Modified Johnson–Cook Model-based Numerical Simulation of Small Arms Bullets Penetration in the Aluminum Alloy Plates

Nauka i Obrazovanie

N. Shash¹  V. N. Zuzov¹ 

[1] Bauman Moscow State Technical University, Moscow;

关键词: armour;    aluminum alloys;    bullet;    modified Johnson-Cook;    Cockcroft-Latham criterion;    LS-DYNA;    finite element model;   

DOI  :  10.7463/0117.0000922

来源: DOAJ

【 摘 要 】

In this paper, we simulated and studied the penetration process of 7,62 x 63 mm bullets "NATO Ball" (with a soft lead core) and 7.62 x 63 mm ones «APM2» (with hard steel core) in three kinds of aluminum plates, namely AA5083- H116, AA6082-T4, and AA7075-T6 with three different thicknesses of 10 mm, 20 mm, and 30 mm. The impact velocity was 830 m / s in all tests. Based on the test results and numerical calculations, all plates and a bullet were modeled as the deformable ones with modified constitutive Johnson-Cook relationship and Cockcroft-Latham fracture criterion. Then they were used in modeling by three-dimensional nonlinear finite element in Ansys Ls-Dyna package. The influence of the finite element size in the finite element model on the length and results of calculations has been investigated as well.

The main calculation results, we have received, include the residual bullet velocity and the residual kinetic energy of the bullet after drilling a hole in the plate and plate failure mechanism for each type and thickness of the plate with two types of bullets. We have noticed that the residual velocities of the bullets for small thicknesses of aluminum alloys (up to 10 mm) have relatively equal values upon penetration of the bullets "NATO Ball" and «APM2» (a bit more), as well as the calculation-obtained failure mechanisms are adequate to experimental. In addition, resistance of AA7075-T651 aluminum alloy to penetration is higher than that of AA5083-H116 and AA6082-T4 ones.

It should also be noted that the accuracy of the results depends mainly on the size of the grid elements. The more is the number of elements, the higher is the accuracy of the results, but the longer is the solution time. Therefore, we advice to use the finite element size of 0.2 mm, at most, to obtain the highly accurate results that are adequate to the experimental results.

【 授权许可】

Unknown