Nondestructive evaluation of adhesive joints by guided waves

Guided waves in an adhesive layer between two adherend half-spaces are shown to be uniquely sensitive to most types of bond defects. A simple experimental technique based on ultrasonic transmission mesurement is introduced to detect leaky guided modes in the interface layer. Experimental results for these dispersive guided modes are shown to be in good quantitative agreement with theoretical predictions. The suggested technique might find numerous applications in nondestructive evaluation of different bonds of layered structure such as adhesive and brazed joints.