Detection target for rapidly interpreting shock wave intensity on site

Abstract

The invention relates to a detection target for rapidly interpreting shock wave intensity on site. The detection target for assisting shock wave intensity interpretation comprises a bottom plate, the surface of the bottom plate is fixedly connected with a protruding detection ring, the surface of the bottom plate is further provided with a base plate, the surface of the base plate is provided with a through placement hole, and the detection ring is located in the placement hole; the surface of the base plate is also connected with a metal diaphragm, the metal diaphragm covers the placing hole, the surface of the metal diaphragm is also provided with a covering sheet, the surface of the covering sheet is also provided with a through placing hole, the two placing holes are correspondingly arranged, and the covering sheet is fixed together with the metal diaphragm, the base plate and the bottom plate; according to the detection target for assisting shock wave intensity interpretation, shock wave loading is conducted on the aluminum foil through the shock tube, free deflection deformation of the aluminum foil and deformation of the detection target during action are obtained, the magnitude of shock wave pressure is judged by comparing deformation patterns of the aluminum foil during action of the detection target, and a method is provided for rapidly recognizing the shock wave pressure in a field explosion test.

Description

Technical Field

[0001] The invention belongs to the technical field of experimental mechanics testing, and in particular relates to a detection target for quickly judging the intensity of shock waves on site. Background Art

[0002] The pressure of explosion shock wave is an important factor causing target damage. At present, the common shock wave pressure measurement methods include equivalent pressure tank method, effect target plate method, simulated biological test method, electrical measurement method, etc. Among them, the electrical measurement method based on pressure sensor has high accuracy and can reflect the entire pressure change process, but the explosion shock wave test is often accompanied by uncertain factors such as high temperature and mechanical shock, and large-scale field tests have complicated wiring, large line inspection and protection workload. The method of evaluating the explosion power based on the plastic deformation of metal sheets under the pressure of explosion shock waves can effectively avoid the interference caused by the above uncertain factors, and is more suitable for indirect measurement of shock wave pressure in large-scale field explosion tests. Dimensional analysis, numerical simulation, shock tube test and chemical explosion test studies have shown that there is a quantitative relationship between the deformation deflection of metal diaphragms under the action of shock waves and the shock wave pressure and impulse. By reasonably designing the diaphragm material and specifications, the pressure-deflection calibration curve can be obtained. At the test site, the shock wave intensity can be obtained only by the deformation of the metal diaphragm. This method is very beneficial to the range test such as weapon explosion damage effectiveness evaluation, structural damage threshold determination, and ammunition explosion power evaluation. However, when using this effect target that indicates the overpressure peak of the shock wave through deflection, it is still necessary to measure the deflection on site and then refer to the deflection-pressure calibration relationship to obtain the overpressure peak, which is not conducive to the rapid interpretation of the overpressure amplitude on site.

[0003] In large-scale tests, target shock wave vulnerability assessments, and target damage assessment tests, it is necessary to determine the shock wave intensity on site by visual inspection or other simpler and more direct methods. This test scenario often only requires the detection, indication, and interpretation of a specific shock wave intensity, and does not require accurate measurement or inversion of its shock wave information. For example, in a simulated target explosion damage assessment test, if the shock wave damage threshold of a target is known to be Ph, the effect target required on site only needs to indicate whether the local shock wave intensity reaches or exceeds Ph to assess the target damage degree or level. This method, which does not require additional measurement or back calculation, can map the target damage degree by detecting the deformation characteristics of the target itself, and is more convenient for large-scale use in damage assessment tests. However, the currently available diaphragm shock wave effect targets do not have the properties of rapid on-site interpretation and mapping the target damage degree based on the diaphragm failure mode.

[0004] The prior art discloses a method for evaluating the damage of explosion shock waves based on effect targets. The method numerically simulates the deformation response of the effect target under the explosion shock wave, and obtains the functional relationship between the deflection and the explosion distance and the TNT equivalent, which provides a basis and reference for the damage evaluation of the warhead explosion shock wave; and the prior art also discloses that a circular effect target thin plate is used as a research object, and an impact response model of a fixed circular thin plate under the action of shock wave pressure is established. Based on the model, the mapping relationship between the plastic deformation of the thin plate and the peak value of the shock wave pressure and the positive pressure action time is obtained. The research results provide a theoretical basis for the application and structural design of pressure effect targets. However, there are relatively few literatures and patents on the rapid interpretation of shock wave pressure by deformation mode or pattern elements, and the prior art cannot quickly interpret the intensity of the shock wave based on the detection target. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that traditional metal diaphragm shock wave effect targets still need to rely on deflection measurement to determine the shock wave intensity and cannot be used in rapid assessment field tests, and to provide a detection target that can quickly judge the shock wave intensity threshold only through the deformation mode of the metal diaphragm.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A detection target for quickly judging the intensity of shock waves on site, the detection target comprises a base plate, the surface of the base plate is fixedly connected with a raised detection ring, the surface of the base plate is also provided with a pad, the surface of the pad is provided with a through placement hole, and the detection ring is located in the placement hole; the surface of the pad is also connected with a metal diaphragm, the metal diaphragm covers the placement hole, the surface of the metal diaphragm is also provided with a cover sheet, the surface of the cover sheet is also provided with a through placement hole, the two placement holes are arranged correspondingly, the cover sheet presses the metal diaphragm, and the cover sheet is fixed together with the metal diaphragm, the pad and the base plate.

[0008] As a further optimization solution of the present invention, the cover sheet is a flange.

[0009] As a further optimization solution of the present invention, the metal diaphragm is in a circumferentially fixed and constrained state.

[0010] As a further optimization solution of the present invention, the cover sheet, the metal diaphragm, the backing plate and the bottom plate are fixed by a plurality of groups of bolts arranged circumferentially.

[0011] As a further optimization solution of the present invention, the material of the metal diaphragm is pure aluminum, aluminum alloy, or copper.

[0012] As a further optimization solution of the present invention, the detection ring is a thin-walled structure of at least two layers from the inside to the outside, and the shape is a continuous geometric convex structure.

[0013] As a further optimization solution of the present invention, the detection ring includes an inner ring detection ring and an outer ring detection ring.

[0014] As a further optimization scheme of the present invention, the thickness of the pad is H=h1+W+Δ; wherein h1 is the height of the innermost detection ring, W is the center deflection of the metal diaphragm without the action of the detection ring when the shock wave is loaded with the minimum intensity threshold that can be indicated by the detection target, and Δ is the negative contact thickness.

[0015] As a further optimization solution of the present invention, the detection ring is adhered, welded or threadedly fixed to the surface of the base plate.

[0016] As a further optimization solution of the present invention, the detection ring and the base plate are formed in one piece.

[0017] The beneficial effects of the present invention are:

[0018] The explosion shock wave detection target provided by the present invention can detect and indicate a single or multiple specific shock wave intensity thresholds, can convert different shock wave intensities into different deformation failure modes of the diaphragm, has visual interpretation characteristics, and is suitable for explosion shock wave intensity monitoring sites such as simulated target damage assessment, without the need for additional measurements;

[0019] The shock wave detection target provided by the present invention has a deformation detection ring installed on the back of the deformable film, and the deformation of the diaphragm is interfered and regulated by the detection ring, so that the diaphragm presents different deformation failure modes under the action of shock waves of different intensities; the structural form and specification size of the detection ring are adjustable, and the display mode of different deformation patterns can be adjusted;

[0020] The present invention adopts a pad to install the diaphragm, and the thickness of the pad is the sum of the preset spacing and the detection ring height. The preset spacing and the detection ring height can be adjusted by the pad thickness, thereby realizing flexible regulation of the device's shock wave intensity detection index and indication method. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is the detection effect of the detection target under the action of 0.3MPa shock wave in the embodiment of the present invention;

[0023] Figure 3 This is the detection effect of the detection target under the action of a 0.45MPa shock wave in an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0025] Figure 5 is a schematic structural diagram of the pull rod member before actuation in Embodiment 2 of the present invention;

[0026] Figure 6 It is a schematic diagram of the structure after the pull rod member in Example 2 of the present invention is actuated. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0028] Example 1

[0029] A detection target for quickly judging the intensity of shock waves on site, the detection target comprises a base plate 4, the surface of the base plate 4 is fixedly connected with a raised detection ring, the surface of the base plate 4 is also provided with a pad 3, the surface of the pad 3 is provided with a through placement hole, and the detection ring is located in the placement hole; the surface of the pad 3 is also connected with a metal diaphragm 2, the metal diaphragm 2 covers the placement hole, the surface of the metal diaphragm 2 is also provided with a covering sheet, the surface of the covering sheet is also provided with a through placement hole, the two placement holes are arranged correspondingly, the covering sheet presses the metal diaphragm 2, and the covering sheet is fixed together with the metal diaphragm 2, the pad 3 and the base plate 4.

[0030] In this solution, the sizes of the upper and lower holes may be inconsistent or consistent, and the best state is that the size is consistent; the covering sheet can be any form of pressing sheet. In this embodiment, the flange 1 structure is selected, and its main function is to cooperate with the bottom plate 4 to press the metal diaphragm 2.

[0031] Furthermore, the metal diaphragm 2 is in a circumferentially fixed and constrained state; in this state, only out-of-plane flexural deformation can occur, and under a certain pressure, the flexural deformation is affected by the limiting effect of the detection ring.

[0032] Specifically, in this embodiment, as shown in the screw holes in the figure, the cover sheet, the metal diaphragm 2, the backing plate 3 and the bottom plate 4 are fixed by using a plurality of groups of bolts arranged circumferentially.

[0033] It should be noted that the material of the metal diaphragm 2 is a low-strength metal with good ductility, such as pure aluminum, aluminum alloy, and copper.

[0034] At the same time, it should be supplemented that the detection ring is a thin-walled structure of at least two layers from the inside to the outside, and the shape is a continuous geometric protrusion structure; specifically, it can be a multi-layer thin-walled structure, a continuous circular ring, a rectangular ring or other forms of protrusion structures, and the indentations produced by the detection rings from the inside to the outside acting on the diaphragm correspond to the shock wave intensity thresholds indicated by several detection targets.

[0035] In this embodiment, the detection ring includes an inner ring detection ring 5 and an outer ring detection ring 6 .

[0036] The thickness of the pad 3 is H=h1+W+Δ; wherein h1 is the height of the innermost detection ring, W is the central deflection of the metal diaphragm 2 without the action of the detection ring when the shock wave is loaded with the minimum intensity threshold that the detection target can indicate, and Δ is the negative contact thickness; it should be noted that the negative contact thickness is used to adjust the strength of the interaction between the detection ring and the diaphragm, which can be determined through experiments.

[0037] The detection ring is adhered, welded or screwed to the surface of the bottom plate 4; or the detection ring and the bottom plate 4 are integrally formed.

[0038] Specifically, refer to Figure 1 The structure shown is a detection target for quickly judging the intensity of shock waves on site, comprising a flange 1, a metal diaphragm 2, a pad 3, a bottom plate 4, an inner ring detection ring 5 and an outer ring detection ring 6, wherein the flange 1, the metal diaphragm 2, the pad 3 and the bottom plate 4 are all processed by laser cutting, and the detection rings 5 ​​and 6 are made of two thin-walled aluminum tubes with different diameters, wherein the metal diaphragm 2 is annealed 1060 aluminum foil with a thickness of 0.2 mm and a size of 160 mm×160 mm, the outer dimensions of the flange 1 and the pad 3 are both 160 mm×160 mm, and the diameter of the central circular hole is 80 mm, which is the flexural deformation area of ​​the metal diaphragm, the flange thickness is 5 mm, and the pad thickness is H, which is determined by calibration experiments, the size of the bottom plate 5 is 160 mm×220 mm, and U-shaped grooves are provided at both ends for installation in the measurement environment, and 8 mounting holes are processed by laser cutting on the outside of the deformation area of ​​the flange, diaphragm, pad and bottom plate, and the hole positions are consistent for assembling the entire structure.

[0039] This embodiment is designed for detecting shock waves of two different intensities, namely p1=0.3MPa and p2=0.45MPa. Therefore, two detection rings with different diameters are used, namely inner and outer detection rings. According to the diameter of the diaphragm deformation zone of 80mm, in order to make the diaphragm deformation display clearer, two kinds of aluminum tubes with diameters of d1=20mm and d2=50mm are used as inner and outer detection rings, and the wall thickness of the aluminum tubes is 1.0mm.

[0040] The process of determining the specifications and dimensions such as the height of the detection ring and the thickness of the pad is as follows:

[0041] First, a shock wave to be detected is generated by a shock tube or explosion experiment, and the shock wave intensity is the minimum detection threshold p1 of the detection target. A metal diaphragm without a detection ring and a bottom plate and with a circumferential fixed constraint that can be deformed freely is loaded, and the deflection of the center point of the loaded aluminum diaphragm is measured, which is recorded as W. In this embodiment, the minimum shock wave threshold to be detected is determined to be p1=0.3MPa. After the shock tube is debugged and the above shock wave is generated, the average value of the center deflection of the diaphragm with a diameter of 80mm and a thickness of 0.2mm is measured, and the average value is about W=10.06mm.

[0042] Secondly, determine the thickness H of the pad. The height of the inner ring detection ring is selected as h1=12mm. When the pad thickness H>W+h1, the inner ring detection ring cannot interfere with the deformation of the diaphragm and cannot play an indicating role; when the pad thickness H=W+h1, the top of the inner ring detection ring just touches the deformed diaphragm, but it still cannot produce an indentation pattern on the diaphragm; therefore, H=W+h1+Δ is set, where Δ<0 is the negative contact thickness set between the diaphragm and the inner ring detection ring. The value of Δ determines the strength of the indentation effect of the inner ring detection ring on the diaphragm. According to the experimental results, when Δ=-2.06mm, that is, the pad thickness H=20.0mm, the diaphragm can produce a circle of indentation pattern under the first detection threshold p1=0.3MPa shock wave, and can ensure that the diaphragm does not produce any indentation when the pressure is lower than 0.3MPa. In this embodiment, the pad thickness is determined to be 20mm. When the shock wave with the first detection threshold p1 = 0.3 MPa acts on the detection target of this embodiment, the deformation effect of the diaphragm is as follows: Figure 2 Compared with the traditional diaphragm shock wave effect target, the present invention provides a detection target with a circle of raised indentation with a diameter of 20 mm formed in the center; when the shock wave intensity does not reach the threshold value p1, the deformed diaphragm has no indentation and remains in a smooth hemispherical shape.

[0043] Finally, considering that the deformation of the diaphragm under higher pressure has been affected by the inner ring detection ring, the height h2 of the outer ring detection ring is determined through experiments. An explosion or shock tube device is used to generate a shock wave with an intensity of p2 to be detected, which acts on the detection target with inner and outer ring detection rings. The outer ring detection ring height h2=h1 is preset. If only the inner ring indentation is still generated on the loaded diaphragm, it means that the height of the outer ring detection ring is too small. The height of the outer ring detection ring is increased in steps of 1mm until the deformed diaphragm can just interact with the outer ring detection ring and form an indentation pattern; otherwise, the height of the outer ring detection ring is gradually reduced in steps of 1mm until the deformed diaphragm can no longer collide with the outer ring detection ring. The critical values ​​of the above two situations are used as the final height of the outer ring detection ring. The outer ring detection ring height h2=13mm determined in this embodiment. When the shock wave intensity p≥p2, the diaphragm deformation effect is as follows: Figure 3 As shown in the figure, the diaphragm forms two raised indentations inside and outside.

[0044] The thickness of the pad determined according to the above process is 20mm, the inner detection ring has a diameter of 20mm, a wall thickness of 1.0mm, and a height of 12mm; the outer detection ring has a diameter of 50mm, a wall thickness of 1.0mm, and a height of 13mm. The above detection targets produce three types of deformation modes under the action of shock waves of different intensities: no indentation, one circle of indentation, and two circles of indentation. The indication effect of deformation mode one is shock wave intensity p<p1, the indication effect of deformation mode two is shock wave intensity p1≤p<p2, and the indication effect of deformation mode three is p≥p2. When used in actual explosions, it is only necessary to visually judge the deformation mode of the diaphragm to determine whether the shock wave intensity reaches the preset damage threshold.

[0045] It should be noted that the detection target for assisting in the judgment of shock wave intensity loads the aluminum foil with shock waves through a shock tube, obtains the free deflection deformation of the aluminum foil and the deformation when the detection target acts, and determines the size of the shock wave pressure by comparing the deformation pattern of the aluminum foil when the detection target acts, providing a method for quickly identifying the shock wave pressure in large-scale on-site explosion tests.

[0046] Example 2

[0047] refer to Figure 4-Figure 6 The structure shown is based on Example 1. In order to automatically withdraw the original metal diaphragm 2 and fix the new metal diaphragm 2, speed up the automatic film loading process, and facilitate the rapid and safe experiment at the explosion site, the following structure is adopted:

[0048] The rear end face of the bottom plate 4 is fixedly connected or detachably connected with a rear fixing member 7, and the rear fixing member 7 includes a shell, and a driving member 73 is fixedly connected inside the shell. The driving member 73 uses a driving motor as a driving source in most cases (generally, it can be an external circuit or an internal battery, which is adjusted and used according to the actual practical environment). The driving end of the driving member 73 is connected to a pull rod member 74, and the pull rod member 74 is a screw or a part of a screw. The pull rod member 74 passes through the bottom plate 4, the pad 3 and the cover sheet, and the through end is connected to a pull plate member 72. The driving member 73 drives the pull rod member 74 to move forward and backward, thereby The pull plate member 72 is used to clamp the pad 3 and the metal diaphragm 2. At this time, the connection form of the bolts and screw holes in the above-mentioned embodiment 1 is not adopted, but the metal diaphragm 2 is fixed by clamping. It is specially noted that the pull rod member 74 does not penetrate the metal diaphragm 2, and the surface of the pull rod member 74 is generally provided with a threaded sleeve. The driving member 73 generally drives the threaded sleeve to rotate, thereby realizing the forward and backward movement of the pull rod member 74. The threaded sleeve is generally rotatably connected to the shell of the rear fixing member 7, and it is sufficient to be able to rotate around its own axis. The driving form of the driving member 73 can be belt connection, gear meshing, etc., which are all existing technologies and will not be repeated here.

[0049] The pad 3 and the bottom plate 4 are also penetrated by the push rod member 71, and the surface of the pull rod member 74 is fixedly connected with the first push plate 75, and the surface of the push rod member 71 is fixedly connected with the second push plate 76. Generally, after the pull rod member 74 moves a certain distance, the first push plate 75 contacts the second push plate 76, driving the push rod member 71 to move forward, thereby facilitating the pushing out of the original metal diaphragm 2, because the original metal diaphragm 2 is deformed and can only fall after leaving the placement hole.

[0050] A spring member is also provided between the push rod member 71 and the bottom plate 4 to assist the push rod member 71 in returning to its original position.

[0051] There are multiple groups of related structures of the push rod member 71 and the pull plate member 72, and the multiple groups of driving members 73 are all synchronously controlled by a control device, which can be a single chip microcomputer or other forms of controller.

[0052] A portion of the pull rod 74 can be set as a square structure, or it can be fixedly connected with the covering sheet to limit the rotation of the pull rod 74; of course, other corresponding limiting structures can also be set in the shell, and other existing technologies are also within the protection scope of this application.

[0053] A film storage box 8 is also arranged above the bottom plate 4, and a plurality of metal diaphragms 2 are arranged in the film storage box 8. A film outlet hole is opened on the bottom surface of the film storage box 8 corresponding to the position of the original metal diaphragm 2. A film push spring 81 is arranged in the film storage box 8. A support plate 9 is also arranged on the surface of the pad 3, and the support plate 9 can be used to support a new metal diaphragm 2.

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A detection target for quickly judging the intensity of shock waves on site, characterized in that: The detection target comprises a bottom plate (4), the surface of the bottom plate (4) being fixedly connected with a protruding detection ring, the surface of the bottom plate (4) being further provided with a pad plate (3), the surface of the pad plate (3) being provided with a through placement hole, and the detection ring being located in the placement hole; the surface of the pad plate (3) being further connected with a metal diaphragm (2), the metal diaphragm (2) covering the placement hole, the surface of the metal diaphragm (2) being further provided with a covering sheet, the surface of the covering sheet also being provided with a through placement hole, the two placement holes being arranged correspondingly, the covering sheet pressing the metal diaphragm (2), and the covering sheet being fixed together with the metal diaphragm (2), the pad plate (3) and the bottom plate (4).

2. A detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The covering piece is a flange (1).

3. A detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The metal diaphragm (2) is in a circumferentially fixed and constrained state.

4. A detection target for quickly judging the intensity of shock waves on site according to claim 3, characterized in that: The cover sheet, the metal diaphragm (2), the backing plate (3) and the bottom plate (4) are fixed by a plurality of groups of bolts arranged circumferentially.

5. The detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The material of the metal diaphragm (2) is pure aluminum, aluminum alloy, or red copper.

6. A detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The detection ring is a thin-walled structure of at least two layers from the inside to the outside, and is in the form of a continuous geometric convex structure.

7. A detection target for quickly judging the intensity of shock waves on site according to claim 6, characterized in that: The detection ring comprises an inner ring detection ring (5) and an outer ring detection ring (6).

8. The detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The thickness of the pad (3) is H=h1+W+Δ; wherein h1 is the height of the innermost detection ring, W is the center deflection of the metal diaphragm (2) without the detection ring when the shock wave is loaded with the minimum intensity threshold that can be indicated by the detection target, and Δ is the negative contact thickness.

9. The detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The detection ring is adhered, welded or threadedly fixed to the surface of the base plate (4).

10. The detection target for quickly judging the intensity of shock waves on site according to claim 1, characterized in that: The detection ring and the bottom plate (4) are integrally formed.

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