In many engineering applications of composite and laminate materials, damage and failure can be caused by impact of various types. Low-velocity impact is potentially dangerous because it can produce extensive sub-surface delamination that may not be visible on the surface. High-velocity impact produced by projectiles, shock waves and fragments from exploding ammunition is a highly dynamic event, leading to the penetration or perforation of composites.
All impact damage is detrimental to the mechanical and structural performance of composites. Accurate evaluation of the damaged state, and a fundamental understanding of the effect of damage upon the resultant properties are therefore essential for the proper design and application of composite materials. The strain-rate dependence of material behavior, fracture propagation and energy-absorbing capacity are also of paramount importance from both the materials science and structural mechanics perspectives.