Mechanisms of solid particle erosion damage in the repair of damaged composite structures

Abstract

With high specific strength, carbon fiber reinforced plastic (CFRP) is used in many fields. Repair is necessary when the strength of the leading edges of aircraft wings (CFRP) and wind power turbine blades (CFRP) are damaged by lightning strikes or collisions with birds. Some studies have been conducted on the mechanical properties of repair methods, but they do not address erosion characteristics. In order to develop a high quality repair method, this study examined the repair patch and fabricating samples that reproduces the conditions associated with the current repair method, the erosion characteristics of the sample were investigated using the erosion test. Differences in the adhesive used to affix the repair patch to the base plate have little effect on the erosion resistance of repaired areas, but deteriorations in adhesion between the repair patch and base plate result in degraded erosion resistance in the repaired area. With regard to the mechanism by which post-repair erosion resistance characteristics changed, our tests revealed that adhesive irregularities between the repair patch and base plate allowed impact energy from particle collisions to cause the repair patch to vibrate, and the resulting fatigue breakdown caused resin and fiber fragments to more readily separate, accelerating erosion.