A method and device for extracting physical quantities of a penetrating body based on d3plot file

Abstract

The present application belongs to the technical field of simulation data processing, and particularly relates to a method and device for extracting physical quantities of a penetrator based on a d3plot file. The method comprises: step S1, extracting the ID of each grid unit and the ID of each substance in the Euler domain in the d3plot file based on a preset flag; step S2, determining the sum of the volume fractions of each substance in all grid units at time 0 in the d3plot file; step S3, taking the substance with the smallest sum of volume fractions as the penetrator; step S4, determining the volume fraction of the penetrator at each time and each grid unit in the d3plot file, and screening the grid units whose volume fractions exceed the set value as data extraction grids; step S5, extracting the data of each physical quantity in the data extraction grid in the d3plot file. The present application can quickly extract the physical quantities of the penetrator, and improve the comprehensiveness and reliability of the penetration effect analysis.

Description

Technical Field

[0001] The present application belongs to the technical field of simulation data processing, and in particular relates to a method and device for extracting physical quantities of a penetrating body based on a d3plot file. Background Art

[0002] Penetration effect refers to the mechanism, phenomenon and effect of the penetrating body formed after the explosion of an object, such as fragments, focused jets, etc., which penetrate the target with its kinetic energy and cause damage.

[0003] LS-DYNA is a full-featured finite element solver, mainly used for dynamic simulation. It supports geometric nonlinearity, material nonlinearity and contact nonlinearity analysis, and is suitable for various complex engineering problems. LS-DYNA mainly uses explicit solution, and also has implicit solution function, which is suitable for structural analysis, thermal analysis and fluid-structure coupling. After using LS-DYNA to simulate the penetration effect, LS-PrePost software is usually used to visualize and analyze the simulation results of LS-DYNA. However, in engineering practice, it is usually necessary to obtain the original physical quantities of the penetrator for more detailed data analysis. The existing LS-PrePost software is difficult to directly extract the penetrator information. Summary of the invention

[0004] In order to solve the above problems, the present application provides a method and device for extracting physical quantities of a penetrator based on a d3plot file, parsing the data format from the LS-DYNA simulation file d3plot and reading the required data blocks, thereby realizing accurate and rapid extraction of the required physical quantities.

[0005] The first aspect of the present application provides a method for extracting physical quantities of a penetrating body based on a d3plot file, mainly comprising:

[0006] Step S1, extracting the ID of each grid cell and the ID of each substance in the Euler domain in the d3plot file based on a preset flag;

[0007] Step S2, determining the sum of the volume fractions of each substance in all grid cells at time 0 in the d3plot file;

[0008] Step S3, taking the material with the smallest sum of volume fractions as the penetrating body;

[0009] Step S4, in the d3plot file, determine the volume fraction of the penetrator at each time and each grid unit, and select the grid units whose volume fraction exceeds the set value as data extraction grids;

[0010] Step S5: extracting the physical quantity data in the data extraction grid from the d3plot file.

[0011] Preferably, in step S4, the set value is selected from any value between 20% and 30%.

[0012] Preferably, step S5 further comprises:

[0013] Step S51, extracting the physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file;

[0014] Step S52: extracting the physical quantity data of the data extraction grid from the physical quantity data block.

[0015] Preferably, in step S5, the physical quantity includes velocity, strain, stress, and acceleration.

[0016] The second aspect of the present application provides a device for extracting physical quantities of a penetrating body based on a d3plot file, mainly comprising:

[0017] The grid unit and material ID extraction module is used to extract the ID of each grid unit and the ID of each material in the Euler domain in the d3plot file based on the preset flag bit;

[0018] The material volume fraction calculation module is used to determine the sum of the volume fractions of each material in all grid cells at time 0 in the d3plot file;

[0019] A penetrator determination module is used to take the material with the smallest sum of volume fractions as the penetrator;

[0020] The data extraction grid determination module is used to determine the volume fraction of the penetrator at each time and each grid unit in the d3plot file, and select the grid units whose volume fraction exceeds the set value as the data extraction grid;

[0021] The physical quantity extraction module is used to extract the physical quantity data in the data extraction grid in the d3plot file.

[0022] Preferably, in the data extraction grid determination module, the set value is selected from any value between 20% and 30%.

[0023] Preferably, the physical quantity extraction module includes:

[0024] A data block extraction unit is used to extract physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file;

[0025] The physical quantity data extraction unit is used to extract the physical quantity data of the data extraction grid in the physical quantity data block.

[0026] Preferably, in the physical quantity extraction module, the physical quantity includes velocity, strain, stress, and acceleration.

[0027] The present application can quickly extract the physical quantities of the penetrator, thereby improving the comprehensiveness and reliability of the penetration effect analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flowchart of a preferred embodiment of the method of extracting physical quantities of a penetrator based on a d3plot file of the present application.

[0029] Figure 2 This is a schematic diagram of the time data block position of the d3plot file.

[0030] Figure 3 It is a time-moment relationship diagram.

[0031] Figure 4 This is a schematic diagram of the Euler domain grid cell ID data block location in the d3plot file.

[0032] Figure 5 This is a schematic diagram of the ID of the resolved Euler domain grid cell.

[0033] Figure 6 This is a schematic diagram of the GROUP data block location in the d3plot file.

[0034] Figure 7 This is a schematic diagram of the parsed GROUP ID.

[0035] Figure 8 It is a schematic diagram of the volume fraction of the penetrating body GROUP at a certain moment.

[0036] Fig. 9 It is a schematic diagram of the physical quantity extraction results of the penetrating body at a certain moment. DETAILED DESCRIPTION

[0037] 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.

[0038] The first aspect of the present application provides a method for extracting physical quantities of a penetrating body based on a d3plot file, such as Figure 1 As shown, it mainly includes:

[0039] Step S1, extracting the ID of each grid cell and the ID of each substance in the Euler domain in the d3plot file based on a preset flag;

[0040] Step S2, determining the sum of the volume fractions of each substance in all grid cells at time 0 in the d3plot file;

[0041] Step S3, taking the material with the smallest sum of volume fractions as the penetrating body;

[0042] Step S4, in the d3plot file, determine the volume fraction of the penetrator at each time and each grid unit, and select the grid units whose volume fraction exceeds the set value as data extraction grids;

[0043] Step S5: extracting the physical quantity data in the data extraction grid from the d3plot file.

[0044] The present application first finds the ID of each grid unit and the ID of each substance from the d3plot file, so as to facilitate the subsequent search for the corresponding data block in the d3plot file according to the ID. Each substance in the d3plot file is only identified by the ID, but the specific meaning of the substance corresponding to each ID is not clear. For this reason, in step S2 and step S3, the penetrator is identified by finding the volume fraction of each substance at time 0. This is because the volume proportion of the penetrator is the smallest at time 0. After determining the ID of the penetrator, all data of the penetrator ID of each grid unit at each time can be found, including volume proportion data and physical quantity data such as velocity and stress. Then, in step S4, in order to reduce the amount of calculation, only the physical quantity data in the grid units whose volume fraction of the penetrator exceeds the set value are prepared to be extracted. In step S4, these grid units are marked as data extraction grids. Finally, in step S5, only the physical quantities of the penetrator at each time are extracted for the data extraction grid.

[0045] In addition, it should be noted that in order to mark the simulation time of each physical quantity of the extracted penetrator, it is necessary to extract the corresponding relationship between the time step and the time in the d3plot file in advance. According to the recording rules of the d3plot file, each data block has a beginning mark and an end mark. Figure 2 The selected part is the beginning of the time data block in the d3plot file, and the following data blocks are the relationship between the time step and the moment. The relationship between the time step and the moment after parsing is as follows Figure 3 shown. Figure 3 In the above example, state1, state2, ... are time steps, and time is the moment.

[0046] In step S1, the ID of each grid unit and the ID of each substance can be further extracted by the above method, such as Figure 4 As shown in the figure, the selected part is the location of the Euler domain grid unit ID data block. After finding this location, the following data block represents the ID of the grid unit. The Euler domain grid unit ID after parsing is as follows Figure 5 As shown. Figure 6 As shown in the figure, the selected part is a schematic diagram of the location of the material data block. In the d3plot file, GROUP is used to represent it. The GROUPID corresponding to different GROUPs is parsed and obtained. The data block containing GROUP information in the Euler domain is searched and read in the file. The GROUP after parsing is as follows Figure 7 As mentioned above, the substance here can be, for example, air, soil, penetrating body, etc., and only the ID can be extracted from the d3plot file, such as Figure 7 The ID numbers are 62-65, but it is not clear what substance each ID corresponds to.

[0047] In step S2, the volume fractions corresponding to different GROUPs at time 0 are read. Two search conditions are formed here, one is that the time step corresponding to time 0 is state1, and the other is the material ID corresponding to each GROUP. By searching in the d3plot file, the volume fraction of each material in each grid in the finite element grid can be obtained, and then the sum of the volume fractions of all grids is counted according to the material ID. In step S3, the material corresponding to the minimum sum of volume fractions is recorded. At this time, the material is the penetrator.

[0048] In step S4, according to the recorded ID of the penetrating body, the volume fraction data blocks at different time steps are searched in the file, and the volume fractions corresponding to the different time steps are read. Figure 8 The volume fraction of each grid cell of the penetrating body GROUP at a certain moment, and then the grid cells whose volume fraction exceeds the set value are selected as data extraction grids.

[0049] In some optional implementations, in step S4, the set value is selected from any value between 20% and 30%.

[0050] Take 25% as an example. Figure 8 The volume fractions of the various grid cells shown are all 100% and greater than 25%, so these grid cells are marked as data extraction grids.

[0051] Finally, in step S5, the grid is extracted according to the data marked at each time, the ID of the marked penetrator is retrieved and extracted from the d3plot file.

[0052] In some optional implementations, step S5 further includes:

[0053] Step S51, extracting the physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file;

[0054] Step S52: extracting the physical quantity data of the data extraction grid from the physical quantity data block.

[0055] In this embodiment, different physical quantities are recorded in different physical quantity data blocks. In step S51, each physical quantity data block may be located first, and then in step S52, the physical quantity data of the penetrating body at each moment may be retrieved and extracted from the physical quantity data block.

[0056] In some optional implementations, in step S5, the physical quantity includes velocity, strain, stress, and acceleration. Fig. 9 The speed physical quantity data extraction results are given. Fig. 9 In the figure, the first column is the grid unit ID, and the second to fourth columns are the velocity values ​​in the xyz directions respectively.

[0057] The second aspect of the present application provides a device for extracting physical quantities of a penetrating body based on a d3plot file, mainly comprising:

[0058] The grid unit and material ID extraction module is used to extract the ID of each grid unit and the ID of each material in the Euler domain in the d3plot file based on the preset flag bit;

[0059] The material volume fraction calculation module is used to determine the sum of the volume fractions of each material in all grid cells at time 0 in the d3plot file;

[0060] A penetrator determination module is used to take the material with the smallest sum of volume fractions as the penetrator;

[0061] The data extraction grid determination module is used to determine the volume fraction of the penetrator at each time and each grid unit in the d3plot file, and select the grid units whose volume fraction exceeds the set value as the data extraction grid;

[0062] The physical quantity extraction module is used to extract the physical quantity data in the data extraction grid in the d3plot file.

[0063] In some optional implementations, in the data extraction grid determination module, the set value is selected from any value between 20% and 30%.

[0064] In some optional implementations, the physical quantity extraction module includes:

[0065] A data block extraction unit is used to extract physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file;

[0066] The physical quantity data extraction unit is used to extract the physical quantity data of the data extraction grid in the physical quantity data block.

[0067] In some optional implementations, in the physical quantity extraction module, the physical quantity includes velocity, strain, stress, and acceleration.

[0068] 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 extracting physical quantities of a penetrating body based on a d3plot file, characterized in that: include: Step S1, extracting the ID of each grid cell and the ID of each substance in the Euler domain in the d3plot file based on a preset flag; Step S2, determining the sum of the volume fractions of each substance in all grid cells at time 0 in the d3plot file; Step S3, taking the material with the smallest sum of volume fractions as the penetrating body; Step S4, in the d3plot file, determine the volume fraction of the penetrator at each time and each grid unit, and select the grid units whose volume fraction exceeds the set value as data extraction grids; Step S5: extracting the physical quantity data in the data extraction grid from the d3plot file.

2. The method for extracting physical quantities of a penetrator based on a d3plot file according to claim 1, characterized in that: In step S4, the set value is selected from any value between 20% and 30%.

3. The method for extracting physical quantities of a penetrator based on a d3plot file according to claim 1, characterized in that: Step S5 further comprises: Step S51, extracting the physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file; Step S52: extracting the physical quantity data of the data extraction grid from the physical quantity data block.

4. The method for extracting physical quantities of a penetrator based on a d3plot file according to claim 1, characterized in that: In step S5, the physical quantities include velocity, strain, stress, and acceleration.

5. A device for extracting physical quantities of a penetrating body based on a d3plot file, characterized in that: include: The grid unit and material ID extraction module is used to extract the ID of each grid unit and the ID of each material in the Euler domain in the d3plot file based on the preset flag bit; The material volume fraction calculation module is used to determine the sum of the volume fractions of each material in all grid cells at time 0 in the d3plot file; A penetrator determination module is used to take the material with the smallest sum of volume fractions as the penetrator; The data extraction grid determination module is used to determine the volume fraction of the penetrator at each time and each grid unit in the d3plot file, and select the grid units whose volume fraction exceeds the set value as the data extraction grid; The physical quantity extraction module is used to extract the physical quantity data in the data extraction grid in the d3plot file.

6. The device for extracting physical quantities of a penetrator based on a d3plot file according to claim 5, characterized in that: In the data extraction grid determination module, the set value is selected from any value between 20% and 30%.

7. The device for extracting physical quantities of a penetrator based on a d3plot file according to claim 5, characterized in that: The physical quantity extraction module comprises: A data block extraction unit is used to extract physical quantity data blocks in the Euler domain corresponding to each moment and each physical quantity in the d3plot file; The physical quantity data extraction unit is used to extract the physical quantity data of the data extraction grid in the physical quantity data block.

8. The device for extracting physical quantities of a penetrator based on a d3plot file according to claim 5, characterized in that: In the physical quantity extraction module, the physical quantities include velocity, strain, stress, and acceleration.

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