Damage Tolerance Analysis and Testing of Unbalanced Bonded Composite Repairs for Aluminum Airframes

In this paper, the authors review damage mechanisms and failure modes of bonded composite repairs applied to aluminum aircraft structures, with a focus on the effects of bending on the performance of asymmetric or one-sided repairs. Failure mechanisms are elucidated using results from testing carried out during the course of the University of British Columbia Bonded Composite Repair Program (UBC-BCRP). The authors then outline the regulatory requirements for damage tolerance and describe the new methods and test data developed under the UBC-BCRP to improve the analysis of bending repairs.