Advanced ultrasonic NDT for weak bond detection in composite-adhesive bonded structures
Bengisu Yılmaz, Elena Jasiūnienė
Abstract
Weak bond detection in composite-adhesive joints is a highly challenging task in the non-destructive testing (NDT) community. This paper aims to evaluate the bonding quality in composite-adhesive bonded structures with high-frequency high-resolution acoustic microscopy. Carbon fibre reinforced epoxy-epoxy bonded single-lap joints containing three different bonding quality -debonding, weak bond with less and more contamination, in addition to perfect bond were investigated. Shape-based feature extraction algorithm in the frequency domain was developed in order to detect weak bonds. The results show that high frequency focused transducers used in acoustic microscopy is a great choice to visualize interface quality in bonded structures. Developed post-processing algorithm performs well on the detection of weak bond, independent from the perfect bond inspection results.