Buckling analysis of the functionally graded sandwich rectangular plates integrated with piezoelectric layers under bi-axial loads

Mechanical stability of the functionally graded rectangular plates bonded with functionally graded piezoelectric layers is studied in the present research. Classical plate theory is employed in the description of three components of the plate displacement. Geometric nonlinearity is considered in the strain-displacement relations using the von Karman equation. The constitutive relations are developed for the functionally graded material core and functionally graded plate material layers in the general state. The top and bottom of the piezoelectric layers is assumed to be short-circuited. Three equilibrium equations as well as Maxwell equation are constituted of four governing differential equations of the problem. Some important nondimensional parameters representing the geometries of the sandwich plate incorporated with nonhomogeneous index of the material properties are considered for this analysis. The results indicate that these parameters have important effects on the buckling loads.