Determination and Verification of Repair Tolerance of Patch Repaired T700SC/EC240A Composite Laminates Based on Progressive Failure Analysis Method

The determination and verification of repair tolerance of patch-repaired laminates based on progressive failure analysis method was studied. The axial tensile tests of intact, perforated, and repaired specimens of T700SC/EC240A composite laminates were carried out. The damage process of composite laminates under tensile load was numerically simulated using the progressive damage degradation model of 3D Hashin–Ye failure criterion. A method for determining the repair tolerance of patch-repaired laminates was proposed, and the upper and lower limits of repair the composite laminates were derived. The result verified by the strength index of Boeing Company showed that the method for determining the repair tolerance proposed is reasonable and feasible.