Vibration based structural health monitoring of adhesively bonded composite scarf repairs

摘要

Structural health monitoring (SHM) may be applied to bonded composite repairs to enable the continuous through-life assessment of structural integrity. Further, adhesively bonded joints are an ideal starting point for real-time, in-situ monitoring due to knowledge of mechanisms and locations of failure. The development of a SHM technique for the detection of debonding in scarf and overply repairs based on the frequency response of the repaired structure is described in this paper. Experimental investigations were conducted on representative carbon / epoxy composite scarf and overply joints. Piezoelectric elements were used to excite and measure the response of the repaired structure. The frequency response signature of the repaired structure with simulated debonds was found to differ significantly from that of the undamaged repair for two sets of boundary conditions. This demonstrates the potential of this technique for the SHM of scarf repaired composite structures.