Ultrasonic Methods for Characterizing the Interface in Composites

Abstract

Micromechanical modeling studies of composite materials have highlighted the need for better characterization of the interface zone in composite materials. Bulk behavior in composites has been predicted to be strongly influenced by the local elastic properties, residual stresses, and adhesion of the interface. Techniques to nondestructively measure these newly perceived quantities of importance do not exist. Thus it is not possible experimentally to (i) confirm the micromechanical model predictions, (ii) explore the relationships between interface properties and processing variables, and (iii) ensure acceptable interface properties in commercially fabricated composites. We report here the current status of a SDIO/ONR funded research program directed at developing experimental techniques for characterizing the interface zone in composites through the use of ultrasonic interface waves [1].

Guest Scientist, The Johns Hopkins University, Baltimore, MD, 21218 (partially supported by the NBS Office of Nondestructive Evaluation.)