Evaluating the compressive strength of stepped scarf repaired single stiffener composite panels

Abstract

In this study, tests were carried out on repaired 300 × 250 mm composite stiffened panels. The initial damage was assumed to be extended in a depth of the first six plies and a repair with scarf ratio of 1:50 was employed. A circular repair took place, utilizing laser-assisted ablation and the wet patches approach. The panels were tested in compression and Digital Image Correlation (DIC) and Acoustic Emission (AE) were used in order to monitor the damage initiation and propagation of the panels. In addition, Phased Array (PA) was used in order to monitor the patch failure. Detailed Finite Elements (FE) models were validated against the test findings and their performance as a prediction tool for the performance of repairs on composite aeronautical structures was assessed.