Polyurea-coated glass-fibre-reinforced laminate under high-speed impact: experimental study

One of the promising methods to increase the resistance of polymer-matrix composite materials to impact damage is the use of protective coatings. In this work, the effect of polyurea coating on impact-performance parameters of a woven glass-fibre-reinforced laminate is studied. The study was performed on a specially developed ballistic experimental test rig employing a pneumatic gun. Eleven polymer composite targets with dimensions 200 mm x 300 mm x 8 mm were impacted orthogonally with a steel projectile with 23.8 mm diameter and weight 54.7 g in the range of the impact speed up to 150 m/s. A comparative assessment of the ballistic limit for targets with a 1.2 mm protective coating on the front and rear faces of the target, as well as for samples without any protective coating, was performed. The impact process was captured using two high-speed cameras for filming the front and top views at 25,000 frames per second. Experimental data on the ballistic limit for uncoated and polyurea coated fiberglass plates on the front and back surfaces were obtained. It was shown that 1.2 mm thick coating on the face surface increases the ballistic limit by 20%. The nature of the damage of the GRP base plate and coating has been analyzed. The obtained data can be used for validation of numerical models of ballistic impacts of polyurea-coated laminates.