Damage prediction of rib-stiffened composite structures subjected to ballistic impact

This paper details a numerical modeling and experimental test program focused on high energy ballistic impacts on composite rib-stiffened structures. The numerical model used in this paper is designated as the Multiconstituent Composite Model (MCM), which is implemented within the CTH shock physics code for simulation of ballistic impact damage on composite structures. The presented work utilized a building block approach, where component level flat panels were studied first, followed by sub-structure level T-joint specimens, both fabricated from a carbon/epoxy composite material. All numerical studies and experimental tests utilized the military grade 0.50 caliber M2 Ball round as a projectile. Following testing, each panel was inspected both visually and using Ultrasonic C-Scan techniques to determine the extent of damage sustained upon impact. Finally, comparisons of the experimental data with the numerical predictions are presented and discussed. Both the flat panel and T-joint damage predictions were in good agreement with the experimental data.