Evaluation of interfacial properties in adhesive joints of aluminum alloys using angle-beam ultrasonic spectroscopy

Abstract

This paper reports an ultrasonic angle-beam technique for the evaluation of interfacial properties of adhesive joints. The technique is based on measurement of the frequency response of obliquely incident ultrasonic signals from an adherend-adhesive interface. A theoretical model was developed for analysis of the interaction between the obliquely incident ultrasonic waves and multilayered adhesive joints. A special ultrasonic goniometer using only one ultrasonic transducer was built to measure the reflected signals. Samples with controlled interfacial properties were prepared for experimental determination of these properties. The experimental results were in good agreement with those predicted from the model. It was found that some of the minima loci in the reflected frequency spectra are independent of either the thickness or the elastic properties of the interfacial layer. This enables us to develop a simple and stable reconstruction procedure to determine the thickness and interfacial properties from ...