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Optimization of a guided wave scanning system on a composite material

A guided wave scanning system was developed and is being refined at NASA Glenn Research Center. Instead of isolating a single Lamb wave mode, this guided wave scan system utilizes a multi-mode ultrasonic response consisting of multiple, overlapping wave modes. Various time and frequency related parameters are calculated from the time domain waveform at each scan location to create images. In order to optimize the performance of the guided wave scanning device, many experimental conditions need to be considered. In this study, the effects of the transducer contact force, dry couplant pad configuration, and scan step size on the repeatability of the guided wave parameters and the intensity and quality of the ultrasonic waveform were investigated. Based on the results, an optimal couplant configuration was recommended for future use with the scanning device.