A test system and method for preventing secondary impact of a light gas gun projectile body

Abstract

The application relates to a test system and method for preventing secondary impact of a light gas gun projectile body, and belongs to the technical field of light gas gun high-speed impact dynamics test. The application is used for solving the problem that the existing light gas gun test system lacks the function of preventing secondary impact, the projectile body rebounds to cause secondary loading to a target, and the evaluation of the first impact damage is distorted. The application comprises a launching tube, an impact projectile body, a velocity measuring device, an intercepting mechanism and a controller. The velocity measuring device is arranged at the outlet end of the launching tube to measure the incident velocity and rebound velocity of the projectile body. The intercepting mechanism comprises a blocking piece, a reset piece and a driving device. The controller controls the driving device according to the rebound velocity to selectively drive the blocking piece to enter or exit the inner hole of the launching tube. The application realizes active interception through the closed-loop control of "velocity measurement-judgment-execution", and an oval long hole is arranged on the launching tube to accelerate exhaust and reduce residual gas disturbance. The impact projectile body is detachably connected by a projectile holder and a projectile head, and different head types can be replaced under the condition that the total mass remains unchanged.

Description

Technical Field

[0001] This invention belongs to the field of high-speed impact dynamics testing technology for light gas guns, specifically relating to a test system for preventing secondary impacts on a target structure by a rebounding projectile after a high-speed impact of a light gas gun. It is used to determine the light gas gun loading test technology and method required for studying the damage characteristics of a target structure under a single impact. Background Technology

[0002] With the development of materials science and advanced manufacturing technology, composite materials and their structures are increasingly widely used in aviation, high-speed rail, automobiles, and other fields. Taking modern civil aircraft as an example, the use of advanced composite materials is approaching 50%, and some business jets even adopt all-composite structures. In actual service, these structures face high-speed impact threats such as bird strikes, hail, sand, or metal fragments. Whether they can maintain sufficient residual strength after impact is one of the core concerns in structural design. Therefore, before conducting full-scale structural verification tests, it is necessary to simulate and introduce visible or invisible impact damage in key areas to verify whether their residual strength meets safety requirements. This requires the test system to be able to accurately apply a single impact load to selected areas from different angles, with different energies, and with different projectile nose shapes, obtaining damage characteristic data without secondary interference. This is a necessary technical means to support research on the residual strength and vulnerability of material structures.

[0003] Currently, equipment used for high-speed impact testing mainly includes light air guns, Hopkinson bars, and drop hammer impact testing machines. While drop hammer testing machines typically have anti-secondary impact capabilities, the more widely used light air guns and Hopkinson bars generally lack this feature. In actual tests, projectiles are highly prone to rebound after high-speed impact on the target. Without an effective interception mechanism, the rebounding projectile will impact the target again, causing unexpected secondary loading. The direct consequence of this deficiency is that secondary impacts severely obscure the source of damage, leading to distorted assessments of primary impact damage. This makes it impossible to accurately obtain the damage behavior characteristics of material structures under real single impacts, thus severely limiting the performance verification capabilities of related material structures under high-speed impact conditions.

[0004] In summary, given the urgent need for accurate primary impact test data for advanced composite materials, existing lightweight gas gun test systems are unable to effectively prevent secondary impacts from projectiles, thus failing to meet the increasingly stringent requirements of scientific research and engineering evaluation. Therefore, there is an urgent need to develop a lightweight gas gun test system capable of actively identifying and intercepting rebounding projectiles and preventing secondary impacts, providing more rigorous and reliable test methods and means for high-speed impact dynamics research and damage tolerance assessment of composite material structures. Summary of the Invention

[0005] To address the problem that existing light gas gun test systems lack secondary impact protection, leading to unexpected secondary loading of the rebounding projectile on the target and thus distorting the assessment of primary impact damage characteristics, this invention provides a test system and method for preventing secondary impacts from light gas gun projectiles.

[0006] In a first aspect, the present invention provides a test system for preventing secondary impacts from light gas cannon projectiles, comprising:

[0007] Launch tube 2;

[0008] Impacting projectile 1;

[0009] The velocity measuring device 6 is located at the outlet end of the launching tube 2 and is used to measure the incident velocity of the impact projectile 1 before it impacts the target and the rebound velocity after it impacts the target.

[0010] The interception mechanism includes a blocking component 5, a resetting component 3, and a driving device 4;

[0011] And the controller;

[0012] The controller controls the action of the drive device 4 based on the rebound speed measured by the speed measuring device 6, so as to drive the blocking member 5 to selectively enter or exit the inner hole of the launch tube 2, thereby intercepting or releasing the rebounding projectile.

[0013] Preferably, the driving device 4 is a cylinder or an electromagnet.

[0014] Preferably, the controller is a PLC control system.

[0015] Preferably, the interception mechanism is configured as follows:

[0016] Before launch, the driving device 4 applies a force to the blocking member 5 to overcome the force of the resetting member 3, causing the blocking member 5 to exit the inner hole of the launch tube 2;

[0017] When the rebound speed is greater than or equal to a set threshold, the controller controls the drive device 4 to remove the force applied to the blocking member 5, so that the blocking member 5 enters the inner hole of the launch tube 2 under the action of the reset member 3, so as to block the rebounding impact projectile 1.

[0018] Preferably, the set threshold is 1 m / s.

[0019] Preferably, the emitting tube 2 is provided with a first exhaust hole 8 for the entry and exit of the blocking member 5 and for gas discharge, and a plurality of evenly distributed second exhaust holes 7 are provided at the front end of the first exhaust hole 8; the first exhaust hole 8 and the second exhaust holes 7 are both elliptical elongated holes.

[0020] Preferably, the speed measuring device 6 is a two-channel laser speed measuring system.

[0021] Preferably, the blocking member 5 is a chuck, and the resetting member 3 is a resetting spring.

[0022] Preferably, the impact projectile 1 is composed of a sabot 12 and a projectile 11 detachably connected; while keeping the total mass of the impact projectile 1 constant, the projectile 11 with different head shapes can be replaced.

[0023] Secondly, the test method for preventing secondary impact of a light gas cannon projectile according to the present invention includes the following steps:

[0024] Step 1: Insert the impact projectile 1 into the predetermined position inside the launch tube 2;

[0025] Step 2: Apply force to the blocking member 5 through the driving device 4 to make the blocking member 5 exit the inner hole of the launching tube 2;

[0026] Step 3: Launch the impact projectile 1, and measure the incident velocity of the impact projectile 1 before it impacts the target using the velocity measuring device 6.

[0027] Step 4: After impacting the target, the projectile 1 bounces back, and its rebound velocity is measured by the velocity measuring device 6.

[0028] Step 5: When the rebound speed is greater than or equal to the set threshold, the controller controls the drive device 4 to remove the force on the blocking member 5, so that the blocking member 5 enters the inner hole of the launch tube 2 under the action of the reset member 3, so as to block the rebounding impact projectile 1 and prevent it from hitting the target again.

[0029] The beneficial effects of this invention are: it provides a reasonably designed, easy-to-manufacture, and laboratory-safe test system and method for secondary impact testing of light gas cannon projectiles. This test system and method can accurately obtain the damage (visible and invisible) behavior characteristics of structures under different energy conditions and single-impact loading conditions with projectiles of the same mass but different head shapes. This provides an effective loading test method for assessing the vulnerability and residual strength of structures, further expanding the testing technology and engineering application capabilities of light gas cannons. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the composition of the anti-light gas projectile secondary impact test system in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram showing the launch preparation state for impacting the projectile.

[0032] Figure 3 A schematic diagram showing the impact of a projectile against a target.

[0033] Figure 4This is a schematic diagram illustrating the rebound state of the impacted projectile.

[0034] Figure 5 Diagram illustrating the activation of the secondary impact protection mode;

[0035] Figure 6 Schematic diagram illustrating the state of preventing secondary impact when capturing the projectile;

[0036] Figure 7 This is a structural diagram of the impact projectile in an embodiment of the present invention;

[0037] Figure 8 These are diagrams illustrating different warhead shapes in embodiments of the present invention, wherein: Figure 8 (a) is a hemispherical warhead with a diameter of 12.7 mm; Figure 8 (b) is a hemispherical projectile with a diameter of 16 mm; Figure 8 (c) is a hemispherical warhead with a diameter of 25.4 mm; Figure 8 (d) is a hemispherical warhead with a diameter of 50 mm.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Impacting projectile body; 11. Projectile head; 12. Sag;

[0040] 2. Transmitter tube; 3. Reset component; 4. Drive device; 5. Blocking component; 6. Speed ​​measuring device; 7. Second exhaust port; 8. First exhaust port. Detailed Implementation

[0041] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0042] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0043] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; and the term "one embodiment" means "at least one embodiment". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0044] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0045] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0046] In related technologies, traditional high-speed impact test systems for light gas guns have significant deficiencies in their ability to acquire single-impact damage characteristics and adaptability to the control of rebounding projectiles. Existing secondary impact prevention schemes mostly rely on passive buffering or manual intervention strategies, which can only achieve limited suppression of secondary impacts in low-speed or low-rebound kinetic energy scenarios. They lack precise modeling mechanisms for the rebound motion characteristics and energy dissipation laws of high-speed projectiles after impacting the target. The transient release of kinetic energy, the uncertainty of the rebound trajectory, and the complex mapping relationship between rebound velocity and incident parameters caused by high-speed projectile impact lack effective decoupling methods. This results in a high degree of coupling between the rebound motion state and the initial launch conditions, making it difficult to achieve accurate prediction and active interception. As a result, the system is prone to secondary impact interference and data failure in high-speed dynamic test scenarios, forming a hidden test blind spot—the equipment is still in working mode, but it can no longer output reliable single-impact damage data, forming a "false normal" test state. Such test failures are particularly dangerous in the verification of impact resistance and residual strength assessment of composite material structures. The test system continuously outputs distorted data containing secondary damage interference, which makes it difficult to support the extraction of the material's true damage tolerance features and the judgment of structural safety. It is very easy for data contamination to lead to the loss of key damage features and misjudgment of damage modes, which in turn causes problems such as overestimation of material performance and insufficient structural safety margin, delaying the timing of design optimization and airworthiness verification.

[0047] Furthermore, the straight-through launch tube structure and passive exhaust method of traditional light gas cannon systems are severely incompatible with the transient motion of high-speed rebounding projectiles, leading to multiple performance bottlenecks in testing. Rebounding projectiles are characterized by abrupt changes in velocity direction and unpredictable trajectories. Traditional solutions rely on a single-channel straight-tube launch and natural depressurization testing mode, lacking rebound path control mechanisms. This makes them prone to complex disturbances such as secondary acceleration or repeated impacts due to the combined effect of the rebounding projectile and the residual pressure of the driving gas, making it difficult to obtain interference-free, continuous single-impact observation data. Simultaneously, the fixed launch tube diameter and length parameters of light gas cannon systems mean that the projectile's motion constraint after rebound relies solely on tube wall limiting, lacking active radial and axial interception mechanisms and the ability to dynamically adjust the interception strategy based on the rebound velocity. More importantly, the launch propellant gas continues to expand and depressurize after the projectile leaves the barrel. The residual pressure distribution inside the tube is coupled with the relative motion of the rebounding projectile, making it difficult for traditional mechanical blocks or simple buffer devices to effectively determine the interception timing. This not only significantly reduces the success rate of rebound interception but also causes secondary collisions between the interception components and the projectile, resulting in distortion of key information such as the target damage boundary and damage mode. Subsequent data processing and damage assessment are extremely difficult, severely restricting the continuous and stable single-load observation efficiency of the test system.

[0048] Meanwhile, in actual high-speed impact tests, both the projectile and the target are in a state of high-energy transient interaction. The projectile material, target stiffness, impact angle, and projectile nose shape collectively cause the rebound motion to exhibit strong nonlinear characteristics. Under these circumstances, the rebound scenarios handled by traditional fixed-parameter mechanical interception devices and manual judgment testing procedures often contain a large number of spurious motion components introduced by unknown rebound parameters, failing to accurately reflect the true damage state of a single projectile impact and the target response characteristics. Therefore, when the projectile is at a high rebound velocity and a large deflection angle, problems such as interception failure and severe secondary impacts are highly likely to occur, resulting in a large number of invalid test results. This not only continuously occupies test resources and interferes with subsequent specimen preparation and testing processes, causing redundant test costs and personnel fatigue, but more seriously, it reduces the confidence of the entire test system, leading to decreased reliability of test results and inaccurate design decisions when facing high-value composite material structure verification tasks.

[0049] In summary, existing technologies have significant systemic deficiencies in terms of the accuracy of single-shot damage acquisition, the stability of rebound projectile control, and the adaptability to test scenarios in high-speed impact tests of lightweight gas guns. They cannot meet the urgent needs of advanced composite material structures for impact resistance verification, which requires highly reliable test data, high-precision damage assessment, and high-confidence safety judgment.

[0050] To address the problems existing in the aforementioned related technologies, the present invention provides a test system and method for preventing secondary impacts from light gas cannon projectiles.

[0051] Combination Figure 1As shown, this embodiment provides a test system for preventing secondary impacts from light gas cannon projectiles, comprising: a launch tube 2; an impact projectile 1; a velocity measuring device 6, disposed at the outlet end of the launch tube 2, used to measure the incident velocity of the impact projectile 1 before impacting the target and the rebound velocity after impacting the target; an interception mechanism, including a blocking member 5, a resetting member 3, and a driving device 4; and a controller. The controller controls the operation of the driving device 4 based on the rebound velocity measured by the velocity measuring device 6, so as to drive the blocking member 5 to selectively enter or exit the inner hole of the launch tube 2, thereby intercepting or releasing the rebounding projectile.

[0052] Specifically, the velocity measuring device 6 acquires real-time velocity data of the projectile before and after impacting the target. During the launch phase, the velocity measuring device 6 measures the incident velocity of the projectile 1 to record the impact energy of this test. After the impact, if the projectile rebounds and passes through the detection area of ​​the velocity measuring device 6 again, the velocity measuring device 6 measures its rebound velocity. The controller receives the velocity signal output by the velocity measuring device 6 and uses the rebound velocity as a decision criterion: when the rebound velocity is greater than or equal to a preset threshold, it is determined that there is a risk of secondary impact with the target; when the rebound velocity is lower than the preset threshold or zero, it is determined that no interception is required. The controller outputs corresponding instructions to the drive device 4 based on the judgment result: when interception is required, the drive device 4 is instructed to remove the force on the blocking member 5, so that the blocking member 5 enters the inner hole of the launch tube 2 under the action of the reset member 3 to form a physical barrier; when interception is not required, the drive device 4 is instructed to maintain the force on the blocking member 5, so that the blocking member 5 remains in the state of being out of the inner hole.

[0053] Furthermore, the drive device 4 can be a cylinder or an electromagnet. The cylinder solution is suitable for test environments with high response speed requirements and sufficient on-site air supply, offering high output force, reliable operation, and simple maintenance. The electromagnet solution is suitable for scenarios with limited installation space and requiring direct electrical drive, offering fast response speed, high control precision, and no need for an air supply. Both solutions can receive electrical control signals from the controller to achieve rapid action, driving the blocking component 5 to switch between the exit and entry states.

[0054] Furthermore, the controller is a PLC control system. PLCs have advantages such as strong anti-interference capability, high reliability, flexible programming, and good scalability, making them suitable for industrial testing scenarios involving sensor signal acquisition, logic judgment, and actuator control. The PLC control system acquires the speed signal output by the speed measuring device 6 in real time, uses built-in comparison logic to determine whether the rebound speed exceeds a set threshold, and outputs a control signal to the drive device 4 based on the judgment result. In addition, the PLC control system can record speed measurement data, interception status, action time, and other information for each test, forming a traceable test database.

[0055] Combination Figures 2 to 6As shown, the interception mechanism is configured as follows: before launch, the drive device 4 applies force to the blocking member 5 to overcome the force of the reset member 3, causing the blocking member 5 to exit the inner hole of the launch tube 2; when the rebound speed is greater than or equal to the set threshold, the controller controls the drive device 4 to remove the force on the blocking member 5, so that the blocking member 5 enters the inner hole of the launch tube 2 under the action of the reset member 3, so as to block the rebounding impact projectile 1.

[0056] Specifically, the interception mechanism operates in two complementary states. The blocking component 5 is implemented using a chuck, while the resetting component 3 is implemented using a return spring. The blocking component 5 is a rotary structure, with one end connected to a rotating shaft and the other end being a hook-shaped or plate-shaped blocking part, allowing it to rotate around the shaft under the action of the driving device 4. The resetting component 3 is sleeved on the rotating shaft or fixed at one end to the blocking component 5, providing continuous rotational torque. In the yielding state: the driving device 4 is energized or vented, applying an active force to the blocking component 5. This force overcomes the elastic force of the resetting component 3, causing the blocking component 5 to rotate around the shaft and exit the inner hole of the launch tube 2. At this time, the internal passage of the launch tube 2 is completely unobstructed, allowing the impacting projectile 1 to accelerate unimpeded under the action of high-pressure driving gas. Interception State: After the controller determines that the rebound speed exceeds the set threshold, it outputs a command to cut off the power source of the drive device 4. The drive device 4 removes its force on the blocking member 5, the elastic potential energy stored in the reset member 3 is released, and the blocking member 5 is driven to rotate in the opposite direction and enter the inner hole of the launch tube 2. The rebounding impact projectile 1 is physically intercepted by the blocking member 5 along the return path along the launch tube 2. This design achieves bidirectional drive of the blocking member 5 through the coordinated work of the drive device 4 and the reset member 3. Even if the drive device 4 is completely de-energized at the moment of interception, the purely mechanical reset member 3 can still reliably push the blocking member 5 into the interception position. The blocking part of the blocking member 5 can be designed with a buffer structure to reduce the impact force when capturing the projectile.

[0057] Furthermore, a threshold of 1 m / s is set. In high-speed impact tests of composite structures, projectile rebound velocities below 1 m / s carry relatively little kinetic energy, typically insufficient to cause observable secondary damage to the target; while rebound velocities above 1 m / s provide sufficient kinetic energy for the projectile to impact the target again, potentially causing additional secondary damage such as dents, crack propagation, or delamination. By setting a threshold of 1 m / s, the system can effectively distinguish between scenarios requiring interception and those not requiring interception.

[0058] Furthermore, combined Figure 1 As shown, the launching tube 2 has a first exhaust port 8 for the entry and exit of the blocking member 5 and for gas discharge, and a plurality of evenly distributed second exhaust ports 7 are also provided at the front end of the first exhaust port 8; both the first exhaust port 8 and the second exhaust port 7 are elliptical elongated holes. Multiple first exhaust ports 8 are evenly distributed around the circumference of the launching tube 2 and appear in pairs to match the entry and exit of the blocking member 5. Multiple second exhaust ports 7 are evenly distributed around the circumference for exhaust.

[0059] Specifically, the elliptical cross-section has a larger flow area than a circular hole, enabling faster discharge of the propulsion gas remaining in the tube after launch. The elongated elliptical hole extends along the axial direction of the launch tube, maximizing exhaust efficiency while ensuring the structural strength of the tube wall. The evenly distributed second exhaust holes 7 ensure uniform circumferential exhaust, preventing the rebounding projectile from deflecting due to lateral forces caused by unilateral exhaust. After the impacting projectile 1 leaves the barrel, high-pressure propulsion gas remains in the launch tube 2. By opening elongated elliptical holes 7 and 8 on the launch tube 2, the residual gas can be quickly discharged to the outside of the tube, significantly reducing the residual pressure inside the tube, reducing the force of the propulsion gas on the rebounding projectile, and ensuring that the trajectory of the rebounding projectile is determined solely by impact dynamics.

[0060] Furthermore, the velocity measuring device 6 is a two-channel laser velocity measuring system, with a distance of 40 mm between the two probes. When the projectile 1 passes the first laser probe, a trigger signal is generated, recording the start time; when the projectile passes the second laser probe, a second trigger signal is generated, recording the end time. The time it takes for the projectile to pass through the distance L=40 mm between the two probes is the time difference between the end time and the start time, thus obtaining the velocity of the projectile through this interval. This two-channel laser velocity measuring system can simultaneously measure the incident velocity and the rebound velocity: during the launch phase, the projectile flies from the launch tube 2 towards the target, passing through the two laser probes sequentially, and the system records the incident velocity; after impact and rebound, the projectile returns from the target direction to the launch tube 2, passing through the two laser probes again sequentially, and the system records the rebound velocity.

[0061] Furthermore, the blocking component 5 is a pawl, and the resetting component 3 is a return spring. The pawl 5 has a rotating structure, with one end connected to the rotating shaft and the other end being a hook-shaped or plate-shaped blocking part, which can rotate around the rotating shaft under the action of the driving device 4. The return spring 3 is sleeved on the rotating shaft or fixed at one end to the pawl 5, providing a continuous rotational torque. When the driving device 4 applies force, the pawl 5 overcomes the torque of the return spring 3 and rotates outward, exiting the inner hole; when the driving device 4 removes the force, the torque of the return spring 3 drives the pawl 5 to rotate inward, entering the inner hole. The blocking part of the pawl 5 can be designed with a buffer structure to reduce the impact force when capturing the projectile.

[0062] Combination Figure 7 , Figure 8 As shown, the impact projectile 1 is composed of a sabot 12 and a projectile 11 that are detachably connected; while keeping the total mass of the impact projectile 1 constant, different types of projectiles 11 can be replaced.

[0063] Specifically, the sabot 12 and the projectile 11 are detachably connected by threads. The outer diameter of the sabot 12 matches the inner diameter of the launch tube 2, ensuring stable flight of the projectile within the tube. The projectile 11 can be designed with various head shapes according to different test requirements, such as hemispherical, flat, and conical. When conducting comparative tests of different projectile head shapes, only the projectile 11 needs to be replaced while keeping the sabot 12 unchanged. By adjusting the material or internal structure of the projectile 11, the mass of each projectile can be made the same, thus achieving a single-variable comparative test with the same impact mass but different head shapes. The outer diameter of the steel sabot 12 is the same as the inner diameter of the light gas gun launch tube 2. Taking a launch tube diameter of 30 mm as an example, the mass of the sabot 12 can be made to be 126 grams. Typical steel projectile head shapes for the projectile 11 are spherical heads with diameters of 12.7 mm, 16 mm, 25.4 mm, and 50 mm, each with a mass of 62 grams, and the total mass impacting the projectile 1 is 188 grams.

[0064] This embodiment also provides a test method for preventing secondary impacts from light gas cannon projectiles using the above-described system, combined with Figures 2 to 6 As shown, it includes the following steps:

[0065] Step 1: For the given structural material target, select a projectile head type 11 for the impact projectile 1, thread it to the sabot 12 of the impact projectile 1, and then install the impact projectile 1 into the predetermined position inside the light gas gun tube 2.

[0066] Step 2: The PLC control system commands the power device 4, which is designed to prevent secondary impacts, to apply force to the pawl 5. Under this force, the pawl 5 overcomes the elastic force of the return spring 3 and rotates around the axis, causing the head of the pawl 5 to exit the elliptical hole 8 of the light air cannon launch tube 2.

[0067] Step 3: Launch the light gas cannon. The high-pressure gas drives the impact projectile 1 to accelerate along the launch tube 2. The impact projectile 1 passes through the two-channel laser velocity measurement system 6 in sequence. The PLC control system records the trigger time interval of the two channels, calculates and stores the incident velocity of the impact projectile 1.

[0068] Step 4: The impact projectile 1 impacts the structural material target at the incident velocity. After the impact, the projectile bounces back and returns along the launch tube 2. It then passes through the two-channel laser velocity measurement system 6 again. The PLC control system records the time interval between the bounces and calculates the bounce velocity.

[0069] Step 5: The PLC control system compares the measured rebound speed with the preset threshold of 1 m / s. When the rebound speed is greater than or equal to 1 m / s, the PLC control system issues a command to cut off the power source of the anti-secondary impact power device 4. The power device 4 removes the force on the pawl 5. Under the elastic force of the return spring 3, the pawl 5 rotates in the opposite direction and enters the inner hole of the launch tube 2. When the rebounding impact projectile 1 flies forward under the action of the residual driving gas, the pawl 5 will capture the incoming impact projectile 1 to prevent the projectile from causing a secondary impact on the target. When the rebound speed is less than 1 m / s or no rebound signal is detected, the PLC control system does not output an interception command. The power device 4 maintains the force on the pawl 5, and the pawl 5 remains in the state of exiting the inner hole. Specific Implementation

[0070] The invention will be further described below with reference to specific parameters.

[0071] Example 1: 30mm Caliber Light Gas Gun Test System

[0072] In this embodiment, the test parameters are set as follows: the diameter of the light gas cannon launch tube 2 is 30 mm, and the gas chamber pressure is set to 0.2 MPa. A two-channel laser velocity measurement system is installed at the outlet end of the launch tube 2 as a velocity measurement device 6, with a distance of 40 mm between the two probes.

[0073] A first vent hole 8 is provided on the launch tube 2. The first vent hole 8 is an elliptical elongated hole, and multiple holes are evenly distributed around the circumference of the launch tube 2 and appear in pairs to match the entry and exit of the blocking component 5. In this embodiment, two pairs of first vent holes 8 are provided, symmetrically distributed radially along the launch tube 2. Each hole is 50 mm long and 12 mm wide. The number of blocking components 5 (implemented by claws) matches the number of first vent holes 8. In this embodiment, two claws are provided, symmetrically arranged, to ensure that a uniform blocking force is applied to the projectile during interception. At a distance of 100 mm from the front end of the first vent holes 8, four second vent holes 7 are evenly distributed around the circumference of the launch tube 2. Each hole is 30 mm long and 8 mm wide, and is an elliptical elongated hole.

[0074] In the interception mechanism, the claws are made of 45 steel with surface hardening treatment, and the claw heads are covered with a 5 mm thick polyurethane buffer layer; the reset component 3 is a torsion spring with a rated torque of 0.8 N·m; the drive device 4 is a single-acting cylinder with a working air pressure of 0.5 MPa and a stroke of 15 mm; the controller is a Siemens S7-1200 PLC.

[0075] The impact projectile 1 has a total mass of 188 grams and is composed of a sabot 12 and a projectile 11 that are detachably connected. The sabot 12 is made of 45 steel, with an outer diameter of 30 mm and a length of 40 mm; the projectile 11 is also made of 45 steel and is machined into hemispherical heads with diameters of 12.7 mm, 16 mm, 25.4 mm, and 50 mm, respectively. The end of the sabot 12 is machined with an M10 internal thread, and the root of the projectile 11 is machined with an M10 external thread.

[0076] Experimental Procedure: A 25.4 mm diameter hemispherical projectile (11) was selected and threadedly connected to a sabot (12) to form an impact projectile (1) with a total mass of 188 grams. This projectile was then inserted into the firing tube (2) in the ready-to-fire position. The PLC controlled the cylinder's operation; the cylinder pressure of 0.5 MPa pushed two blocking components (5) (claws) to overcome the torsion spring torque and rotate out of the inner hole. The light gas cannon fired, with a chamber pressure of 0.2 MPa driving high-pressure gas to accelerate the projectile. The velocity measuring device (6) measured the incident velocity as 28.81 m / s. After impacting the carbon fiber composite target plate, the projectile rebounded; the velocity measuring device (6) measured the rebound velocity as 3.2 m / s. The PLC determined that the rebound velocity of 3.2 m / s was greater than the set threshold of 1.0 m / s and immediately cut off the cylinder's gas supply. The two claws, under the action of the torsion spring, rotated synchronously into the inner hole, successfully intercepting the returning projectile. Non-destructive testing of the target plate showed only delamination damage caused by the first impact, with no traces of secondary impacts. The PLC control system records all data from this test, including the test number, warhead diameter, incident velocity, rebound velocity, and interception status, forming a traceable test record.

[0077] Example 2: Comparison Test of Different Head Shapes

[0078] Using the system described in Example 1, five effective tests were conducted with four hemispherical warheads (12.7mm, 16mm, 25.4mm, and 50mm in diameter) under the same incident velocity of 120m / s ± 2% and the same target plate conditions. Interception was initiated in each test when the rebound velocity was greater than 1m / s. The test results show that as the warhead diameter increases, the diameter of the pit on the target plate surface increases but the depth decreases. The delamination damage area first increases and then decreases, reaching its maximum at a diameter of 25.4mm. This comparative data provides a quantitative basis for the impact-resistant design of composite material structures.

[0079] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A test system for preventing secondary impact from light gas cannon projectiles, characterized in that, include: Launch tube (2); Impacting the projectile (1); A velocity measuring device (6) is installed at the outlet end of the launch tube (2) to measure the incident velocity of the impact projectile (1) before it impacts the target and the rebound velocity after it impacts the target. The interception mechanism includes a blocking component (5), a resetting component (3), and a driving device (4); And the controller; The controller controls the action of the drive device (4) based on the rebound speed measured by the speed measuring device (6) to drive the blocking member (5) to selectively enter or exit the inner hole of the launch tube (2) to intercept or release the rebounding projectile.

2. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The driving device (4) is a cylinder or an electromagnet.

3. The test system for preventing secondary impact of a light gas cannon projectile according to claim 2, characterized in that, The controller is a PLC control system.

4. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The interception mechanism is configured as follows: Before launch, the drive device (4) applies force to the blocking member (5) to overcome the force of the reset member (3) and cause the blocking member (5) to exit the inner hole of the launch tube (2); When the rebound speed is greater than or equal to the set threshold, the controller controls the drive device (4) to remove the force on the blocking member (5), so that the blocking member (5) enters the inner hole of the launching tube (2) under the action of the reset member (3) to block the rebounding impact projectile (1).

5. The test system for preventing secondary impact of a light gas cannon projectile according to claim 4, characterized in that, The set threshold is 1 m / s.

6. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The emitting tube (2) is provided with a first exhaust hole (8) for the entry and exit of the blocking member (5) and for gas discharge, and a plurality of evenly distributed second exhaust holes (7) are provided at the front end of the first exhaust hole (8); the first exhaust hole (8) and the second exhaust hole (7) are both elliptical elongated holes.

7. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The speed measuring device (6) is a two-channel laser speed measuring system.

8. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The blocking component (5) is a pawl, and the resetting component (3) is a resetting spring.

9. The test system for preventing secondary impact of a light gas cannon projectile according to claim 1, characterized in that, The impact projectile (1) is composed of a sabot (12) and a projectile (11) that are detachably connected; while the total mass of the impact projectile (1) remains unchanged, the projectile (11) with different head shapes can be replaced.

10. A test method for preventing secondary impact from a light gas cannon projectile using the system described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Insert the impact projectile (1) into the predetermined position inside the launch tube (2); Step 2: Apply force to the blocking member (5) through the driving device (4) to make the blocking member (5) exit the inner hole of the launching tube (2); Step 3: Launch the impact projectile (1), and measure the incident velocity of the impact projectile (1) before it impacts the target using the velocity measuring device (6); Step 4: Impacting the projectile (1) After impacting the target, it bounces back, and its rebound speed is measured by the velocity measuring device (6); Step 5: When the rebound speed is greater than or equal to the set threshold, the controller controls the drive device (4) to remove the force on the blocking member (5), so that the blocking member (5) enters the inner hole of the launching tube (2) under the action of the reset member (3) to block the rebounding impact projectile (1) and prevent it from hitting the target again.

Images