Ballistic impact behavior of thick composites: Analytical formulation

Structures undergo different loading conditions during their service life. Impact is one of the typical cases of loading. In this study, an analytical method is presented for the prediction of ballistic impact behavior of thick composites based on wave theory and energy balance between the projectile and the target. For thick composites the wave propagation along the thickness direction is also considered. During the ballistic impact event, energy transfer takes place from the projectile to the target. As the energy is absorbed by different mechanisms, kinetic energy and velocity of the projectile decrease. Different damage and energy-absorbing mechanisms for a typical woven fabric composite are compression of the target directly below the projectile, possible reverse bulge formation on the front face, compression in the surrounding region of the impacted zone, tension in the yarns, shear plugging, bulge formation on the back face, delamination and matrix cracking, friction between the target and the projectile, and heat generation caused by impact. Based on the analytical method presented, typical results are generated and compared with the experimental values.