Analytical buckling temperature prediction of FG piezoelectric sandwich plates with lightweight core

Abstract

Buckling temperature prediction of a functionally graded piezoelectric (FGP) sandwich plate with lightweight core is studied in the present work. The composite plate is made of three layers. The upper and lower layers are made of two different piezoelectric materials so that the electrical and mechanical properties are smoothly varied through the thickness based on a power law distribution. Whereas, the lightweight core is considered as hexagonal honeycomb structure or functionally graded porous structure. The porous core contains internal pores with different porosity distributions. According to a modified four-unknown shear deformation plate theory, the displacement field is described. The smart advanced plate is subjected to thermal and humid loadings as well as external electric voltage. The thermal and humid loadings may be uniform, linear or non-linear through the thickness. The stability equations are constructed from the principle of virtual work based on the proposed shear deformation plate theory. The obtained results will be validated by introducing some comparison examples. Finally, the influences of different parameters like the side-to-thickness ratio, aspect ratio, core type, core thickness, power law index, moisture concentration, external applied voltage and boundary conditions on the buckling temperature change of the sandwich plates with honeycomb core or with porous core are discussed. It is found that the buckling temperature of the sandwich plate with honeycomb core is greater than that of the sandwich plate with porous core. Moreover, with increasing the lightweight core thickness, the sandwich plate stiffness decreases leading to a reduction of the buckling temperature.