Measurement method, measurement device and measurement system for PBX detonation pressure

Abstract

The invention relates to a PBX detonation pressure measuring method, device and system, and belongs to the technical field of explosive detonation pressure measurement. Comprising the following steps: acquiring PBX detonation pressure data measured by using a manganese-copper piezoresistive meter mounted between the end face of a steel column and a PBX charge projectile body subjected to PBX detonation and PBX detonation stress data measured by using resistance strain gauges symmetrically mounted on the side wall of the steel column, and if the stress data is a set proportion of the pressure data, determining whether the PBX detonation occurs or not; taking the pressure data as actual pressure data of PBX detonation; otherwise, considering that the pressure data and the stress data are inaccurate; the proportion is set to be 2%-5%. According to the method, whether the pressure data and the stress data meet the condition that the measurement result is accurate or not is judged, if yes, the pressure data serves as accurate actual pressure data of PBX detonation, and whether the results of the two measurement methods are accurate and reliable or not is judged through mutual verification of the two measurement methods.

Description

Technical Field

[0001] The invention relates to a method, a device and a system for measuring PBX detonation pressure, and belongs to the technical field of explosive detonation pressure measurement. Background Art

[0003] During use, PBX is often installed in a metal projectile. When the projectile is subjected to external loads, the explosive is often in a state of passive confinement and needs to withstand instantaneous strong impact during the launch and penetration process. The safety performance of PBX explosives will affect its safe use during launch and its killing effect when it acts on the target.

[0004] At present, in the safety test of explosives detonated by applying impact load, the detonation power is mainly assessed by the pressure generated by the detonation of the explosives. The pressure generated by the detonation is generally indirectly judged by observing the phenomena produced after the detonation of the explosives and the degree of damage caused by the explosion such as the degree of damage to the witness plate. This method has certain empiricism and limitations. It does not use quantitative data to characterize the numerical value of the detonation pressure, resulting in an objective and inaccurate assessment of the detonation power of the explosives.

[0005] In order to measure the detonation pressure generated when explosives are detonated, the detonation pressure of explosives is measured by a manganese-copper piezoresistive meter based on the physical property that the resistance value of manganese-copper alloy changes when subjected to external pressure; the detonation pressure of explosives is also measured by a resistance strain gauge in combination with a bridge circuit; but the measured result is single, and there is no way to prove that the result is accurate and reliable, resulting in the possibility of misjudgment in the assessment of the detonation power of explosives. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for measuring PBX detonation pressure, so as to solve the problem that the accuracy of the existing explosive detonation pressure measurement results is difficult to ensure; and also to provide a PBX detonation pressure measurement device, so as to solve the problem that the accuracy of the detonation pressure measurement results is difficult to ensure due to the single measurement method of the existing measurement device.

[0007] To achieve the above object, the solution of the present invention includes:

[0008] A method for measuring PBX detonation pressure of the present invention comprises the following steps:

[0009] Obtain: The pressure data of the PBX detonation measured by the manganese copper piezoresistive gauge installed between the end face of the steel column and the PBX charge body where the PBX detonation occurs, and the stress data of the PBX detonation measured by the resistance strain gauge symmetrically installed on the side wall of the steel column. If the stress data is a set proportion of the pressure data, the pressure data is used as the actual pressure data of the PBX detonation; otherwise, the pressure data and stress data are considered inaccurate; the set proportion is 2% to 5%.

[0010] A device for measuring PBX detonation pressure of the present invention comprises a steel column, a manganese copper piezoresistor gauge is arranged on one end surface of the steel column, the other side surface of the manganese copper piezoresistor gauge is used to set a PBX charge projectile for causing PBX detonation, resistance strain gauges for measuring the attenuation of the force of PBX detonation are symmetrically distributed on the side wall of the steel column, the manganese copper piezoresistor gauge is used to connect a pulse constant current source and a first data acquisition device respectively, and the resistance strain gauge is used to connect a second data acquisition device; the first data acquisition device uses the manganese copper piezoresistor gauge to measure the pressure data of PBX detonation, and the second data acquisition device uses the resistance strain gauge to measure the stress data of PBX detonation.

[0011] Furthermore, the first data acquisition device is an oscilloscope.

[0012] Furthermore, the second data acquisition device adopts a dynamic strain gauge or an oscilloscope.

[0013] A PBX detonation pressure measurement system of the present invention includes a processor, and the processor is used to execute a computer program to implement the following steps:

[0014] Obtain: The pressure data of the PBX detonation measured by the manganese copper piezoresistive gauge installed between the end face of the steel column and the PBX charge body where the PBX detonation occurs, and the stress data of the PBX detonation measured by the resistance strain gauge symmetrically installed on the side wall of the steel column. If the stress data is a set proportion of the pressure data, the pressure data is used as the actual pressure data of the PBX detonation; otherwise, the pressure data and stress data are considered inaccurate; the set proportion is 2% to 5%.

[0015] Beneficial effects of the present invention:

[0016] The present invention is a combined invention, providing a method and system for measuring the detonation pressure of a PBX, by judging whether the pressure data of the PBX detonation measured by a manganese copper piezoresistive meter and the stress data of the same PBX detonation measured by a resistance strain gauge meet the conditions for accurate measurement results. If they meet the conditions, the pressure data is used as the accurate actual pressure data of the PBX detonation. The present invention verifies the two measurement methods to determine whether the results of the two measurement methods are accurate and reliable. Among them, the conditions for meeting the accurate measurement results are that the stress data is a set proportion of the pressure data, and the set proportion is 2% to 5%; the manganese copper piezoresistive meter is installed between the end face of the steel column and the PBX charge body where the PBX detonation occurs; the resistance strain gauge is symmetrically installed on the side wall of the steel column.

[0017] The present invention also provides a device for measuring the detonation pressure of a PBX, which can measure the pressure data of the PBX detonation using a manganese copper piezoresistive gauge, and can also measure the stress data of the same PBX detonation using a resistance strain gauge, and the pressure data and the stress data are used as the pressure measurement data of the PBX detonation in a method for obtaining accurate and reliable actual pressure data of the PBX detonation. The manganese copper piezoresistive gauge is installed between the end face of the steel column and the PBX charge body where the PBX detonation occurs, and the manganese copper piezoresistive gauge is used to connect the pulse constant current source and the first data acquisition device respectively, and the first data acquisition device uses the manganese copper piezoresistive gauge to measure the pressure data of the PBX detonation; the resistance strain gauge is symmetrically installed on the side wall of the steel column, and the resistance strain gauge is connected to the second data acquisition device, and the second data acquisition device uses the resistance strain gauge to measure the stress data of the PBX detonation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a simplified diagram of the structure of the measuring device;

[0019] Figure 2 It is the schematic diagram of the test circuit of the manganese copper piezoresistive meter;

[0020] Figure 3 This is the schematic diagram of the Wheatstone bridge;

[0021] Figure 4 This is the schematic diagram of the half-bridge circuit of the Wheatstone bridge.

[0022] Reference numerals:

[0023] 1. Charged projectile; 2. Manganese-copper piezoresistive gauge; 3. Steel column; 4. Resistance strain gauge. DETAILED DESCRIPTION

[0024] In order to solve the problem in the background technology, the present invention verifies each other through two measurement methods to determine whether the results of the two measurement methods are accurate and reliable. The two measurement methods are to measure the pressure data of PBX detonation using a manganese copper piezoresistive gauge and to measure the stress data of the same PBX detonation using a resistance strain gauge. According to the relationship between the calibrated pressure data and stress data, it is determined whether the results of the two measurement methods are accurate and reliable.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] An embodiment of a method for measuring PBX detonation pressure:

[0027] A method for measuring PBX detonation pressure comprises the following steps:

[0028] Obtain pressure data of a PBX detonation and stress data of the same PBX detonation;

[0029] The pressure data is measured by a manganese copper piezoresistive gauge, which is installed between the end face of the steel column and the PBX charge body where the PBX detonation occurs;

[0030] The stress data are measured using resistance strain gauges, which are symmetrically installed on the side walls of the steel column;

[0031] Among them, considering that the manganese copper piezoresistive gauge is in direct contact with the projectile that produces the detonation, it can directly receive the detonation pressure during the detonation, while the resistance strain gauge receives the stress wave remaining after the detonation wave penetrates the steel column and performs plastic work. Therefore, the pressure data measured by the manganese copper piezoresistive gauge will be much greater than the stress data measured by the resistance strain gauge.

[0032] In summary, the condition for setting accurate measurement results is that the stress data is a set proportion of the pressure data.

[0033] If the stress data is the set percentage of the pressure data, the pressure data and stress data are considered accurate, and the pressure data is used as the actual pressure data of the PBX explosion, that is, the actual pressure data is the pressure data measured by the manganese copper piezoresistive sensor; the set percentage is 2% to 5%;

[0034] Otherwise the pressure and stress data are considered inaccurate.

[0035] Specifically, when the explosive undergoes a detonation reaction, the stress measured by the strain gauge is approximately 2% to 5% of the pressure measured by the manganese copper piezoresistive gauge. If the test result is outside this range, it is considered inaccurate.

[0036] The method for characterizing the overpressure after PBX detonation mainly adopts a method of indirectly qualitatively judging the PBX detonation pressure by observing the phenomena after PBX detonation and witnessing the degree of damage to the plate caused by PBX detonation. Taking into account the limitations of the method of indirectly qualitatively judging the PBX detonation pressure, the present invention proposes a method for measuring the pressure generated after PBX detonation. The measurement method uses two measurement means, a manganese copper piezoresistive gauge and a resistance strain gauge, to measure simultaneously. While the manganese copper piezoresistive gauge is used to measure the detonation wave pressure, the resistance strain gauge on the steel column is used to measure the force attenuation. The two measurement means are measured simultaneously and verified with each other, so that it can be judged whether the results of the two measurement means are accurate and reliable, and the pressure generated when the PBX explosive is detonated can be quantified to obtain accurate quantitative data, and the numerical value of the detonation pressure can be quantitatively characterized by the quantitative data.

[0037] Among them, the method of measuring pressure using a manganese copper piezoresistive gauge and the method of measuring force attenuation using a resistance strain gauge are both existing.

[0038] The test circuit of the thin film manganese copper sensor is as follows: Figure 2 As shown, the manganese copper piezoresistive meter is connected to a pulse constant current source and an oscilloscope on the left and right sides. Figure 2 The cable in the figure is the part to be measured, i.e. the manganese bronze piezoresistive meter. The main function of the constant current source is to output four constant currents with a certain pulse width. When the pressure reaches the manganese bronze piezoresistive sensor, the resistance of the manganese bronze piezoresistive sensor itself changes. Since the whole process is constant current, all resistance changes are equivalent to voltage changes, so the pressure change is the voltage change.

[0039] The manganese copper piezoresistive gauge uses an H-type or double π-type manganese copper piezoresistive sensor. The sensor resistance R0 is 0.1Ω~0.2Ω. The relationship between the resistance and the pressure signal after calibration is:

[0040]

[0041] Wherein, P is pressure (in megapascals, GPa), ΔR / R0=ΔU / U0, under the action of the detonation shock wave, the sensor resistance R0 will produce an increment ΔR due to the piezoresistive effect of the manganese-copper material, U0 represents the voltage displayed on the oscilloscope after the probe is triggered but the shock wave has not yet reached the corresponding sensor position, ΔU represents the voltage increment caused by the piezoresistive effect when the detonation wave of the explosive reaches the position of the manganese-copper piezoresistive sensor, A, B, and C are the sensitivity coefficients of the manganese-copper sensor, and the specific values ​​are determined according to the corresponding relationship between the resistance and pressure of this type of manganese-copper piezoresistive gauge after calibration.

[0042] The stress wave test in the steel column adopts the test principle of Wheatstone bridge, such as Figure 3As shown, the bridge is powered by a DC power supply U0, and the four bridge arms are composed of resistors R1, R2, R3 and R4. The four bridge arm resistors are respectively composed of precision standard resistors and high-resistance strain gauges. The arm bridge working mode can be adopted, R1 and R4 adopt high-resistance strain gauges, and R2 and R3 adopt precision standard ohmic resistors.

[0043] When the output is open, the current in the bridge is:

[0044]

[0045]

[0046] Where U0 is the input bridge voltage; R1, R2, R3 and R4 are Figure 3 The resistors connected in the middle bridge box. Then the voltages on resistors R1 and R3 are:

[0047]

[0048]

[0049] The voltage ΔU between AB is:

[0050]

[0051] When the bridge is balanced, we have:

[0052]

[0053] Assuming that the resistances R1, R2, R3 and R4 of each bridge arm change, the changes in their resistance values ​​are ΔR1, ΔR2, ΔR3 and ΔR4 respectively, and the output ΔU of the bridge is:

[0054]

[0055] Here, the resistance values ​​of R1, R2, R3, and R4 are the same, so they are directly represented by R in the calculation formula below.

[0056] When ΔR i <<R i When , the output ΔU of the bridge is approximately:

[0057]

[0058] When only one arm is working, the resistance of R1 and R4 increases by ΔR, and the resistance of R2 decreases by ΔR. The output voltage is:

[0059]

[0060] When the full bridge is working, the resistance of R1 and R4 increases by ΔR, the resistance of R2 and R3 decreases by ΔR, and the output voltage is:

[0061]

[0062] In the experiment of testing the stress in the steel column, the strain measurement uses the half-bridge working mode of the Wheatstone bridge. The schematic diagram of the half-bridge circuit of the Wheatstone bridge is as follows: Figure 4 As shown in the figure, the two strain gauges are symmetrically pasted on both sides of the steel column and placed on the same cross section of the steel column to ensure the synchronization of the signals measured by the two, and at the same time eliminate the interference signal of non-axial strain.

[0063] When a strain signal is generated in the steel column, the resistance of the strain gauge attached to the surface of the steel column will change. The change in resistance of the strain gauge is linearly related to the change in strain. Assume that the amplification factor of the strain gauge is K2 and the sensitivity coefficient of the strain gauge is K1.

[0064] Then according to the principle of the arm working bridge, the relationship between the strain value ε(t) measured by the strain gauge and the output voltage ΔU(t) of the dynamic strain gauge can be obtained as follows:

[0065]

[0066] The stress can be calculated based on the relationship between stress and strain:

[0067] σ(t)=Eε

[0068] Where E is the Young's modulus of the rod and ε is the strain.

[0069] An embodiment of a device for measuring PBX detonation pressure:

[0070] A device for measuring the detonation pressure of a PBX, such as Figure 1 As shown, it includes experimental equipment and measurement equipment.

[0071] The experimental device includes a charged projectile 1, a manganese copper piezoresistive gauge 2, a steel column 3 and a resistance strain gauge 4, and the measuring device includes a first data acquisition device and a second data acquisition device.

[0072] Among them, the first data acquisition device is an instrument for collecting changes in pressure signals, and an oscilloscope is preferably used because the oscilloscope has better accuracy and is easy to use.

[0073] Wherein, the second data acquisition device adopts a dynamic strain gauge or an oscilloscope.

[0074] One side of the manganese copper piezoresistor gauge 2 is connected to one end face of the steel column 3, and the other side of the manganese copper piezoresistor gauge 2 is used to set the explosive body 1 in which the PBX detonation occurs, and the explosive body 1 contains PBX. The side wall of the steel column 3 is symmetrically distributed with resistance strain gauges 4 for measuring the attenuation of the force of the PBX detonation. The manganese copper piezoresistor gauge is used to connect the pulse constant current source and the first data acquisition device respectively, and the first data acquisition device uses the manganese copper piezoresistor gauge to measure the pressure data of the PBX detonation; the resistance strain gauge is used to connect the second data acquisition device, and the second data acquisition device uses the resistance strain gauge to measure the stress data of the PBX detonation.

[0075] The detonation wave pressure generated after the detonation of the charged projectile is measured by a manganese-copper piezoresistive gauge, and the pressure signal is transmitted to the oscilloscope through the manganese-copper piezoresistive gauge and converted into a voltage signal for display; the force attenuation is measured by the resistance strain gauge on the steel column, and the signal is transmitted to the ultra-dynamic strain gauge through a cable and converted into a voltage signal for display.

[0076] Among them, the attenuation of the shock wave pressure after the explosion is measured by the resistance strain gauge on the steel column. The strain gauge is the sensor element. The quality of pasting has a great influence on the measurement data. When pasting, the measuring point base is required to be flat, clean, and dry. The electrical insulation, chemical stability and process performance of the bonding base are good, and the pasting strength is high. The specific pasting steps are as follows:

[0077] (1) Screening of strain gauges

[0078] Including appearance and resistance inspection.

[0079] The appearance inspection should be carried out with the help of a magnifying glass. The resistance strain gauge should be free of bubbles, mildew spots, and rust spots. The grid should be straight, neat, and uniform. The resistance value should be measured with a multimeter. There should be no short circuit or open circuit.

[0080] (2) Processing measurement points

[0081] Check the surface condition at the measuring point. The measuring point should be flat, without defects or cracks.

[0082] Use sandpaper or a grinder to polish the surface of the measuring point to make it smooth, rust-free and free of laitance.

[0083] Clean the test points with acetone or alcohol to ensure there are no contaminants.

[0084] (3) Paste the strain gauge

[0085] Use epoxy resin to apply glue with a thickness of 0.05 to 0.1 mm. After the glue hardens, use sandpaper to smooth it.

[0086] Draw vertical and horizontal center lines on the measuring points to locate the measuring lines. The vertical line should be consistent with the strain direction.

[0087] Apply a thin layer of glue on the back of the strain gauge and also on the measuring point. Align the cross center line on the measuring point with the mark on the strain gauge. Cover the strain gauge with a small piece of cellophane and roll in one direction to squeeze out excess glue. The glue layer should be as thin as possible and the position should not slide. Then apply pressure to fix it.

[0088] (4) Curing treatment

[0089] It can be dried naturally or by artificial heating (infrared lamp irradiation or hair dryer), the heating temperature should not exceed 50℃ and the heating should be uniform.

[0090] (5) Paste quality inspection

[0091] Including appearance inspection, resistance inspection, and insulation inspection.

[0092] The appearance inspection should be carried out with the naked eye using a magnifying glass to ensure that the strain gauge has no bubbles, is firmly pasted, and is accurately positioned; the resistance value should be measured with a multimeter to ensure that there is no short circuit or open circuit, and the resistance value should be basically the same as before pasting; the insulation inspection should be carried out with a megohmmeter to check the insulation between the test piece and the strain gauge, which should be greater than 50 megohms.

[0093] (6) Wire connection

[0094] Stick adhesive tape or tape under the lead wire of the strain gauge to ensure that the lead wire does not form a short circuit with the test piece.

[0095] Set the fixed points, fix the terminals with glue or fix the wires with tape to ensure that the lead wires are not broken when the wires are slightly pulled.

[0096] Wire welding: Use an electric soldering iron to solder the lead wire to the wire. The soldering point should be smooth, plump and without voids.

[0097] (7) Sealing and moisture-proof protection

[0098] After the patch is inspected and wired, it is generally sealed and moisture-proofed by pouring glue.

[0099] An embodiment of a PBX detonation pressure measurement system:

[0100] A PBX detonation pressure measurement system includes a processor, and the processor is used to execute a computer program to implement the steps of a PBX detonation pressure measurement method. The PBX detonation pressure measurement method has been described in detail in an embodiment of a PBX detonation pressure measurement method, and will not be repeated here.

Claims

1. A method for measuring PBX detonation pressure, It is characterized in that The steps include: Obtain: the pressure data of the PBX detonation measured by a manganese copper piezoresistive gauge installed between the end face of a steel column and a PBX charge body where the PBX detonation occurs, and the stress data of the PBX detonation measured by a resistance strain gauge symmetrically installed on the side wall of the steel column; if the stress data is a set proportion of the pressure data, the pressure data is used as the actual pressure data of the PBX detonation; otherwise, the pressure data and stress data are considered inaccurate; the set proportion is 2% to 5%.

2. A device for measuring PBX detonation pressure, It is characterized in that It comprises a steel column, one end surface of which is provided with a manganese copper piezoresistive meter, the other side surface of which is used to set a PBX charge projectile for causing PBX detonation, and resistance strain gauges for measuring the attenuation of the force of PBX detonation are symmetrically distributed on the side wall of the steel column, the manganese copper piezoresistive meter is used to connect a pulse constant current source and a first data acquisition device, and the resistance strain gauge is used to connect a second data acquisition device; The first data acquisition device uses a manganese copper piezoresistive meter to measure the pressure data of the PBX detonation, and the second data acquisition device uses a resistance strain gauge to measure the stress data of the PBX detonation.

3. The PBX detonation pressure measuring device according to claim 2, It is characterized in that The first data acquisition device is an oscilloscope.

4. The PBX detonation pressure measuring device according to claim 2, It is characterized in that The second data acquisition device is a dynamic strain gauge or an oscilloscope.

5. A PBX detonation pressure measurement system, comprising a processor, It is characterized in that The processor is used to execute a computer program to implement the following steps: Obtain: the pressure data of the PBX detonation measured by a manganese copper piezoresistive gauge installed between the end face of a steel column and a PBX charge body where the PBX detonation occurs, and the stress data of the PBX detonation measured by a resistance strain gauge symmetrically installed on the side wall of the steel column; if the stress data is a set proportion of the pressure data, the pressure data is used as the actual pressure data of the PBX detonation; otherwise, the pressure data and stress data are considered inaccurate; the set proportion is 2% to 5%.

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