Influence of prestress on ballistic performance of bi-layer ceramic composite armors: Experiments and simulations

The effect of prestress on the ballistic performance of bi-layer ceramic composite armors was explored both experimentally and numerically. Three types of target plate with different prestress levels were prepared using the method of shrink-fit, and tested with ballistic experiments. Residual velocity and length of the projectile were recorded and failure mode of each target was examined. A numerical technique was also proposed to explore the penetration process of projectile and the enhancement mechanism of prestress, with the effectiveness of simulation results validated by experimental measurements. Prestressing the ceramic led to more kinetic energy dissipated by plastic deformation and erosion of the projectile, causing more than 25% increase in ballistic limit. The effects of key geometrical parameters – thickness and diameter of ceramic tile – on ballistic limit were systematically explored, and a critical tile thickness for the influence of prestressing on ballistic performance was identified.