A method and device for determining shock wave parameters of an airborne launch device

Abstract

The present application belongs to the technical field of aircraft launch device design, and particularly relates to a method and device for determining the shock wave parameters of the launch port of an airborne launch device. The method comprises step S1, obtaining the time domain peak value of the surface pressure of the vibration reduction cabin at the front end of the launch device according to the measured results of the aircraft and the launch device matching test; step S2, giving the initial values ​​of each parameter in the shock wave JWL equation; step S3, constructing a finite element model of the launch device without the vibration reduction cabin, and determining the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter according to the initial values, and determining the parameter with the highest sensitivity; step S4, constructing a finite element model including the vibration reduction cabin and the launch device, and adjusting the parameter with the highest sensitivity so that the calculated structural surface pressure of the launch device and the time domain peak value of the surface pressure of the vibration reduction cabin measured in the matching test are within a set range. The present application improves the parameter prediction accuracy of the shock wave equation.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft launch device design, and in particular relates to a method and device for determining shock wave parameters of a launch port of an airborne launch device. Background Art

[0002] During the launch of an airborne launcher, the launch port shock wave will cause a structural shock response, resulting in structural damage and failure of the internal accessories. In order to accurately predict the shock response of the vibration reduction structure at the rear end of the launch port, it is necessary to provide the vibration reduction structure with as accurate load input as possible, and to predict the shock wave load in a more targeted manner. The commonly used shock wave load prediction method is to use the JWL state equation, and the parameters in the equation need to be determined through standard cylinder experiments. The determination method is mainly based on the repeated cycle of "parameter matching-numerical simulation" based on cylinder experiments. This "trial and error method" relies on experience to adjust 6 parameters, and the fitting process is complicated. Summary of the invention

[0003] In order to solve the above problems, the present application provides a method for determining the shock wave parameters of the launch port of an airborne launch device. By accumulating a large amount of measured shock response data, the measured data are fully utilized to invert the parameters in the JWL equation for the shock response analysis of the vibration reduction cabin at the front end of the launch cabin.

[0004] The first aspect of the present application provides a method for determining the shock wave parameters of a launch port of an airborne launch device, mainly comprising:

[0005] Step S1, obtaining the time-domain peak value of the surface pressure of the vibration reduction cabin at the front end of the launch device according to the actual measurement results of the aircraft and the launch device matching test;

[0006] Step S2, giving the initial values ​​of various parameters in the shock wave JWL equation;

[0007] Step S3, constructing a finite element model of the launch device without the vibration damping cabin, and determining the sensitivity of the launch port pressure of the launch device to the change of each parameter individually according to the initial value, and determining the parameter with the highest sensitivity;

[0008] Step S4, constructing a finite element model including the vibration reduction cabin and the launch device, and adjusting the parameter with the highest sensitivity so that the time domain peak error between the calculated structural surface pressure of the launch device and the vibration reduction cabin surface pressure measured in the matching test is within a set range.

[0009] Preferably, in step S2, the parameters R1, R2, and w in the shock wave JWL equation are given according to the parameters of TNT explosive, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C.

[0010] Preferably, the first setting multiple is 10-50, and the second setting multiple is 10-50.

[0011] Preferably, in step S4, the setting range is 5%.

[0012] The second aspect of the present application provides a device for determining the shock wave parameters of an airborne launch device, which mainly includes:

[0013] The test parameter acquisition module is used to obtain the time-domain peak value of the surface pressure of the vibration reduction cabin at the front end of the launcher according to the actual test results of the aircraft and the launcher matching test;

[0014] The module for giving initial parameters of the equation is used to give the initial values ​​of various parameters in the shock wave JWL equation;

[0015] A sensitivity parameter selection module is used to construct a finite element model of a launch device without a vibration damping cabin, determine the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter according to the initial value, and determine the parameter with the highest sensitivity;

[0016] The sensitivity parameter adjustment module is used to construct a finite element model including a vibration reduction cabin and a launch device. By adjusting the parameter with the highest sensitivity, the time domain peak error between the calculated structural surface pressure of the launch device and the vibration reduction cabin surface pressure measured in the matching test is within a set range.

[0017] Preferably, in the equation initial parameter setting module, the parameters R1, R2, and w in the shock wave JWL equation are given according to the parameters of TNT explosives, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C.

[0018] Preferably, the first setting multiple is 10-50, and the second setting multiple is 10-50.

[0019] Preferably, in the sensitivity parameter adjustment module, the setting range is 5%.

[0020] The present application improves the parameter prediction accuracy of the shock wave equation, improves the prediction accuracy of the shock wave load, and thereby improves the accuracy of the shock response analysis of the vibration reduction cabin, providing support for the response control of the vibration reduction cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of a preferred embodiment of a method for determining the shock wave parameters of a launch port of an airborne launch device of the present invention.

[0022] Figure 2 This is a schematic diagram of the launch device and vibration reduction cabin structure.

[0023] Among them, 1-launching device, 2-vibration reduction cabin. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0025] The present application provides a method and device for determining the parameters of the launch port shock wave of an airborne launch device, which uses the measured data of the shock response of the vibration cabin to invert the parameters of the JWL equation of the launch port shock wave of the launch cabin, avoiding the complex and empirical process of parameter fitting using a standard cylinder test. Figure 2 As shown, the vibration reduction cabin 2 is arranged at the rear end of the launch port of the launch cabin 1, and is used to suppress the vibration of the missile launched from the launch port to prevent vibration from affecting the airborne equipment.

[0026] like Figure 1 As shown, the first aspect of the present application provides a method for determining the shock wave parameters of the launch port of an airborne launch device, which mainly includes:

[0027] Step S1, according to the measured results of the aircraft and the launch device matching test, the time domain peak value of the surface pressure of the vibration reduction cabin 2 at the front end of the launch device 1 is obtained.

[0028] Step S2: giving initial values ​​of various parameters in the shock wave JWL equation.

[0029] The shock wave JWL equation is shown below:

[0030] ;

[0031] ;

[0032] ;

[0033] Among them, A, B, C, R1, R2, and w are equation coefficients, that is, the six parameters that need to be determined in this application, D J is the ammunition detonation velocity, P Jis the initial explosion pressure of the ammunition, E0 is the energy of the ammunition, ρ0 is the density of the explosive, e is a natural constant, ,in, According to the parameters of TNT explosives, R1=4.5, R2=1.1, w=0.35 are determined; the D J , P J , E0, ρ0 and other parameters and the initial values ​​of parameters A and B in the JWL equation. In some optional implementations, in step S2, the parameters R1, R2, and w in the shock wave JWL equation are given according to the parameters of TNT explosives, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C. In some optional implementations, the first set multiple is 10-50, and the second set multiple is 10-50.

[0034] Step S3, constructing a finite element model of the launch device 1 without the vibration damping cabin 2, determining the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter according to the initial value, and determining the parameter with the highest sensitivity.

[0035] In order to reduce the amount of calculation, in step S3, the present application uses LS-Dyna software to solve the dynamic finite element model of the launch device 1 with no vibration damping cabin 2, obtains the launch port pressure curve when each parameter changes individually, and then obtains the sensitivity of each parameter to the change of the launch port pressure, selects the high-sensitivity parameter as the variable, and participates in the calculation of step S4.

[0036] Step S4, constructing a finite element model including the vibration reduction cabin 2 and the launch device 1, and adjusting the parameter with the highest sensitivity so that the time domain peak error between the calculated structural surface pressure of the launch device 1 and the surface pressure of the vibration reduction cabin 2 measured in the matching test is within a set range.

[0037] In some optional implementations, in step S4, the set range is 5%.

[0038] In step S4, the system dynamics finite element model composed of the vibration reduction cabin 2 and the launch device 1 is solved to obtain the surface pressure of the vibration reduction cabin 2 structure; by comparing and analyzing the surface pressure of the vibration reduction cabin 2 obtained by the test, the JWL equation parameters are adjusted until the error between the test and the simulation analysis at each measuring point is within 5%. The parameter values ​​of the JWL equation thus determined are used for the subsequent impact response analysis of the launch device and the vibration reduction cabin.

[0039] The second aspect of the present application provides a device for determining the shock wave parameters of the launch port of an airborne launch device corresponding to the above method, mainly comprising:

[0040] The test parameter acquisition module is used to obtain the time domain peak value of the surface pressure of the vibration reduction cabin 2 at the front end of the launch device 1 according to the actual measurement results of the aircraft and the launch device matching test;

[0041] The module for giving initial parameters of the equation is used to give the initial values ​​of various parameters in the shock wave JWL equation;

[0042] A sensitivity parameter selection module is used to construct a finite element model of the launch device 1 without the vibration damping cabin 2, determine the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter according to the initial value, and determine the parameter with the highest sensitivity;

[0043] The sensitivity parameter adjustment module is used to construct a finite element model including the vibration reduction cabin 2 and the launch device 1. By adjusting the parameter with the highest sensitivity, the time domain peak error between the calculated structural surface pressure of the launch device 1 and the surface pressure of the vibration reduction cabin 2 measured in the matching test is within a set range.

[0044] In some optional embodiments, in the equation initial parameter setting module, the parameters R1, R2, and w in the shock wave JWL equation are given according to the parameters of TNT explosives, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C.

[0045] In some optional implementations, the first setting multiple is 10-50, and the second setting multiple is 10-50.

[0046] In some optional implementations, in the sensitivity parameter adjustment module, the setting range is 5%.

[0047] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for determining the shock wave parameters of an airborne launch device, characterized in that: include: Step S1, obtaining the time-domain peak value of the surface pressure of the vibration reduction cabin (2) at the front end of the launch device (1) according to the actual measurement results of the aircraft and the launch device matching test; Step S2, giving the initial values ​​of various parameters in the shock wave JWL equation; Step S3, constructing a finite element model of the launch device (1) without the vibration damping cabin (2), and determining the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter according to the initial value, and determining the parameter with the highest sensitivity; Step S4, constructing a finite element model including the vibration reduction cabin (2) and the launch device (1), and adjusting the parameter with the highest sensitivity so that the time domain peak error between the calculated structural surface pressure of the launch device (1) and the surface pressure of the vibration reduction cabin (2) measured in the matching test is within a set range; The shock wave JWL equation is as follows: Among them, A, B, C, R1, R2, ω are equation coefficients, D J is the ammunition detonation velocity, p J is the initial explosion pressure of the ammunition, E0 is the energy of the ammunition, ρ0 is the density of the explosive, e is a natural constant, in 2. The method for determining the shock wave parameters of the launch port of an airborne launch device according to claim 1, characterized in that: In step S2, the parameters R1, R2, and ω in the shock wave JWL equation are given according to the parameters of TNT explosives, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C.

3. The method for determining the shock wave parameters of the launch port of the airborne launch device according to claim 2, characterized in that: The first setting multiple is 10-50, and the second setting multiple is 10-50.

4. The method for determining the shock wave parameters of the launch port of an airborne launch device according to claim 1, characterized in that: In step S4, the setting range is 5%.

5. A device for determining shock wave parameters of an airborne launcher, characterized in that: include: A test parameter acquisition module is used to obtain a time-domain peak value of the surface pressure of a vibration reduction cabin (2) at the front end of a launch device (1) based on the actual measurement results of the aircraft and the launch device matching test; The module for giving initial parameters of the equation is used to give the initial values ​​of various parameters in the shock wave JWL equation; A sensitivity parameter selection module is used to construct a finite element model of a launch device (1) without a vibration damping cabin (2), and to determine the sensitivity of the launch port pressure of the launch device to the individual changes of each parameter based on the initial value, and to determine the parameter with the highest sensitivity; A sensitivity parameter adjustment module is used to construct a finite element model including a vibration reduction cabin (2) and a launch device (1), and by adjusting the parameter with the highest sensitivity, a time domain peak error between a calculated structural surface pressure of the launch device (1) and a surface pressure of the vibration reduction cabin (2) measured in a matching test is within a set range; The shock wave JWL equation is as follows: Among them, A, B, C, R1, R2, ω are equation coefficients, D J is the ammunition detonation velocity, p J is the initial explosion pressure of the ammunition, E0 is the energy of the ammunition, ρ0 is the density of the explosive, e is a natural constant, in 6. The device for determining shock wave parameters of an airborne launcher as claimed in claim 5, characterized in that: In the equation initial parameter setting module, the parameters R1, R2, and ω in the shock wave JWL equation are given according to the parameters of TNT explosives, parameter A is a first set multiple of parameter B, and parameter B is a second set multiple of parameter C.

7. The device for determining shock wave parameters of an airborne launcher as claimed in claim 6, characterized in that: The first setting multiple is 10-50, and the second setting multiple is 10-50.

8. The device for determining shock wave parameters of an airborne launcher as claimed in claim 5, characterized in that: In the sensitivity parameter adjustment module, the setting range is 5%.

Images