Abstract
Acousto-ultrasonic (AU) is a nondestructive testing technique for evaluating composites and composite like materials. The name is based on the fact that advantages of the acoustic emission and ultrasonic testing techniques are combined in this NDE technique. In previous research, AU has been used to evaluate carbon/carbon and GFRP composite materials. The work reported in this paper uses Au to examine the adhesive bond strength of lap-jointed graphite/aluminum composite structures. The Stress Wave Factor (SWF), an AU parameter, was used to quantify the strengths of the two types of adhesives used in this research. Also, AU was used to identify delaminations present in the bond area. AU was used to see if the transverse tensile strength of these composites could be determined and to see if this NDE technique was sensitive to progressive damage. The results indicate that AU can be used to effectively identify the bond strength, the transverse tensile strength, and progression of damage in transverse specimens.