Experimental study on structure optimization of functionally graded sandwich plates under ballistic impact

Abstract

In this study, the ballistic performance of Al6061-SiC functionally graded sandwich plate (FGSP) with varying number of layers and volume fractions was examined experimentally. For this purpose, the two outmost layers of the FGSP were designed to be aluminum and the volume fraction of remaining constituents was gradually changing in intermediate layers through the plate thickness. The specimen plates were manufactured via powder stacking-hot pressing method. Ballistic tests of specimens were conducted with a single-stage gas gun, shooting 0.3 caliber fragment simulated projectiles onto specimens. After the ballistic tests, deformation and damage mechanisms in the front and rear surfaces were examined and ballistic performance evaluation was carried out in terms of depth of penetration of the projectile measurements. Results showed that the composition of the projectile impact surface, which was beneath the top aluminum layer, had a considerable effect on ballistic resistance capability. A volume fraction of ceramic constituent greater than 60% in the projectile impact surface reduced the ballistic performance of the specimen. Likewise, a decreasing volume fraction of ceramic constituent of projectile impact surface below 60% increased projectile penetration. Furthermore, increasing the number of layers within the functionally graded region did not have a significant effect on the ballistic resistance of the FGSPs.