Evaluation of the Impact Damages of Scarf-Repaired Composites

Abstract

A CFRP scarf-repaired specimen is manufactured using the autoclave method on the assumption that it is a part of the repaired composite airframes. Such specimens are composed of a scarf joint and a step-lap joint. Though the in-plane mechanical properties of the scarf-repaired composites have been studied, few researches on out-of-plane behavior have been reported. Thus, the mechanism of the impact damages in the scarf-repaired composites was clarified through two kinds of experiments, the low-velocity impact test and the static indentation test. Through the low-velocity impact test, the damage configuration was observed and the influences of the scarf angle and stacking sequence on impact damage were investigated. As a result, the debonding at the interface between the adhesive layer and the repair laminate was observed in all the specimens. Moreover, damage growth was observed through the static indentation test. The indentation results indicated that the debonding at the interface between the adhesive layer and the repair laminate occurs at the intersection of the adhesive layer and the delamination of the repair laminate.