Investigation of mode I / fracture toughness behaviours of adhesivelly bonded composite joints subjected to impact loads under low temperature and room temperature conditions

In this thesis study, the mode I fracture toughness behavior of composite joints bonded with adhesive and exposed to impact loads under low temperature and room conditions was examined. The aim of th study is to examine the fracture mechanism and energy releases of adhesive connections under different temperatures and impact loads. Through experimental research, samples of composite materials were produced and adhesive connections were created according to the ASTM D5528 test standard. Afterwards, impact were applied under different temperatures and energy levels according to this standard. Crack propagation speed and fracture energy were examined according to the applied impacts. According to the obtained data, the behavior of the adhesive material and its performance under the influence of temperature were examined. The changes in material performance, especially at low temperatures and the effect of impact loading on fracture toughness were examined with experimental results. The literature was examined and theoetical studies and experimental studies were interpreted. The aim of this study is to contribute to design studies, material selection and support technical studies to increase the mechanical strength of adhesive joined composite connections under the influence of low temperature and impact.