Strain-based health assessment of bonded composite repairs

摘要: Structural health monitoring (SHM) technology may be applied to composite bonded repairs enable the continuous through-life assessment of repair's efficacy. This paper describes an SHM technique for detection debonding in patches based on relative strain measurements. Two types known as external doubler repair and scarf are examined this paper. A finite element study showed that debonded region changes significantly compared undamaged state. An experimental investigation was conducted, using carbon/epoxy substrates fibre Bragg grating sensors measurement strain, validate theoretically predicted results repair. Debonds were detected by means a differential approach, where two strategically positioned so their increased with disbond length. threshold value set indicate imminent critical failure. The measurements agreed well numerical findings, indicating proposed scheme has great potential simple repairs.