The effect of compressive loading on the ultrasonic detectability of kissing bonds in adhesive joints

The effect of compressive loading on the ultrasonic detectability of kissing bonds in adhesive joints was studied. Two distinct types of kissing bond were considered. The first type was a dry contacting interface that represented a disbonded adhesive interface subsequently subjected to compressive loading. The second type were manufactured by contaminating the joint with a thin layer of various liquids. The interaction of normal incidence 10-MHz ultrasound with both these kissing bond types has been quantified. In particular the effect of compressive loading on their detectability was investigated. A quasistatic spring model has been used to predict the interaction of ultrasound with the solid-solid interfaces in the dry-contacting kissing bonds. The reasons for the discrepancy between the experiments and the model are discussed.