Analysis Of Piezoelectric-piezomagnetic Laminated Structures

Piezoelectric-piezomagnetic composites have shown a wide and brilliant prospect of applications due to the multi-field coupling effects among mechanical, electric, and magnetic fields, and have attracted a lot of research interests in recent years. We consider a piezoelectric-piezomagnetic bilayer for the development of a new zig-zag structural theory. In each layer, the displacements and electric and magnetic potentials are assumed to vary linearly along the thickness direction, and after making use of the continuity conditions of displacements and shear stresses at the interface as well as the zero shear stresses conditions at the two surfaces, the independent unknown functions (or constant) are reduced to seven. Then, by virtue of the variational principle, the governing equations as well as the boundary conditions are derived. For a bilayer plate with four edges simply supported, we present an analytical solution which is similar to the classical Navier solution. Numerical results are given, which show that, with the developed zig-zag theory, the shear stresses can be continuous across the interface between the piezoelectric layer and the piezomagnetic layer. This is a very important aspect in the piezoelectric-piezomagnetic composites since the electric and magnetic fields are coupled mechanically through the interface. Based on the three-dimensional exact theory of electromagnetoelasticity, we also use the transfer matrix method to analyse the same piezoelectric-piezomagnetic bilayer plate. Numerical comparison shows a good agreement, thus validating the zig-zag theory derived in the thesis.