Aircraft repair is gaining importance for extending the service life of aging aircraft and also for improving its structural integrity. In this paper, a new repair method of aircraft structures is presented, and the performance of this method in mixed mode fracture has been evaluated and compared with other two repair methods by conducting experimental and numerical investigations. To do so, four batches of specimens were prepared and each of them subjected to five level of mixed mode loading using a modified version of Arcan fixture. Further, finite element simulations were utilized to find stress intensity factors to explain the experimental test results. The experimental results indicate that the hybrid repair method is the most effective method in terms of increasing fracture load and it was observed a significant increase in the tensile strength of the repaired parts by all three methods compared to the simple cracked samples. Repaired samples with the hybrid method, composite patch and bolt clamping exhibited up to 49%, 44%, and 24% increase in tensile strength under pure tensile mode respectively. However, in pure shear mode, the fracture strength increased to 28%, 18%, and 9% by the hybrid method, bolt clamping and composite patch respectively.
Bonded Composite Patch Repairs on Cracked Aluminum Plates: Theory, Modeling and Experiments