Comparison of models for radial and thickness modes in piezoceramic disks

In a comparison of theoretical models and experimental results, the traditional MMOT and Mason models for isolated R and TE modes in thin circular piezoceramic disks, have been found to yield a reasonable agreement with FEM and experimental results in their expected ranges of validity, i.e. for D/T≫η_n, and D/T≫1, respectively. (Here, η_n is root No. N of the R mode resonance frequency equation.) However, deviations have been observed between the results using Brissaud's model for coupled R and TE modes, and both the experimental results and the other theoretical model results, even for large D/T ratios. Reasons for such deviations are suggested and discussed