Investigation of mechanical properties and impact strength depending on the number of fiber layers in glass fiber reinforced plastic composite materials

The rapid growth of automotive, aviation, aerospace and defense industries has required lightweight and high strength materials. Glass fiber reinforced plastic composite materials have been manufactured for this purpose and increasingly used over time. Glass fiber reinforced plastic composite materials have higher strength and rigidity to weight ratios when compared with the commonly used industrial materials. Therefore, this material finds a wide range of use because of its outstanding features.In this study, the mechanical properties of glass fiber reinforced plastic composite materials having different number of layers and manufactured by two different methods; namely, hand lay-up method and resin transfer molding method, were investigated. Average ultimate strength values of the manufactured samples were obtained by three-points bending test and tensile test. Along with these tests, low speed impact tests were conducted to predict the impact strength of the materials. Macro and micro photographs of samples were taken before and after the tests, and the samples were metallographically characterized. Damage zones in the after-test images were examined in detail. The variation of mechanical properties depending on the number of fiber layers and production method were identified considering the experimental and theoretical results.