Experimental and numerical analysis of high velocity impact on Kevlar/Epoxy composite plates

In this paper, the ballistic performance of two and four-layer composite plates made of Kevlar fabric and epoxy has been investigated. Composite samples were made by hand-laying method and ballistic tests were conducted. The ballistic limit and absorbed energy were evaluated as a criteria of the ballistic performance of composite plates. Experiments were carried out using a hemispherical projectile in a velocity range of 20-120 m/s. Damage and failure of composites was evaluated. Also, using the LS-DYNA software, high velocity impact simulation on composite plates was performed. So, a precise model of projectile and target was prepared. The composite layers are individually modeled and connected to each other by appropriate constraints. This numerical model can accurately determine the ballistic limit of composite targets. Maximum error was 6 and 10% for 2 and 4 layer composites respectively. In order to investigate the effect of the projectile shape on the ballistic performance of the Kevlar/Epoxy composite, simulation was carried out using a hemispherical and blunt projectile at different velocities and ballistic limit and absorbed energy for two types of projectiles were compared. The ballistic limit for 4 and four-layer composites under impact of blunt projectile is 32.5 and 43.7 m/s, which is 14 and 16% higher than the hemispherical projectile.