends of the probe (4) are respectively connected to the detector (5) through signal cables. The method includes the following steps: Step 1: Place the sleeve (301) of the striking sleeve (3) into the striking sleeve mounting countersunk hole (102) of the base (1), and the growth conductor (302) of the striking sleeve (3) is locked in the positioning slot (103); Step 2: Insert the probe (4) into the probe mounting hole (305), with both ends of the probe (4) extending 0.5mm out of the probe mounting hole (305), and then fix it with glue; Step 3: Place a striking pin (2) into the ignition hole (303) and push the striking pin (2) to contact the base (1); Step 4: Weigh 50mg to 100mg of explosive sample and place it on the upper surface of the striking post (2), and spread the explosive sample on the upper surface of the striking post so that all the upper surfaces of the striking post (2) are covered with explosive sample. Step 5: Place another striking post (2) on the surface of the explosive sample through the ignition hole (303) and rotate it 1 to 2 times; Step 6: Fill the explosive sample in the explosive sample filling groove (304) in a natural stacking state, with the height of the explosive sample being 2 / 3 of the height of the explosive sample filling groove (304). Step 7: Place the test device for characterizing ignition growth under explosive impact into the positioning sleeve below the impact sensitivity tester. Step 8: Connect the signal cable between the probe (4) and the detector (5). The detector (5) is triggered and the voltage signal change is measured using the on-off method. Select a hammer of the same mass according to the impact sensitivity result of the explosive sample and raise the hammer to the corresponding position. Step 9: Put detector (5) into the test state, release the hammer and strike the impact column (2); Step 10: If there is an explosion sound, light, or smoke, it indicates that the explosive sample has exploded. If there is no explosion sound, light, or smoke, it indicates that the explosive sample has not exploded. Repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. If no explosion sound, light, or smoke is observed after 25 tests, increase the drop hammer height and repeat steps 1 to 9 until there is an explosion sound, light, or smoke, indicating that the explosive sample has exploded. Continue the test at this height. Step 11: When the explosive sample explodes, if the probe (4) is destroyed and the detector (5) collects a signal, it indicates that the explosive sample will grow and propagate after ignition; otherwise, the explosive sample will not grow and propagate after ignition. Step 12: Continue repeating steps 1 through 11 for a total of 25 shots; Step thirteen, based on the 25 test results obtained in step twelve, according to... Calculate the probability of growth and propagation after ignition of the explosive sample. P ; P The probability magnitude indicates the increased likelihood of an explosive igniting under impact. In the formula: n 1 indicates the number of shots that caused post-growth and propagation in a sample of 25 explosives.

2. The test method for characterizing ignition growth under explosive impact as described in claim 1, characterized in that, The striking post (2) is a solid cylindrical structure.

3. The test method for characterizing ignition growth under explosive impact as described in claim 1, characterized in that, The explosive sample filling groove (304) is a rectangular groove.

4. The test method for characterizing ignition growth under explosive impact as described in claim 1, characterized in that, The probe (4) is an electrical probe.

5. The test method for characterizing ignition growth under explosive impact as described in claim 4, characterized in that, The probe (4) is made of high-strength enameled wire or nickel-chromium alloy wire with a diameter of 0.04-0.07 mm.

6. The test method for characterizing ignition growth under explosive impact as described in claim 1, characterized in that, The detector (5) is an oscilloscope or a data logger.

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