Frequency spectra of beam-plates revisited

Based on Mindlin’s plate theory, the frequency spectra for flexural and thickness-shear vibrations of a finite beam-plate with different combinations of boundary conditions are presented and studied. Comparing them with the dispersion curves of the infinite beam-plate reveals an intrinsic relation between resonant vibration and guided wave propagation. The fundamental frequency spectra, which are for beam-plates with hinged and/or guided edges, are found to play an important role in understanding the spectra of beam-plates with other boundary conditions.