| Summary: | 碩士 === 國防大學理工學院 === 兵器系統工程碩士班 === 106 === In this research, we proposed the armor design based on the arrangement of bionic scale structures, an oblique structure was formed by overlapped ceramic sheets. Through oblique impact, the projectile was deformed and flipped, resulting in a higher penetration resistance of the armor structure. The disk specimens used in this research were all made of alumina (Al2O3), each with 50 mm diameter and three types of thickness, 7 mm, 8 mm and 9 mm, were adopted. The specimens were all made of 25 alumina disks arranged to scale-like armor structure and 1 mm aluminum was used as a backplane. The impact resistant performance of the three specimens with different thickness was investigated. Further, when the total thickness of the armor structure was set to 9 mm, the 8 mm and 7 mm ceramic disks were added by 1 mm and 2 mm circular aluminum plates individually, the 1mm aluminum backplane was also used in these specimens as a back plate. Impact resistance capability of different combinations of the target was again investigated.
The ballistic test was under a 0.30" armor-piercing bullet impact. The energy absorption was calculated by measuring the velocity before and after the impact. The results from test and simulation showed that the overlapping ceramics transmitted stress to bonded ceramics. It was also shown that, the specimen with 8 mm alumina and 1 mm aluminum disk combination has the best impact resistant performance than the others when total thickness is 9 mm.
By using LS-DYNA code, the energy absorption, damage state, stress transmission mode, and bullet residual velocity of the scale-like armor penetrated by projectile were investigated by finite element model. Moreover, the D_1 and D_2 parameters of the Johnson-Holmquist damage model (JH-2) were corrected by comparing simulation model and the experimental results. Finally, the simulation was also implemented to analyze the impact resistance of different impact position and angle. The results showed significant difference.
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