Variable cross-section shock tube testing device for simulating 0.4 MPa air explosion shock waves

Abstract

The utility model provides a variable cross-section shock tube testing device for simulating 0.4 MPa level air explosion shock waves. The variable cross-section shock tube testing device comprises a high-pressure gas cylinder, a high-pressure driving section, an expansion section and a pressure relief section, the high-pressure driving section is connected with a high-pressure gas cylinder through a pipeline; a diaphragm is arranged at the joint of the high-pressure driving section and the expansion section; a diaphragm clamping mechanism is arranged between the high-pressure driving section and the expansion section; the small end of the expansion section is connected with the high-pressure driving section through a flange, and the large end of the expansion section is welded with the pressure relief section; the output end of the pressure relief section is connected with a to-be-tested structural member, and a pressure relief hole is formed in the outer wall of the pressure relief section and is circular; the pressure relief section is of a uniform-section hollow structure, the section of the pressure relief section is circular, and the whole device is of an axisymmetric structure. According to the explosion wave simulation device, standard exponential-like attenuated explosion waves of 0.4 MPa level can be simulated.

Description

Technical Field

[0001] The utility model belongs to the technical field of explosion wave simulation test devices, and particularly refers to a variable cross-section shock tube test device for simulating 0.4 MPa-class air blast shock waves. Background Art

[0002] A shock tube can simulate a quasi-exponential decay waveform similar to that of an air explosion shock wave, and has many advantages such as a controllable overpressure peak value and duration, safety, high efficiency, good repeatability, and low test cost. It is an ideal platform for carrying out explosion damage effect research in the laboratory and is often applied to explosion damage experimental research in fields such as weaponry, building structures, and biomedicine.

[0003] The Φ1485 mm anti-explosion shock tube of the Third Institute of Engineering Corps Research in Luoyang has a total tube length of 42 meters. Its driving section uses explosives as the high-pressure energy source, with an inner diameter of 348 mm and an inner diameter of 1485 mm in the test section; the variable cross-section shock tube of the University of Ottawa uses a compressed air driving method. The high-pressure section is composed of a series of pipes with an inner diameter of 0.597 m spliced together. The expansion section is 6.096 m long, and the cross-sectional size at the end is 2 m × 2 m.

[0004] The above variable cross-section shock tube test device has the following deficiencies: The large-scale shock tube test device is too long, has high requirements for the site, and uses detonation driving, resulting in problems such as high economic costs, poor repeatability, and high danger; while the traditional compressed air-driven variable cross-section shock tube has insufficient reflected overpressure (less than 0.15 MPa) and does not fully achieve the ideal quasi-exponential decay waveform. Summary of the Invention

[0005] The purpose of the utility model is to provide a variable cross-section shock tube test device for simulating 0.4 MPa-class air blast shock waves, which can simulate a standard quasi-exponential decay waveform of 0.4 MPa-class. To achieve the above purpose, the technical solution adopted is as follows:

[0006] A variable cross-section shock tube test device for simulating 0.4 MPa-class air blast shock waves, which is of an axisymmetric structure and includes:

[0007] A high-pressure gas cylinder 1;

[0008] And a high-pressure driving section 2, an expansion section 3, and a pressure relief section 4, which are connected in sequence. The high-pressure driving section 2 is connected to the high-pressure gas cylinder 1 through a pipeline; among them, there are a gas pressure control valve and an air flow control valve on the pipeline.

[0009] A diaphragm 23 is provided at the connection between the high-pressure driving section 2 and the expansion section 3;

[0010] A diaphragm clamping mechanism is provided between the high-pressure driving section 2 and the expansion section 3;

[0011] The said extension section 3, its small end is connected to the high-pressure drive section 2 through a flange 31, and its large end is welded to the pressure relief section 4;

[0012] The output end of the pressure relief section 4 is connected to the structural member to be tested, and pressure relief holes 41 are opened on its outer wall, and the pressure relief holes 41 are circular;

[0013] The pressure relief section 4 is a hollow structure with a constant cross-section, and its cross-section is circular.

[0014] Preferably, the high-pressure drive section 2 includes a closed-end fixing seat 21, a high-pressure drive section body, and an open-end fixing seat 22 that are connected in sequence;

[0015] For the closed-end fixing seat 21, an air injection hole 211 is opened thereon, one end thereof facing the high-pressure gas cylinder 1 is closed, and it is connected to the high-pressure drive section body through the air injection hole 211, and the high-pressure gas cylinder 1 injects driving gas into the high-pressure drive section 2 through the air injection hole 211;

[0016] The open-end fixing seat 22 is a ring structure, and its inner ring is fixed to the high-pressure drive section body;

[0017] For the open-end fixing seat 22, a first opening 221 that penetrates the open-end fixing seat 22 axially is opened thereon; the first opening 221 allows the movable end of the diaphragm clamping mechanism to pass through;

[0018] The open-end fixing seat 22 is connected to the flange 31 of the extension section 3;

[0019] The flange 31 is aligned with the open-end fixing seat 22, and a second opening 311 is provided thereon, and the second opening 311 allows the movable end of the diaphragm clamping mechanism to pass through; the second opening 311 is arranged corresponding to the first opening 221;

[0020] For the diaphragm clamping mechanism, its movable end passes through the first opening 221 and the second opening 311 in sequence to clamp the high-pressure drive section 2 and the extension section 3.

[0021] Preferably, the diaphragm clamping mechanism is a hydraulic jack or a bolt;

[0022] When it is a hydraulic jack, its main body is arranged in the high-pressure drive section 2, and its piston forms its movable end;

[0023] When it is a bolt, the bolt is tightened by a torque wrench of 1000 N·m.

[0024] Preferably, the cross-section of the large end of the extension section 3 is a circular cross-section, and its cross-sectional diameter is 3 m. The extension section is a hollow frustum structure.

[0025] Preferably, 12 of the pressure relief holes 41 are evenly distributed on the wall surface of the pressure relief section 4.

[0026] Preferably, an overpressure sensor is provided at the center of the wall surface of the pressure relief section 4.

[0027] Preferably, the high-pressure driving section 2, the expansion section 3, and the pressure relief section 4 are all made of steel materials.

[0028] Preferably, the high-pressure driving section 2 and the expansion section 3 are both supported by supports.

[0029] Preferably, the gas in the high-pressure gas cylinder 1 is one or more of gases such as nitrogen, carbon dioxide, and argon.

[0030] Compared with the prior art, the advantages of the present utility model are as follows:

[0031] 1. In the present utility model, a high-pressure driving section, an expansion section, and a pressure relief section are provided, and a compressed air driving mode is adopted, which causes less damage to the shock tube, has a lower economic cost, and is safe and controllable, and is suitable for ordinary scientific research institutions.

[0032] 2. The present utility model can simulate an air blast shock wave with a maximum reflected overpressure of 0.4 MPa according to the test requirements by changing the pressure of the high-pressure driving section, and the waveform is a standard exponential decay type.

[0033] "Reflected overpressure" refers to the overpressure after the shock wave is reflected when encountering an obstacle during operation. "Peak reflected overpressure" refers to the maximum value of the reflected overpressure.

[0034] 3. In the present utility model, the diameter of the end of the expansion section is 3 m, and various types of full-scale tests can be carried out. Description of the Drawings

[0035] Figure 1 Side view of a variable cross-section shock tube test device for simulating a 0.4 MPa-class air blast shock wave;

[0036] Figure 2 For Figure 1 exploded schematic diagram;

[0037] Figure 3 Structural schematic diagram of the high-pressure driving section;

[0038] Figure 4 Structural schematic diagram of the expansion section and the pressure relief section;

[0039] Figure 5 Simulation schematic diagram of the peak reflected overpressure of 0.4 MPa simulated by air;

[0040] Figure 6 Comparison diagram of simulation results.

[0041] Among them, 1 - high-pressure gas cylinder;

[0042] 2 - High - pressure drive section, 21 - Closed - end fixing seat, 211 - Air injection hole, 22 - Open - end fixing seat, 221 - First opening, 23 - Diaphragm;

[0043] 3 - Expansion section, 4 - Pressure - relief section, 41 - Pressure - relief hole. Detailed implementation manner

[0044] The following will describe in more detail the variable - cross - section shock tube test device for simulating 0.4MPa - level air - burst shock waves of the present utility model with reference to the schematic diagrams. Among them, the preferred embodiments of the present utility model are shown. It should be understood that those skilled in the art can modify the present utility model described herein while still achieving the advantageous effects of the present utility model. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present utility model.

[0045] Refer to the attached Figures 1-2 , A variable - cross - section shock tube test device for simulating 0.4MPa - level air - burst shock waves includes: a high - pressure gas cylinder, a high - pressure drive section, an expansion section, and a pressure - relief section.

[0046] The high - pressure gas cylinder is arranged at the front end of the shock tube and is connected to the high - pressure drive section through a pipeline to provide high - pressure drive gas for the shock tube for the test.

[0047] Among them, the ambient pressure is 0.1MPa. Higher than the ambient pressure is high - pressure. The maximum pressure that the high - pressure drive section can maintain normal and safe operation is 10MPa.

[0048] Refer to the attached Figure 3 , The high - pressure drive section is of a cylindrical structure. The open end is connected to the expansion section, and a diaphragm is arranged at the open end.

[0049] Refer to the attached Figure 4 , The expansion section is an axisymmetric frustum - shaped structure with a large - end diameter of 3m; its small end is connected to the high - pressure drive section, and the large end is welded to the pressure - relief section.

[0050] Refer to the attached Figure 4 , The pressure - relief section is a cylindrical rigid frame. One end is welded to the expansion section, and the other end is connected to the structural member to be tested; there are 12 evenly distributed circular pressure - relief holes on the side, which can reduce the secondary waves and tertiary waves generated by multiple reflections of the shock wave in the tube; an over - pressure sensor is arranged at the center of the wall surface for measuring the reflected over - pressure load acting on the surface of the member.

[0051] Specifically, a variable - cross - section shock tube test device for simulating 0.4MPa - level air - burst shock waves includes:

[0052] High - pressure gas cylinder 1;

[0053] and a high-pressure driving section 2, an expansion section 3 and a pressure relief section 4, which are connected in sequence. The high-pressure driving section 2 is connected to the high-pressure gas cylinder 1 through a pipeline.

[0054] The high-pressure driving section 2, the expansion section 3 and the pressure relief section 4 are all made of high-strength steel. The high-pressure driving section 2 and the expansion section 3 are both provided with supports for support.

[0055] At the connection between the high-pressure driving section 2 and the expansion section 3, a diaphragm 23 is provided, which is a polyester film.

[0056] A diaphragm clamping mechanism is provided between the high-pressure driving section 2 and the expansion section 3.

[0057] Before the diaphragm 13 ruptures, it closes the gas channel in the high-pressure driving section 2.

[0058] After the diaphragm 23 ruptures, the high-pressure driving section 2, the expansion section 3 and the pressure relief section 4 are connected in sequence.

[0059] The small end of the expansion section 3 is connected to the high-pressure driving section 2 through a flange 31 and bolts, and its large end is welded to the pressure relief section 4.

[0060] The output end of the pressure relief section 4 is connected to the structural member to be tested.

[0061] Specifically, the high-pressure driving section 2 includes a closed-end fixing seat 21, a high-pressure driving section body and an open-end fixing seat 22 that are connected in sequence;

[0062] The closed-end fixing seat 21 is provided with an air injection hole 211 on it. One end facing the high-pressure gas cylinder 1 is closed, and it communicates with the high-pressure driving section body through the air injection hole 211. The high-pressure gas cylinder 1 injects driving gas into the high-pressure driving section 2 through the air injection hole 211;

[0063] The open-end fixing seat 22 is a ring structure, and its inner ring is fixed to the high-pressure driving section body;

[0064] The open-end fixing seat 22 is provided with a first through-hole 221 that axially penetrates the open-end fixing seat 22; the first through-hole 221 allows the movable end of the diaphragm clamping mechanism to pass through;

[0065] The open-end fixing seat 22 is connected to the flange 31 of the expansion section 3;

[0066] The flange 31 is aligned with the open-end fixing seat 22, and is provided with a second through-hole 311. The second through-hole 311 allows the movable end of the diaphragm clamping mechanism to pass through; the second through-hole 311 is correspondingly arranged with the first through-hole 221;

[0067] The cross-section of the large end of the expansion section 3 is a circular cross-section. Considering that the building storey height in our country is about 3m, and the spans of components such as beams, slabs and columns are about 3m, in order to meet the needs of carrying out full-scale tests and ensure the uniformity of the load, its cross-sectional diameter is 3m.

[0068] The pressure relief section 4 is welded to the expansion section 3, and 12 evenly distributed pressure relief holes 41 are provided on its wall surface. The pressure relief holes 41 are circular.

[0069] The pressure relief section 4 is a hollow structure with a constant cross-section, and its cross-section is circular.

[0070] An overpressure sensor is provided at the center of the wall surface of the pressure relief section 4.

[0071] The diaphragm clamping mechanism has its main body disposed in the high-pressure driving section 2, and its movable end sequentially passes through the first opening 221 and the second opening 311 to clamp the high-pressure driving section 2 and the expansion section 3.

[0072] The diaphragm clamping mechanism is a hydraulic jack, and its piston forms its movable end.

[0073] Specifically, when the diaphragm clamping mechanism is a hydraulic jack, its housing is adsorbed on the high-pressure driving section body of the high-pressure driving section 2 through a suction cup, and its output end sequentially passes through the first opening 221 and the second opening 311 to clamp the high-pressure driving section 2 and the expansion section 3.

[0074] Wherein, one end of the suction cup is connected to the main body (housing) of the diaphragm clamping mechanism, and the other end is the adsorption end, which is adsorbed on the high-pressure driving section 2.

[0075] Before the hydraulic jack works, the high-pressure driving section 2 and the expansion section 3 are aligned and in contact.

[0076] When the diaphragm clamping mechanism is a bolt, the bolt sequentially passes through the second opening 311 and the first opening 221, and then the bolt is tightened by a torque wrench of 1000 N·m.

[0077] Before tightening, the high-pressure driving section 2 and the expansion section 3 are aligned and in contact.

[0078] The working principle of this shock tube test device:

[0079] During the test, the high-pressure gas cylinder fills the high-pressure driving section with high-pressure driving gas through the gas injection hole. When the pressure difference across the diaphragm reaches the critical value, the diaphragm ruptures, and then the driving gas in the high-pressure driving section expands to generate a shock wave.

[0080] The driving gas further expands in the expansion section to form a uniformly distributed overpressure load similar to the explosion shock wave, which acts on the test structural member installed at the end of the pressure relief section.

[0081] Then, the overpressure load is reflected at the structural member and discharged from the pressure relief holes on the side of the pressure relief section.

[0082] The explosion load measured at the center of the side of the pressure relief section can represent the reflected overpressure load acting on the surface of the member.

[0083] Among them, the pressure relief hole can reduce the secondary wave and the tertiary wave generated by the multiple reflections of the shock wave in the shock tube test device.

[0084] As Figure 5 shown, the shock tube test device simulates an air blast shock wave with a maximum reflected overpressure of 0.4 MPa, and it is a standard waveform with approximately exponential decay.

[0085] Among them, the abscissa is time, and the ordinate is the reflected overpressure.

[0086] It is known from the prior art that the incident overpressure refers to the situation where the pressure suddenly increases due to external factors, such as an explosion or an impact.

[0087] The reflected overpressure refers to the pressure reflection phenomenon caused by the incident overpressure. When the incident overpressure reaches a certain level, a shock wave will be generated when it collides with the surface of an object or a building, and its energy will be reflected back. This reflected wave will cause additional pressure on nearby objects or buildings.

[0088] As Figure 6 shown, the cross-section of the pressure relief section 4 and the cross-section of the pressure relief hole are both circular, while in the comparative experiment, the cross-section of the pressure relief section 4 and the cross-section of the pressure relief hole both adopt a square structure, and the side length of the square is the same as the diameter of the circle.

[0089] Under the same conditions, the reflected overpressure of the air blast shock wave simulated by the square structure can only reach 0.35 MPa, while by using an axisymmetric circular structure, the reflected overpressure of the air blast shock wave simulated can exceed 0.4 MPa.

[0090] The above are only the preferred embodiments of the present invention and do not impose any limitation on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, makes any form of equivalent substitution or modification and other changes to the technical solution and technical content disclosed by the present invention, which are all within the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A variable cross-section shock tube test device for simulating 0.4 MPa-level air-burst shock waves, characterized in that, Comprising: A high-pressure gas cylinder (1); And a high-pressure driving section (2), an expansion section (3) and a pressure relief section (4), which are connected in sequence, and the high-pressure driving section (2) is connected to the high-pressure gas cylinder (1) through a pipeline; At the connection between the high-pressure driving section (2) and the expansion section (3), a diaphragm (23) is provided; A diaphragm clamping mechanism is provided between the high-pressure driving section (2) and the expansion section (3); For the expansion section (3), its small end is connected to the high-pressure driving section (2) through a flange (31), and its large end is welded to the pressure relief section (4); The output end of the pressure relief section (4) is connected to the structural member to be tested, and a pressure relief hole (41) is opened on its outer wall, and the pressure relief hole (41) is circular; The pressure relief section (4) is a hollow structure with equal cross-sections, and its cross-section is circular.

2. The variable cross-section shock tube test device for simulating 0.4 MPa-level air blast shock waves according to claim 1, characterized in that, The high-pressure driving section (2) includes a closed-end fixing seat (21), a high-pressure driving section body and an open-end fixing seat (22) that are connected in sequence; For the closed-end fixing seat (21), an air injection hole (211) is opened thereon, one end thereof facing the high-pressure gas cylinder (1) is closed, and it is connected to the high-pressure driving section body through the air injection hole (211), and the high-pressure gas cylinder (1) injects driving gas into the high-pressure driving section (2) through the air injection hole (211); The open-end fixing seat (22) is of an annular structure, and its inner ring is fixed to the high-pressure driving section body; For the open-end fixing seat (22), a first opening (221) that penetrates the open-end fixing seat (22) axially is opened thereon; the first opening (221) allows the movable end of the diaphragm clamping mechanism to pass through; The open-end fixing seat (22) is connected to the flange (31) of the expansion section (3); The flange (31) is aligned with the open-end fixing seat (22), and a second opening (311) is provided thereon, and the second opening (311) allows the movable end of the diaphragm clamping mechanism to pass through; the second opening (311) is correspondingly arranged with the first opening (221); For the diaphragm clamping mechanism, its movable end passes through the first opening (221) and the second opening (311) in sequence to clamp the high-pressure driving section (2) and the expansion section (3).

3. The variable cross-section shock tube test device for simulating 0.4 MPa-level air-burst shock waves according to claim 2, characterized in that, The diaphragm clamping mechanism is a hydraulic jack or a bolt; When it is a hydraulic jack, its main body is arranged in the high-pressure driving section (2), and its piston forms its movable end; When it is a bolt, the bolt is tightened by a torque wrench of 1000 N·m.

4. The variable cross-section shock tube test device for simulating 0.4 MPa-class air-burst shock waves according to claim 2, characterized in that, The cross-section of the large end of the expansion section (3) is a circular cross-section, and its cross-sectional diameter is 3 m.

5. The variable cross-section shock tube test device for simulating 0.4 MPa level air-burst shock waves according to claim 1, characterized in that, 12 of the pressure relief holes (41) are evenly distributed on the wall surface of the pressure relief section (4).

6. The variable cross-section shock tube test device for simulating 0.4 MPa-class air-burst shock waves according to claim 1, wherein An overpressure sensor is provided at the center of the wall surface of the pressure relief section (4).

7. The variable cross-section shock tube test device for simulating 0.4MPa-class air-burst shock waves according to claim 1, characterized in that, The high-pressure driving section (2), the expansion section (3) and the pressure relief section (4) are all made of steel materials.

8. The variable cross-section shock tube test device for simulating 0.4 MPa level air-burst shock waves according to claim 1, wherein Both the high-pressure driving section (2) and the expansion section (3) are provided with supports for support.

9. The variable cross-section shock tube test device for simulating 0.4 MPa-level air blast shock waves according to claim 1, wherein The gas in the high-pressure gas cylinder (1) is one or more of nitrogen, carbon dioxide, and argon gases.

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