An investigation on the behavior of high-strength stacked perforated armor plates against 7.62 armor-piercing bullets using the finite element methodology
Abstract:
The purpose of this research was to investigate the deformation behavior of stacked perforated metal armor plates and to analyze the attained stress from stacked perforated metal armor plates with high strength against 7.62 armor-piercing bullets using the finite element methodology according to the NIJ Level 3 standards. The analysis of dynamic response problems in solids mechanics was conducted using ANSYS Explicit/Dynamics and the time integration method. The bullet used in the simulation was a 7.62 x 51 mm tungsten carbide bullet with a velocity according to the NIJ 3 standard. The Johnson-Holmquist Failure model was used to analyze the bullet damage pattern. The perforated armor plate was made of SKD 11, defined as homogeneous and isotropic materials. The damage that happened was considered from the linear-elastic range to the high strain rate plastic range. The perforated armor plates had dimensions of width and length equal to 300 x 300 mm. and the thickness of the perforated armor plate might also change in various cases. The porosity helped deflect the bullet direction that penetrated the armor at a zero angle. SKD11 material was chosen to use as the front plate material. The rear armor plate was made of SUS304 material that absorbed the energy of the bullet's movement. The finite element model was validated by comparing the analytical results with the experimental results. According to the analysis results, it was found that making the armor plate with a perforated pattern throughout the thickness of the armor plate could not increase the penetration resistance. However, the perforated armor plate that did not penetrate through the thickness would increase the ability to deflect the bullet direction, increase the ability to resist penetration and reduce the weight of the armor plates as well.