A study on low velocity impact damage evaluation and repair technique of small aircraft composite structure

Composite structures are very prone to damage at fairly modest levels of impact energy due to foreign object damages. A repair technique using external patch is recognized as an effective method to recover the damaged structures during service life. This work is focusing on the impact damage evaluation and the external patch repair techniques of the aircraft composite structure. The impact damages of composite laminates of the carbon/epoxy UD laminate and the carbon/epoxy fabric face sheets-honeycomb core sandwich laminate are simulated by the drop-weight type impact test equipment. The damaged specimens are repaired using the external patch repair method after removing the damaged area. The compressive strength test and analysis results of the repaired impact damaged specimens are compared with the compressive strength test and analysis results of the undamaged specimens and the impact damaged specimens. Finally, the strength recovery capability after repairing is investigated.