Damage Identification for Composite Structures Using a CrossCorrelation Reverse-Time Migration Technique

Abstract

This paper presents a cross-correlation reverse-time migration (CCRTM) technique to quantify and image damages in composite structures using flexural wave signals. A linear piezoelectric transducer array is surfaced-mounted on a composite plate to image a circular-shaped damage. The suitable frequency range for this method has been discussed prior to the testing. The forward wavefield excited by the actuator is formed by a finite difference (FD) method. The scattered wavefield is reversed in time and back-propagated using the same FD method to perform the migration as the backward wavefield. Cross-correlation values between the forward and backward wavefields are obtained for every grid on the plate to image the damage. It is demonstrated that this CCRTM can accurately locate and image multiple damages with improved resolution and higher efficiency.