Effect of impactor noses in different forms on impact behaviour of composite materials used in ballistic applications

Composite materials are widely used in many high-performance applications such as, defence industry, automotive industry ve aircraft industry due to their high specific strength and stiffness properties. One of the most important problem that has restricted the full potential of composites is their response to impact loading. Composite materials are exposed to various external influences over the life of the product and these impacts can cause local deflection of the face sheet adn delamination. This study reports on the results of an experimental investigation on the influence of impactor shape and ambient temperature on low velocity impact behavior of the composite panels manufactured different type of reinforcement at the same thicknesses. 3 / 1 twill Kevlar woven fabric with areal density of 300 g/m2, plain weave carbon woven fabric with areal density of 200 g/m2 and plain weave S-2 glass woven fabric with areal density of 190 g/m2 and epoxy matrix were used to produced thermoset composite with the vacuum-assisted resin infusion molding (VARIM) method. Impact tests were performed by using Fractovis Plus test machine with 12.7 mm diameter hemispherical, conical 1 (d= 9 mm, D= 12.7 mm) and conical 2 (d= 2 mm, D= 12.7mm) impactor noses. The result of impactor shape characteristic and performance are indicated and compared for 20J, 40J and 60J energy levels by comparing te results on the force-deformation graphics. In addition, three different composite panels are tested with hemispherical and conical 1 impact noses and results are compared for effect of 23oC, 50oC 80oC ambient temperatures by the energy graphics.