Characterization of the damage mechanism of composites against low velocity ballistic impact using computed tomography (CT) techniques

Abstract

Low velocity impact damages are particularly considered as risky and dangerous since the detection of the damage from the surface is almost impossible for extensive evaluation. The mechanisms of penetration and damage for E-glass reinforced polyester resin composite which was hit by a low velocity projectile has been investigated using computed tomography (CT) scanning techniques. Laminated, 11mm thick plates with [0°/90°] ply architecture with 18 layers were impacted by a 9x19mm FMJ Round Nose 8g bullet with a speed of 380m/s. Since the low velocity impact of the bullet is well below the ballistic limit only a partial penetration has occurred and the kinetic energy is fully absorbed following some local matrix cracking, fiber fractures, delamination and friction-erosion. Computed Tomography (CT) technique is found to be a powerful technique that the full extent of the damage progression in 3-D can be visualized through the interfaces of the composite laminates.