Guided Lamb and edge wave excitation by piezoelectric transducers in elastic plates
* Presenting author
Elastic guided waves (GWs) are widely employed in ultrasonic NDT/NDE for damage characterization due to their capabilities for long-range propagation and sensitivity to defects. For excitation and sensing of GWs, thin piezoelectric transducers adhesively attached to the structure are among commonly utilized tools. The complexity of these mechanical processes conditioned by, e.g., the multimodality of GW motion, dynamics of piezotransducers and the quality of their contact with the host structure should be properly addressed for better performance of GW-based NDT/NDE systems. In this contribution, the results of theoretical and experimental studies of GW excitation by piezotransducers attached at an edge or a face of an elastic plate are reported. The semi-analytical methods relying on integral transform and modal expansion techniques are applied for numerical analysis. Wave energy distribution amongst excited GWs (Lamb and edge waves) is carefully analysed and discussed to improve the quality of damage identification with GW-based techniques. The influence of partial debonding of a piezotransducer on GW excitation is carefully analysed. The potential of edge waves for practical NDT/NDE applications is discussed. Namely, it is demonstrated that edge waves excited in plates and scattered by surface-breaking cracks can be employed for crack detection at the edges.