Accurate determination of coupling effects on free edge interlaminar stresses in piezoelectric laminated plates

A layerwise laminate theory is used to investigate analytically the electromechanical coupling effects on the interlaminar stresses and the electric field strengths near the free edges of laminated plates with piezoelectric material properties. The angle-ply and cross-ply piezoelectric laminated plates with finite width subjected to uniform axial strain are considered and full three-dimensional stresses and the electric field strengths in the interior and boundary layer regions are calculated. Equilibrium equations along with the appropriate boundary conditions are obtained by using the principle of minimum total potential energy. The analytical solutions are developed and through the comparison of the present results with those available in the literature, the accuracy of the theory is verified. It is found that the interlaminar stresses and electric field strengths at the free edges are significantly higher in the coupled case for cross-ply laminates, whereas the coupling effect for symmetric angle-ply laminates is of minor significance.