Impact on carbon fiber composite: Ballistic tests, material tests, and computer simulations

Carbon fiber composites are now common in the aerospace industry because of their high specific stiffness and strength. They are ideal for decreasing the weight of structures, but it is well-known that they can suffer delamination and failure under relatively mild impact loads. In particular, under ballistic impact, carbon fiber composites underperform compared to other materials like S-2 glass, Kevlar®, or polyethylene composites. Hence, it is difficult to find in the literature a complete study aimed at obtaining a reliable computer model for ballistic impact on carbon fiber composites. This paper presents a thorough experimental campaign of both the material constituents and the composite, including loads in the different directions (longitudinal and transverse tension, shear, delamination, etc.) at low and high strain-rates, and ballistic tests. The study is performed on non-woven (2D) composite as well as a 3D woven composite with the same constituents. The material properties were determined using computations that reproduce the material tests. A mesoscale computer model was developed that is validated by comparing the results from the mechanical and ballistic test with the computations. It is shown that, using the properties obtained in the material test computations, the predictions for the ballistic tests are very good both for ballistic limits and deflections.