Device for directly measuring detonation velocity based on photon Doppler test system and test method

Abstract

The invention discloses a device for directly measuring detonation velocity based on a photon Doppler test system and a test method, the device comprises a constraint shell, one end of the constraint shell is fixed with a constraint screw cap, and the other end of the constraint shell is connected with a multimode quartz optical fiber; a PC transparent window is arranged, and an initiating explosive charging ring filled with an initiating explosive and an explosive charging ring filled with an explosive to be tested are pressed in the constraint shell; the initiating explosive charging ring filled with the initiating explosive is close to the PC transparent window; and the multimode quartz optical fiber is connected with the Doppler test system PDV. According to the method, the detonation wave propagation characteristics of an explosive system can be directly tested by using the PDV, and the detonation velocity can be obtained after correction. According to the invention, the detonation velocity of the to-be-measured explosive can be simply, efficiently and conveniently measured. The measuring method is easy to implement, has high feasibility and can measure the detonation velocity of the explosive system.

Description

Technical field:

[0001] The invention relates to the field of detonation performance testing of energetic materials, in particular to a device and a testing method for directly measuring detonation velocity based on a photon Doppler testing system. Background technology:

[0002] The detonation velocity of explosives is the propagation speed of the detonation wave, which reflects the explosive performance of the explosive and indirectly indicates other detonation parameters. The detonation velocity is an important quality indicator of explosives. The higher the detonation velocity, the greater the power of the explosive. There are many methods for measuring the detonation velocity of explosives, which can be divided into three categories according to their principles: detonating cord method, probe method and high-speed photography method.

[0003] The detonating cord method requires that the detonation velocity of the detonating cord has been accurately measured in order to calculate the detonation velocity of the unknown explosive. This method has low testing accuracy and has been basically eliminated.

[0004] The probe method uses various types of probes and timing instruments to measure the time t that a detonation wave takes to propagate from one point to another, and then uses the formula v=h / t to calculate the average detonation velocity between two points or the continuous detonation velocity within a certain distance. According to the type of probe, it can be divided into electrical probes and optical fiber probes. However, it requires the precise deployment of the relative position of the probe, and the production, installation and deployment of the measuring device are very time-consuming, that is, the work efficiency is very low.

[0005] The high-speed camera method mainly relies on the luminous effect of the detonation wavefront to record the detonation trajectory. High-speed cameras that can meet the performance requirements are extremely expensive and are easily damaged during the measurement process. Repairs after damage require professional equipment, which is inconvenient and extremely costly.

[0006] It can be seen that although the detonating cord method, probe method and high-speed photography method are simple, stable and reliable, and their application is very mature; however, their shortcomings or defects have also been found in the actual production process. Summary of the invention:

[0007] The invention provides a device and a test method for directly measuring detonation velocity based on a photon Doppler test system, which can test the detonation velocity of explosives, is convenient to test, has high precision, low cost, and is easy to use and maintain.

[0008] The present invention provides a device for directly measuring detonation velocity based on a photon Doppler test system, comprising:

[0009] Constraint enclosure;

[0010] One end of the restraining housing is fixed to the restraining screw cap, and the other end is connected to the multi-mode quartz optical fiber;

[0011] A PC transparent window is provided for pressing a detonator charge ring containing detonator and a reagent charge ring containing explosive to be tested into the confinement housing;

[0012] The explosive charge ring containing the explosive is close to the PC window;

[0013] The multimode quartz optical fiber is connected to the Doppler test system PDV;

[0014] The laser wavelength of the PDV is 1550-1552nm; the PDV is a device used to directly test the detonation wave propagation characteristics of the explosive system, and the detonation velocity can be obtained after correction.

[0015] Furthermore, the connection interface between the multimode quartz optical fiber and the constraining housing is SMA905.

[0016] Furthermore, the inner diameter of the reagent charging ring should be larger than the diameter of the multi-mode quartz optical fiber, and the multi-mode quartz optical fiber is required to maintain close contact with the surface of the explosive to be tested.

[0017] Furthermore, a sealing ring is provided between the restraining shell and the restraining rotary cover; and a sealing ring is provided between the restraining shell and the multi-mode quartz optical fiber.

[0018] Furthermore, the multimode quartz optical fiber is connected to the PDV via a connection conversion device or directly.

[0019] The present invention provides a test method for directly measuring detonation velocity based on a photon Doppler test system, comprising the following steps:

[0020] S1. Process a series of test tools according to actual requirements or actual working conditions;

[0021] S2. Press the explosive and the test agent into the test tooling described in S1;

[0022] S3. Fix the test fixture described in S2 and connect the PDV to the multimode quartz optical fiber;

[0023] S4. Using the energy source to detonate the explosive to be tested, the signal is recorded by the oscilloscope of the PDV system;

[0024] S5. Input the PDV signal obtained in S4 into the prepared software or use Matlab to perform Fourier transform to obtain the velocity curve;

[0025] S6. Read the effective speed of the curve, calculate using the corresponding correction formula, and obtain the corresponding detonation speed.

[0026] The specific requirements in the above S6 are as follows: Calculate the detonation velocity of the explosive to be tested based on the finite numerical aperture correction factor formula (1) and the refractive index of the medium where the reflecting surface is located.

[0027]

[0028] Where NA is the numerical aperture of the multimode silica fiber, and n is the refractive index of the core of the multimode silica fiber.

[0029] D=v×C÷n×1.38

[0030] Wherein, v is the apparent velocity obtained by the PDV velocity measurement system, C is the correction factor obtained by formula (1), and n is the refractive index of the core of the multimode silica optical fiber.

[0031] Compared with the existing device and method for testing the detonation velocity of explosives, the present invention has the following significant beneficial effects:

[0032] (1) Directly use the PDV test device to test the detonation wave propagation characteristics of the explosive system. After correction, the detonation velocity can be obtained. PDV has the advantages of high measurement accuracy, large test range, high reliability, and easy operation.

[0033] (2) The entire device is composed of the above-mentioned components and has the characteristics of being detachable, safe, convenient, low-cost, easy to process and easy to install. It can be mass-produced, individually packaged and stored for a long time.

[0034] (3) The test device can be miniaturized, and the minimum charge size can be slightly larger than the diameter of the multimode quartz optical fiber, reducing the amount of reagents used. The minimum applicable amount of explosives can be controlled at the hundred milligram level, reducing the burden of medication and improving the safety of the test.

[0035] (4) By connecting to the data line through a long multimode quartz optical fiber, the data collector can be placed at a safe distance, which is safe and reliable. Description of the drawings:

[0036] Figure 1 It is a schematic diagram of the structure of a device for directly measuring detonation velocity based on a photon Doppler test system according to the present invention.

[0037] Figure 2 It is a schematic diagram of the device and fixed tooling structure used when the present invention is tested on site.

[0038] Figure 3 It is a speed curve diagram obtained when the present invention is tested on site.

[0039] Figure 4 1 is a physical picture of the speed measuring device of the present invention.

[0040] Figure 5 It is a physical picture of the fixing tool and assembly of the present invention. Specific implementation method:

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0042] like Figure 1As shown, the present invention provides a device for directly measuring detonation velocity based on a photon Doppler test system, comprising a constrained rotary cover 1, a constrained housing 2, a PC transparent window 3, an explosive charging ring 4, an agent charging ring 5, a multimode quartz optical fiber 6, a PDV system and an energy source.

[0043] Among them, the explosive charged in the explosive charge ring 4 is a kind of sensitive energetic material, which is easily stimulated by external stimuli. Under the input of external energy, the explosive quickly changes from combustion to detonation and detonates the high explosive. The explosive to be tested is charged in the reagent charge ring 5. After the charge of each level is pressed, it is loaded into the restraint shell 1, and the restraint screw cover 1, the restraint shell 2, and the PC transparent window 3 complete the connection and sealing of the whole system.

[0044] The other end of the restraining shell 2 is connected to the multimode quartz optical fiber 6 using an SMA905 interface, and the multimode quartz optical fiber 6 is directly in close contact with the surface of the drug to be tested. The tail end of the light passes through a connection conversion device or is directly connected to the PDV system. The laser wavelength of the PDV is 1550-1552nm.

[0045] The explosive and the explosive to be tested are pressed into the explosive charge ring 4 and the reagent charge ring 5 in turn with corresponding density. The PC transparent window 3 is fixed on the surface of the explosive by the restraining screw cover 1 and the restraining shell 2, so that the device can be sealed and can pass laser.

[0046] Sealing rubber rings are installed at the threaded connections between the restraining shell 2 and the restraining screw cover 1 and between the restraining shell 2 and the multi-mode quartz optical fiber 6 to ensure that the deflagration of the detonator is reliably transformed into detonation to detonate the high explosive.

[0047] A test method for directly measuring detonation velocity based on a photon Doppler test system of the present invention is characterized by comprising the following steps:

[0048] S1. Design and process the dimensions of the test fixture according to actual requirements or actual working conditions;

[0049] S2. Press the explosive and the test agent into the test tooling described in S1;

[0050] S3. Fix the test fixture described in S3 and connect the PDV to the multimode quartz optical fiber;

[0051] S4. Using the energy source to detonate the explosive to be tested, the signal is recorded by the oscilloscope of the PDV system;

[0052] S5. Input the PDV signal obtained in S4 into the prepared software or use Matlab to perform Fourier transform to obtain the velocity curve;

[0053] S6. Effective speed of reading curve, according to the finite numerical aperture correction factor formula The apparent velocity is corrected by using the correction formula D=v×C÷n×1.38 according to the refractive index of the medium where the reflecting surface is located to obtain the corresponding detonation velocity.

[0054] Where NA is the numerical aperture of the multimode silica fiber, n is the refractive index of the core of the multimode silica fiber, and v is the apparent velocity obtained by the PDV velocity measurement system.

[0055] The working principle of the test device and the test method is as follows: when the detonation wave propagates to the bottom surface of the charge column, the detonation wave directly enters the multimode quartz optical fiber, and due to the rapid change in the material density of the detonation wave front, a reflection surface is formed. This reflection surface reflects the PDV detection laser, so that the PDV can obtain the information of the propagation of the detonation wave front.

[0056] Figure 2 During use, the added fixed base counterweight 7 and fixing clamp 8 play a role in fixing the device, constraining the shell 2 and the fixing clamp 8 to fit together through threads and be fixed to the fixed base counterweight 7 to avoid vibration of the device after the explosive is detonated.

[0057] Example

[0058] In this embodiment, all parts and fixtures of the test device are made of stainless steel, with a wall thickness greater than 1 mm. The PC window has a diameter of 8 mm and a thickness of 3 mm. The outer diameter of the explosive charge ring is 8 mm, the inner diameter is 4 mm, and the thickness is 1.5 mm. The explosive is lead azide, and the compressed density is 3.52 g / cm 3 The outer diameter of the charge ring is 8mm, the inner diameter is 4mm, and the thickness is 3mm. The explosive is aluminum-containing RDX, and the compressed density is 1.65g / cm 3 . According to the present embodiment, the charges of each level are pressed according to the above parameters. The energy source is selected as a pulsed laser, the voltage is set to 660V, the energy is 114.3mJ, and the pulse width is 6.5ns. The multimode quartz optical fiber is connected to the PDV system via a UPC / APC adapter. The laser wavelength of the PDV is 1550.52nm, and the correction formula is integrated into the data processing program to obtain the result Figure 3 .

[0059] As can be seen from the figure, the apparent velocity of the wavefront is 7870 m / s. The parameters required for the quartz optical fiber used in the experiment are NA = 0.22, n = 1.44. Substituting them into the velocity correction formula, the corrected detonation velocity can be calculated as

[0060] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A device for directly measuring detonation velocity based on a photon Doppler test system, characterized in that: include A restraining housing (2); One end of the restraining housing (2) is fixed to the restraining rotary cover (1), and the other end is connected to the multi-mode quartz optical fiber (6); A PC transparent window (3) is provided for press-fitting a detonator charge ring (4) filled with detonator and a reagent charge ring (5) filled with explosive to be tested into the confinement housing (2); A priming charge ring (4) filled with priming charge is close to the PC transparent window (3); The multimode quartz optical fiber (6) is connected to the Doppler test system PDV; The laser wavelength of the PDV is 1550-1552nm; the PDV is a device used to directly test the detonation wave propagation characteristics of the explosive system, and the detonation velocity can be obtained after correction.

2. The device for directly measuring detonation velocity based on a photon Doppler test system according to claim 1, characterized in that: The connection interface between the multimode quartz optical fiber (6) and the constraining housing (2) is SMA905.

3. The device for directly measuring detonation velocity based on a photon Doppler test system according to claim 1, characterized in that: The inner diameter of the reagent charging ring (5) is larger than the diameter of the multimode quartz optical fiber (6), and the multimode quartz optical fiber (6) is required to maintain close contact with the surface of the explosive to be tested.

4. The device for directly measuring detonation velocity based on a photon Doppler test system according to claim 1, characterized in that: A sealing ring is provided between the restraining shell (2) and the restraining rotary cover (1); and a sealing ring is provided between the restraining shell (2) and the multi-mode quartz optical fiber (6).

5. The device for directly measuring detonation velocity based on a photon Doppler test system according to claim 1, characterized in that: The multimode quartz optical fiber (6) is connected to the PDV via a connection conversion device or directly connected to the PDV.

6. A method for directly measuring detonation velocity based on a photon Doppler test system according to any one of claims 1 to 5, characterized in that: The steps include: S1. Process the test device according to actual requirements or actual working conditions; S2. Press the explosive and the test agent into the test device of S1; S3. Fix the test device in S2 and connect the PDV to the multimode quartz optical fiber; S4. Using the energy source to detonate the explosive to be tested, the signal is recorded by the oscilloscope of the PDV system; S5. Input the PDV signal obtained in S4 into the prepared software or use Matlab to perform Fourier transform to obtain the velocity curve; S6. Read the effective speed of the curve, calculate using the corresponding correction formula, and obtain the corresponding detonation speed.

7. The method for directly measuring detonation velocity based on a photon Doppler test system according to claim 6 is characterized in that: The specific requirements in S6 are as follows: Calculate the detonation velocity of the explosive to be tested based on the finite numerical aperture correction factor formula (1) and the refractive index of the medium where the reflecting surface is located; Where NA is the numerical aperture of the multimode silica fiber, and n is the refractive index of the core of the multimode silica fiber; D=v×C÷n×1.38 Wherein, v is the apparent velocity obtained by the PDV velocity measurement system, C is the correction factor obtained by formula (1), and n is the refractive index of the core of the multimode silica optical fiber.

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