Effect of porosity on fundamental frequencies of FGM sandwich plates

In this paper, the porosities effect on the dynamic analysis of the simply supported FGM sandwich plates is studied using a new refined shear deformation theory taking into account transverse shear deformation effects. This porosity may possibly occur inside the Functionally Graded Materials (FGMs) during their fabrication. Two common types of FGM sandwich plates are considered, namely, the sandwich with the FGM face sheet and the homogeneous core and the sandwich with the homogeneous face sheet and the FGM core. The results are presented for two constituent metal-ceramic functionally graded plates that have a power law through-the-thickness variation of the volume fractions of the constituents. The results obtained reveal that the dynamic response is significantly influenced by the volume fraction of the porosity, power law index, the thickness-side ratios and the thickness of the functionally graded layer.