Computation of the electromechanical coupling coefficient k in piezoelectric bounded plates by means of a two-dimensional model

Using the two-dimensional model of a piezoelectric bounded plate, previously proposed by the authors (1989), the authors compute in the frequency domain the dynamic electromechanical coupling coefficient k_d, evaluating the internal energy distribution of the plate and applying the definition reported by D.H. Berlincourt (1964). The electromechanical coupling coefficient computed in this way depends on the piezoelectric material, on the plate dimensions, and also on the frequency. The authors compared the results at the resonance with the appropriate quasi-static coupling factors and with the effective coupling factor of the plate computed by the same model, applying the classical formula: k_eff²=(f_p² -f_s²)/f_p²