Biaxial loading after low-velocity impact response on scarf repair glass fibre reinforced polymer (GFRP)

Abstract The composite material has become one of the most used materials in several applications, such as aviation, marine, and civil sectors, because of its lightweight and high-strength properties. Therefore, the wide use of this material has made it essential to explore its durability and efficiency, in particular, after repair processes. The present work investigates the effect of impact energy and its location on the remaining strength of scarf-repaired glass fibre composite. The study was conducted in two phases; in the first phase, a low-velocity impact test was carried out at specified impact locations according to the central composite statistical experimental model. A visual inspection was then performed to evaluate the damage size to the impact energy. In the second phase, tests based on biaxial loading were performed up to the failure of the repair. Then, a central composite design model was used to explore the effect of various factor levels. Results showed that the model fits firmly by 93.07% of the variability in biaxial loading. Additionally, the model showed that both factors were significant and correlated negatively with the response; however, the impact location was more sensitive than the impact energy. The critical locations were found to be around the edge of the repair.