The objectives of the book are: 1) Numerical evaluation and validation of the ballistic limit velocity, shapes of the residual velocity curves and failure modes of the monolithic plate under normal impact by projectiles of different nose shapes. 2) Numerical evaluation of the parameters in the penetration problem (ballistic limit velocity, residual velocity and energy absorption) and failure modes of multilayered plates (plates in contact and plates with air-gap) under normal impact by projectiles of different nose shapes. 3) Comparison of the parameters in the penetration problem and failure modes of monolithic and multilayered plates.