This thesis was an analysis of the significance of angle of inclination and the thickness of the armor plate on the penetration resistance of bullets on aluminum and stainless steel armor plates determined by the finite element method. In this study the information results obtained from actual firing of bulletproof armor and the finite element simulation according to NIJ 3 standards were compared to create a pattern of bulletproof and bulletproof armor using the SolidWorks program. The simulation model of the armor shooting was created by the Ansys/Explicit Dynamics program. The bullet material was 7.62 mm tungsten carbide (WC). There were three plate types used in the simulation were made of different bulletproof armor materials: 1) stainless steel SUS304 using for the plate thickness of 5 6 8 10 14 20 30 40 45 and 55 mm. 2) aluminum AL7075 using for the plate thicknesses of 6 8 10 and 20 mm. Additionally 3) tungsten carbide using for the plate thicknesses of 6 8 and 10 mm. Each of these plates had a width x length of 300 x 300 mm. The simulation models were divided into two types: Type 1 a simulation firing at one plate at a time. Type II a simulation firing at two layered plates stacked together without any gaps between plates. The front and the back plates made of stainless steel and aluminum respectively or tungsten carbide and stainless steel respectively were determined. The angles of firing at bulletproof armor were set at 0 30 and 45 degrees. The output results were that in Type I the stainless-steel plate with a thickness of 30 mm or more could resist the penetration of bullets. However in Type II 2 stacked layers of the armor plates using the front stainless plate with a thickness of only 20 mm and the back aluminum plate with a thickness of only 8 mm could provide the same constructive results as those of tungsten carbide and stainless steel plates for the front and back plates with both thickness setting at 16 mm. All of them showed the resistance of the penetration to the bullets. More observation was that the increases in angles as a result enhanced more resistance of the bulletproof plates to bullet penetration.

This research is aimed at investigating the amount of chromium carbide (Cr23C6) in stainless steel AISI 304 by electrochemical technique testing in calculating the Pa values that corresponding to sensitization stage and the corrosion behavior. The results will carry on to developing the welding process. The specimens were produced with Shielded Metal Arc Welding method. Moreover it was bending at the angle 0 90 and 180 degree and the process finished on post-heat treatment with different cool down conditions are 800ºC annealed in air cooled 1100ºC annealed in water cooled and annealed 1100ºC in air cooled respectively. The results show that: first conditional is appeared the maximum amount of Pa value (Pa > 0.4) indicating that more precipitation of Cr23C6 in heat affected zone (HAZ) of specimen. The second conditional is not found the sensitization stage because when the specimens were annealed at high temperature the chromium carbide will break up and residual stress in HAZ will decrease. At last conditional is found the less amount of Pa value; the reason of using high temperature on annealing process will decrease chromium carbide but slowly air-induced cooling must pass the critical temperature then some Cr23C6 will appear at grain boundary and cause of high corrosion rate. Concerning to the corrosion behavior the second conditional present the lowest corrosion rate corresponding to the better-quality of passive film. Whereas the first conditional shown the highest corrosion rate and low quality of passive film. Thus 1100ºC annealed with water cooled is excellent condition for developing the welding process.

The purpose of this research is to find the relation between stress and strain called as the Flow Stress Curve for 0.4 mm thickness stainless steel (SS 304). Two main methods are used: the Uniaxial tensile test and the Hydraulic Bulge Test (HBT). The relation between stress and strain from both methods would then be compared and simulated into cubic-shaped models by using Finite Element method. Results show that sheet metal formation simulated by using the flow stress curve obtained from Hydraulic bulge test can have the height of up to 40 millimeters before the work piece starts to lacerate. On the other hand if the flow stress curve obtained from Uniaxial tensile test is used the work piece will only be able to form about 15 millimeters before lacerating. The preliminary summary for this research can be said that the analysis for Hydraulic bulge test gives better results than Uniaxial tensile test as it has similar conditions to the actual formation process.