PARAMETER ANALYSIS OF SKD11 AND SUS304 BULLETPROOF PLATE THAT RESISTANCE PENETRATION OF BULLET 7.62 MM ACCORDING TO STANDARD NIJ 4 BY FINITE ELEMENT METHOD

The research and the development of bulletproof armor or equipment to have the potential to prevent destruction or attacks from opponents by the analysis of 2-layer armor plates which consist of SKD11 which is a front plate that used to destroy the bullet when the bullet hit the armor plate and a SUS304 rear plate which is a high tensile stress material to restrain metal fragment of damaged the bullet when the bullet is made from Tungsten Carbide (WC) with the size of 7.62 mm and the speed is 878±9.1 m/s according to NIJ (National Institute of Justice) test level 4. The study is done by finite element simulation by using Ansys/Explicit Dynamic software, material damage according to Johnson-Cook Model (JC) theory and Johnson-Holmquist Model (JH-2). The thicknesses of SKD11 armor plate are 6, 8, and 10 mm. The thicknesses of SUS304 armor plate are 5, 6, 8, and 10 mm. With the FEA simulation of 1-layer SKD11 at the thickness of 6 and 8 mm, the bullet can penetrate completely and broken when hit the armor plate. When the thickness is 10 mm, the armor plate can resist the puncture incompletely. Therefore, using SUS304 plate as the rear plate to be 2-layer bulletproof plate when the first layer is SKD11 and the second layer is SUS304. From the simulation, the armor plate can eventually resist so it is compared with the NIJ standard level 3.