Effect of Glass Yarn Reinforcements and Their Configurations in Enhancing the Effectiveness of Repair in Composites

ABSTRACT Composite structures in wind turbine blades and aerospace components are primarily subjected to flexural loads. Hence, it becomes imperative to evaluate the effectiveness of the repaired composite specimens under flexural loading conditions. This study investigates the possibility of improving the efficiency of plug‐and‐patch repair by using multiple plugs rather than a single plug, as well as strengthening the repaired zone with different yarn reinforcement configurations. To this end, the flexural responses of specimens repaired using different repair techniques are studied. The repairs are carried out using a single or multiple plugs, patches, various yarn reinforcement configurations, yarn reinforcements sandwiched between multiple plugs, and yarn reinforcements sandwiched between multiple plugs with patches. The responses of the repaired specimens are compared with those of the undamaged specimen. Specimens repaired using multiple plugs with patches recovered up to 71% of the undamaged specimen's strength, whereas the specimens repaired just with yarn reinforcements recovered up to 77% of the undamaged specimen's strength. Specimens repaired using yarn reinforcements sandwiched between multiple plugs with patches recovered up to 85% of the undamaged specimen's strength. These results demonstrate the potential of multiple plugs and yarn reinforcements in enhancing the efficiency of plug‐and‐patch repairs.