A dynamic load calculation method under the condition of combined driving of explosive explosion and high-pressure gas

Abstract

The invention relates to the technical field of explosion shock wave test, and discloses a method for calculating dynamic load under the condition of joint driving of explosive explosion and high-pressure gas, including: measuring relevant parameters such as the cross-sectional area of ​​the detonation point; calculating the cross-sectional equivalent diameter at the pressure measurement point, the spatial volume between the detonation point and the pressure measurement point, and the final inflation absolute pressure value before the explosion of the explosive, and determining the overpressure peak correlation coefficient of the shock wave generated by the explosion of the explosive under the high-pressure gas, and then calculating the overpressure peak of the shock wave generated by the explosion of the explosive under the high-pressure gas; calculating the dynamic load peak under the joint driving condition according to the overpressure peak; measuring the volume of the sealed air, the cross-sectional area at the outlet of the explosion wave simulation device, and the temperature of the sealed air before the explosion of the explosive, and combining the dynamic load peak to obtain the dynamic load continuous action time under the joint driving condition. The invention realizes the accurate and simple calculation of the dynamic load peak and continuous action time under the condition of joint driving of the explosion of the explosive and the high-pressure gas.

Description

Technical Field

[0001] The invention relates to the technical field of explosion shock wave testing, in particular to a method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas. Background Art

[0002] The blast wave simulation device is an important means to simulate shock waves, dynamic loads of external flow fields during the flight of aircraft, and dynamic loads of internal flow fields during the separation of aircraft mechanisms. Although the simulation of the above loads by means of explosive explosion can achieve the simulation of high-peak dynamic loads, it is difficult to simulate dynamic loads that last for more than 1 second due to the rapid release rate of explosive explosion energy. With the development of the driving technology of blast wave simulation devices in recent years, the combined driving technology of explosive explosion and high-pressure gas has gradually become an important means of simulating dynamic loads. This driving technology combines the advantages of the controllability of the high-pressure gas energy release rate and the high density of explosive explosion energy, and can achieve the simulation of long-lasting and high-peak dynamic loads.

[0003] At present, the combined driving method of explosive explosion and high-pressure gas can produce a dynamic load environment with high peak value, long duration and good repeatability in the explosion wave simulation device, and has achieved good application results in the impact resistance test of protective structures or materials, and the separation and strength assessment test of aircraft mechanisms. However, the research on dynamic load under the conditions of combined driving of explosive explosion and high-pressure gas is still in the engineering practice stage. Most of the applications rely on practical experience, and there is no corresponding calculation method. It is difficult to predict the relevant parameters of dynamic load, which directly affects the accuracy of the test.

[0004] In summary, there is no mature theoretical calculation method for the dynamic load under the combined driving mode of explosive explosion and high-pressure gas. Therefore, an accurate and simple dynamic load calculation method is urgently needed to guide the experimental design and the surface design of the explosion wave simulation device. Summary of the invention

[0005] The purpose of the present invention is to provide a method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas. By obtaining relevant parameters such as the cross-sectional area of ​​the detonation point, the dynamic load peak value and its continuous action time under the combined driving condition are accurately calculated, and the calculation process is significantly simplified, providing effective technical support for the surface design and dynamic load prediction of the explosion wave simulation device.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A method for calculating dynamic loads under the conditions of combined driving of explosive explosion and high-pressure gas, comprising:

[0008] S1, measurement related parameters: cross-sectional area of ​​​​the detonation point Sc , cross-sectional area at the pressure measurement point S j , the distance between the detonation point and the pressure measurement point L、 Initial atmospheric pressure P 0 、 Final inflation relative pressure value of explosive before explosion P X , Charge amount Q ;

[0009] S2, calculate the equivalent diameter of the cross section at the pressure measurement point based on the relevant parameters d , the volume of space between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c , and determine the peak overpressure correlation coefficient of the shock wave generated by the explosion of explosives under high pressure gas;

[0010] S3, according to the overpressure peak correlation coefficient, the space volume between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c And the amount of charge Q , calculate the peak overpressure of the shock wave generated by the explosion of explosives under high pressure gas Δp ;

[0011] S4, according to the overpressure peak Δp Calculation of peak dynamic loads under combined drive conditions P z ;

[0012] S5, measuring the volume of sealed air in the blast wave simulator V q , Cross-sectional area at the exit of explosion wave simulation device S t , the temperature of the sealed air before the explosive explodes T , and combined with the peak dynamic load under the combined driving condition P z , and the duration of dynamic load under combined driving conditions is obtained.

[0013] Further, the S2 calculates the cross-sectional equivalent diameter at the pressure measurement point according to the relevant parameters. d , the volume of space between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c, and determine the overpressure peak correlation coefficient of the shock wave generated by the explosion of explosives under high-pressure gas, including:

[0014] Step S201: according to the cross-sectional area at the pressure measurement point S j , calculate the equivalent diameter of the cross section at the pressure measurement point d , the volume of space between the detonation point and the pressure measurement point V t ; Wherein, the equivalent diameter of the cross section at the pressure measurement point d The calculation formula is as follows:

[0015] d= 2×( S j / π) 0.5 (1)

[0016] Step S203: according to the cross-sectional area at the pressure measurement point S j 、 The cross-sectional area of ​​the detonation point S c 、 The cross-sectional equivalent diameter at the pressure measurement point d , the distance between the detonation point and the pressure measurement point L , calculate S j / S c , L / d These two ratios;

[0017] Step S204, according to the initial atmospheric pressure P 0 、 Final inflation relative pressure value of explosive before explosion P X , use the following formula to calculate the final inflation absolute pressure value before the explosive explodes P c :

[0018] P c = P 0 +P X (2)

[0019] Step S205, according to S j / S c , L / d and the final inflation absolute pressure Pc , determine the peak overpressure correlation coefficient of the shock wave generated by the explosion of explosives under high pressure gas A pc 、B pc 、C pc ,in, A pc is the ratio of the cross-sectional area at the detonation point to the cross-sectional area at the measurement point S j / S c The relevant coefficients, B pc , C pc is the ratio of the distance from the measuring point to the detonation point to the equivalent diameter of the cross section at the measuring point L / d The relevant coefficients.

[0020] Further, the S3, according to the overpressure peak correlation coefficient, the space volume between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c And the amount of charge Q , calculate the peak overpressure of the shock wave generated by the explosion of explosives under high pressure gas Δp Specifically include:

[0021] Step S301, according to the charge amount Q Calculate the charge density ρ, where ρ= Q / V t ;

[0022] Step S302, calculating the overpressure peak value of the shock wave generated by the explosion of explosives under high pressure gas Δp , the formula is:

[0023] (3).

[0024] Further, the S4, according to the overpressure peak Δp Calculation of peak dynamic loads under combined drive conditions P z , the formula is:

[0025] (4).

[0026] Furthermore, in S5, the peak value of the dynamic load under the combined driving condition is P z , the duration of dynamic load under combined driving conditions is obtained, including:

[0027] Step S501, calculating the temperature of the sealed air before the explosive explodes T H , the formula is:

[0028] T H =273.15+ T (5)

[0029] Step S502: Calculate the duration of dynamic load under combined driving conditions t t , the formula is:

[0030] (6)

[0031] In the formula, c is the adiabatic index.

[0032] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas provided by the present invention measures the cross-sectional area at the detonation point, the cross-sectional area at the pressure measurement point, the distance between the detonation point and the pressure measurement point, the initial atmospheric pressure and other parameters, and obtains the accurate dynamic load peak value and its continuous action time under the condition of combined driving through calculation. In short, based on dimensional analysis, the present invention combines the high-pressure gas pressure, the mass of explosives and the cross-sectional form of the driving section to form a method for calculating the dynamic load peak value and continuous action time under the condition of combined driving of explosive explosion and high-pressure gas. This method significantly simplifies the calculation process of similar loads, improves the calculation efficiency, has good practical and academic value, and has strong guiding significance for the surface design and load prediction of explosion simulation devices under combined driving conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 This is a flow chart of calculating the dynamic load peak value under the combined driving condition in Example 1 of the present invention;

[0035] Figure 2 This is a flow chart for calculating the duration of dynamic load under combined driving conditions in Example 2 of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The purpose of the present invention is to provide a method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas. By obtaining relevant parameters such as the cross-sectional area of ​​the detonation point, the dynamic load peak value and its continuous action time under the combined driving condition are accurately calculated, and the calculation process is significantly simplified, providing effective technical support for the surface design and dynamic load prediction of the explosion wave simulation device.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0039] like Figure 1 As shown, the method for calculating the dynamic load peak value under the conditions of explosive explosion and high-pressure gas combined driving provided by the embodiment of the present invention includes the following steps:

[0040] S1, measurement related parameters: cross-sectional area of ​​​​the detonation point S c , cross-sectional area at the pressure measurement point S j , the distance between the detonation point and the pressure measurement point L、 Initial atmospheric pressure P 0 、 Final inflation relative pressure value of explosive before explosion P X , Charge amount Q ;

[0041] In this embodiment, the cross-sectional area of ​​the detonation point of a certain explosion wave simulation device is S c 7.07m 2 , cross-sectional area at the pressure measurement point S j 2.46m 2 , the distance between the burst point and the pressure measurement point L is 30.88m, initial atmospheric pressure P 0 0.1MPa, the final inflation relative pressure value before the explosive explodes P X It is 0.4MPa.

[0042] S2, calculate the equivalent diameter of the cross section at the pressure measurement point based on the relevant parameters d , the volume of space between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c , and determine the overpressure peak correlation coefficient of the shock wave generated by the explosion of explosives under high-pressure gas; specifically including:

[0043] Step S201: according to the cross-sectional area at the pressure measurement point S j , calculate the equivalent diameter of the cross section at the pressure measurement point d , the volume of space between the detonation point and the pressure measurement point V t ; Wherein, the equivalent diameter of the cross section at the pressure measurement point d The calculation formula is as follows:

[0044] d= 2×( S j / π) 0.5 (1)

[0045] Step S203: according to the cross-sectional area at the pressure measurement point S j 、 The cross-sectional area of ​​the detonation point S c 、 The cross-sectional equivalent diameter at the pressure measurement point d , the distance between the detonation point and the pressure measurement point L , calculate S j / S c , L / d These two ratios; In this embodiment, the explosion wave simulation device S j / S c = 0.348, L / d =17.446;

[0046] Step S204, according to the initial atmospheric pressure P 0 、 Final inflation relative pressure value of explosive before explosion P X , use the following formula to calculate the final inflation absolute pressure value before the explosive explodes P c :

[0047] P c = P 0 +P X (2)

[0048] In step S1 P 0 =0.1MPa and P X =0.4MPa Substituting into the above formula, we can obtain the final inflation absolute pressure value of 0.5MPa before the explosion of the explosive.

[0049] Step S205, according to S j / S c , L / d and the final inflation absolute pressure P c , determine the peak overpressure correlation coefficient of the shock wave generated by the explosion of explosives under high pressure gas A pc 、B pc 、C pc ,in, A pc is the ratio of the cross-sectional area at the detonation point to the cross-sectional area at the measurement point S j / S The relevant coefficients, B pc , C pc is the ratio of the distance from the measuring point to the detonation point to the equivalent diameter of the cross section at the measuring point L / d The relevant coefficients need to be determined by experiments or numerical calculations. In this embodiment, A pc 、B pc 、C pc They are -0.514, -126.546 and -2.507 respectively.

[0050] S3, according to the overpressure peak correlation coefficient, the space volume between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c And the amount of charge Q , calculate the peak overpressure of the shock wave generated by the explosion of explosives under high pressure gas Δp ; Specifically include:

[0051] Step S301, according to the charge amount Q Calculate the charge density ρ, where ρ= Q / V t In this embodiment, the dosage Q is the total mass of the explosives loaded. The total charge is 1.2 kg TNT, and the charge density is calculated to be 0.00622 kg / m 3 .

[0052] Step S302, calculating the overpressure peak value of the shock wave generated by the explosion of explosives under high pressure gas Δp , the formula is:

[0053] ; (3)

[0054] In this embodiment, the peak overpressure Δp It is 0.348MPa.

[0055] S4, according to the overpressure peak Δp Calculation of peak dynamic loads under combined drive conditions P z ; The formula is as follows:

[0056] (4)

[0057] The dynamic load peak value obtained in this embodiment P z It is 0.848MPa.

[0058] Example 2

[0059] like Figure 2 As shown, the method for calculating the duration of dynamic load under the condition of combined driving of explosive explosion and high-pressure gas provided by the embodiment of the present invention, steps S1 to S4 of the method are the same as the method for calculating the peak value of dynamic load under the combined driving condition, and the relevant physical meanings and calculation methods are consistent with it. The difference from the method for calculating the peak value of dynamic load under the combined driving condition is that step S5 is added, mainly:

[0060] S5, measuring the volume of sealed air in the blast wave simulator V q , Cross-sectional area at the exit of explosion wave simulation device S t , the temperature of the sealed air before the explosive explodes T , and combined with the peak dynamic load under the combined driving condition P z , and the duration of dynamic load under the combined driving condition is obtained; in this embodiment, the volume of sealed air in the explosion wave simulation device is V qis 194.617 m 3 , Cross-sectional area at the exit of the explosion wave simulation device S t 1.093 m 2 , the temperature of the sealed air before the explosive explodes T is 25℃.

[0061] In S5, the peak value of the dynamic load under the combined driving condition is P z , the duration of dynamic load under combined driving conditions is obtained, including:

[0062] Step S501, calculating the temperature of the sealed air before the explosive explodes T H , the formula is:

[0063] T H =273.15+ T (5)

[0064] Will T =25℃ Substituting into the above formula, we can get the driving section temperature before the explosion of the explosive. T H It is 298.15K.

[0065] Step S502: Calculate the duration of dynamic load under combined driving conditions t t , the formula is:

[0066] (6)

[0067] In the formula, c is the adiabatic index, which is generally 1.4 for air. P z and P 0 The physical meaning is the same as that in the calculation method of the dynamic load peak value under combined driving conditions; reference to obtain the dynamic load peak value P z The values ​​of various parameters used when P 0 =0.1MPa, P z =0.848MPa, V q =194.617 m 3 , S t =1.093 m 2 , TH =298.15K, constant c= Substituting 1.4 into the above formula, we can obtain that the continuous action time of the dynamic load under the combined driving condition is 1592.28ms.

[0068] Example 3

[0069] The embodiment of the present invention provides a dynamic load calculation system under the condition of explosive explosion and high-pressure gas combined driving, which is applied to execute a dynamic load calculation method under the condition of explosive explosion and high-pressure gas combined driving, including:

[0070] Related parameter acquisition module, used to obtain the relevant parameters of the measurement, including: the cross-sectional area of ​​the detonation point S c , cross-sectional area at the pressure measurement point S j , the distance between the detonation point and the pressure measurement point L、 Initial atmospheric pressure P 0 、 Final inflation relative pressure value of explosive before explosion P X , Charge amount Q ;

[0071] The correlation coefficient acquisition module is used to calculate the cross-sectional equivalent diameter at the pressure measurement point according to the correlation parameters. d , the volume of space between the detonation point and the pressure measurement point V t , Final inflation absolute pressure value before explosive explosion P c , and determine the peak overpressure correlation coefficient of the shock wave generated by the explosion of explosives under high pressure gas;

[0072] The overpressure peak value calculation module is used to calculate the overpressure peak value according to the overpressure peak correlation coefficient, the space volume between the detonation point and the pressure measurement point. V t , Final inflation absolute pressure value before explosive explosion P c And the amount of charge Q， Calculation of the peak overpressure of the shock wave generated by explosive explosion under high pressure gas Δp ;

[0073] A dynamic load peak value calculation module is used to calculate the overpressure peak value according to the overpressure peak value. Δp Calculation of peak dynamic loads under combined drive conditions P z ;

[0074] Dynamic load duration calculation module, used to measure the volume of sealed air in the blast wave simulation device Vq , Cross-sectional area at the exit of explosion wave simulation device S t , the temperature of the sealed air before the explosive explodes T , and combined with the peak dynamic load under the combined driving condition P z , and the duration of dynamic load under combined driving conditions is obtained.

[0075] In summary, the method and system for calculating dynamic loads under the conditions of combined driving of explosive explosion and high-pressure gas provided by the present invention are accurate, simple, and efficient, and can effectively guide experimental design and surface design of blast wave simulation devices; by establishing a calculation method for the peak value and continuous action time of dynamic loads under combined driving conditions, necessary technical means are provided for surface design and dynamic load prediction of blast wave simulation devices.

[0076] The remaining technical features in this embodiment can be flexibly selected by those skilled in the art according to actual conditions to meet different specific practical needs. However, it is obvious to those skilled in the art that it is not necessary to adopt these specific details to implement the present invention. In other examples, in order to avoid confusing the present invention, the well-known components, structures or parts are not specifically described, which are all within the technical protection scope defined by the technical solution claimed for protection in the claims of the present invention.

[0077] Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the scope of protection of the claims attached to the present invention. In the above description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details are not necessary to practice the present invention. In other examples, in order to avoid confusing the present invention, well-known technologies, such as specific construction details, operating conditions and other technical conditions, are not specifically described.

[0078] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for calculating dynamic loads under the conditions of explosive explosion and high-pressure gas combined driving, characterized in that: The following steps are involved: S1, measurement of relevant parameters, including: detonation point cross-sectional area S c , cross-sectional area S at the pressure measurement point j , the distance L between the detonation point and the pressure measurement point, the initial atmospheric pressure P0, the final inflation relative pressure value P before the explosive explodes X , charge quantity Q; S2, according to the relevant parameters, calculate the cross-sectional equivalent diameter d at the pressure measurement point and the spatial volume V between the detonation point and the pressure measurement point t , the final inflation absolute pressure value P before the explosive explodes c , and determine the peak overpressure correlation coefficient of the shock wave generated by the explosion of explosives under high pressure gas; S3, according to the overpressure peak correlation coefficient, the space volume V between the detonation point and the pressure measurement point t , the final inflation absolute pressure value P before the explosive explodes c and the charge Q, calculate the overpressure peak value Δp of the shock wave generated by the explosion of the explosive under high pressure gas; S4, calculating the dynamic load peak value P under the combined driving condition according to the overpressure peak value Δp z ; S5, measuring the volume V of the sealed air in the explosion wave simulation device q , Cross-sectional area S at the exit of explosion wave simulation device t , the Celsius temperature of the sealed air before the explosion of the explosive T, and combined with the peak value of the dynamic load P under the combined driving condition z , and the duration of dynamic load under combined driving conditions is obtained.

2. The method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas according to claim 1 is characterized in that: S2: Calculate the cross-sectional equivalent diameter d at the pressure measurement point and the spatial volume V between the detonation point and the pressure measurement point according to the relevant parameters. t , the final inflation absolute pressure value P before the explosive explodes c , and determine the overpressure peak correlation coefficient of the shock wave generated by the explosion of explosives under high-pressure gas, including: Step S201: according to the cross-sectional area S at the pressure measurement point j , calculate the equivalent diameter d of the cross section at the pressure measurement point, and the volume V of the space between the detonation point and the pressure measurement point t ; Wherein, the calculation formula of the equivalent diameter d of the cross section at the pressure measurement point is as follows: d=2×(S j / p) 0.5 (1) Step S203: according to the cross-sectional area S at the pressure measurement point j , the cross-sectional area S of the detonation point c , the cross-sectional equivalent diameter d at the pressure measurement point, the distance L between the detonation point and the pressure measurement point, and calculate S j / S c , the two ratios L / d; Step S204, according to the initial atmospheric pressure P0, the final inflation relative pressure value P before the explosive explosion X , use the following formula to calculate the final inflation absolute pressure value P before the explosive explodes c : P c =P0+P X (2) Step S205, according to S j / S c , L / d and final inflation absolute pressure value P c , determine the overpressure peak correlation coefficient A of the shock wave generated by the explosion of explosives under high pressure gas pc , B pc , C pc , where A pc is the ratio of the cross-sectional area at the detonation point to the cross-sectional area at the measurement point S j / S c The relevant coefficient, B pc , C pc It is a coefficient related to the ratio L / d of the distance from the measuring point to the detonation point and the equivalent diameter of the cross section at the measuring point.

3. The method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas according to claim 2 is characterized in that: S3, according to the overpressure peak correlation coefficient, the space volume V between the detonation point and the pressure measurement point t , the final inflation absolute pressure value P before the explosive explodes c And the charge Q, calculate the overpressure peak value Δp of the shock wave generated by the explosion of explosives under high pressure gas, specifically including: Step S301, calculate the charge density ρ according to the charge quantity Q, where ρ = Q / V t ; Step S302, calculating the overpressure peak value Δp of the shock wave generated by the explosion of explosives under high pressure gas, the formula is:

4. The method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas according to claim 3 is characterized in that: S4, calculating the dynamic load peak value P under the combined driving condition according to the overpressure peak value Δp z , the formula is: P z =Δp+P c (4)。 5. The method for calculating dynamic load under the condition of combined driving of explosive explosion and high-pressure gas according to claim 4 is characterized in that: In S5, combined with the dynamic load peak value P under the combined driving condition z , the duration of dynamic load under combined driving conditions is obtained, including: Step S501, calculate the absolute temperature T of the sealed air before the explosive explodes H , the formula is: T H =273.15+T (5) Step S502, calculating the duration of dynamic load under the combined driving condition τ t , the formula is: Where γ is the adiabatic index.

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