Experimental Evaluation of Repair Efficiency of Composite Patching by ESPI

In this paper, the electronic speckle pattern interferometry (ESPI) technique was first used to investigate repair efficiency of patching by using composite materials on aluminum alloy plates containing a central crack. The effect of single-sided and double-sided patchings with same total thickness and four different fiber orientations of the patchings was discussed. A self-developed computer program for analyzing mode I stress intensity factor (SIF), K1 was performed to evaluate the repair efficiency. To verify the correctness of the experimental results, recontruction technique was employed. Well-matched condition between the experimentally obtained and reconstructed fringes indicates the correctness of the experimental results.