On Analytical Ballistic Penetration Fundamental Model and Design

This paper presents a new fresh theoretical study of the ballistic penetration phenomena into hard materials due to low-energy bodies' motion. This model based on the energy balance between the kinetic energy of the piercing body and the protective body thermal energy. Following this equilibrium alongside the equation of the projectile motion, the resulting deceleration value is analytically calculated. Substituting the obtained deceleration value into the kinematic equilibrium results with the penetration thickness expression as well as the time of penetration inside the mono and multi layers materials (like, monolithic and composite materials). In addition, equivalently to the Johnson-Cook model, a proposed impact stress for penetrative and non-penetrative cases was developed. Additionally, a residual velocity expression alongside the evaluation of the total energy and deceleration parameters were also determined. Key parameters are the projectile effective length, which defines the projectile geometry alongside the material strength parameters (heat capacity, Yield, compressive and tensile strengths). Finally, good numerical agreement (order of magnitude and numerical values) has been found between various literature experimental tests and current analytic solution for the kinematic parameters.

Ballistic penetration damages and energy absorptions of stacked cross-plied composite fabrics and laminated panels

Flexible fabrics have been widely used in body armor designs. Here we report ballistic impact damage of stacked cross-plied composite fabric and cross-plied laminated panels. The ballistic impact behaviors of stacked cross-plied composite fabric and cross-plied laminated panel have been tested with fragment-simulating projectiles under the strike velocity 550–600 m/s to explore the influence of the layers combination of fabric target on ballistic impact. Two types of macroscopic anisotropy continua finite element models based on fabric targets structures are established to analyze the ballistic mechanism of stacked cross-plied composite fabric and cross-plied laminated panels. The impact damage morphologies and energy absorptions have also been compared between the tests and finite element analysis results. We have found the stacked fabric construction absorbed more energy than their counterpart cross-plied laminated panel, while the laminated panel shows better structural integrity and stability during ballistic penetration.