Device and method for testing impact sensitivity under thermal-mechanical coupling effect

Abstract

The invention provides an impact sensitivity testing device and method under a thermal-mechanical coupling effect, and relates to the technical field of testing equipment. The test device comprises a temperature control system, an extremely low temperature adjusting module, an impact device, a drop hammer replacement window and a host. The temperature control system is used for setting an experimental temperature to complete tests under different temperature conditions from room temperature to 200 DEG C; the extremely low temperature adjusting module is used for rapidly cooling and controlling the temperature from the room temperature to-40 DEG C; the impact device is used for releasing a drop hammer impact sample for experiment; the drop hammer replacement window is used for safely and conveniently replacing the drop hammer; the host is used for starting impact. The device has the advantages of being accurate in data, high in safety protection level and wide in test temperature range, and impact sensitivity data under the coupling effect of heat and mechanical impact can be obtained. The method can be widely applied to research, production, process optimization, storage, safe use and the like of energetic materials.

Description

Technical Field

[0001] The present disclosure relates to the technical field of testing equipment, and particularly relates to an impact sensitivity testing device and a testing method under thermo-mechanical coupling action. Background Art

[0002] Energetic materials generally refer to gunpowder, explosives and propellants. Energetic materials are the basis for the development of national defense and are the basic components of various types of advanced aircraft and warheads. Impact sensitivity is one of the important properties to measure the safety of energetic materials. It represents the ease of explosion or combustion of the material when it is impacted under certain hammer weight and certain drop height conditions, and temperature is one of the important factors affecting the properties of energetic materials.

[0003] Traditional tests are usually carried out at room temperature. However, since there is no clear regulation on the temperature requirements of the samples, the obtained data often have deviations. Minor differences in room temperature can also affect the test results. Especially in high-temperature environments, the impact sensitivity parameters of the samples will change significantly, showing obvious differences from the room-temperature data. For specific fields such as aerospace and polar scientific research, it is necessary to test the impact sensitivity of materials at extremely low temperatures, otherwise their applications will be restricted. Under these extreme conditions, the materials may accidentally explode or burn due to the failure to reach the expected impact sensitivity, thus causing serious casualties and property losses.

[0004] In the experiment, due to the need to frequently replace drop hammers of different specifications (weights ranging from 0.5 kg to 10 kg), the operation of traditional instruments is quite cumbersome. The experimenter needs to stand on a platform, disassemble the drop hammer release device, and then lift the drop hammer to the top of the guide rail with both hands for replacement. In addition, since the drop hammer release device is heavy, the replacement process takes a long time, and improper operation may cause the drop hammer to slip out of the hand or the experimenter to slip, thus triggering an accident.

[0005] Both the traditional guide rail and the drop hammer are made of stainless steel. Although their contact surfaces are relatively smooth, due to the high hardness of the stainless steel surface, certain friction will still be generated when the drop hammer falls. This friction will gradually increase as the drop hammer accelerates downward, thereby affecting the stability and accuracy of the drop hammer's fall, and thus having a certain adverse impact on the experimental results.

[0006] Before the experiment starts, the drop hammer in traditional instruments is usually firmly fixed by a buckle. After the experiment starts, the release device buckle is opened by a remote control to release the drop hammer. When the buckle is opened, a lateral force is generated at the fixing point of the drop hammer, resulting in an S-shaped curve of the drop hammer's falling trajectory, causing the drop hammer to collide frequently with the inner wall of the guide rail, generating significant friction and collision forces. Such collisions will cause kinetic energy loss, reduce the falling speed of the drop hammer, and prolong the falling time, thus seriously affecting the accuracy of the experimental results. In the impact sensitivity experiment, the data mainly relies on the gravitational acceleration to calculate the impact energy, and excessive frictional resistance will lead to a smaller actual acceleration, with a large deviation from the gravitational acceleration, thereby causing a large deviation in the experimental results.

[0007] Therefore, it is urgent to develop an impact sensitivity test device under thermo-mechanical coupling and provide its test method, which can be used to test the impact sensitivity under different temperature conditions, eliminate the errors in the traditional test process, reduce the risks in the traditional test process, and obtain the impact sensitivity data under the coupling action of heat and mechanical impact. Summary of the Invention

[0008] Aiming at the above problems, the present invention provides an impact sensitivity test device and test method under thermo-mechanical coupling, which can solve the problems of low accuracy of test data, temperature limitation, and dangerous operation process, and can also obtain the impact sensitivity data under the coupling action of heat and mechanical impact.

[0009] An impact sensitivity test device and test method under thermo-mechanical coupling, characterized in that the impact sensitivity test device under thermo-mechanical coupling includes: a temperature control system, an extremely low temperature adjustment module, an impact device, a drop hammer replacement window, and a mainframe.

[0010] The temperature control system is used to set the experimental temperature to complete tests under different temperature conditions within the range from room temperature to 200 °C; the extremely low temperature adjustment module is used to quickly cool down and control the temperature within the range from room temperature to -40 °C; the impact device is used to release the drop hammer to impact the sample for the experiment; the drop hammer replacement window is used for safely and conveniently replacing the drop hammer; the mainframe is used to initiate the impact.

[0011] The temperature control system includes a temperature controller, a micro heating rod, a PT100 temperature sensor, a sample temperature calibrator, and a central anvil. The sample temperature calibrator consists of a steel cylinder and a calibration PT100 temperature sensor. There is a small hole in the center of the steel cylinder, and the aperture size is such that the calibration PT100 temperature sensor can be inserted and fit perfectly with the steel cylinder.

[0012] The side of the central anvil is drilled with holes, and four micro heating rods are installed in the holes at four symmetrical positions, which can achieve uniform heating of the sample; another hole is inserted with a PT100 temperature sensor, and this PT100 temperature sensor is connected to a temperature controller.

[0013] During the experiment, first install the positioning ring on the central anvil, place the first steel cylinder into the positioning ring, connect a guiding ring to the steel cylinder to form an open container for placing the sample; add the sample into the above container, and then install the second steel cylinder into the guiding ring to form a complete and closed sample placement area for the experiment.

[0014] The temperature control system can perform accurate temperature difference calibration, and the steps are as follows: ① Remove the second steel cylinder in the installed sample placement area, install the sample temperature calibrator into the guiding ring, and the temperature sensor on the sample temperature calibrator can accurately read the real-time temperature of the sample. ② The micro heating rods start to heat the central anvil. When the temperature shown by the PT100 temperature sensor inserted into the central anvil reaches the target temperature, in fact, the temperature in the sample placement area has not reached the target temperature. Read the temperature shown by the sample temperature calibrator, that is, the actual temperature in the sample placement area, calculate the difference between it and the temperature shown by the PT100 temperature sensor (target temperature), and write it as the temperature calibration value. ③ After writing, the temperature shown by the PT100 temperature sensor will become "target temperature - calibration value". Next, without adjusting the target temperature, the temperature controller will control the micro heating rods to continue heating. Wait until the PT100 temperature sensor shows that the target temperature is reached and stabilize for 1 min. At this time, the temperature shown on the sample temperature calibrator is within ±1 °C of the target temperature. Repeat the above operations and complete two more calibrations to accurately control the temperature in the sample placement area at the target temperature.

[0015] The extremely low temperature adjustment module includes a micro heating rod for defrosting, a liquid nitrogen cooling annular tube, and a heat insulation container. The liquid nitrogen cooling annular tube is installed around the central anvil, the heat insulation container is installed outside the liquid nitrogen cooling annular tube, the liquid nitrogen cooling annular tube is fixed to the impact device, the nozzle is connected to a solenoid valve, and the terminal is connected to a liquid nitrogen cylinder.

[0016] Furthermore, the nozzles on the liquid nitrogen cooling annular tube are evenly distributed around the central anvil, and a micro heating rod for defrosting is installed corresponding to each nozzle. The micro heating rod for defrosting will quickly heat for 3 - 5 s during the interval between two adjacent liquid nitrogen jets. The micro heating rod for defrosting can prevent the surrounding air from condensing and frosting on the liquid nitrogen nozzles to block the nozzles during the interval when the liquid nitrogen nozzles eject liquid nitrogen.

[0017] The temperature control system is used in conjunction with an ultra-low temperature regulation module to accurately obtain the temperature difference between the temperature of the sample placement area and the temperature of the central anvil under ultra-low temperature conditions. This temperature difference is introduced into subsequent tests to calculate the sample temperature, i.e., sample temperature = central anvil temperature - temperature difference. The specific steps are as follows: ① Install the sample temperature calibrator on the guide ring, install the liquid nitrogen cooling annular tube around the central anvil, and install the heat insulation container. Set the experimental temperature and start the instrument for testing. At this time, the temperature controller will control the solenoid valve to open, so that liquid nitrogen continuously sprays around the central anvil, and the central anvil quickly cools down. When the temperature displayed by the PT100 temperature sensor in the central anvil drops below the target temperature by 10 °C, stop spraying liquid nitrogen. ② After stopping the spraying of liquid nitrogen, the system temperature will slowly rise. Due to the installation of the heat insulation container, the central anvil will slowly absorb the heat in the surrounding environment, and the PT100 temperature sensor will display the temperature rising slowly in real time. When it rises to the target temperature, the PID of the temperature control system starts, which can control the heating of the heating rod and the cooling of the liquid nitrogen nozzle at the same time. Once the temperature displayed by the sample temperature calibrator is higher than the set temperature, the liquid nitrogen nozzle starts to cool the central anvil. If the measured temperature is lower than the set temperature, the micro heating rod will perform a small amount of heating to supplement. The whole process is monitored and dynamically controlled by the temperature control system in real time, and finally the temperature of the central anvil is stabilized at "target temperature ± 0.5 °C". ③ After the temperature is stabilized, the liquid nitrogen nozzle and the micro heating rod will still work continuously to ensure stable temperature control. After being stable for 5 minutes like this, the temperature in the sample placement area also reaches stability, and the sample can be placed for testing.

[0018] The hammer release part of the impact device consists of a mechanical buckle and an electromagnet suction cup. The hammer can not only be fixed on the mechanical buckle, but also be firmly attracted by the electromagnet suction cup at the same time. Specifically, the disc structure at the top of the hammer can be firmly attracted by the electromagnet suction cup, and the columnar structure below the disc can be fixed by the mechanical buckle.

[0019] Further explanation: When the mechanical buckle is opened, a horizontal force is applied to the contact part between the buckle and the drop hammer. This force causes the drop hammer to jitter left and right during its fall. If the drop hammer is directly released at this time, then during the sliding process, the drop hammer will collide with the inner side of the guide rail multiple times. This kind of collision ultimately causes the sliding trajectory of the drop hammer to present an irregular S-shaped curve. During the entire sliding process, the frictional resistance received by the drop hammer will gradually increase, resulting in a decrease in the actual acceleration during the fall and an extension of the falling time, making the deviation of the test results too large. However, in the release device of the present invention, after the mechanical buckle is opened, it will wait for 3 - 5 seconds. Due to the influence of the horizontal force, the drop hammer will tremble slightly when the mechanical buckle is opened. But after waiting for 3 - 5 seconds, the drop hammer will be in a completely stationary state. At this time, the electromagnet suction cup is powered off, and the drop hammer will smoothly fall along the guide rail in a free-fall manner without colliding with the guide rail multiple times.

[0020] In summary, if only relying on the traditional mechanical buckle to fix and release the drop hammer, the trajectory of the drop hammer during the sliding process will surely present an S-shaped curve, resulting in a large deviation in the measurement results. On the other hand, if only using the electromagnet suction method to fix and release the drop hammer, once the electromagnet is powered off or the suction is not tight, the situation of the drop hammer falling accidentally may occur, and there is a certain operation risk in this process. Therefore, the present invention innovatively combines these two methods, which can not only ensure that the drop hammer is firmly locked by the mechanical device when it is stationary, avoiding the risk of accidental sliding, but also ensure that the drop hammer is not affected by the lateral force generated after the mechanical buckle is opened during the release process, thereby improving the accuracy of the test results and the safety of the operation.

[0021] Brass is inlaid on the contact surface between the drop hammer and the guide rail. This structure can reduce the frictional resistance during the sliding process. Since the texture of brass is relatively soft, when it generates relative friction with the stainless steel guide rail, the brass will be worn to produce extremely fine particles, which will play a self-lubricating role for the drop hammer, reducing the frictional resistance and making the drop hammer slide as close as possible to free fall.

[0022] There is a notch on one of the guide rails of the impact device. The notch divides this guide rail into two unconnected upper and lower parts, and the drop hammer replacement window is installed here; the drop hammer replacement window includes: a movable guide rail, a brass bolt, a position sensor, and a positioning knob. The brass bolt will limit the position of the movable guide rail to ensure seamless connection between the movable guide rail and the upper and lower sections of the guide rail.

[0023] When it is necessary to open the drop hammer replacement window for drop hammer replacement, the positioning knob can be loosened first, and then the movable guide rail can be pulled outwards. Because a brass bolt is installed on the drop hammer replacement window, when the movable guide rail is pulled to a certain position, it cannot be pulled any further, and the brass bolt will limit the position of the movable guide rail.

[0024] Further explanation: When the drop hammer replacement window is closed, the movable guide rail and the upper and lower guide rails will combine to form a complete guide rail chute, ensuring that the drop hammer can be smoothly removed from the guide rail. The structure of the drop hammer replacement window has extremely high requirements for the processing technology. It is necessary to ensure that the connection of the guide rails is tight, without protrusions or gaps, to achieve a perfect seamless connection, thereby ensuring the stability and reliability of the entire system.

[0025] When closing the drop hammer replacement window, the movable guide rail needs to be pushed towards the inner side of the guide rail first. The brass pin can ensure that the movable guide rail is pushed smoothly and straight. At the same time, the brass pin can provide good frictional lubrication, ensuring that the movable guide rail is pushed smoothly without being stuck. In addition, the brass pin can also limit the position of the movable guide rail in the drop hammer window when it is pushed back, ensuring a seamless connection between these two sections of the guide rail and the movable guide rail after closing.

[0026] Further explanation: Since a position sensor is installed on the drop hammer replacement window, the position sensor can only be activated when the movable guide rail is pushed back to the correct position. Only then can the drop hammer release device be started. If the movable guide rail is not pushed back to the correct position, the position sensor will not be activated. At this time, even if the drop hammer release device is started, the drop hammer cannot be successfully released.

[0027] The beneficial effects brought by the technical solution provided by the present disclosure at least include:

[0028] 1. By coupling heat and mechanical impact to act on the sample to be tested together, the present invention can obtain impact sensitivity data under any temperature condition from room temperature to 200 °C, thus significantly improving the accuracy of the test results. This innovative method can not only more accurately and perfectly simulate real working conditions, providing important guidance for the performance characterization, formulation optimization, quality control, transportation, storage and classification of energetic materials, but also is expected to promote the technological progress and application development in related fields.

[0029] 2. The present invention has the ability to test the change of impact sensitivity of the same sample under extremely low temperature conditions, and the test temperature range covers from room temperature to -40 °C. This innovative function expands the practical application range of energetic materials under extreme conditions, and its test results have wide application value in fields such as aerospace and polar scientific research.

[0030] 3. The instrument in the present invention is specially provided with a drop hammer replacement window. This innovative design enables the tester to directly and easily remove the drop hammer from the middle section of the guide rail without disassembling the drop hammer release device. This improvement not only simplifies the operation process, making it possible for a single person to complete, but also significantly improves the experimental efficiency, at least by five times. At the same time, due to the reduction of disassembly steps, the potential risks during the test process are also reduced.

[0031] 4. The instrument of the present invention ingeniously combines the traditional mechanical buckle structure with an electromagnet suction cup, providing a dual safety guarantee for the release process of the falling hammer and greatly enhancing the reliability of operation. When the falling hammer is placed in the release device, it is first firmly locked by the mechanical buckle, effectively preventing the risk of accidental sliding. At the same time, the platform at its top is tightly attracted by the electromagnet, further enhancing the overall stability. When the falling hammer needs to be released, the system first opens the mechanical buckle and waits for 3 - 5 seconds to ensure that the falling hammer is in a completely stationary state. Subsequently, the electromagnet suction cup is powered off, and the falling hammer can smoothly slide down along the guide rail in a free - fall manner. This unique design not only ensures the safety of the falling hammer within the release device but also successfully avoids the interference of the lateral force generated when the mechanical buckle is opened on the release process of the falling hammer, thus achieving a more accurate and reliable test effect.

[0032] 5. In the present invention, brass is embedded in the side groove of the guide rail where the falling hammer contacts. This innovative design significantly reduces the frictional resistance during the sliding process. The soft texture of brass causes fine particles to be generated during friction, thereby forming a self - lubricating effect and greatly reducing the frictional force between the falling hammer and the guide rail. This design makes the falling hammer closer to free - fall motion during sliding, effectively eliminating the influence of contact friction on the falling motion of the falling hammer, thus ensuring the accuracy of the test results. Description of the Drawings

[0033] Figure 1 is the front view of the instrument of the present invention;

[0034] Figure 2 is the detailed view of the falling - hammer replacement window of the present invention;

[0035] Figure 3 is the detailed view of the falling - hammer structure of the present invention;

[0036] Figure 4 is the detailed view of the temperature control system of the present invention;

[0037] Figure 5 is the detailed view of the extremely low - temperature regulation module of the present invention.

[0038] Wherein: 1 temperature control system, 1-1 temperature controller, 1-2 micro heating rod, 1-3 PT100 temperature sensor, 1-4 sample temperature calibrator, 1-41 steel cylinder, 1-42 PT100 temperature sensor for calibration, 1-43 guide ring, 1-44 positioning ring, 1-5 center anvil, 2 cryogenic temperature adjustment module, 2-1 micro heating rod for defrosting, 2-2 liquid nitrogen refrigeration annular tube, 2-3 heat insulation container, 2-4 liquid nitrogen cylinder, 2-5 solenoid valve, 3 impact device, 3-1 mechanical buckle, 3-2 electromagnet suction cup, 3-3 drop hammer, 3-4 guide rail, 4 drop hammer replacement window, 4-1 moving guide rail, 4-2 brass bolt, 4-3 position sensor, 4-4 positioning knob, 5 mainframe. Detailed implementation mode

[0039] The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0040] As shown in the attached drawings, an impact sensitivity test device and test method under thermal-mechanical coupling, characterized in that the impact sensitivity test device under thermal-mechanical coupling includes: a temperature control system (1), a cryogenic temperature adjustment module (2), an impact device (3), a drop hammer replacement window (4) and a mainframe (5).

[0041] The temperature control system (1) is used to set the sample temperature to complete tests under different temperature conditions in the range from room temperature to 200 °C; the cryogenic temperature adjustment module (2) is used to quickly cool down and control the temperature in the range from room temperature to -40 °C; the impact device (3) is used to release the drop hammer (3-3) to impact the sample for experiments; the drop hammer replacement window (4) is used to safely and conveniently replace the drop hammer (3-3); the mainframe (5) is used to initiate the impact.

[0042] The temperature control system (1) includes a temperature controller (1-1), a micro heating rod (1-2), a PT100 temperature sensor (1-3), a sample temperature calibrator (1-4) and a center anvil (1-5). The sample temperature calibrator (1-4) consists of a steel cylinder (1-41) and a PT100 temperature sensor for calibration (1-42). There is a small hole in the center of the steel cylinder (1-41), and the aperture size is such that the PT100 temperature sensor for calibration (1-42) can be inserted and fit perfectly with the steel cylinder (1-41).

[0043] The center anvil (1-5) is drilled with holes on the side. Four symmetric holes are respectively installed with four micro heating rods (1-2) to achieve uniform heating of the sample; the remaining one hole is inserted with a PT100 temperature sensor (1-3), and this PT100 temperature sensor (1-3) is connected to the temperature controller (1-1).

[0044] During the experiment, first install the positioning ring (1-44) onto the central anvil (1-5), place the first steel cylinder (1-41) into the positioning ring (1-44), connect a guiding ring (1-43) to the steel cylinder (1-41) to form an open container for placing the sample; add the sample into the above container, then install the second steel cylinder (1-41) into the guiding ring (1-43) to form a complete sample placement area, and conduct the experiment.

[0045] The temperature control system (1) can perform accurate temperature difference calibration, and the steps are as follows: ① Remove the first steel cylinder (1-41) in the installed sample placement area, install the sample temperature calibrator (1-4) into the guiding ring (1-43), and the calibration PT100 temperature sensor (1-42) on the sample temperature calibrator (1-4) can accurately read the real-time temperature of the sample. ② The heating rod starts to heat the central anvil (1-5). When the PT100 temperature sensor (1-3) inserted into the central anvil (1-5) shows a temperature of 150 °C, in fact, the temperature in the sample placement area has not reached 150 °C. Read the temperature shown by the calibration PT100 temperature sensor (1-42), that is, the actual temperature in the sample placement area, calculate the difference between it and the temperature shown on the PT100 temperature sensor (1-3) inserted into the central anvil (1-5), and write it as the temperature calibration value. ③ After writing, the temperature on the PT100 temperature sensor (1-3) inserted into the central anvil (1-5) will become "150 °C - calibration value". Next, without adjusting the set temperature, the micro heating rod (1-2) will continue to heat. After the micro heating rod (1-2) reaches 150 °C, stabilize for one minute. At this time, the temperature shown on the sample temperature calibrator (1-4) is within "150 ± 1 °C". Repeat the above operations and complete two more calibrations to accurately control the temperature in the sample placement area at the set 150 °C.

[0046] The extremely low temperature adjustment module (2) includes a defrosting micro heating rod (2-1), a liquid nitrogen refrigeration annular tube (2-2), and a heat insulation container (2-3). The liquid nitrogen refrigeration annular tube (2-2) is installed around the central anvil (1-5); the heat insulation container (2-3) is installed outside the liquid nitrogen refrigeration annular tube (2-2). The liquid nitrogen refrigeration annular tube (2-2) is fixed to the impact device (3), the pipe orifice is connected to a solenoid valve (2-5), and its terminal is connected to a liquid nitrogen cylinder (2-4).

[0047] The temperature control system is used in conjunction with the ultra-low temperature regulation module to accurately obtain the temperature difference between the temperature of the sample placement area and the temperature of the central anvil under ultra-low temperature conditions. This temperature difference is introduced into subsequent tests to calculate the sample temperature, that is, sample temperature = central anvil temperature - temperature difference. The specific steps are as follows: ① Install the sample temperature calibrator (1-4) on the guide ring (1-43), install the liquid nitrogen refrigeration annular tube (2-2) around the central anvil (1-5), and install the heat insulation container. Set the experimental target temperature and start the instrument for testing. At this time, the temperature controller (1-1) will control and open the solenoid valve (2-5) to continuously spray liquid nitrogen around the central anvil (1-5), and the central anvil (1-5) will quickly cool down. When the temperature displayed by the PT100 temperature sensor (1-3) in the central anvil (1-5) drops below the target temperature by 10 °C, stop spraying liquid nitrogen. ② After stopping the spraying of liquid nitrogen, the system will slowly rise. Due to the installation of the heat insulation container, the central anvil (1-5) will also slowly absorb the heat in the surrounding environment, and the PT100 temperature sensor (1-3) will display the temperature rising slowly in real time. When it rises to the target temperature, the temperature controller (1-1) can simultaneously control the heating of the micro heating rod (1-2) and the refrigeration of the solenoid valve (2-5). Once the sample temperature calibrator (1-4) shows that the temperature is higher than the target temperature, the solenoid valve (2-5) is activated to cool down the central anvil (1-5). If the measured temperature is lower than the target temperature, the micro heating rod (1-2) will perform a small amount of heating to supplement. The whole process is monitored and dynamically controlled by the temperature control system in real time, and finally the temperature of the central anvil (1-5) is stabilized at "target temperature ± 0.5 °C". ③ After the temperature is stabilized, the micro heating rod (1-2) and the solenoid valve (2-5) will still work continuously to ensure stable temperature control. After being stable for five minutes like this, the temperature at the sample temperature calibrator (1-4) also reaches stability.

[0048] The hammer release part of the impact device (3) consists of a mechanical buckle (3-1) and an electromagnet suction cup (3-2). The hammer (3-3) can not only be fixed on the mechanical buckle (3-1), but also be firmly attracted by the electromagnet suction cup (3-2) at the same time. Specifically, the disc structure at the top of the hammer (3-3) can be firmly attracted by the electromagnet suction cup (3-2), and the columnar structure below the disc can be fixed by the mechanical buckle (3-1).

[0049] In the present invention, all hammers (3-3) are embedded with brass on the contact surface with the guide rail (3-4). This structure can reduce the frictional resistance during the sliding process. Since the brass is relatively soft, when it generates relative friction with the stainless steel guide rail (3-4), the brass will be worn to produce extremely fine particles, which will play a self-lubricating role for the hammer, reduce the frictional resistance, and make the hammer (3-3) as close as possible to free-fall sliding.

[0050] One of the guide rails (3-4) of the impact device (3) has a notch, which divides this guide rail (3-4) into two unconnected upper and lower parts, and the drop hammer replacement window (4) is installed here; the drop hammer replacement window (4) includes: a moving guide rail (4-1), a brass bolt (4-2), a position sensor (4-3) and a positioning knob (4-4), and the brass bolt limits the position of the moving guide rail (4-1) to ensure seamless connection between the moving guide rail (4-1) and the upper and lower guide rails (3-4).

[0051] The impact sensitivity test device and test method under thermo-mechanical coupling provided in the present invention are mainly used for the impact sensitivity test of energetic materials. The specific operation steps for the extremely low temperature test are as follows:

[0052] 1. Check the instrument: Turn on the power supply to ensure that the instrument is in good operating condition. Check and adjust the control system of the equipment to ensure the stable operation of the micro heating rod (1-2), liquid nitrogen cylinder (2-4), solenoid valve (2-5), etc.

[0053] 2. Prepare the sample: Select the energetic material to be tested and prepare the sample according to the test requirements. Ensure that the size, shape and quality of the sample meet the test standards.

[0054] 3. Extremely low temperature calibration: Install the center anvil (1-5) on the main anvil, place a positioning ring (1-44) in the center of the center anvil (1-5), and place the steel cylinder (1-41) in the positioning ring (1-44). Take a guide ring (1-43) and place it above the steel cylinder (1-41). Install the sample temperature calibrator (1-4) on the guide ring (1-43), install the liquid nitrogen cooling annular tube (2-2) around the center anvil (1-5), and install the heat insulation container (2-3). Set the experimental temperature, start the sample temperature calibrator (1-4), and wait for the extremely low temperature adjustment module (2) to cool the center anvil (1-5). After the temperature stabilizes, record the temperature difference data between the temperature control point and the sample point for five minutes.

[0055] 4. Sample loading: Remove the sample temperature calibrator (1-4), place the sample at the center of the guide ring (1-43) of the test equipment, cover it with the steel cylinder (1-41) without holes, start the temperature control, and wait for five minutes for the temperature to stabilize.

[0056] 5. Equip the drop hammer: Loosen the positioning knob (4-4), pull out the moving guide rail (4-1) outward, and release it when it reaches the position limited by the brass bolt (4-2). Suck the drop hammer (3-3) onto the electromagnet chuck (3-2) and lock the mechanical buckle (3-1). Pull the moving guide rail (4-1) back to its original position, tighten the positioning knob (4-4), and check whether the position sensor (4-3) is activated.

[0057] 6. Conduct an impact test: Use the remote control to release the mechanical buckle (3-1), and you can hear the sound of metal collision. After 5 s, release the electromagnet chuck (3-2) to loosen the drop hammer (3-3), so that the drop hammer (3-3) impacts the specimen in a free-fall manner. Record the material reaction after the impact, including whether there is an explosion, combustion, etc., and the severity of the reaction.

[0058] 7. End of the test. After the impact sensitivity test is completed, take out the drop hammer (3-3) from the drop hammer replacement window, close the solenoid valve (2-5) and the micro heating rod (1-2) in sequence. After the surface temperature of the specimen drops to room temperature, remove it and clean the test residues on the surface of the device.

[0059] 8. Repeat the test and verification: To improve the accuracy and reliability of the test results, multiple repeated tests need to be carried out, and the results are statistically analyzed and compared. After the experiment is completed, turn off the power supply.

[0060] It should be noted that the temperature difference between the sample temperature calibration (1-4) and the center anvil (1-5) is affected by the ambient temperature. Since the laboratory ambient temperature will change, we recommend recalibrating the temperature difference between the temperature control point and the sample point every 4 hours. After calibration, a new temperature difference value will be generated for result calculation to ensure the accuracy and reliability of the test results.

Claims

1. An impact sensitivity testing device and testing method under thermal coupling, characterized in that: The impact sensitivity testing device under the action of thermal coupling comprises: a temperature control system (1), an extremely low temperature adjustment module (2), an impact device (3), a drop hammer replacement window (4) and a main machine (5); The temperature control system (1) is used to set the experimental temperature to complete the test under different temperature conditions ranging from room temperature to 200° C.; The extremely low temperature adjustment module (2) is used for rapid temperature reduction and temperature control in the range from room temperature to -40°C; The impact device (3) is used to release a drop hammer to impact the sample for testing; The drop hammer replacement window (4) is used to replace the drop hammer safely and conveniently; The host (5) is used to start the impact.

2. The impact sensitivity testing device and testing method under thermal coupling according to claim 1, characterized in that: The temperature control system (1) comprises a temperature controller (1-1), a micro heating rod (1-2), a PT100 temperature sensor (1-3), a sample temperature calibrator (1-4) and a central anvil (1-5).

3. The impact sensitivity testing device and testing method under thermal coupling according to claim 2, characterized in that: The sample temperature calibrator (1-4) is composed of a steel cylinder (1-41) and a PT100 temperature sensor (1-42) for calibration. A small hole is provided at the center of the steel cylinder (1-41). The hole diameter is large enough to allow the PT100 temperature sensor (1-42) for calibration to completely match the steel cylinder (1-41) after being inserted.

4. The impact sensitivity testing device and testing method under thermal coupling according to claim 2, characterized in that: The central anvil (1-5) is punched with holes on its side, wherein four holes at symmetrical positions are respectively installed with four micro-heating rods (1-2) to ensure uniform heating; the other hole is inserted with a PT100 temperature sensor (1-3), and the PT100 temperature sensor (1-3) is connected to a temperature controller (1-1).

5. The impact sensitivity testing device and testing method under thermal coupling according to claim 1, characterized in that: The extremely low temperature regulating module (2) comprises a defrosting micro heating rod (2-1), a liquid nitrogen refrigeration annular tube (2-2) and a heat-insulating container (2-3).

6. The impact sensitivity testing device and testing method under thermal coupling according to claim 5, characterized in that: The liquid nitrogen refrigeration annular tube (2-2) is installed around the central anvil (1-5), the heat-insulating container (2-3) is installed outside the liquid nitrogen refrigeration annular tube (2-2), the liquid nitrogen refrigeration annular tube (2-2) is fixed to the impact device (4), the tube mouth is connected to the electromagnetic valve (2-5), and the tube terminal is connected to the liquid nitrogen cylinder (2-4).

7. The impact sensitivity testing device and testing method under thermal coupling according to claim 1, characterized in that: The drop hammer release part of the impact device (3) is composed of a mechanical buckle (3-1) and an electromagnetic suction cup (3-2). The drop hammer (3-3) can not only be fixed on the mechanical buckle, but also be firmly sucked by the electromagnetic suction cup (3-2).

8. The impact sensitivity testing device and testing method under thermal coupling according to claim 7, characterized in that: The drop weight (3-3) is embedded with brass on the contact surface with the guide rail (3-4), and this structure can reduce the friction resistance during the sliding process.

9. The impact sensitivity testing device and testing method under thermal coupling according to claim 1, characterized in that: A notch is provided on one of the guide rails (3-4) of the impact device (3), the notch dividing the guide rail (3-4) into two unconnected upper and lower parts, and the drop hammer replacement window (4) is installed here; The drop-hammer replacement window (4) comprises: a movable guide rail (4-1), a brass latch (4-2), a position sensor (4-3) and a positioning knob (4-4); the brass latch (4-2) limits the position of the movable guide rail (4-1) to ensure that the movable guide rail (4-1) is seamlessly connected to the upper and lower guide rails (3-4).

10. The impact sensitivity testing device and testing method under thermal coupling according to claim 1, characterized in that: After the impact sensitivity testing device is started, the impact sensitivity testing method according to any one of claims 1 to 9 is implemented.

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