An experimental investigation into the high velocity impact responses of S2-glass/SC15 epoxy composite panels with a gas gun

Abstract

The single-stage gas gun testing methodology was investigated. A thermodynamics based method was used to estimate the required pressures for a targeted velocity. The transmitted impact force was measured with four load cells installed behind the testing frame. The out-of-plane deformation was measured with a projection grating profilometry method using a high speed camera. The velocity of the projectile was determined from the high speed video footage. The improved gas gun experiment was used to investigate the high velocity impact behavior of a S2-glass/SC15 epoxy composite. The ballistic limit was found to be 338 m/s and 406 m/s for the 6-ply and 10-ply composite panels, respectively. It was observed that the failure modes of the composite panels evolved with the impact velocity. The area of damage and failure first increased and then became localized. The panels absorbed the same or even a slightly higher amount of energy beyond the ballistic limit before damage localization. The ballistic protection capability of the S2-glass composite was compared with other materials in terms of EBL, a new parameter proposed in this work. EBL is the energy absorbed by the target at the ballistic limit normalized by the contact area.