Electroelastic guided wave dispersion in piezoelectric plates: spectral methods and laser-ultrasound experiments

Electroelastic waves in piezoelectric media are widely used in sensing and filtering applications. Despite extensive research, computing the guided wave dispersion remains challenging. This paper presents semi-analytical approaches based on spectral methods to efficiently and reliably compute dispersion curves. We systematically assess the impact of electrical boundary conditions on a 128{\deg} Y-cut LiNbO3 wafer, examining open-open, open-shorted and shorted-shorted surfaces configurations. Multi-modal dispersion maps obtained from laser-ultrasonic experiments for each boundary condition exhibit excellent agreement with the computational predictions. A straightforward implementation of the spectral collocation method is made available as "GEW piezo plate" (https://doi.org/10.5281/zenodo.14205789), while the spectral element method will be integrated to "GEWtool" (http://doi.org/10.5281/zenodo.10114243). Therewith, we aim to make advanced semi-analytical techniques more accessible to physicists and engineers relying on dispersion analysis.