Steel armor plates

Abstract

This research project aimed to analyze and design the pattern of a bulletproof metal armor plate as well as build a bulletproof metal armor plate for a small armored regular truck. The methodology consisted of the NIJ standard test and the finite element analysis. The bulletproof plates created were tested for a real firing. Their firing results were compared with those of NIJ-standard using a finite element program, in this case applying with the program Ansys/Explicit Dynamic. SolidWorks program is employed as a tool to design and create 3D models of armor plates and bullets. The materials taken in the finite element simulation were SKD11 and SUS304 and the parameters utilized in the research were material types, hardness values, spacing between the plates and thickness. In the case of two armor plates stacked, SKD11 material was designed for the first armor plate to be hit by the bullet. It served to destroy bullets. In addition, the second armor plate made of SUS304 material served to absorb energy and obstruct the movement of bullets. For testing, a 30-06 caliber M2 AP 166 Gr bullet was selected at a 0-degree angle and the velocities measured and set by the Ansys/Explicit Dynamic program were 901.7 m/s and 880 m/s, respectively. The front plate made of SKD11 material with a thickness of 10 mm and the back plate made of SUS304 material with a thickness of 10 mm were fired 1 shot. The results showed that the bullet could penetrate the front armor plate but not penetrate the back-armor plate. In the NIJ 3 standard tests, the shooting with a 7.62x51 mm NATO FMJ 148 Gr shell at a 0-degree angle for 5 times with velocities equal to 846.4, 841.3, 839.1 838.2 and 845.3 m/s was performed on the stacking front and back armor plates, both made of SUS304 material with a thickness of 8 mm. The bullet velocity simulated by the Ansys program was 847 m/s, resulting in the front plate having a bullet penetration and a slight bulge on the back plate. From the finite element simulation results and the actual test results, it was found that the damage to the armor plates detected by both methods was consistent. Therefore, the finite element program was selected to simulate the damage of armor plates resistant to penetration according to the NIJ standard Level 4. The results of the research could be concluded that the use of armor plates stacked with suitable different materials in multiple layers would affect the penetration resistance. Increased thickness and optimal spacing between the armor plates were important parameters in penetration resistance. Moreover, it revealed that the higher the material hardness, the better its ability to resist penetration. In particular, this suggestion should be applied to the first armor plate or front armor plate.