  The present work attempts to present a consistent and efficient approach to
piezoelectric laminated beams. The influence of hypotheses on three-dimensional
sectional deformations and stress distributions on the estimate of the beam
electromechanical properties is analyzed. By exploiting a mixed variational
formulation and Lagrange multipliers method, an Euler- Bernoulli-like beam
model which accounts for transverse interactions between different is
presented. The fully coupled electromechanical nature of the system is
described by including both mechanical and electrical kinematical descriptors
and both direct and inverse piezoelectric effects. For a sandwich piezoelectric
beam and for a two-layers beam, expressions of the beam constitutive
coefficients are provided and the main features of the proposed model are
highlighted. Comparisons with experimental data and results from standard
modelling approaches are presented. As main peculiarity, the proposed beam
model coherently estimates the equivalent piezoelectric capacitance and
transverse normal stress distribution also for beam composed by elastic and
piezoelectric layers of comparable thickness.
