An energetic powder shock wave velocity characterization platform and methods of use thereof

Abstract

The application discloses a kind of energetic powder shock wave velocity characterization platform and its use method, and the launch device of the characterization platform is composed of stage, ignition wire and DC power supply;Ignition wire is contacted with test sample on stage, and is connected with DC power supply;Measuring device is composed of base, shell and two sensors;Base has guide rail;Shell is tubular structure, one end is opposite to test sample along horizontal direction;Shell and guide rail are slidingly fitted;Sensor includes metal thin film electrode that can generate electricity by friction and friction power generation sheet;Metal thin film electrode is attached to the inner wall of one side of shell;Friction power generation sheet is elastic, one end is fixedly installed on the inner wall of other side of shell, and other end is free end and elastically attached to metal thin film electrode;Collecting device includes signal-connected oscilloscope and signal processing module.The above-mentioned characterization platform has the characteristics of simple structure, easy operation, low cost and easy manufacturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energetic material characterization test, in particular to an energetic powder shock wave velocity characterization platform and a use method thereof. BACKGROUND

[0002] Energetic metastable composites (MECs) are a kind of energetic materials composed of fuel and oxidizer, which can store a large amount of chemical energy and release it quickly when needed. Due to its high energy density, adjustable and controllable reaction characteristics, etc., it has become an ideal choice for energetic fuels such as explosives, propellants, and pyrotechnics, and has wide application prospects in military, aerospace, welding, blasting, and other fields.

[0003] Quantitative characterization of MECs energy release characteristics, and in-depth understanding of its energy release mechanism and rules under specific conditions, are the key to meet the performance regulation requirements. In recent years, MECs energy release characteristics include reaction energy, self-propagating combustion performance, pressure performance, thermal behavior, and shock wave effect, among which, shock wave velocity is an important parameter to measure shock wave propagation characteristics.

[0004] Currently, high-speed schlieren system is an important means to characterize MECs shock wave, its principle is to use optical imaging technology to convert the motion of compressible gas flow field into visual images. High-speed schlieren system can realize the measurement of shock wave image evolution process, in addition to obtaining basic parameters such as shock wave propagation distance and shock wave velocity, it has significant advantages in understanding and analyzing the formation and evolution of shock wave. However, due to the complexity of the system composition, high equipment cost, and tedious operation and maintenance tasks, the threshold of shock wave test is increased.

[0005] Therefore, it is necessary to provide a new device that is simple, convenient, fast, efficient, and low-cost to supplement the measurement of shock wave velocity. SUMMARY

[0006] In order to solve the problems existing in the prior art, the present application provides an energetic powder shock wave velocity characterization platform and a use method thereof, which has the characteristics of simple structure, convenient operation, low cost, and easy manufacturing, to effectively supplement the existing shock wave characterization platform and characterization method under the existing conditions.

[0007] The present application adopts the following specific technical solutions:

[0008] The present application provides an energetic powder shock wave velocity characterization platform, which includes a launching device, a measuring device, and a collecting device.

[0009] The emitting device is composed of a height-adjustable stage, a firing wire and a direct current power supply; the stage is used for placing a test sample; the firing wire is in contact with the test sample placed on the stage and is connected with the direct current power supply to realize excitation of the firing;

[0010] The measuring device is composed of a base, a shell and two sensors; the base has guide rails for linear motion guiding of the sensors; the shell is an insulating tubular structure with open ends, and the opening at one end is arranged opposite to the test sample in the horizontal direction; the bottom end of the shell is slidingly fitted on the guide rails; the sensor includes a metal thin film electrode capable of generating electricity by friction and a friction power generation sheet; the metal thin film electrode is attached to the inner wall of one side of the shell; the friction power generation sheet is elastic, one end is fixedly installed on the inner wall of the other side of the shell opposite to the metal thin film electrode, and the other end is a free end and elastically attached to the metal thin film electrode;

[0011] The collecting device includes an oscilloscope and a signal processing module connected in sequence; the oscilloscope is connected with the metal thin film electrode, used for amplifying and obtaining the waveform curve of the voltage signal change; the signal processing module is used for capturing the rising edge of the voltage signal curve and recording the time.

[0012] Further, the two sensors are installed in the shell along the extension direction of the guide rails;

[0013] Along the horizontal direction perpendicular to the extension direction of the guide rails, the friction power generation sheets are staggered between them.

[0014] Further, the shell corresponds to each sensor one by one, and one sensor is installed in each shell; the shells are spaced apart along the extension direction of the guide rails;

[0015] Along the horizontal direction perpendicular to the extension direction of the guide rails, the friction power generation sheets are staggered between them.

[0016] Further, the surface of the base is provided with a scale for conveniently reading the position information of the shell.

[0017] Further, the guide rail is a dovetail type sliding rail;

[0018] The bottom end of the shell is provided with a dovetail groove slidingly fitted with the dovetail type sliding rail.

[0019] Further, the stage further includes a counterweight base, two columns and a stop knob;

[0020] The two columns are symmetrically arranged in the vertical direction, and the bottom ends are fixedly installed on the counterweight base;

[0021] The loading platform is provided with a double-ear flange; the double-ear flange is provided with two through holes penetrating through the thickness thereof in the vertical direction and a threaded hole penetrating through the outer wall of the through hole in the horizontal direction;

[0022] The double-ear flange is sleeved on the column through the two through holes;

[0023] The stop knob is screwed with the threaded hole, and is used for fixing the loading platform on the column.

[0024] Further, the projection of the friction power generation sheet on the horizontal plane falls in the projection of the metal thin film electrode.

[0025] Further, the metal thin film electrode is made of silver foil, copper foil or aluminum foil;

[0026] The friction power generation sheet is made of polyimide film, polyfluoroethylene propylene film or polytetrafluoroethylene film.

[0027] Further, the shell is made of acrylic plate.

[0028] In addition, the application also provides a use method of the energetic powder shock wave velocity characterization platform, and the use method comprises the following steps:

[0029] The first step is to assemble the energetic powder shock wave velocity characterization platform, adjust the loading platform and the guide rail to be in the same straight line, add the test sample in the loading platform, adjust the height of the loading platform, ensure that the center of the test sample and the center of the friction power generation sheet are in the same horizontal height, and measure the center distance S of the two sensors;

[0030] The second step is to open the direct current power supply, ignite the test sample through the ignition wire, and the generated shock wave passes through the two sensors in turn, and the collecting device records the time T1 and T2 when the shock wave reaches the two sensors and the waveform, and the power is turned off after the test is completed;

[0031] The third step is to calculate the wave velocity of the shock wave generated by the test sample by using the formula S / (T2-T1).

[0032] The application has the following beneficial effects:

[0033] The energetic powder shock wave velocity characterization platform of the present application provides a new scheme with simple structure and convenient operation for shock wave testing; the core device is the sensor of the measuring device, the sensor adopts a metal thin film electrode capable of generating electricity by friction and a friction power generation sheet, one end of the friction power generation sheet is attached to the metal thin film electrode through elasticity; the sensor is made of common metal foil and polymer, has the advantages of low cost and easy manufacturing; the metal thin film electrode and the friction power generation sheet can sense the shock wave through slight contact separation and relative sliding, have the advantage of high sensitivity, and the energetic powder shock wave velocity characterization platform of the present application is an effective supplement to the current shock wave characterization platform. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is an axial view of the energetic powder shock wave velocity characterization platform;

[0035] Figure 2 It is Figure 1 It is a working principle local section view of the measuring device;

[0036] Figure 3 It is a top view distribution diagram of the measuring device-integral structure;

[0037] Figure 4 It is a top view distribution diagram of the measuring device-separable structure;

[0038] Figure 5 It is the time when the shock wave reaches and generates the corresponding signal waveform diagram of the embodiment 1;

[0039] Among them, 1 is a counterweight base, 2 is a column, 3 is a loading platform, 4 is a stop knob, 5 is a base, 6 is a dovetail guide rail, 7 is a metal thin film electrode, 8 is a friction power generation sheet, 9 is an outer shell, 10 is an oscilloscope, and 11 is a signal processing module. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0041] The present embodiment provides an energetic powder shock wave velocity characterization platform, as shown in Figure 1 The characterization platform includes a launching device, a measuring device, and a collecting device;

[0042] The launching device is used for igniting the test sample and generating the shock wave, and is composed of a height-adjustable carrier 3, an ignition wire and a direct current power supply; the carrier 3 is used for placing the test sample and can adjust the height of the test sample through height adjustment, so that the test sample is at the same height as the sensor; the ignition wire is in contact with the test sample placed on the carrier 3 and is connected with the direct current power supply to realize ignition excitation, and the ignition of the test sample can be directly controlled by controlling the switch of the direct current power supply; the ignition wire can be a resistance wire;

[0043] The measuring device is oppositely arranged with the launching device and is used for sensing the shock wave generated by the test sample ignited by the launching device, and is composed of a base 5, a shell 9 and two sensors; the base 5 has guide rails for linear motion guiding of the sensors, as shown in Figure 1 The base 5 can be composed of a bottom plate and guide rails on the top of the bottom plate, and the bottom plate and the guide rails can be an integral structure; the shell 9 is a tubular structure with insulation and open ends, and the cross section of the shell 9 can be a square tube or a rectangular tube; the opening at one end is oppositely arranged with the test sample in the horizontal direction, so that the shock wave generated by the test sample can directly enter the opening of the shell 9, so that the sensor is directly affected by the shock wave, and the test error is minimized; the bottom end of the shell 9 is slidingly fitted on the guide rails; the guide rails can be dovetail type sliding rails or other shaped sliding rails; when the dovetail type sliding rails are used, the bottom end of the shell 9 is provided with dovetail grooves slidingly fitted with the dovetail type sliding rails, and the guide rails guide the shell 9 through the shape cooperation of the dovetail grooves and the dovetail type sliding rails, so that the shell 9 moves along a straight line; the shell 9 can be made of acrylic plate; the surface of the base 5 is provided with a scale for conveniently reading the position information of the shell 9, and the scale can be printed or engraved on the bottom plate constituting the base 5; the position information of the sensor is conveniently read through the scale on the surface of the base 5, so that the center distance between the two sensors is obtained;

[0044] The sensor comprises a metal thin film electrode 7 capable of generating electricity by friction and a friction power generation sheet 8; the metal thin film electrode 7 is attached to the inner wall of one side of the shell 9; the friction power generation sheet 8 is elastic, one end of which is fixedly installed on the inner wall of the other side of the shell 9 opposite to the metal thin film electrode 7, and the other end is a free end and is elastically attached to the metal thin film electrode 7; in this embodiment, the metal thin film electrode 7 is attached to the inner top wall of the shell 9, and the friction power generation sheet 8 is fixedly installed on the inner bottom wall of the shell 9, one end of which is directed to the objective table 3, and the other end is elastically raised and in contact with the metal thin film electrode 7 on the top, and the middle part is curved into an arc structure; the metal thin film electrode 7 is made of silver foil, copper foil or aluminum foil; the friction power generation sheet 8 is made of polyimide film, polytetrafluoroethylene film or polytetrafluoroethylene film; attention should be paid to the relative position of the metal thin film electrode 7 and the friction power generation sheet 8 during installation, the projection of the friction power generation sheet 8 on the horizontal plane falls in the projection of the metal thin film electrode 7, that is, the horizontal projection of the polyimide film falls on the aluminum foil electrode; the aluminum foil electrode is led out by a wire and connected with an oscilloscope 10;

[0045] The collection device comprises the oscilloscope 10 and a signal processing module 11 connected in signal; the oscilloscope 10 is connected with the metal thin film electrode 7, used for amplifying and obtaining the waveform curve of the voltage signal change; the signal processing module 11 is used for capturing the rising edge of the voltage signal curve, that is, the time when the shock wave reaches the friction power generation sheet 8, and recording the time when the shock wave reaches the friction power generation sheet 8. The signal processing module 11 can also transmit the waveform and time information to the terminal such as mobile phone and computer through wired or wireless connection, and store the waveform and time information through the terminal.

[0046] The two sensors can adopt the following two implementation manners:

[0047] Implementation manner one: as shown in Figure 3 , the two sensors are installed in the same shell 9 and are spaced apart in the shell 9 along the extension direction of the guide rail; along the horizontal direction perpendicular to the extension direction of the guide rail, the friction power generation sheets 8 are staggered.

[0048] Implementation manner two: as shown in Figure 4 , the shell 9 corresponds to each sensor one by one, and one sensor is installed in each shell 9, that is, the above-mentioned representation platform has two shells 9 and two sensors, one sensor is installed in each shell 9, and the shells 9 are spaced apart along the extension direction of the guide rail; along the horizontal direction perpendicular to the extension direction of the guide rail, the friction power generation sheets 8 are staggered.

[0049] By interleaving the two sensors' triboelectric nanogenerators 8, the effect of the shock wave on each sensor can be ensured, thereby ensuring the accuracy of the measurement results.

[0050] In the above characterization platform, as shown in Figure 1 The object table 3 further comprises a counterweight base 1, two columns 2 and a stop knob 4; the two columns 2 are symmetrically arranged in the vertical direction, and the bottom end of the column 2 is fixedly installed on the counterweight base 1, and the bottom end of the column 2 can be threadedly connected to the counterweight base 1; the object table 3 is provided with a double lug flange; the double lug flange is provided with two through holes penetrating through its thickness in the vertical direction and a threaded hole penetrating through the outer side wall of the through hole in the horizontal direction; the double lug flange is slidably sleeved on the column 2 through the two through holes; the stop knob 4 is threadedly connected with the threaded hole, and is used for fixing the object table 3 to the column 2 by abutting between the end of the stop knob and the column 2.

[0051] As shown in Figure 2 Before the above characterization platform works, the metal thin film electrode 7 and the triboelectric nanogenerator 8 are partially in contact, and due to the triboelectric effect, charge transfer occurs between them; under the action of the shock wave, the triboelectric nanogenerator 8 and the metal thin film electrode 7 are separated to a certain extent, and due to the electrostatic induction effect, a potential difference is generated between the metal thin film electrode 7 and the triboelectric nanogenerator 8, and the transmitted electrical signal is received by the acquisition unit.

[0052] The above-mentioned shock wave velocity characterization platform for energetic powder provides a new scheme with simple structure and convenient operation for shock wave testing; the core device is the sensor of the measuring device, the sensor adopts a metal thin film electrode 7 and a triboelectric nanogenerator 8 capable of generating electricity by friction, and one end of the triboelectric nanogenerator 8 is attached to the metal thin film electrode 7 through elasticity; the sensor is made of common metal foil and polymer, and has the advantages of low cost and easy manufacturing; the metal thin film electrode 7 and the triboelectric nanogenerator 8 can perceive the shock wave through slight contact separation and relative sliding, and have the advantage of high sensitivity; the energetic powder shock wave velocity characterization platform of the present application is an effective supplement to the present shock wave characterization platform.

[0053] The use method of the above-mentioned shock wave velocity characterization platform for energetic powder comprises the following steps:

[0054] The first step is to assemble the shock wave velocity characterization platform for energetic powder, adjust the object table 3 to be in the same straight line with the guide rail, add a certain amount of test sample in the object table 3, loosen the stop knob 4 to adjust the height of the object table 3, ensure that the center of the test sample and the center of the triboelectric nanogenerator 8 are at the same horizontal height, and measure the center distance S of the two sensors;

[0055] The second step, the direct current power is turned on, the test sample is ignited by the ignition wire, the shock wave generated is sequentially passed through the two sensors, and the time T1 and T2 when the shock wave reaches the two sensors and the waveforms are recorded by the acquisition device; and the direct current power is turned off after the test is completed.

[0056] The third step, the center distance S of the two sensors and the time difference when the shock wave reaches the two sensors are obtained, and the shock wave speed generated by the test sample is calculated by the formula S / (T2-T1).

[0057] Embodiment one

[0058] 1. The Al / Fe2O3 thermite with a mass of 2g is placed in the center of the object table 3, the resistance wire is connected and good contact is maintained, two groups of separately set sensors are used, the distance between one of the sensors and the explosion center is 5mm, the position of the other sensor is adjusted so that the center distance S between the two sensors is 25mm;

[0059] 2. The direct current power is turned on, the resistance wire ignites the test sample, the shock wave is measured by the two sensors, the time when the shock wave reaches is recorded by the acquisition device, and the waveform diagram of the corresponding signal is generated, and the corresponding results are shown in Figure 5

[0060] 3. According to the time difference of the time, the propagation time of the shock wave between the two sensors is 23ms, and then the center distance of the two sensors is divided by the propagation time to obtain the shock wave speed generated by the test sample, which is 1.1km / s.

[0061] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and the equivalent technology thereof, the present application also intends to include these modifications and variations.​

Claims

1. An energetic powder shock wave velocity characterization platform, characterized in that, The device comprises a launching device, a measuring device and a collecting device; The launching device is composed of a height-adjustable stage, a firing wire and a direct current power supply; the stage is used for placing a test sample; the firing wire is in contact with the test sample placed on the stage and is connected with the direct current power supply to realize excitation of the firing; The measuring device is composed of a base, a shell and two sensors; the base has guide rails for linear motion of the sensors; the shell is an insulating tubular structure with two open ends, and the opening at one end is arranged opposite to the test sample in the horizontal direction; the bottom end of the shell is slidingly fitted on the guide rails; the sensor comprises a metal thin film electrode capable of generating electricity by friction and a friction power generation sheet; the metal thin film electrode is attached to the inner wall of one side of the shell; the friction power generation sheet is elastic, one end of which is fixedly installed on the inner wall of the other side of the shell opposite to the metal thin film electrode, and the other end is a free end and elastically attached to the metal thin film electrode; The collecting device comprises an oscilloscope and a signal processing module connected in signal; the oscilloscope is connected with the metal thin film electrode, used for amplifying and obtaining the waveform curve of the voltage signal change; the signal processing module is used for capturing the rising edge of the voltage signal curve and recording the time.

2. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The two sensors are installed in the shell along the extension direction of the guide rails; The friction power generation sheets are staggered between each other in the horizontal direction perpendicular to the extension direction of the guide rails.

3. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The shell corresponds to each sensor one by one, and one sensor is installed in each shell; the shells are spaced apart along the extension direction of the guide rails; The friction power generation sheets are staggered between each other in the horizontal direction perpendicular to the extension direction of the guide rails.

4. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The surface of the base is provided with a scale for conveniently reading the position information of the shell.

5. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The guide rail is a dovetail type slide rail; The bottom end of the shell is provided with a dovetail groove slidingly fitted with the dovetail type slide rail.

6. The energetic powder shock wave velocity characterization platform of claim 5, wherein, The stage further comprises a counterweight base, two columns and a stop knob; The two columns are symmetrically arranged in the vertical direction, and the bottom ends are fixedly installed on the counterweight base; The stage is provided with a double lug flange; the double lug flange is provided with two through holes penetrating through its thickness in the vertical direction and a threaded hole penetrating through the outer side wall of the through hole in the horizontal direction; The double lug flange is slidingly sleeved on the column through the two through holes; The stop knob is threadedly connected with the threaded hole, used for fixing the stage to the column.

7. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The projection of the friction power generation sheet on the horizontal plane falls in the projection of the metal thin film electrode.

8. The energetic powder shock wave velocity characterization platform of claim 1, wherein, The metal thin film electrode is made of silver foil, copper foil or aluminum foil; The friction power generation sheet is made of polyimide film, polyperfluoroethylene propylene film or polytetrafluoroethylene film.

9. The energetic powder shock wave velocity characterization platform of any one of claims 1-7, wherein, The shell is made of acrylic plate.

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