Investigating ballistic resistance of CFRP/polyurea composite plates subjected to ballistic impact

Abstract As composite structures develop, polyurea coating has been applied to improve the protective performance of multi-layered composite structures subjected to blast or impact loading. In order to investigate the ballistic resistance of polyurea coated Carbon Fiber Reinforced Plastics (CFRP) composites, impact experiments were conducted using a 14.5 mm ballistic gun with cylindrical projectile. The effect of polyurea coating position and coating thickness were analyzed and discussed. The impact velocity of projectile was selected from 600 m/s to 1406 m/s for polyurea coated CFRP composite plates. The energy absorption ratios were calculated to assess the ballistic behavior. Damage zone of CFRP plates were determined by ultrasonic C-scan images. The failure mechanism of CFRP laminates and polyurea were analyzed by an optical microscope and scanning electron microscopy (SEM). The results showed that the deformation of projectiles increased with the increase of initial impact velocity. Energy absorption ratio and damage level of RPU2 configuration was better than pure CFRP plates. The optical microscope and SEM images showed that failure modes were compression-shear failure on the front side of polyurea, tension-shear failure, petaling failure, spallation and punching perforation failure on the rear side of polyurea. Overall, polyurea coating can significantly boost the composite plates’ ballistic performance when spraying polyurea on the CFRP composites’ rear side.