A model for evaluating the ballistic resistance of stratified packs

7th International Conference on Advanced Concepts in Mechanical Engineering

Pirvu, C.^1 ; Georgescu, C.^2 ; Badea, S.^3 ; Deleanu, L.^2

Tncas Bucharest, Romania^1

Faculty of Engineering, Dunarea de Jos University of Galati, Galati, Romania^2

Scientific Research Center for CBRN Defense and Ecology, Bucharest, Romania^3

关键词: Ballistic performance;    Ballistic resistance;    Equivalent plastic strain;    Impact velocities;    Isotropic hardenings;    Level of safeties;    Orthotropic materials;    Thermal influence;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/147/1/012098/pdf
DOI  :  10.1088/1757-899X/147/1/012098

来源: IOP

【 摘 要 】

Models for evaluating the ballistic performance of stratified packs are useful in reducing the time for laboratory tests, understanding the failure process and identifying key factors to improve the architecture of the packs. The authors present the results of simulating the bullet impact on a packs made of 24 layers, taking into consideration the friction between layers (μ = 0.4) and the friction between bullet and layers (μ = 0.3). The aim of this study is to obtain a number of layers that allows for the bullet arrest in the packs and to have several layers undamaged in order to offer a high level of safety for this kind of packs that could be included in individual armors. The model takes into account the yield and fracture limits of the two materials the bullet is made of and those for one layer, here considered as an orthotropic material, having maximum equivalent plastic strain of 0.06. All materials are considered to have bilinear isotropic hardening behavior. After documentation, the model was designed as isothermal because thermal influence of the impact is considered low for these impact velocities. The model was developed with the help of Ansys 14.5. Each layer has 200 mm × 200 × 0.35 mm. The bullet velocity just before impact was 400 m/s, a velocity characterizing the average values obtained in close range with a ballistic barrel and the bullet model is following the shape and dimensions of the 9 mm FMJ (full metal jacket). The model and the results concerning the number of broken layers were validated by experiments, as the number of broken layers for the actual pack (made of 24 layers of LFT SB1) were also seveneight. The models for ballistic impact are useful when they are particularly formulated for resembling to the actual system projectile - target.