Electromechanically Coupled Zigzag Third-Order Theory for Thermally Loaded Hybrid Piezoelectric Plates

An efficient coupled zigzag theory is presented for hybrid piezoelectric plates under thermoelectromechanical loads. The thermal and potential fields are approximated as piecewise linear across sublayers. The deflection is approximated as a combination of a global uniform term across the thickness and local piecewise quadratic variations across sublayers, which explicitly account for the transverse normal strain resulting from thermal and electric fields. The in-plane displacements are approximated as a combination of a third-order global variation across the thickness and a piecewise linear variation across layers. The shear continuity conditions at the layer interfaces and the shear traction-free conditions at the top and bottom are imposed for a general electric field to formulate the theory in terms of five primary displacement variables and potentials. The field equations and boundary conditions are derived from a variational principle. The accuracy of the developed theory is established by direct comparison with three-dimensional exact piezothermoelasticity solutions for simply supported plates under two thermal loads for two very inhomogeneous laminate configurations and different aspect ratios.