An experimental study on ballistic limit: the effect of hole drilling on the mechanical properties of a polymeric composite plate produced by the resin transfer molding method

Abstract

The high fracture strength and exceptional impact resistance of polymer-based composites are of paramount importance to various industries like aerospace, automotive, and construction. The resin transfer molding (RTM) process is used to produce composite samples of superior quality, minimal porosity, and reduced lamination defects. In the present study, the RTM method was employed to fabricate glass fiber-reinforced composites, aiming to investigate their specific mechanical properties and structural performance. The study initially determined the ballistic limit of the produced samples. Subsequently, experimental investigations were carried out to examine the impact of hole drilling on the tensile strength, flexural strength, and impact resistance of the samples. The results revealed that the produced polymer plate demonstrated a ballistic limit with a pressure of 11 bar and a speed of 104 m/s, leading to ball restriction in the plate. The sample without holes showed the highest fracture force, while samples with three and five holes exhibited reduced fracture forces. Additionally, bending force and impact resistance were lower in samples with multiple holes compared to the sample without holes. The impact resistance of the sample with five holes was the lowest among all configurations. The study revealed that the presence of three holes arranged in a row has a lesser impact on reducing the ultimate tensile force compared to the effect of five holes. Moreover, the bending test results indicated that sample failure occurred on the side under tension, resulting in higher bending forces than tensile forces.