จำนวน Repository ( 7 )
แผ่นเกราะเซรามิกส์กันกระสุนด้วยวัสดุเชิงประกอบ
This research has been studied and created the ceramic armor plates with composite materials that been proceeded from drying compression process with mold. Al2O3 that use for compression forming has been analyzed by SEM and XRD. It showed that compound and powder particle led to 5 microns-sized. It had flat circle shape of colundum Al2O3 and hexagonal crystal system. Upper punch of molding has designed and analyzed by FEA to 2 forms first form was the end-point had flat face and second form was the end-point had a convex. Upper punch had been made from AISI 52100 with 64 HRC ceramic armor plate had been produced by compression at 1000 kN which had hexagon side shape of width 25.98 mm for each side or height between parallel side of 45 mm. Al2O3 had been compressed to investigate the distribution of relative density for the height after compression of 15 and 30 mm by analyzing 4 cases that consist of 1.) a case of smooth face of upper punch which has green compact of 15 mm height 2.) a case of convex face of upper punch which has green compact of 15 mm height 3.) a case of smooth end face of upper punch which has green compact of 30 mm height 4.) a case of convex face of upper punch which has green compact of 30 mm height. The result of this study is to propose the distribution of relative density on horizontal axis as it is a relative radius and vertical axis is a relative distance from the upper punch that is an axis of moving down action. This study found that the distribution of relative density form had analogous form for these 4 cases the density had few differences and had high value at the town edge of green compact due friction between die wall and upper punch. The ceramic armor plate has been set up on UHMWPE fiber plate and used special silicone to connect them together then will get the NIJ 3 standard of ceramic armor plate with Composite materials
Finite element analysis of armor piercing bullet penetrating hard steel
The bulletproof plates with materials that can convincingly be destroyed by the 7.62 mm bullet with its speed at 878 ± 9.1 m/s were developed by designing according to the National Institute of Justice Level 4 (NIJ 4). The plates were made of two flat sheets stacking SKD11 and SUS304. Their components were composed of the front and back plates; the first sheet made of SKD11 material hardening at 65 HRC with a thickness of 6 mm and the back plate made of SUS 304 material with a thickness of 5 mm. The finite element method was applied to simulate and analyze the results to demonstrate the bullet resistance to the perforation by setting perpendicular sheet to the bullets. Therefore the simulating studies for the bullet firing were demonstrated by locating its angles of 15 30 45 and 60 degrees to the SKD11 sheet with a thickness of 6 8 and10 mm coupled with the SUS304 sheet with a thickness of 5 6 8 and 10 mm. These plates were stacking into two layers then the finite element method was applied to simulate one at a time. The results showed that the first sheet of SKD11 with 6 mm of thickness could resist the perforation of the bullet at 60 degree and the plate thickness of 8 and 10 mm could start resisting to the perforation at 45 degree. The second sheet of SUS304 with the thickness of 5 6 8 and 10 mm were incapable to resist to the perforation and the refraction of the bullet direction as good as that of SKD11. Therefore the principle applying two metal sheets stacked into layers was essential to impel the resistance of the bullet perforation and change the direction of the bullet.