An automatic statistical method for fragment quantitative information based on ls-dyna calculation results

Abstract

The invention provides an LS-DYNA calculation result-based automatic statistical method for quantitative information about fragments. The number, the mass and the speed of each fragment in a calculation result can be obtained, and can be directly output as a text file for evaluating the efficiency of a warhead or providing references for the design of the warhead and a protective structure. The method comprises the following steps of first reconstructing a fragment data file on the basis of an LS-DYNA calculation result; then searching and identifying the fragments in groups, and endowing serial numbers to the fragments; next making statistics on the mass of each fragment, and outputting the mass data of each fragment to a result file; finally making statistics on the speed of each fragment, and outputting the speed data of each fragment to the result file.

Description

technical field [0001] The invention belongs to the technical field of finite element numerical simulation, and relates to an automatic statistical method for quantitative information such as the number, quality and speed of warhead fragments based on LS-DYNA calculation results. Background technique [0002] Conventional warheads will form a large number of high-speed flying fragments during the explosion and penetration process. The quantitative information of fragments plays an important role in the analysis and evaluation of the use efficiency of natural fragment warheads, prefabricated fragment warheads, etc. important role. For example, after the high-explosive grenade explodes, it forms natural fragments with a certain initial velocity and different shapes and sizes, which penetrate and kill the target. The quantity, quality and flying speed of natural fragments are important basis for evaluating its power. For another example, under high-speed / ultra-high-speed con...

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Problems solved by technology

However, through numerical simulation calculations, although the mechanical phenomena in the process of fragment formation and the resulting macroscopic damage effects can be described, quantitative information such as the quantity, quality, and scattering speed of fragments at each moment cannot be fully described.

The existing LS-DYNA general-purpose post-processing program cannot automatically output fragment data files from the calculation results to describe the size and velocity of each fragment, and there is no search and identification for the natural fragments formed by the warhead fragmentation and the secondary fragments generated by penetration The ability of the software limits the efficient application of the calculation results, so it is necessary to further analyze and process the software calculation results to obtain the detailed information of the fragments

Beijing University of Aeronautics and Astronautics uses the SPH method to simulate the fragments in the explosion and impact, and then uses the grid generation method to reconstruct the fragment field, and counts the number, speed, quality and other information of the fragments. It is reported that the introduction of human factors may cause large errors in the statistical results; Wang Shuo, Li Dongyang and others generated fragment fields through the Lagrange method and used secondary development software to make statistics on the fragment information, but the fragment identification process relies on the fact that the fragment unit has 4 The judging relationship of four common nodes may lead to the omission of some fragment units belonging to the same fragment but not having four common nodes in the statistical process, which affects the reliability of the calculation results.

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