Piezoelectric actuation for smart sandwich structures - Closed form solutions

A new piezoelectric actuation mechanism for smart sandwich structures is investigated and its performances are compared with the traditional one, which is based on an induced bending moment. This piezoelectric mechanism deals with inducing shear forces and it is the result of piezoelectric materials, which are constrained and poled perpendicular to the applied electric field direction (across the thickness). The three-coupled equations of motion of a general nonsymmetric piezolaminated composite beam subjected to axial and lateral tractions with the new actuation mechanism are derived. The displacement field is based on a first order shear deformation theory. The static case is investigated for continuous piezoelectric layers and for piezoelectric patches embedded into the carrying beam. Closed form solutions for the bending angle and the axial and lateral displacements along the beam are presented for various configurations of lay-up, boundary conditions and lateral tractions.