Abstract
In this study, the finite element is used to analyze and compare the performances of the double- and single-sided composite repair in aircraft structures in mode I and mixed mode. The stress intensity factors in modes I and II at the crack tip are computed to perform the objective of the study. The effects of the different parameters of repair such as adhesive and patch properties on the SIF variation were highlighted. The obtained results show that the adhesive properties must be optimized in order to increase the advantage of the double patch and to avoid adhesive failure. The patch properties have a significant effect on the beneficial effects of the double symmetric patch.