Investigating and determining the stress intensity factors and fracture initiation angle for the cracked plates repaired by single-side composite patches under mode I and mixed- mode loading

Due to various benefits of composite materials such as light weight, high strength and their excellent formability, the external bonded composite patches have been proved to be a preferable method of repairing flaws and cracks in various engineering structures. In this paper, the effect of some parameters such as the composite patch material, the adhesive material and the base plate material on the reduction of the stress intensity factor and the variation of fracture initiation angle has been studied using the 3D finite element method. The results showed that the composite patch material and base plate material have significant effect on reduction of stress intensity factor. However, the adhesive material has insignificant effect on it. One of the other important results of this study is that the use of patch does not have a significant impact on the fracture initiation angle.