Target resistance characteristic testing device

Abstract

The invention discloses a target body resistance characteristic testing device which comprises a projectile body head, a projectile body, a testing rod, a top plate, an energy absorption part, a bottom plate and a projectile-borne testing storage device. According to the invention, a Hopkinson bar test mode is utilized, a response test problem of a direct collision end of a projectile body is converted into a test problem of stress waves in the bar, the area of the test bar in the projectile body can be used as a test area, the state of a test interface of a test sensor is controllable, and test signal data can be ensured to be effective; a test signal in the test rod is directly related to the impact end response of the projectile body, and the test signal can directly reflect the resistance characteristic of the target body at the impact end; according to the invention, resistance characteristics of the target body under dynamic conditions of different impact speeds and the like can be reflected, and a test environment can be closer to a real research impact scene; by monitoring the deformation condition of the energy absorption part in the target collision process, the energy characteristic of the target body resistance can be quantitatively evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of impact testing, and in particular to a target resistance characteristic testing device. Background Art

[0002] In the study of the scenario of projectiles impacting different medium targets, the method of projectiles impacting different medium targets is often used to carry out experimental research. Common target media include concrete, water, sand, etc. The equivalence of different medium targets to different medium targets is the first question that needs to be answered in the study. The common method of demonstrating the equivalence of the target is to demonstrate the equivalence of the target by comparing the mechanical properties of the target sample and the target medium sample. Usually, only the quasi-static compression mechanical properties of the sample are compared, and the mechanical properties under dynamic and complex stress states are basically not compared. In addition, it is very difficult to obtain representative target medium samples, especially for sandy soil media. Although the water medium has good consistency, auxiliary structures are often required to construct the water target when conducting water impact tests, and the impact of these structures is also difficult to evaluate. Therefore, identifying the resistance characteristics of the target is of great significance for demonstrating the equivalence of the target.

[0003] In the test, the acceleration response and strain response of the projectile during the impact of the target can often be measured through measuring points, but the measuring point data generally gives the response of the concerned components in the projectile structure, and cannot directly reflect the resistance characteristics of the target. In some tests, attempts were made to arrange measuring points in the impact area of ​​the projectile head, but due to the complexity of the projectile-target impact interface, it was difficult to determine whether it could meet the test requirements of the sensor, which increased the difficulty of identifying the validity of the test data.

[0004] Therefore, it is necessary to develop a target resistance characteristic testing device to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to design a target resistance characteristic testing device in order to solve the above problems.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: A target resistance characteristic testing device, comprising: The projectile head has a central opening axially arranged in the projectile head; The projectile body; a stepped opening is axially arranged in the projectile body, and the stepped opening includes small holes and large holes that are interconnected; the first end of the projectile head is connected to the first end of the projectile body; A test rod; the first end of the test rod is mounted to match the shape and position of the second end of the projectile head; the test rod is slidably placed in the central opening and the small hole; The top plate; the first end of the top plate contacts the stepped surface of the stepped opening; the second end of the test rod passes through the central opening, the small hole and the large hole and is connected to the center of the first end of the top plate; The energy absorbing member; the second end of the top plate contacts the first end of the energy absorbing member; the top plate and the energy absorbing member are slidably disposed in the large hole; The second end of the energy absorbing member is in contact with the first end of the bottom plate; the outer wall of the bottom plate is connected to the inner wall of the large hole; The on-board test storage device is used to record the stress / strain signal measured at the test rod and the compression deformation signal measured at the energy absorbing component in real time, and the on-board test storage device is connected to the second end of the base plate.

[0007] Preferably, the projectile head and the projectile body are both gyroscope structures.

[0008] Preferably, the test rod is a one-dimensional stress rod.

[0009] Preferably, the test rod is made of high-strength steel.

[0010] The beneficial effects of the present invention are: 1. The present invention utilizes the Hopkinson bar test method to transform the response test problem of the direct collision end of the projectile into the test problem of the stress wave in the bar. The area of ​​the test bar inside the projectile can be used as the test area. The state of the test sensor test interface is controllable, which can ensure the validity of the test signal data. 2. The test signal in the test rod is directly related to the response of the projectile impact end, and the test signal can directly reflect the resistance characteristics of the target at the impact end; 3. The resistance characteristics of the target body are related to the structure of the projectile head. The present invention can adjust the diameter of the test rod to retain the projectile head structure as realistically as possible, and the resistance characteristics of the target body tested are more meaningful for reference; 4. The present invention can reflect the resistance characteristics of the target under dynamic conditions such as different impact speeds, and the test environment can be closer to the actual research impact scene; 5. By monitoring the deformation of the energy-absorbing components during the target impact process, the energy characteristics of the target resistance can be quantitatively evaluated; 6. The impact load test technology is the same as that of the Hopkinson bar. The test technology is mature. The overall structure of the device is similar to that of test pieces such as artillery and air cannon. The technologies such as launch and test data storage are universal, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a target resistance characteristic testing device of the present invention; Figure 2 It is a simulation model of the ball head target resistance characteristic test device and a schematic diagram of the measurement point positions on the test rod; Figure 3 Comparison of stress responses in the impact direction at measuring points A and B after the test device collides with a C20 concrete target at a speed of 350m / s in the simulation calculation; Figure 4 Comparison of the stress responses in the impact direction at the measuring points C and D after the test device directly hits the C20 concrete target at a speed of 350m / s in the simulation calculation; Figure 5 Comparison of the stress responses in the impact direction at the measuring points E and F after the test device directly hits the C20 concrete target at a speed of 350m / s in the simulation calculation; Figure 6 Comparison of stress responses in the impact direction at points A, C and E after the test device collides with a C20 concrete target at a speed of 350m / s in the simulation calculation; Figure 7 Comparison of stress responses in the impact direction at points A, C and E after the test device hits the water target at a speed of 350m / s in the simulation calculation; Figure 8 Comparison of stress responses in the impact direction at points A, C and E after the test device hits the soil target at a speed of 350m / s in the simulation calculation; Fig. 9 This paper compares the thickness changes of the energy-absorbing components after the test device collides with the C20 concrete target, water target and soil target at a speed of 350m / s in the simulation calculation.

[0012] Legend: 1- projectile head; 2- projectile body; 3- test rod; 4- top plate; 5- energy absorbing component; 6- bottom plate; 7- projectile-loaded test storage device. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0016] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0017] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0018] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, a target resistance characteristic testing device comprises: The projectile head 1; a central opening is axially arranged in the projectile head 1, and the shape of the projectile head 1 is generally determined according to the projectile head shape to be assessed; The projectile body 2; the projectile body 2 is axially provided with a stepped opening, the stepped opening comprising small holes and large holes interconnected with each other; the first end of the projectile head 1 is connected to the first end of the projectile body 2; The test rod 3; the first end of the test rod 3 is mounted to match the shape and position of the second end of the projectile head 1, and the test rod 3 is a cylindrical rod; the test rod 3 can be slidably placed in the central opening and the small hole; Top plate 4; the first end of the top plate 4 contacts the stepped surface of the stepped opening; the second end of the test rod 3 passes through the central opening, the small hole and the large hole and is connected to the center of the first end of the top plate 4; The energy absorbing member 5; the second end of the top plate 4 contacts the first end of the energy absorbing member 5; the top plate 4 and the energy absorbing member 5 are slidably placed in the large hole; The second end of the energy absorbing member 5 is in contact with the first end of the bottom plate 6; the outer wall of the bottom plate 6 is connected to the inner wall of the large hole; The on-board test storage device 7 is used to record the stress / strain signal measured at the test rod 3 and the compression deformation signal measured at the energy absorbing component 5 in real time, and the on-board test storage device 7 is connected to the second end of the bottom plate 6. The projectile body 2, the projectile head 1 and the on-board test storage device 7 together form a projectile form that can be fired by a driving device such as a cannon or an air cannon. The working method of the on-board test storage device 7 draws on mature on-board test technical solutions such as cannons or air cannons.

[0021] In some embodiments, the projectile head 1 and the projectile body 2 are both gyroscope structures.

[0022] In some embodiments, the test rod 3 is a one-dimensional stress rod.

[0023] In some embodiments, the energy absorbing component 5 is made of foamed aluminum, and the test rod 3 is made of high-strength steel.

[0024] In some embodiments, when the resistance energy characteristics of the target body are not of concern, the top plate 4 and the energy absorbing component 5 may be eliminated as appropriate, so that the second end of the test rod 3 is directly connected to the bottom plate 6 .

[0025] In the present invention, the test rod 3 is placed at the central opening of the projectile head 1, can move freely, and is initially connected to the top plate 4. The installation and positioning are achieved through the close contact between the top plate 4 and the stepped opening inside the projectile body 2 and the close contact between the energy absorbing component 5 and the top plate 4. The outer and inner surfaces of the projectile body 2 can be in the shape of a cone, etc., and are not limited to a cylindrical shape. After the present invention impacts the target body, the projectile head 1 and the test rod 3 form a deformation area related to the shape of the projectile head 1 at the local impact of the target body, and the impact load response formed by the impact of the target body and the test rod 3 in the central area of ​​the impact end is transmitted to the test rod 3, and the stress / strain signal characteristics that can reflect the resistance characteristics of the target body are tested and obtained from the test rod 3. Subsequently, under the action of the impact load transmitted to the test rod 3, the test rod 3 and the top plate 4 move as a whole to squeeze the energy absorbing component 5, and repeatedly squeeze and collide with the energy absorbing component 5 during the subsequent target impact process. The stress / strain signal measured at the test rod 3 and the compression deformation signal measured at the energy absorbing component 5 are recorded in real time in the storage and on-board test storage device 7. After the target impact is completed, the on-board test storage device 7 is recovered to read the target resistance characteristic test information.

[0026] The present invention utilizes the testing concept of the Hopkinson bar to transform the measurement problem of the complex projectile-target impact interface response into the measurement problem of the stress wave signal in the one-dimensional stress bar, and uses the stress / strain signal propagated in the test rod 3 as the characterization quantity of the target resistance characteristic. By arranging the energy absorbing component 5, the deformation of the energy absorbing component 5 caused by the target resistance during the target impact process is used as the energy characteristic characterization quantity of the target resistance characteristic, thereby realizing the test of the target resistance characteristic during the target impact process.

[0027] The technical features of the present invention are as follows: 1. The shape and structure of the projectile head 1 should be designed according to the head characteristics of the projectile to be actually tested, and can be integrated or multi-layered. During the target collision process, the projectile head 1 can form a stress state response area in the target collision area that is similar to the stress state response area when the projectile is actually tested and hits the target, so that the measured target resistance characteristics are closer to the situation when the real projectile hits; 2. The size of the test rod 3 should meet the requirements of a one-dimensional stress rod. During the collision process, the deformation in the test rod 3 should meet the "flat section" assumption. At the same time, in order to avoid the influence of the strain rate effect in the rod, the test rod 3 should be in an elastic state or only produce a small plastic strain state during the collision process; 3. When the top plate 4 compresses the energy absorbing component 5, no significant structural deformation should occur and no significant deformation should be generated in the test rod 3; 4. The energy absorbing component 5 can be an energy absorbing material such as foamed aluminum, or a structural member that is easy to judge the deformation condition.

[0028] In the embodiment, a ball head target resistance characteristic test device is used for illustration, and a simulation model of the ball head target resistance test device and a schematic diagram of the position of the measuring point on the test rod 3 are shown in FIG. Figure 2 As shown, the position of the measuring point on the test rod 3 is arbitrarily selected. In order to ensure the effective data length of the measuring point, the measuring point is not selected in the tail area of ​​the test rod 3. Among them, the distance between the measuring point A and the measuring point B and the tail end of the test rod 3 is the same, which is 225.8mm, the distance between the measuring point C and the measuring point D and the tail end of the test rod 3 is the same, which is 159.4mm, and the distance between the measuring point E and the measuring point F and the tail end of the test rod 3 is the same, which is 116.2mm. According to the distance between the measuring point E and the measuring point F and the tail end of the test rod 3, the time required for the stress wave at the test rod 3 and the top plate 4 to reflect to the measuring point E and the measuring point F is 0.077ms. It can be seen that within the 0.077ms time, the stress response in the measuring point A-measuring point F is only related to the process of impacting the target body, and the test signal during this period of time is a valid signal. The ball head target resistance test device has a diameter of 100mm and a length of 353mm. The projectile head 1 is a hemispherical head structure; the test rod 3 has a diameter of 20mm and a length of 282mm; the top plate 4 has a diameter of 70mm and a thickness of 8mm; the bottom plate 6 has a diameter of 70mm and a thickness of 8mm. For the convenience of comparison, in the simulation calculation, except for the energy-absorbing component 5 which uses foam aluminum, the remaining structural materials are all G50 steel. At this time, the total weight of the ball head target resistance test device is about 16kg. Since the missile-borne test storage device 7 has no obvious effect in the numerical simulation calculation, this part is not included in the simulation model. In the simulation calculation, after the ball head target resistance characteristic test device collides with the C20 concrete target at a speed of 350m / s, the comparison of the stress responses in the impact direction at measuring points A and B is as follows. Figure 3 As shown in the figure, the stress response comparison between the measuring point C and the measuring point D in the impact direction is Figure 4 As shown in the figure, the stress response comparison between the impact direction at the measuring point E and the measuring point F is Figure 5As shown, it can be seen that the stress responses of the comparison measuring points are basically the same, especially within 0.077ms, which can explain that the test rod 3 meets the assumption of "plane section" deformation during the impact process. The ball head target resistance characteristic test device also has similar results when it hits the water target and the soil target at a speed of 350m / s, which will not be shown here. Within 0.077ms, the stress response obtained from the test of each measuring point has the following characteristics: the stress increases rapidly in the first stage, and the stress gradually drops to a certain stress level in the second stage and begins to oscillate and decline. The stress response characteristics of the first stage represent the impact response of the target to the projectile in the initial stage of the target impact, while the stress response of the second stage represents the resistance of the target to the projectile during the stable invasion of the target. From the response of the measuring point, it can be seen that after the ball head target resistance characteristic test device hits the C20 concrete target at a speed of 350m / s, the peak impact response of the C20 concrete target to the device is 1.27GPa, and then the stress drops to around 500MPa, reflecting the resistance characteristics of the stable invasion stage of the target. In the simulation calculation, the stress response comparison of the impact direction at the measuring points A, C and E after the ball head target resistance characteristic test device hits the C20 concrete target at a speed of 350m / s. Figure 6 As shown in the figure, within 0.077ms, the stress responses measured at the three measuring points are basically the same, and can all be used as a representation of the resistance characteristics of the target at this time. In the simulation calculation, the stress response comparison of the impact direction at measuring points A, C and E after the ball head target resistance characteristic test device hits the water target at a speed of 350m / s. Figure 7 As shown in the figure, within 0.077ms, the three measuring points measured the double-wave response characteristics, which is significantly different from the impact on the C20 concrete target. The first stress response peak in the double-wave response characteristics of the three measuring points is relatively consistent, which can be used as a representation of the resistance characteristics of the water target. At this time, the peak of the impact response of the water target on the device is 700MPa, and then the stress drops to around 72MPa, reflecting the response characteristics of the water target. In the simulation calculation, the comparison of the stress response in the impact direction at the measuring points A, C and E after the ball head target resistance characteristic test device hits the soil target at a speed of 350m / s is shown in the figure. Figure 8 As shown in the figure, within 0.077ms, the three measuring points measured relatively complex waveform responses, among which the first stress response of each measuring point still has good consistency. The first stress response peak consistency of measuring points C and E near the center of the test rod 3 is better, which can be used as the resistance characteristics of hitting the soil target. At this time, the peak impact response of the soil target to the device is 563MPa, and then the stress drops to around 260MPa, reflecting the response characteristics of hitting the soil target. In the simulation calculation, the thickness change of the energy-absorbing component 5 after the ball head target resistance characteristic test device hits the C20 concrete target, water target and soil target at a speed of 350m / s is compared. Fig. 9 As shown, the curve changes can intuitively show the energy characteristics of different target resistances.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A target resistance characteristic testing device, characterized in that: include: Projectile head; A central opening is axially arranged in the head of the projectile body; Bullet body; A stepped opening is axially arranged in the body of the projectile, and the stepped opening includes small holes and large holes that are interconnected; the first end of the head of the projectile is connected to the first end of the body of the projectile; A test rod; the first end of the test rod is mounted to match the shape and position of the second end of the projectile head; the test rod is slidably placed in the central opening and the small hole; The top plate; the first end of the top plate contacts the stepped surface of the stepped opening; the second end of the test rod passes through the central opening, the small hole and the large hole and is connected to the center of the first end of the top plate; The energy absorbing member; the second end of the top plate contacts the first end of the energy absorbing member; the top plate and the energy absorbing member are slidably disposed in the large hole; The second end of the energy absorbing member is in contact with the first end of the bottom plate; the outer wall of the bottom plate is connected to the inner wall of the large hole; The on-board test storage device is used to record the stress / strain signal measured at the test rod and the compression deformation signal measured at the energy absorbing component in real time, and the on-board test storage device is connected to the second end of the base plate.

2. A target resistance characteristic testing device according to claim 1, characterized in that: The projectile head and projectile body are both gyroscopic structures.

3. A target resistance characteristic testing device according to claim 1, characterized in that: The test rod is a one-dimensional stress rod.

4. A target resistance characteristic testing device according to claim 1, characterized in that: The test rod is made of high-strength steel.

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