Vibration resulting from high-velocity projectiles impacting a structure was simulated at multiple scales. Local impact simulations were performed to predict the material deformation and penetration phenomena at the location of impact. The resulting penetration behavior of a steel panel was analyzed for various projectile velocities, sizes, and panel thicknesses. Three-layer panels with Kevlar as the core material were simulated to understand the effects of structural layering on the reduction of the impact force. The forces acting on the panel in the longitudinal and transverse directions were calculated from the obtained stress distribution in the local deformation model. Using the estimated force input, transient longitudinal and flexural wave propagations were calculated to analyze the radiation of the impact energy along the structural span. Vulnerable positions with high possibilities of damage to crucial components due to impact loading were identified from the resulting vibration responses.