Experimental observation of theoretically predicted spectrum of edge waves in a thick elastic plate with facets

The existence of the edge waves spectrum predicted in a series of recent theoretical studies is investigated and confirmed experimentally. Wave motion in 20 mm thickness aluminium rectangular plate with two facets is generated by a circular piezoelectric transducer and measured by laser Doppler vibrometry. Eight edge modes (four symmetric and four antisymmetric) are clearly observed by means of wavenumber-frequency analysis applied to out-of-plane velocities measured at the edge. The semi-analytical method used by the authors in previous theoretical studies is modified to take into account the facets. By the numerical investigations of edge waves in the plate with facets, the sensitivity of attenuation of higher order edge waves to the form of edge profile is revealed. A good agreement between experimental data and theoretical predictions is demonstrated for dispersion curves and the waveforms of individual modes extracted by means of 2D bandpass filters.