EVALUATION OF CFRP PANELS WITH SCARF REPAIR PATCHES

The scarf patch repair of CFRP panels has been evaluated using a test rig to statically load the panels in a square frame, clamped at the ed ges and loaded diagonally through pin joints. Three repair systems wer e used, two wet lay-ups and one prepreg system. The most consistent re sults were obtained with one of the wet lay-up repairs whilst the prep reg system appears to offer the greatest potential increase in load to failure. The failure load appears to be governed by the amount of buc kling the repair is subjected to. Because of the buckling it was not p ossible to predict the failure load of repaired panels using standard test coupons. Studies on unrepaired panels containing a central hole i ndicated that buckling identified using photoelastic and strain gauge techniques could be predicted using finite element and empirical metho ds.