Nondestructive Evaluation of Composite Structures Using System Identification Technique

Abstract

A system identification technique is presented for nondestructive test to detect and to characterize the existence and location of cracks and other damages in composite structures. Various composite structures, including Kevlar-epoxy plate, graphite epoxy ring, and graphite-epoxy coupon have been tested for different damages such as crack, delamination, impact damage, fatigue damage, etc. In addition, the correlation between severity of any type of the damages mentioned above and changes in identified system parameters has also been systematically studied.