Damage of Composite Materials Subjected to Projectile Penetration Using High Resolution X-Ray Micro Computed Tomography

A fundamental understanding associated with the damage resulting from a localized impact from a penetrating spherical projectile in carbon fiber reinforced polymer composites is evaluated using a micro-focus based and high resolution x-ray computed tomography system. Radiation (x-rays) based imaging provides three dimensional information of the microstructure of the composite sample in terms of the state of the matter and distribution of various phases corresponding to fibers, resin, initial manufacturing defects, resulting cracks and delaminations in quantitative fashion for identifying underlying damage and failure mechanisms. Detailed damage associated with the composite panels subjected to intermediate (194 m/s) and high velocity (354 m/s) impact of a 12 mm steel projectile on normal and oblique loading is reported in this paper. Though the energy absorbed by the panels are similar in both types of impact loading, damage and the dominant failure mechanism are observed to be very different for various lay-ups through thickness.