A dynamic explosion point calculation method based on target structural response

Abstract

The present invention relates to a dynamic explosion point analysis and calculation method based on the target structure response. Under the premise of not increasing the target damage effect measurement content in the dynamic explosion test of weapons and ammunition, it is required that the damage effect numerical calculation model is consistent with the actual target effect object model and the acceleration measurement point position is consistent. The acceleration measurement point is mainly located on the strong structure of the building or ship to reduce the propagation of stress waves across the medium and across the components. The dynamic explosion point analysis method mainly extracts the characteristic parameters of the measured and simulated acceleration data of the same measurement point on the basis of the consistency between the actual and simulation calculation models, and obtains the dynamic explosion point through the processes of constructor, traversal calculation, comparative analysis, etc. The present invention effectively solves the problem that the explosion point position cannot be directly obtained by optical methods inside buildings or ships, and ultimately lays the foundation for testing the coordination of warhead ignition and accurate evaluation of the damage efficiency of weapons and ammunition.

Description

Technical Field

[0001] The invention belongs to the technical fields of explosion electrical signal measurement, target damage effect simulation calculation, and damage assessment, and relates to a dynamic explosion point analysis and calculation method based on target structure response. Background Art

[0002] The force field of weapons and ammunition can be represented using parameters related to damage elements such as shock waves and fragments, such as shock wave overpressure, dynamic pressure, fragment density, and impulse. These parameters can be measured during static explosion tests of warheads. Based on accurate measurement and analysis of the force field of weapons and ammunition, dynamic explosion tests on target effectors can be conducted to assess their destructive capabilities, thereby providing a baseline for the destructive effectiveness of the weapons and ammunition. A characteristic of dynamic explosion tests is that the weapons and ammunition and the target are relatively well-defined, but the location of the explosion when the weapons and ammunition strike the target is random within a certain range. Dynamic explosion tests can effectively measure physical parameters of the target effector, such as rupture, deformation, strain, displacement, velocity, and acceleration. A key challenge in these tests is accurately determining the projectile-target intersection position at the time of explosion, enabling better verification of warhead ignition and coordination and precise evaluation of the destructive effectiveness of the weapons and ammunition.

[0003] When the target effector is a tank, armored vehicle, or parked aircraft, the explosion point of the weapon or ammunition is outside the target or explodes on contact. The explosion point can be accurately determined through optical measurements such as high-speed photography of appropriate scenes, combined with binocular or multi-camera positioning image processing technology. The error mainly comes from the performance parameters of the optical measurement equipment, the binocular or multi-camera positioning algorithm and calibration, etc. The error size is controllable and knowable, meeting the input requirements of the explosion point position in the damage effectiveness assessment. This method is a direct measurement of the explosion point position.

[0004] When the target effector is a building or ship, explosive or semi-armor-piercing weapons and ammunition are generally used, and their explosion point is located inside the target effector. It is difficult to measure and analyze the explosion point location using optical measurement equipment. The main reasons are: there are many rooms in the building or ship cabin. Considering the hit accuracy of weapons and ammunition and the coordination of ignition and warhead, it is impossible to pre-confirm the room or cabin to be hit in the dynamic test, making it difficult to deploy optical measurement equipment. When distributed optical measurement equipment is deployed in each room or cabin of the building or ship, due to the quasi-static pressure generated by the explosion in the confined space and the close proximity of the optical equipment to the explosion point, although effective data can be obtained to a certain extent, the shock wave, fragments and other damage elements are likely to damage the optical equipment. If the optical measurement equipment is a high-speed camera, the cost is too high and it is difficult to transmit the acquired image data in real time. If the optical measurement equipment is a front-mounted ordinary high-definition camera, the accuracy does not meet the damage assessment requirements due to the low frame rate. In order to solve the above problems, the present invention proposes a dynamic explosion point analysis and calculation method based on the target structure response, which achieves high-precision explosion point measurement and calculation under the premise of considering economy, which belongs to indirect measurement method. Summary of the Invention

[0005] Technical problems to be solved

[0006] To overcome the shortcomings of existing technologies, this paper proposes a dynamic explosion point analysis and calculation method based on the target structure response. The technical solution includes three modules: damage effect measurement, damage effect numerical calculation, and dynamic explosion point analysis and calculation.

[0007] Technical Solution

[0008] A dynamic explosion point analysis and calculation method based on target structural response is characterized by the following steps:

[0009] Step 1: Damage effect measurement: Based on the ammunition's combat performance parameters, the possible explosion point of the ammunition is predicted before the dynamic test. Based on relevant mechanical principles, multiple acceleration sensors are deployed on the target structure. The sampling frequency of the acceleration sensors is greater than 200 kHz.

[0010] Step 2: Determine the macroscopic location of the explosion point after the test: Determine the cabin where the explosion point is located based on the macroscopic damage results of the target;

[0011] Step 3: Numerical calculation of damage effect:

[0012] According to the target structure construction drawings or the target object, perform 3D geometric modeling of the target structure, perform finite element meshing on the model, and add material properties and boundary conditions of the target structure;

[0013] Model the warhead, set the explosion solution parameters and warhead motion constraints;

[0014] Set the relative position between a certain ammunition and the target, and establish a finite element numerical calculation model of the damage caused by explosive ammunition to the target;

[0015] According to the position of the acceleration measurement point in the actual measurement, the acceleration data extraction parameters are set at the corresponding position of the finite element model. The data extraction frequency is consistent with the sampling rate of the actual measurement.

[0016] Submit the solver for solution and extract the acceleration data from the calculation results;

[0017] Step 4: traverse calculation:

[0018] The cabin on the target structure obtained in step 2 is evenly divided into N small areas. The center of each small area is used as the placement position of the warhead model, and the acceleration time domain data of all measurement points corresponding to the N working conditions are extracted;

[0019] Step 5: Dynamic explosion point analysis and calculation:

[0020] Based on the acceleration time domain signals measured and simulated at the corresponding measurement points, the take-off time and peak characteristic parameters are extracted. These characteristic parameters at multiple points are used to construct the objective function. The data of N working conditions are input, and the optimal value of the objective function is used as the evaluation criterion. The coordinates of the explosion point under this working condition are obtained as the analysis and calculation results.

[0021] Specifically, the explosion point is determined by using a single variable, acceleration take-off time, and the reference point take-off time of the measured acceleration signal is set as T Bm , the corresponding simulation calculation point acceleration signal reference point jump time is T Bs , G T The objective function for determining the explosion point position by acceleration take-off time is:

[0022]

[0023] Among them, i ranges from 1 to N. When G Ti When it is minimum, the small area where the explosion point is located is obtained, and the center position is the explosion point position.

[0024] In step 5, a single variable such as the acceleration peak is used to determine the explosion point, and P T The objective function for determining the explosion point position by the acceleration peak is:

[0025]

[0026] Among them, i ranges from 1 to N, P Ti The minimum is the small area where the explosion point is located, and the center position is the explosion point position.

[0027] In step 5, the multivariate analysis method is used to determine the explosion point by using the acceleration take-off time and the acceleration peak value multivariate, and the meaning remains unchanged. The multi-objective optimization G T 、P T Method to find multi-G T 、P T The Pareto optimal solution of the objective function is to locate the small area where the explosion point is located.

[0028] The measuring points are selected as follows: for buildings, the measuring points are distributed on the steel bars inside the main load-bearing structure; for ships, the measuring points are distributed on the longitudinal strength structure.

[0029] The number of N small areas divided depends on the accuracy requirement of the damage assessment for the explosion point.

[0030] When dividing the explosion point cabin into areas, a rough division is first performed to obtain an optimal area; then the optimal area is divided into smaller areas until the accuracy requirement is met.

[0031] The acceleration sensor is replaced by a strain gauge, and the acceleration signal is the strain signal of the strain gauge.

[0032] Beneficial effects

[0033] The present invention proposes a dynamic explosion point analysis and calculation method based on the target structure response. Without increasing the target damage effect measurement content in the dynamic explosion test of weapons and ammunition, it combines numerical simulation calculation technology to obtain the target structure acceleration or strain dynamic response characteristic parameters obtained by measurement and simulation calculation. Through comparative analysis and calculation, it indirectly gives the high-precision explosion point coordinate position, effectively solving the problem that the explosion point position cannot be directly obtained by optical methods inside buildings or ships, and ultimately lays the foundation for testing the coordination of warhead ignition and accurate evaluation of the damage effectiveness of weapons and ammunition.

[0034] The present invention comprises three modules: damage effect measurement, damage effect numerical calculation, and dynamic impact point analysis and calculation. The numerical damage effect calculation model must be consistent with the actual target effector model and the acceleration measurement points must be located consistently. Acceleration measurement points are primarily located on the strong structures of buildings or ships to reduce the propagation of stress waves across media and components. The dynamic impact point analysis method primarily extracts characteristic parameters from measured and simulated acceleration data at the same measurement point, based on the consistency between the actual and simulated calculation models. The dynamic impact point is then determined through a process of construction, traversal calculation, and comparative analysis.

[0035] Based on measured acceleration signals and those derived through numerical calculations, this method employs univariate analysis, multivariate analysis, and artificial intelligence analysis to calculate the explosion point location. This method can be applied to dynamic explosion point positioning within targets such as ships and buildings. The accuracy of the explosion point can be adjusted based on the number of iterative calculations required. Furthermore, the target response parameter is not limited to acceleration; strain and other parameters can also be selected.

[0036] The present invention does not increase the measurement method and content of the target damage effect in the dynamic explosion test, but proposes a method of comprehensive measurement and simulation data processing to effectively obtain the location of the explosion point inside the building or ship. The result is highly reliable and the method is economical.

[0037] The present invention is based on electrical signal measurement of acceleration parameters and is not affected by environmental smoke and dust. It can analyze and calculate the dynamic explosion points when multiple warheads continuously strike buildings or ships. The number of working conditions for simulation calculation can be adjusted according to accuracy requirements, and the overall adaptability is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : Schematic diagram of ship cabin distribution in the embodiment

[0039] Figure 2 : Schematic diagram of the explosion point compartment division and acceleration measurement points in the embodiment DETAILED DESCRIPTION

[0040] The present invention will now be further described with reference to the embodiments and accompanying drawings:

[0041] The following is an example in which the target effector is a ship structure and the measurement parameter is acceleration. The target effector is a building and the measurement parameter is strain, etc., which can be used as a reference.

[0042] 1. Damage effect measurement: In the context of dynamic explosion tests, acceleration is selected as the measurement parameter for the damage effect of the target structure, and the measurement method is consistent with the normal dynamic explosion test. It should be noted that: First, according to the damage assessment input requirements, the sampling frequency should be relatively high, generally greater than 200K, and most data acquisition equipment can meet the requirements. Second, for buildings, the measuring points should be distributed on the steel bars inside the main load-bearing structure; for ships, considering that most ships are longitudinal skeleton structures, the measuring points should be distributed on the longitudinal bone strength structure. This method of measuring point layout is to reduce the propagation of stress waves across media and components. The reason for the distributed layout is that the room or cabin where the explosion point is located is unknown. Specifically:

[0043] Step 1: Accelerometer sensor layout

[0044] Based on the dynamic explosion test measurement plan and incorporating weapon and ammunition combat parameters, acceleration sensors are deployed in all compartments that may implode. Generally, for a compartment implosion, acceleration is measured in three directions with a sampling frequency of no less than 200kHz. Sensors are primarily deployed on the longitudinal reinforcement structure, primarily using bolted connections.

[0045] Step 2: Acceleration measurement and processing

[0046] Collect and store acceleration time domain signals, remove abnormal data, and extract characteristic point parameters such as starting point and peak point.

[0047] Step 3: Analysis of damage to target effectors in dynamic explosion tests

[0048] Based on the damage of the target effector in the dynamic explosion test, we can preliminarily determine the cabin where the explosion point is located. Assuming that the explosion point is located in cabin 0 (such as Figure 1 As shown in the figure, it is a longitudinal section diagram of the cabin distribution of the ship section, and the coordinate system direction is specified), where the adjacent cabins are marked as cabin No. 1, cabin No. 2, cabin No. 3, cabin No. 4, cabin No. 5 (positive Y direction), and cabin No. 6 (negative Y direction), and the common surface between No. 0 and No. 1 is marked as plate 01, the common surface between No. 0 and No. 2 is marked as plate 02, the common surface between No. 0 and No. 3 is marked as plate 03, the common surface between No. 0 and No. 4 is marked as plate 04, the common surface between No. 0 and No. 5 is marked as plate 05, and the common surface between No. 0 and No. 6 is marked as plate 06.

[0049] If the damage to cabin 0 is primarily near plate 01, the analysis will focus on the acceleration signals from cabin 3 and its adjacent cabin walls (excluding cabin 0), which are located further away from plate 01. This is primarily because damage to plate 01 (especially large breaches) alters the propagation paths of shock and stress waves, creating significant nonlinear factors. Furthermore, considering that linear elasticity calculations are more accurate than plasticity and breaches in subsequent simulations, the analysis will focus on the acceleration signals from cabins further away from plate 01. If the damage is near plate 02, the analysis will focus on the acceleration signals from cabin 4 and its adjacent cabin walls (excluding cabin 0), which are located further away from plate 02. And so on.

[0050] 2. Numerical calculation of damage effect:

[0051] 1) 3D modeling of target structures: 3D modeling of target structures is performed based on construction drawings of buildings and ships to ensure consistency between the 3D model and the actual structure.

[0052] 2) Numerical modeling: Based on the three-dimensional modeling of the target structure, finite element meshing is performed, and material properties, boundary conditions, and other content are added. The warhead is modeled, and the parameters for the explosion solution and the warhead motion constraints are set. The finite element units or nodes from which the acceleration is to be extracted are added, and the unit or node positions are consistent with the positions of the acceleration measurement points in the actual measurement, and the model is submitted to the solver for solution. It is important to note how to select the placement of the warhead in the numerical calculation: first, based on the results of the dynamic explosion test, determine the room or cabin where the explosion occurred; second, based on the accuracy requirements of the explosion point for damage assessment, the room or cabin is evenly divided into several small areas; finally, the center of each block is used as the warhead placement location. If the room or cabin is divided into N small areas, then N working conditions of the model need to be solved, which requires a large amount of calculation and data.

[0053] 3) Result data extraction: Extract the acceleration time domain data of all measuring points corresponding to N working conditions in sequence.

[0054] Specifically:

[0055] Step 4: Target 3D structure modeling

[0056] The target structure is 3D modeled based on the ship's construction drawings to ensure consistency between the 3D model, especially the explosion point and nearby cabins, and the actual structure.

[0057] Step 5: Target numerical calculation modeling

[0058] Based on the three-dimensional modeling of the target structure, finite element meshing is performed, and material properties, boundary conditions, and other contents are added. Finite element units or nodes from which accelerations are to be extracted are added, and the positions of the units or nodes are consistent with the positions of the acceleration measurement points in the actual measurement.

[0059] Step 6: Numerical calculation modeling of the warhead

[0060] Model the warhead, set the parameters for explosion solution and the warhead motion constraints (such as speed, etc.).

[0061] 3. Dynamic Explosion Point Analysis and Calculation: Based on the measured and simulated acceleration time-domain signals at the corresponding measurement points, characteristic parameters such as take-off time and peak value are extracted. These characteristic parameters at multiple points are used to construct an objective function. Data from N operating conditions are input, and the optimal value of the objective function is used as the evaluation criterion to determine the optimal operating condition. The coordinates of the explosion point under this condition are then obtained as the analysis and calculation results.

[0062] Specifically:

[0063] Step 7: Explosion point traversal calculation

[0064] like Figure 2As shown in the figure, if the damaged part of cabin 0 is mainly close to plate 01, the acceleration measurement point data are mainly selected from A1, A2, A3, A4, A5 on the longitudinal reinforcement structure. 11 、A 21 、A 31 、A 41 ...and other measuring points. Based on the requirements of explosion point positioning accuracy, compartment 0 is divided into areas, such as Figure 2 As shown in the figure, the cabin 0 is divided into 5×5×5=125 small areas, and the coordinates of the center point of each small area are (x 00 ,y 00 , z 00 )、(x 01 ,y 01 , z 01 )、(x 02 ,y 02 , z 02 )……. According to the coordinates of the center points of 125 small areas set as the explosion point coordinates, traversal finite element numerical calculation is performed to obtain A1, A2, A3, A4, A 11 、A 21 、A 31 、A 41 ......The acceleration time domain signal of the measurement point.

[0065] Step 8: Explosion point data analysis

[0066] Set points A1, A2, A3, A4, A 11 、A 21 、A 31 、A 41 ...and the acceleration take-off time of the corresponding measured point is T 1m 、T 2m 、T 3m 、T 4m 、T 11m 、T 21m 、T 31m 、T 41m ...etc. (m is the measure), the acceleration take-off time of the corresponding simulation point is T 1s 、T 2s 、T 3s 、T 4s 、T 11s 、T 21s 、T 31s 、T 41s ...etc. (s is simulation); the peak acceleration value corresponding to the measured point is P 1m 、P 2m 、P 3m 、P 4m 、P 11m 、P21m 、P 31m 、P 41m ...etc. (m is measure), the acceleration take-off time of the corresponding simulation point is P 1s 、P 2s 、P 3s 、P 4s 、P 11s 、P 21s 、P 31s 、P 41s ...etc. (s stands for simulation).

[0067] The following three methods are used to determine the location of the explosion point:

[0068] (1) Univariate analysis

[0069] First, the explosion point is determined by using the single variable of acceleration take-off time. The point with the ideal measured signal is selected as the acceleration signal reference point, and its take-off time is marked as T. Bm The corresponding simulation calculation point acceleration take-off time is marked as T Bs , mark G T The objective function for determining the explosion point position by the acceleration take-off time is:

[0070]

[0071] Let G T The smallest area where the explosion point is located can be obtained.

[0072] The second is to use a single variable such as the acceleration peak to determine the explosion point, let P T The objective function for determining the explosion point position by the acceleration peak is:

[0073]

[0074] Let P T The smallest area where the explosion point is located can be obtained.

[0075] (2) Multivariate analysis

[0076] The explosion point is determined by using multiple variables such as acceleration take-off time and acceleration peak value. T , G P The meaning remains unchanged. Through multi-objective optimization method, we can find multiple G T 、P T The Pareto optimal solution of the objective function can be used to locate the small area where the explosion point is located.

[0077] (3) Artificial Intelligence Analysis

[0078] Taking the acceleration take-off time, acceleration peak simulation results of a large number of randomly located explosion points, the acceleration take-off time and acceleration peak numerical simulation results of the center of a small area as training samples, a deep model is constructed for supervised learning. By adjusting the level and weight of the deep model, a explosion point prediction neural network is constructed, and then the explosion point location is predicted based on the measured acceleration data.

[0079] When dividing the explosion point cabin into areas, you can first make a rough division and obtain the optimal area according to the above method; then divide the area and continue to obtain smaller areas according to the above method until the accuracy requirements are met.

Claims

1. A dynamic explosion point analysis and calculation method based on target structural response, characterized in that Here are the steps: Step 1: Damage effect measurement: Based on the ammunition's combat performance parameters, the possible explosion point of the ammunition is predicted before the dynamic test. Based on relevant mechanical principles, multiple acceleration sensors are deployed on the target structure. The sampling frequency of the acceleration sensors is greater than 200 kHz. Step 2: Determine the macroscopic location of the explosion point after the test: Determine the cabin where the explosion point is located based on the macroscopic damage results of the target; Step 3: Numerical calculation of damage effect: According to the target structure construction drawings or the target object, the target structure is 3D modeled, the model is meshed by finite elements, and the material properties and boundary conditions of the target structure are added; Model the warhead, set the explosion solution parameters and warhead motion constraints; Set the relative position between a certain ammunition and the target, and establish a finite element numerical calculation model of the damage caused by explosive ammunition to the target; According to the position of the acceleration measurement point in the actual measurement, the acceleration data extraction parameters are set at the corresponding position of the finite element model. The data extraction frequency is consistent with the sampling rate of the actual measurement. Submit the solver for solution and extract the acceleration data from the calculation results; Step 4: traverse calculation: The cabin on the target structure obtained in step 2 is evenly divided into N small areas. The center of each small area is used as the placement position of the warhead model, and the acceleration time domain data of all measurement points corresponding to the N working conditions are extracted; Step 5: Dynamic explosion point analysis and calculation: Based on the acceleration time domain signals measured and simulated at the corresponding measurement points, the take-off time and peak characteristic parameters are extracted. These characteristic parameters at multiple points are used to construct the objective function. The data of N working conditions are input, and the optimal value of the objective function is used as the evaluation criterion. The coordinates of the explosion point under this working condition are obtained as the analysis and calculation results. Specifically, the explosion point is determined by using a single variable, acceleration take-off time, and the reference point take-off time of the measured acceleration signal is set as T Bm , the corresponding simulation calculation point acceleration signal reference point jump time is T Bs , G T The objective function for determining the explosion point position by acceleration take-off time is: Among them, i ranges from 1 to N. When G Ti When it is minimum, it is the small area where the explosion point is located, and the center position is the explosion point position.

2. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1, characterized in that: In step 5, the acceleration peak value single variable is used to determine the explosion point, and P T The objective function for determining the explosion point position by the acceleration peak is: Among them, i ranges from 1 to N, P Ti The minimum is the small area where the explosion point is located, and the center position is the explosion point position.

3. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1, characterized in that: In step 5, the multivariate analysis method is used to determine the explosion point by using the acceleration take-off time and the acceleration peak value multivariate, and the meaning remains unchanged. The multi-objective optimization G T 、P T Method to find multi-G T 、P T The Pareto optimal solution of the objective function is to locate the small area where the explosion point is located.

4. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1, characterized in that: The measuring points are selected as follows: for buildings, the measuring points are distributed on the steel bars inside the main load-bearing structure; for ships, the measuring points are distributed on the longitudinal strength structure.

5. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1 is characterized in that: The number of N small areas divided depends on the accuracy requirement of the damage assessment for the explosion point.

6. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1 or 5, characterized in that: When dividing the explosion point cabin into areas, a rough division is first performed to obtain an optimal area; then the optimal area is divided into smaller areas until the accuracy requirement is met.

7. The dynamic explosion point analysis and calculation method based on target structural response according to claim 1, characterized in that: The acceleration sensor is replaced by a strain gauge, and the acceleration signal is the strain signal of the strain gauge.

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