A Theoretical and Numerical Study of Ultrasonic Waves in Laminated Composites for Nondestructive Evaluation of Structures

The current work investigates guided waves in laminated composite plates subjected to ultrasonic sources for potential applications in nondestructive evaluation of composite structures. The propagation of free ultrasonic waves in laminated plates is first considered and their dispersion curves are obtained using numerical computation. The problem of wave motion generated by a time-harmonic load in the composites is theoretically derived in a simple manner using reciprocity theorems. Analytical and numerical results of the generated wave fields are compared, and they show excellent agreement for several material combinations. Scattering of guided waves by a delamination at the interface of laminates is also discussed. The expressions and calculations found in this investigation are critical to explore the potential of using ultrasound-based methods for nondestructive evaluation of composite structures.